U.S. patent number 9,271,291 [Application Number 13/627,706] was granted by the patent office on 2016-02-23 for common anchor based aggregation.
This patent grant is currently assigned to InterDigital Patent Holdings, Inc.. The grantee listed for this patent is INTERDIGITAL PATENT HOLDINGS, INC.. Invention is credited to Amith V. Chincholi, Alpaslan Demir, Rocco Di Girolamo, Jean-Louis Gauvreau, Liangping Ma.
United States Patent |
9,271,291 |
Gauvreau , et al. |
February 23, 2016 |
Common anchor based aggregation
Abstract
Embodiments contemplate techniques for managing aggregation
between using an anchor channel over a first frequency band as the
anchor band between an Access Point and a wireless
receiver/transmitter unit (WTRU). One or more embodiments may
include the WRTU receiving one or more beacons via the anchor
channel, where the one or more beacons may provide allocation
information for allocating a supplementary channel on a second
frequency band as a supplementary band that may be different from
the first frequency band. Embodiments also contemplate establishing
the supplementary channel over the supplementary band using the
allocation information provided in the one or more beacons.
Embodiments also contemplate exchanging data over the established
supplementary channel on the supplementary band.
Inventors: |
Gauvreau; Jean-Louis (Montreal,
CA), Di Girolamo; Rocco (Montreal, CA),
Chincholi; Amith V. (West Babylon, NY), Ma; Liangping
(San Diego, CA), Demir; Alpaslan (East Meadow, NY) |
Applicant: |
Name |
City |
State |
Country |
Type |
INTERDIGITAL PATENT HOLDINGS, INC. |
Wilmington |
DE |
US |
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Assignee: |
InterDigital Patent Holdings,
Inc. (Wilmington, DE)
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Family
ID: |
47040809 |
Appl.
No.: |
13/627,706 |
Filed: |
September 26, 2012 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20130077554 A1 |
Mar 28, 2013 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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61539268 |
Sep 26, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L
5/001 (20130101); H04W 72/0453 (20130101); H04W
76/15 (20180201); H04W 16/14 (20130101); H04W
72/042 (20130101) |
Current International
Class: |
H04L
1/00 (20060101); H04W 72/04 (20090101); H04L
5/00 (20060101); H04W 16/14 (20090101); H04W
76/02 (20090101) |
Field of
Search: |
;370/252,255 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2012-503944 |
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Feb 2012 |
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JP |
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2012-513715 |
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Jun 2012 |
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JP |
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WO 2010-072624 |
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Jul 2010 |
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WO |
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WO 2012-141628 |
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Oct 2012 |
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WO |
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Other References
European Telecommunications Standards Institute (ETSI), TR 102 907.
V0.0.9, "Reconfigurable Radio Systems (RRS), Use cases for
Operation in White Space Frequency Bands", Jan. 2011, 54 pages.
cited by applicant.
|
Primary Examiner: Rinehart; Mark
Assistant Examiner: Hopkins; Matthew
Attorney, Agent or Firm: Condo Roccia Koptiw LLP
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Patent
Application No. 61/539,268, titled "Methods, Apparatus and Systems
for Common Anchor Based Aggregation", filed Sep. 26, 2011, the
disclosure of which hereby incorporated by reference herein in its
entirety, for all purposes.
Claims
What is claimed is:
1. A wireless transmit/receive unit (WTRU), the WTRU in
communication with an access point (AP) via an anchor channel over
a first frequency band, the first frequency band being an anchor
band, the WTRU configured at least to: receive one or more beacons
via the anchor channel, the one or more beacons providing operating
information for a supplementary channel on a second frequency band,
as a supplementary band, different from the first frequency band,
at least a first beacon of the one or more beacons having a first
structure and at least a second beacon of the one or more beacons
having a second structure, the at least first beacon including
control information for the anchor channel and the at least second
beacon including control information for the supplementary channel;
establish the supplementary channel over the supplementary band
using the operating information; and exchange data over the
established supplementary channel on the supplementary band.
2. The WTRU of claim 1, wherein the receiving the one or more
beacons via the anchor channel includes receiving a series of
beacons, one or more of the series of beacons including control
information for a respective series of supplementary channels.
3. The WTRU of claim 2, wherein the series of beacons are
periodically received from the AP.
4. The WTRU of claim 1, wherein the operating information includes
at least one of: a usage mode of the supplementary channel;
activation or deactivation of the supplementary channel; an
indication of whether the WTRU is scheduled for uplink or downlink
transmission on the supplementary channel before a next beacon
interval; an indication of whether the WTRU is restricted from
using the supplementary channel for a current beacon interval;
dynamic spectrum management information; a channel switch
announcement; or a beacon interval number identifying a particular
beacon interval.
5. The WTRU of claim 4, wherein the dynamic spectrum management
information includes at least one of: a quieting period during
which the WTRU is restricted from transmitting over the
supplementary channel; transmitted power limits for the
supplementary channel; or coexistence information.
6. The WTRU of claim 1, wherein the exchanging of the data over the
established supplementary channel includes one of: sending the data
over the established supplementary channel; receiving the data over
the established supplementary channel; or sending and receiving
data over the established supplementary channel.
7. The WTRU of claim 1, wherein the at least first beacon is
received at a first periodicity and the at least second beacon is
received at a second periodicity.
8. The WTRU of claim 1, wherein the anchor band is in an
industrial, scientific, and medical (ISM) band and the
supplementary band is in a television white space (TVWS) band.
9. The WTRU of claim 1, wherein the operating information provides
for an allocation of the supplementary channel as a downlink only
channel, and communication via the supplementary channel is
reserved for at least one of frames not requiring acknowledgement,
broadcast frames, or multicast frames.
10. The WTRU of claim 1, wherein the operating information provides
for an allocation of the supplementary channel as an uplink only
channel, and the WTRU is further configured to: send one or more
reservations via the anchor channel for supplemental channel
capacity; receive one or more assigned supplemental channel
capacities in response to the one or more reservations; and send
uplink data via the supplementary channel in one or more of the
assigned supplemental channel capacities.
11. A method performed by a wireless transmit/receive unit (WTRU),
the WTRU in communication with an access point (AP) via an anchor
channel over a first frequency band, the first frequency band being
an anchor band, the method comprising: receiving one or more
beacons via the anchor channel, the one or more beacons providing
operating information for a supplementary channel on a second
frequency band, as a supplementary band, different from the first
frequency band, at least a first beacon of the one or more beacons
received at a first periodicity and at least a second beacon of the
one or more beacons received at a second periodicity, the at least
first beacon including control information for the anchor channel
and the at least second beacon including control information for
the supplementary channel; establishing the supplementary channel
over the supplementary band using the operating information; and
exchanging data over the established supplementary channel on the
supplementary band.
12. An access point (AP), the AP in communication with a wireless
transmit/receive unit (WTRU), via an anchor channel over a first
frequency band, the first frequency band being an anchor band, the
AP configured at least to: send one or more beacons via the anchor
channel, the one or more beacons providing operating information
for a supplementary channel on a secondary frequency band, as a
supplementary band, different from the first frequency band, at
least a first beacon of the one or more beacons being sent to a
broadcast address and at least a second beacon of the one or more
beacons being sent to a multicast address, the at least first
beacon including control information for the anchor channel and the
at least second beacon including control information for the
supplementary channel; establish the supplementary channel over the
supplementary band using the operating information; and exchange
data over the established supplementary channel on the
supplementary band.
13. The AP of claim 12, wherein the sending of the one or more
beacons via the anchor channel includes providing additional
operating information for at least one additional supplementary
channel on a further frequency band, as an additional supplementary
band, different from the anchor or supplementary bands, the AP
being further configured to: establish the additional supplementary
channel over the additional supplementary band using the additional
operating information provided by the one or more beacons; and
exchange additional data over the additional supplementary channel
on the additional supplementary band.
14. The AP of claim 13, wherein the sending the one or more beacons
via the anchor channel includes sending a first series of beacons
and a second series of beacons, the first series of beacons
including control information for the anchor channel and the second
series of beacons including control information for the
supplementary channel and the additional supplementary channel,
wherein the AP being further configured to: determine whether to
modify one or more channel allocations for exchanging data on the
supplementary and the additional supplementary channels; insert
into the second series of beacons, control information to allocate
the supplementary channel as one of: an uplink only channel or a
downlink only channel; and insert into the second series of
beacons, control information to allocate the additional
supplementary channel as one of: an uplink only channel or a
downlink only channel.
15. The AP of claim 12, wherein the AP being further configured to:
send via the supplementary channel, frames including data; and
receive via the anchor channel, a block acknowledgement for the
frames received on the supplementary channel.
Description
BACKGROUND OF THE INVENTION
The analog TV bands include the Very High Frequency (VHF) band and
the Ultra High Frequency (UHF) band. The VHF is composed of the low
VHF band operating from 54 MHz to 88 MHz (excluding 72 MHz to 76
MHz), and the high VHF band operating from 174 MHz to 216 MHz. The
UHF band is composed of the low UHF band operating from 470 MHz to
698 MHz, and the high UHF band operating from 698 MHz to 806 MHz.
Within the TV bands, each TV channel has 6 MHz bandwidth. Channels
2 to 6 are in the low VHF band; Channels 7 to 13 are in the high
VHF band; Channels 14-51 are in the low UHF band; Channels 52 to 69
are in the high UHF band.
In the United States, the Federal Communications Commission (FCC)
set Jun. 12, 2009 as the deadline for replacing analog TV
broadcasting by digital TV broadcasting. The digital TV channel
definitions are the same as the analog TV channel. The digital TV
bands use analog TV channels 2 to 51 (except 37), while the analog
TV channels 52 to 69 may be used for new non-broadcast users. The
frequency allocated to a broadcasting service but not used locally
is called White Space (WS). The TVWS refers to the TV channels 2 to
51 (except 37).
Besides TV signals, there are other licensed signals transmitted on
the TV bands. Channel 37 is reserved for radio astronomy and
Wireless Medical Telemetry Service (WMTS), where the latter may
operate on any vacant TV channels 7 to 46. Private Land Mobile
Radio System (PLMRS) uses channels 14 to 20 in certain metropolitan
areas. Remote control devices use any channels above channel 4,
except channel 37. The starting frequency of FM channel 200 is 87.9
MHz, with partial overlapping on TV channel 6. The wireless
microphone uses channels 2 to 51 with a bandwidth of 200 kHz. The
FCC has ruled that the wireless microphone usage is restricted to
two pre-specified channels, and its operation on other channels
requires a pre-registry.
Because of the transition from analog to digital TV transmissions
in the 470-862 MHz frequency band, certain portions of the spectrum
are no longer used for TV transmissions, though the amount and
exact frequency of unused spectrum varies from location to
location. The FCC has opened up these TVWS frequencies for a
variety of unlicensed uses.
SUMMARY
The Summary is provided to introduce a selection of concepts in a
simplified form that are further described below in the Detailed
Description. This Summary is not intended to identify key features
or essential features of the claimed subject matter, nor is it
intended to be used to limit the scope of the claimed subject
matter.
Embodiments of the disclosure are directed to methods, systems and
apparatus for managing aggregation between an access point (AP) and
a Wireless Receiver/Transmitter Unit (WRTU) using an anchor channel
over a first frequency band between the AP and the WRTU. One
representative method may include wirelessly receiving, by the
WRTU, one or more beacons via the anchor channel, the one or more
beacons providing allocation information for allocating a
supplementary channel on a second frequency band, as a
supplementary band, different from the first frequency band;
establishing the supplementary channel over the supplementary band
using the allocation information provided in the one or more
beacons; and wirelessly exchanging, by the WRTU, data over the
established supplementary channel on the supplementary band.
In one or more embodiments, the wirelessly exchanging of the data
over the established supplementary channel may include one of: (1)
wirelessly sending the data over the established supplementary
channel; (2) wirelessly receiving the data over the established
supplementary channel or (3) wirelessly sending and receiving data
over the established supplementary channel.
In one or more embodiments, the wirelessly receiving of the one or
more beacons via the anchor channel may include receiving a series
of beacons, each beacon including control information for the
anchor channel and control information for the supplementary
channel.
In one or more embodiments, the wirelessly receiving of the one or
more beacons via the anchor channel may include receiving a series
of beacons, a first portion of the series of beacons including
control information for the anchor channel and a second portion of
the series of beacons including control information for the
supplementary channel.
In one or more embodiments, the series of beacons may be received
in each beacon transmission interval such that the first beacon in
each beacon transmission interval may be broadcast and other
respective beacons in each beacon transmission interval may be
multicast.
In one or more embodiments, the series of beacons may be
periodically received such that the first beacon associated with
the anchor channel may be broadcast and other respective beacons
associated with the supplementary channels may be multicast.
In one or more embodiments, the WRTU may determine which of the
series of beacons are the beacons that include the control
information for the supplementary channel based on a predetermined
number of beacon intervals and may search for the control
information in the determined beacons.
In one or more embodiments, the wirelessly receiving of the one or
more beacons via the anchor channel may include providing
allocation information for allocating at least one further
supplementary channel on the second frequency band or a further
frequency band,
In one or more embodiments, the further supplementary channel may
be established using the allocation information provided by the one
or more beacons; and the WRTU may wirelessly exchange further data
over the further supplementary channel.
In one or more embodiments, the wirelessly exchanging of the data
over the established supplementary channel and the further data
over the further supplementary channel may include one of: (1)
wirelessly sending the data over the established supplementary
channel and wirelessly receiving the further data over the
established further supplementary channel; (2) wirelessly receiving
the data over the established supplementary channel and wireless
sending the further data over the established further supplementary
channel; (3) wirelessly sending the data and the further data over
the established supplementary channel and the established further
supplementary channel; or (4) wirelessly receiving the data and the
further data over the established supplementary channel and the
established further supplementary channel.
In one or more embodiments, the WRTU may: (A) determine from the
control information in the second portion of the series of beacons
whether to modify channel allocation for sending/receiving data on
at least one of: (1) the supplementary channel; or (2) the further
supplementary channel, (B) change, based on the control information
in each beacon of the second portion of beacons, an allocation on
the supplementary channel to provide one of: (1) an uplink only
channel on the supplementary channel; or (2) a downlink only
channel on the supplementary channel; and (C) change, based on the
control information in each beacon of the second portion of the
beacons, an allocation on the further supplementary channel to
provide one of: (1) an uplink only channel on the further
supplementary channel; or (2) a downlink only channel on the
further supplementary channel.
In one or more embodiments, the anchor channel and one channel of
the supplementary channel and further supplementary channel may be
switched, responsive to the one channel having less beacon losses
relative to the anchor channel such that the one channel becomes a
new anchor channel and the previous anchor channel becomes one of
the supplementary channels.
In one or more embodiments, the anchor channel may be in an ISM
band and the supplementary channel may be in a TVWS band.
In one or more embodiments, the beacons that include the allocation
information for the supplementary channel may include quieting
information indicating one or more quiet periods for quieting the
WRTU.
In one or more embodiments, the WRTU may determine the quieting
information from the beacons, and may restrict transmissions during
the quiet periods to enable a search for other transmissions on the
TVWS band.
In one or more embodiments, the WRTU may receive one or more
beacons indicating updated allocation information to move the WRTU
from the supplementary channel, responsive to finding other
transmissions on the TVWS band.
In one or more embodiments, the allocation information in the
beacons sent over on the anchor channel may include operating
information regarding the supplementary channel associated with at
least one of: (1) an association procedure; or (2) a discovery
procedure.
In one or more embodiments, the wirelessly receiving of the one or
more beacons via the anchor channel may include detecting at least
one beacon in a beacon portion that is associated with control
information indicating the allocation information for the anchor
channel, and detecting a beacon in a payload portion of the frame
used for data exchange on the anchor channel, the beacons detected
in the payload portion indicating the allocation information for
the supplementary channel.
In one or more embodiments, the WRTU may detect the allocation
information from the received one or more beacons that may include
determining at least one of: (1) a usage mode of the supplementary
channel; (2) activation or deactivation of the supplementary
channel; (3) a traffic indication map indicating whether the WRTU
is scheduled for uplink or downlink transmission on the
supplementary channel before the next beacon interval; (4) a
resource sharing map indicating whether the WRTU is restricted from
using the supplementary channel for the current beacon interval;
(5) dynamic spectrum management information indicating at least one
of (i) a quieting period during which the WRTU is restricted from
transmitting over the supplementary channel, (ii) transmitted power
limits for the supplementary channel, or (iii) coexistence
information; (5) a channel switch announcement; and/or (6) a beacon
interval number identifying a particular beacon interval.
In one or more embodiments, the WRTU may send a request including
capability information indicating the capability of the WRTU to use
the supplementary channel or further supplementary channels.
In one or more embodiments, the WRTU may receive via the anchor
channel, at least one of: a scaling factor indicating a channel
synchronization relative to the anchor channel or a secondary
channel sync signal in a management frame on the anchor
channel.
In one or more embodiments, the WRTU may receive via the
supplementary channel, frames including data; and may send via the
anchor channel, a block acknowledgement for the frames received on
the supplementary channel.
In one or more embodiments, the sending of the block
acknowledgement for the frames received on the supplementary
channel may be sent responsive to expiration of a timer or the
initiation of a subsequent beacon interval.
In one or more embodiments, the sending of the block
acknowledgement for the frames received on the supplementary
channel may be sent when a time since reception of the oldest
unacknowledged frame exceeds a threshold.
In one or more embodiments, the WRTU may receive a broadcast
acknowledgement query on the anchor channel to initiate a block
acknowledgment response, and responsive to reception of the
broadcast acknowledgement query, the block acknowledgement on the
anchor channel for the frames received on the supplementary channel
may be sent.
In one or more embodiments, the WRTU may determine whether
predetermined portions used for data exchange on the anchor channel
are available for acknowledgements; and may insert the block
acknowledgment into one of the predetermined portions that is
available for acknowledgements such that the sending of the block
acknowledgement for the frames received on the supplementary
channel may include sending the frame that includes the inserted
block acknowledgment.
In one or more embodiments, the supplementary channel may be
allocated based on one of: (1) a fixed reservation-access scheme in
which the supplementary channel is shared between or among the
plurality of WRTUs in a fixed round-robin manner; (2) a demand
reservation-based access scheme in which the anchor channel is used
as a reservation channel; or (3) a contention access scheme in
which each WRTU follows pre-existing rules for sensing the
supplementary channel and transmits if the supplementary channel is
sensed to be free for a threshold period.
Another representative method may include wirelessly transmitting,
by the AP, one or more beacons via the anchor channel, the one or
more beacons providing allocation information for allocating a
supplementary channel on a second frequency band, as a
supplementary band, different from the first frequency band;
establishing the supplementary channel over the supplementary band
using the allocation information provided by the one or more
beacons; and wirelessly exchanging, by the AP, data over the
established supplementary channel on the supplementary band.
In one or more embodiments, the AP may determine which of the
series of beacons are the beacons that are to include the control
information for the supplementary channel based on a predetermined
number of beacon intervals; and may insert the control information
in the determined beacons.
In one or more embodiments, the AP may determine whether to modify
one or more channel allocations for exchanging data on the
supplementary and further supplementary channels; may insert into
the second portion of the series of beacons control information to
allocate the supplementary channel as one of: (1) as an uplink only
channel; or (2) a downlink only channel; may insert into the second
portion of the series of beacons, control information to allocate
the further supplementary channel as one of: (1) as an uplink only
channel; or (2) a downlink only channel; and may send the series of
beacons on the anchor channel.
In one or more embodiments, the beacons that include the allocation
information of the supplementary channel further may include
quieting information indicating one or more quiet periods for
quieting the WRTU.
In one or more embodiments, the AP may determine during the one or
more quiet periods, whether transmissions are present on the TVWS
band, as a determined result; and may send to the WRTU, updated
allocation information, responsive to the determined result.
In one or more embodiments, the AP may receive a message including
capability information indicating the capability of the WRTU to use
the supplementary channel or further supplementary channels; may
determine an allocation of at least one of: (1) the supplementary
channel or (2) the further supplementary channels for the WRTU in
accordance with the received capability information; and may insert
the allocation information corresponding to the determined
allocation for the WRTU in the series of beacons destined for the
WRTU.
A representative Wireless Receiver/Transmitter Unit (WRTU) may
include a wireless receiver/transmitter configured to wirelessly
receive one or more beacons via the anchor channel, the one or more
beacons providing allocation information for allocating of a
supplementary channel on a second frequency band, as a
supplementary band, different from a first frequency band; and a
processor in conjunction with the wireless receiver/transmitter
configured to establish the supplementary channel over the
supplementary band using the allocation information provided by the
one or more beacons.
In one or more embodiments, the wireless receiver/transmitter
wirelessly may exchange data over the established supplementary
channel on the supplementary band.
In one or more embodiments, a MAC layer may aggregate the flows
over the anchor and supplementary channels.
One or more embodiments contemplate a wireless access point that
may include a wireless receiver/transmitter configured to
wirelessly transmit one or more beacons via the anchor channel, the
one or more beacons providing allocation information for allocating
a supplementary channel on a second frequency band, as a
supplementary band, different from a first frequency band; and a
processor in conjunction with the wireless receiver/transmitter
configured to establish the supplementary channel over the
supplementary band using the allocation information provided by the
one or more beacons.
BRIEF DESCRIPTION OF THE DRAWINGS
A more detailed understanding may be had from the Detailed
Description below, given by way of example in conjunction with
drawings appended hereto. Figures in such drawings, like the
detailed description, are examples. As such, the Figures and the
detailed description are not to be considered limiting, and other
equally effective examples are contemplated, wherein:
FIG. 1 is a diagram illustrating exemplary TV band spectrum usage
in the United States consistent with embodiments;
FIG. 2A is a diagram illustrating a representative communication
system in which one or more disclosed embodiments may be
implemented;
FIG. 2B is a diagram illustrating a representative wireless
transmit/receive unit (WRTU) that may be used within the
communication system illustrated in FIG. 2A;
FIGS. 2C, 2D, and 2E are system diagrams of representative radio
access networks and representative core networks that may be used
within the communication system illustrated in FIGS. 1A, 2A and/or
2B;
FIG. 3A is a diagram illustrating a representative system deploying
core network based access technologies and Internet-based access
technologies consistent with embodiments;
FIG. 3B is a diagram illustrating a representative system deploying
supplementary carriers in an opportunistic fashion consistent with
embodiments;
FIG. 4 is a diagram illustrating exemplary carrier aggregation
using a representative anchor channel and multiple supplementary
channels consistent with embodiments;
FIG. 5 is a diagram illustrating exemplary communication over the
anchor channel and supplementary channels of FIG. 4 consistent with
embodiments;
FIG. 6 is a diagram illustrating a representative frame structure
consistent with embodiments;
FIG. 7 is a diagram illustrating an exemplary carrier aggregation
procedure consistent with embodiments;
FIG. 8 is a diagram illustrating an exemplary SuppChan sync sent on
the anchor channel consistent with embodiments;
FIG. 9 is a diagram illustrating a representative transmission
operation on an anchor channel and a supplementary channel
consistent with embodiments;
FIG. 10 is a diagram illustrating another representative
transmission operation on the anchor channel and supplementary
channel consistent with embodiments;
FIG. 11 is a diagram illustrating a representative acknowledgment
procedure consistent with embodiments;
FIG. 12 is a diagram illustrating another representative
acknowledgment procedure consistent with embodiments;
FIG. 13 is a diagram illustrating a further representative
acknowledgment procedure consistent with embodiments;
FIG. 14 is a diagram illustrating an additional representative
acknowledgement procedure consistent with embodiments;
FIG. 15 is a diagram illustrating an additional representative
acknowledgement procedure consistent with embodiments;
FIG. 16 is a diagram illustrating a representative AP coverage area
using a plurality of supplementary channels/carriers consistent
with embodiments;
FIG. 17A is a diagram illustrating an exemplary coverage area
change when changing channels from TVWS to ISM band consistent with
embodiments;
FIG. 17B is a diagram illustrating an exemplary coverage area
change when changing channels from ISM band to TVWS band consistent
with embodiments;
FIG. 18 is a block diagram illustrating a representative
transceiver architecture for inter-band MAC-layer aggregation using
multiple radio front-ends consistent with embodiments;
FIG. 19 is a block diagram illustrating another representative
transceiver architecture consistent with embodiments; and
FIG. 20 is a block diagram illustrating another representative
transceiver architecture consistent with embodiments.
DETAILED DESCRIPTION
A detailed description of illustrative embodiments will now be
described with reference to the various Figures. Although this
description provides a detailed example of possible
implementations, it should be noted that the details are intended
to be exemplary and in no way limit the scope of the application.
As used herein, the article "a" or "an", absent further
qualification or characterization, may be understood to mean "one
or more" or "at least one", for example.
The FCC may allow unlicensed radio transmitters to operate on the
TVWS except channels 3, 4 and 37, as long as minimum interference
is caused to the licensed radio transmissions. The operation of
unlicensed radio transmitters may satisfy several restrictions.
Embodiments recognize at least three kinds of unlicensed TV Band
Devices (TVBDs): (1) fixed TVBD; (2) mode I portable (or personal)
TVBD and (3) mode II portable (or personal) TVBD. Both fixed TVBD
and mode II portable TVBD may have geo-location database access
capability and may register to the TV band database. Access to the
TV band database may be obtained by querying the allowed TV
channels to avoid interference with digital TV signals and licensed
signals transmitted on the TV bands. Spectrum sensing may be
considered as an add-on feature for TVBDs to enable low
interference to be caused to digital TV signals and licensed
signals. Sensing-only TVBDs may be allowed to operate on TVWS
perhaps if their access to the TV band database is limited or
restricted.
FIG. 1 shows the TV band spectrum usage. Embodiments recognize that
fixed TVBDs may operate on channels 2 to 51, perhaps except
channels 3, 4, 37, and they may not operate on the same or the
first adjacent channel to a channel used by TV services. The
maximum transmission power of fixed TVBD may be 1 W, with at most 6
dBi antenna gain. The maximum Effective Isotropic Radiated Power
(EIRP) may be 4 W. A portable TVBD may only operate on channels 21
to 51, perhaps except channel 37, and may not operate on the same
channel used by TV services. The maximum transmission power of
portable TVBD may be 100 mW or 40 mW if it is on the first adjacent
channel to a channel used by TV services. If a TVBD device is a
sensing-only device, then its transmission power may not exceed 50
mW. Some or all of the TVBDs may have strict out-of-band emissions.
The antenna (outdoor) height of a fixed TVBD may be less than 30
meters, while there may not be any limitation on the antenna height
for portable TVBD.
Embodiments contemplate that the opportunistic use of White Space,
for example, in the 470-790 MHz bands may be used by secondary
users for any radio communication (e.g., if the use does not
interfere with other incumbent/primary users). As a result, the use
of LTE and other cellular technologies within the TVWS bands may
enable carrier aggregation. Current wireless networks may be
reaching their limits in terms of maximum throughput offered. These
networks are typically designed for targeted applications (for
example, voice, video and/or data, among others) and for an
envisioned load. Embodiments recognize that wireless networks
continue to evolve, for example, wireless local area networks
(WLANs) may be used for streaming video and for providing hotspot
coverage (e.g., in coffee shops and other public areas), and
cellular networks may be used for web browsing. Certain businesses
may use WLANs and forego wiring Ethernet for the simplicity of
wireless connectivity. Certain residential homes and other entities
may have at least one WiFi access point.
Wireless networks have relied on using their spectrum more
efficiently. In one or more embodiments, carrier aggregation may be
used to aggregate transmission over multiple chunks of spectrum.
Spectrum may be available in many bands including licensed bands
and/or License Exempt (LE) bands (e.g. ISM bands, TVWS bands,
and/or 60 GHz bands, among others). The TVWS band is a generic name
that may be used to represent spectrum in the UHF and VHF bands
that is not reserved (e.g., for TV distribution, for wireless
microphone use, or for other reserved use).
FIG. 2A is a diagram of a representative communications system 100
in which one or more disclosed embodiments may be implemented. The
communications system 100 may be a multiple access system that
provides content, such as, data, video, messaging, broadcast, etc.,
to multiple wireless users. The communications system 100 may
enable multiple users to access such content through the sharing of
system resources, including wireless bandwidth. For example, the
communications systems 100 may employ one or more channel access
methods, such as code division multiple access (CDMA), time
division multiple access (TDMA), frequency division multiple access
(FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), and
the like.
As shown in FIG. 2A, the communication system 100 may include
wireless transmit/receive units (WRTUs) 102a, 102b, 102c, 102d, a
radio access network (RAN) 104, a core network 106, a public
switched telephone network (PSTN) 108, the Internet 110, and other
networks 112, though it will be appreciated that the disclosed
embodiments contemplate any number of WRTUs, base stations,
networks, and/or network elements. Each of the WRTUs 102a, 102b,
102c, 102d may be any type of device configured to operate and/or
communicate in a wireless environment. By way of example, the WRTUs
102a, 102b, 102c, 102d may be configured to transmit and/or receive
wireless signals and may include user equipment (UE), a mobile
station, a fixed or mobile subscriber unit, a pager, a cellular
telephone, a personal digital assistant (PDA), a smartphone, a
laptop, a netbook, a personal computer, a wireless sensor, consumer
electronics, and the like.
The communication systems 100 may also include a base station 114a
and a base station 114b. Each of the base stations 114a, 114b may
be any type of device configured to wirelessly interface with at
least one of the WRTUs 102a, 102b, 102c, 102d to facilitate access
to one or more communication networks, such as the core network
106, the Internet 110, and/or the networks 112. By way of example,
the base stations 114a, 114b may be a base transceiver station
(BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a site
controller, an access point (AP), a wireless router, and the like.
While the base stations 114a, 114b are each depicted as a single
element, it will be appreciated that the base stations 114a, 114b
may include any number of interconnected base stations and/or
network elements.
The base station 114a may be part of the RAN 104, which may also
include other base stations and/or network elements (not shown),
such as a base station controller (BSC), a radio network controller
(RNC), relay nodes, etc. The base station 114a and/or the base
station 114b may be configured to transmit and/or receive wireless
signals within a particular geographic region, which may be
referred to as a cell (not shown). The cell may further be divided
into cell sectors. For example, the cell associated with the base
station 114a may be divided into three sectors. Thus, in one
embodiment, the base station 114a may include three transceivers,
i.e., one for each sector of the cell. In another embodiment, the
base station 114a may employ multiple-input multiple output (MIMO)
technology and, therefore, may utilize multiple transceivers for
each sector of the cell.
The base stations 114a, 114b may communicate with one or more of
the WRTUs 102a, 102b, 102c, 102d over an air interface 116, which
may be any suitable wireless communication link (e.g., radio
frequency (RF), microwave, infrared (IR), ultraviolet (UV), visible
light, etc.). The air interface 116 may be established using any
suitable radio access technology (RAT).
More specifically, as noted above, the communication system 100 may
be a multiple access system and may employ one or more channel
access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the
like. For example, the base station 114a in the RAN 104 and the
WRTUs 102a, 102b, 102c may implement a radio technology such as
Universal Mobile Telecommunication System (UMTS) Terrestrial Radio
Access (UTRA), which may establish the air interface 116 using
wideband CDMA (WCDMA). WCDMA may include communication protocols
such as High-Speed Packet Access (HSPA) and/or Evolved HSPA
(HSPA+). HSPA may include High-Speed Downlink Packet Access (HSDPA)
and/or High-Speed Uplink Packet Access (HSUPA).
In another embodiment, the base station 114a and the WRTUs 102a,
102b, 102c may implement a radio technology such as Evolved UMTS
Terrestrial Radio Access (E-UTRA), which may establish the air
interface 116 using Long Term Evolution (LTE) and/or LTE-Advanced
(LTE-A).
In other embodiments, the base station 114a and the WRTUs 102a,
102b, 102c may implement radio technologies such as IEEE 802.16
(i.e., Worldwide Interoperability for Microwave Access (WiMAX)),
CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000
(IS-2000), Interim Standard 95 (IS-95), Interim Standard 856
(IS-856), Global System for Mobile communications (GSM), Enhanced
Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the
like.
The base station 114b in FIG. 2A may be a wireless router, Home
Node B, Home eNode B, or access point, for example, and may utilize
any suitable RAT for facilitating wireless connectivity in a
localized area, such as a place of business, a home, a vehicle, a
campus, and the like. In one embodiment, the base station 114b and
the WRTUs 102c, 102d may implement a radio technology such as IEEE
802.11 to establish a wireless local area network (WLAN). In
another embodiment, the base station 114b and the WRTUs 102c, 102d
may implement a radio technology such as IEEE 802.15 to establish a
wireless personal area network (WPAN). In yet another embodiment,
the base station 114b and the WRTUs 102c, 102d may utilize a
cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, etc.)
to establish a picocell or femtocell. As shown in FIG. 2A, the base
station 114b may have a direct connection to the Internet 110.
Thus, the base station 114b may not be required to access the
Internet 110 via the core network 106.
The RAN 104 may be in communication with the core network 106,
which may be any type of network configured to provide voice, data,
applications, and/or voice over internet protocol (VoIP) services
to one or more of the WRTUs 102a, 102b, 102c, 102d. For example,
the core network 106 may provide call control, billing services,
mobile location-based services, pre-paid calling, Internet
connectivity, video distribution, etc., and/or perform high-level
security functions, such as user authentication. Although not shown
in FIG. 2A, it will be appreciated that the RAN 104 and/or the core
network 106 may be in direct or indirect communication with other
RANs that employ the same RAT as the RAN 104 or a different RAT.
For example, in addition to being connected to the RAN 104, which
may be utilizing an E-UTRA radio technology, the core network 106
may also be in communication with another RAN (not shown) employing
a GSM radio technology.
The core network 106 may also serve as a gateway for the WRTUs
102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110,
and/or other networks 112. The PSTN 108 may include
circuit-switched telephone networks that provide plain old
telephone service (POTS). The Internet 110 may include a global
system of interconnected computer networks and devices that use
common communication protocols, such as the transmission control
protocol (TCP), user datagram protocol (UDP) and the internet
protocol (IP) in the TCP/IP internet protocol suite. The networks
112 may include wired or wireless communications networks owned
and/or operated by other service providers. For example, the
networks 112 may include another core network connected to one or
more RANs, which may employ the same RAT as the RAN 104 or a
different RAT.
Some or all of the WRTUs 102a, 102b, 102c, 102d in the
communication system 100 may include multi-mode capabilities, i.e.,
the WRTUs 102a, 102b, 102c, 102d may include multiple transceivers
for communicating with different wireless networks over different
wireless links. For example, the WRTU 102c shown in FIG. 2A may be
configured to communicate with the base station 114a, which may
employ a cellular-based radio technology, and with the base station
114b, which may employ an IEEE 802 radio technology.
FIG. 2B is a system diagram of a representative WRTU 102. As shown
in FIG. 2B, the WRTU 102 may include a processor 118, a transceiver
120, a transmit/receive element 122, a speaker/microphone 124, a
keypad 126, a display/touchpad 128, non-removable memory 106,
removable memory 132, a power source 134, a global positioning
system (GPS) chipset 136, and other peripherals 138. It will be
appreciated that the WRTU 102 may include any sub-combination of
the foregoing elements while remaining consistent with an
embodiment.
The processor 118 may be a general purpose processor, a special
purpose processor, a conventional processor, a digital signal
processor (DSP), a plurality of microprocessors, one or more
microprocessors in association with a DSP core, a controller, a
microcontroller, Application Specific Integrated Circuits (ASICs),
Field Programmable Gate Array (FPGAs) circuits, any other type of
integrated circuit (IC), a state machine, and the like. The
processor 118 may perform signal coding, data processing, power
control, input/output processing, and/or any other functionality
that enables the WRTU 102 to operate in a wireless environment. The
processor 118 may be coupled to the transceiver 120, which may be
coupled to the transmit/receive element 122. While FIG. 2B depicts
the processor 118 and the transceiver 120 as separate components,
it will be appreciated that the processor 118 and the transceiver
120 may be integrated together in an electronic package or
chip.
The transmit/receive element 122 may be configured to transmit
signals to, or receive signals from, a base station (e.g., the base
station 114a) over the air interface 116. For example, in one
embodiment, the transmit/receive element 122 may be an antenna
configured to transmit and/or receive RF signals. In another
embodiment, the transmit/receive element 122 may be an
emitter/detector configured to transmit and/or receive IR, UV, or
visible light signals, for example. In yet another embodiment, the
transmit/receive element 122 may be configured to transmit and
receive both RF and light signals. It will be appreciated that the
transmit/receive element 122 may be configured to transmit and/or
receive any combination of wireless signals.
In addition, although the transmit/receive element 122 is depicted
in FIG. 2B as a single element, the WRTU 102 may include any number
of transmit/receive elements 122. More specifically, the WRTU 102
may employ MIMO technology. Thus, in one embodiment, the WRTU 102
may include two or more transmit/receive elements 122 (e.g.,
multiple antennas) for transmitting and receiving wireless signals
over the air interface 116.
The transceiver 120 may be configured to modulate the signals that
are to be transmitted by the transmit/receive element 122 and to
demodulate the signals that are received by the transmit/receive
element 122. As noted above, the WRTU 102 may have multi-mode
capabilities. Thus, the transceiver 120 may include multiple
transceivers for enabling the WRTU 102 to communicate via multiple
RATs, such as UTRA and IEEE 802.11, for example.
The processor 118 of the WRTU 102 may be coupled to, and may
receive user input data from, the speaker/microphone 124, the
keypad 126, and/or the display/touchpad 128 (e.g., a liquid crystal
display (LCD) display unit or organic light-emitting diode (OLED)
display unit). The processor 118 may also output user data to the
speaker/microphone 124, the keypad 126, and/or the display/touchpad
128. In addition, the processor 118 may access information from,
and store data in, any type of suitable memory, such as the
non-removable memory 106 and/or the removable memory 132. The
non-removable memory 106 may include random-access memory (RAM),
read-only memory (ROM), a hard disk, or any other type of memory
storage device. The removable memory 132 may include a subscriber
identity module (SIM) card, a memory stick, a secure digital (SD)
memory card, and the like. In other embodiments, the processor 118
may access information from, and store data in, memory that is not
physically located on the WRTU 102, such as on a server or a home
computer (not shown).
The processor 118 may receive power from the power source 134, and
may be configured to distribute and/or control the power to the
other components in the WRTU 102. The power source 134 may be any
suitable device for powering the WRTU 102. For example, the power
source 134 may include one or more dry cell batteries (e.g.,
nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride
(NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and
the like.
The processor 118 may also be coupled to the GPS chipset 136, which
may be configured to provide location information (e.g., longitude
and latitude) regarding the current location of the WRTU 102. In
addition to, or in lieu of, the information from the GPS chipset
136, the WRTU 102 may receive location information over the air
interface 116 from a base station (e.g., base stations 114a, 114b)
and/or determine its location based on the timing of the signals
being received from two or more nearby base stations. It will be
appreciated that the WRTU 102 may acquire location information by
way of any suitable location-determination method while remaining
consistent with an embodiment.
The processor 118 may further be coupled to other peripherals 138,
which may include one or more software and/or hardware modules that
provide additional features, functionality, and/or wired or
wireless connectivity. For example, the peripherals 138 may include
an accelerometer, an e-compass, a satellite transceiver, a digital
camera (for photographs or video), a universal serial bus (USB)
port, a vibration device, a television transceiver, a hands free
headset, a Bluetooth.RTM. module, a frequency modulated (FM) radio
unit, a digital music player, a media player, a video game player
module, an Internet browser, and the like.
FIG. 2C is a system diagram of the RAN 104 and the core network 106
according to an embodiment. As noted above, the RAN 104 may employ
a UTRA radio technology to communicate with the WRTUs 102a, 102b,
and 102c over the air interface 116. The RAN 104 may also be in
communication with the core network 106. As shown in FIG. 2C, the
RAN 104 may include Node-Bs 140a, 140b, 140c, which may each
include one or more transceivers for communicating with the WRTUs
102a, 102b, 102c over the air interface 116. The Node-Bs 140a,
140b, 140c may each be associated with a particular cell (not
shown) within the RAN 104. The RAN 104 may also include RNCs 142a,
142b. It will be appreciated that the RAN 104 may include any
number of Node-Bs and RNCs while remaining consistent with an
embodiment.
As shown in FIG. 2C, the Node-Bs 140a, 140b may be in communication
with the RNC 142a. Additionally, the Node-B 140c may be in
communication with the RNC142b. The Node-Bs 140a, 140b, 140c may
communicate with the respective RNCs 142a, 142b via an Iub
interface. The RNCs 142a, 142b may be in communication with one
another via an Iur interface. Each of the RNCs 142a, 142b may be
configured to control the respective Node-Bs 140a, 140b, 140c to
which it is connected. In addition, each of the RNCs 142a, 142b may
be configured to carry out or support other functionality, such as
outer loop power control, load control, admission control, packet
scheduling, handover control, macrodiversity, security functions,
data encryption, and the like.
The core network 106 shown in FIG. 2C may include a media gateway
(MGW) 144, a mobile switching center (MSC) 146, a serving GPRS
support node (SGSN) 148, and/or a gateway GPRS support node (GGSN)
150. While each of the foregoing elements are depicted as part of
the core network 106, it will be appreciated that any one of these
elements may be owned and/or operated by an entity other than the
core network operator.
The RNC 142a in the RAN 104 may be connected to the MSC 146 in the
core network 106 via an IuCS interface. The MSC 146 may be
connected to the MGW 144. The MSC 146 and the MGW 144 may provide
the WRTUs 102a, 102b, 102c with access to circuit-switched
networks, such as the PSTN 108, to facilitate communications
between the WRTUs 102a, 102b, and 102c and traditional land-line
communications devices.
The RNC 142a in the RAN 104 may also be connected to the SGSN 148
in the core network 106 via an IuPS interface. The SGSN 148 may be
connected to the GGSN 150. The SGSN 148 and the GGSN 150 may
provide the WRTUs 102a, 102b, 102c with access to packet-switched
networks, such as the Internet 110, to facilitate communications
between and the WRTUs 102a, 102b, 102c and IP-enabled devices.
As noted above, the core network 106 may also be connected to the
networks 112, which may include other wired or wireless networks
that are owned and/or operated by other service providers.
FIG. 2D is a system diagram of the RAN 104 and the core network 106
according to another embodiment. As noted above, the RAN 104 may
employ an E-UTRA radio technology to communicate with the WRTUs
102a, 102b, and 102c over the air interface 116. The RAN 104 may
also be in communication with the core network 106.
The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will
be appreciated that the RAN 104 may include any number of eNode-Bs
while remaining consistent with an embodiment. The eNode-Bs 160a,
160b, 160c may each include one or more transceivers for
communicating with the WRTUs 102a, 102b, 102c over the air
interface 116. In one embodiment, the eNode-Bs 160a, 160b, 160c may
implement MIMO technology. Thus, the eNode-B 160a, for example, may
use multiple antennas to transmit wireless signals to, and receive
wireless signals from, the WRTU 102a.
Each of the eNode-Bs 160a, 160b, and 160c may be associated with a
particular cell (not shown) and may be configured to handle radio
resource management decisions, handover decisions, scheduling of
users in the uplink and/or downlink, and the like. As shown in FIG.
2D, the eNode-Bs 160a, 160b, 160c may communicate with one another
over an X2 interface.
The core network 106 shown in FIG. 2D may include a mobility
management gateway (MME) 162, a serving gateway 164, and a packet
data network (PDN) gateway 166. While each of the foregoing
elements are depicted as part of the core network 106, it will be
appreciated that any one of these elements may be owned and/or
operated by an entity other than the core network operator.
The MME 162 may be connected to each of the eNode-Bs 160a, 160b,
and 160c in the RAN 104 via an S1 interface and may serve as a
control node. For example, the MME 162 may be responsible for
authenticating users of the WRTUs 102a, 102b, 102c, bearer
activation/deactivation, selecting a particular serving gateway
during an initial attach of the WRTUs 102a, 102b, 102c, and the
like. The MME 162 may also provide a control plane function for
switching between the RAN 104 and other RANs (not shown) that
employ other radio technologies, such as GSM or WCDMA.
The serving gateway 164 may be connected to each of the eNode Bs
160a, 160b, 160c in the RAN 104 via the S1 interface. The serving
gateway 164 may generally route and forward user data packets
to/from the WRTUs 102a, 102b, 102c. The serving gateway 164 may
also perform other functions, such as anchoring user planes during
inter-eNode B handovers, triggering paging when downlink data is
available for the WRTUs 102a, 102b, 102c, managing and storing
contexts of the WRTUs 102a, 102b, 102c, and the like.
The serving gateway 164 may also be connected to the PDN gateway
166, which may provide the WRTUs 102a, 102b, 102c with access to
packet-switched networks, such as the Internet 110, to facilitate
communications between the WRTUs 102a, 102b, and 102c and
IP-enabled devices.
The core network 106 may facilitate communications with other
networks. For example, the core network 106 may provide the WRTUs
102a, 102b, 102c with access to circuit-switched networks, such as
the PSTN 108, to facilitate communications between the WRTUs 102a,
102b, and 102c and traditional land-line communications devices.
For example, the core network 106 may include, or may communicate
with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server)
that serves as an interface between the core network 106 and the
PSTN 108. In addition, the core network 106 may provide the WRTUs
102a, 102b, 102c with access to the networks 112, which may include
other wired or wireless networks that are owned and/or operated by
other service providers.
FIG. 2E is a system diagram of the RAN 104 and the core network 106
according to another embodiment. The RAN 104 may be an access
service network (ASN) that employs IEEE 802.16 radio technology to
communicate with the WRTUs 102a, 102b, and 102c over the air
interface 116. As will be further discussed below, the
communication links between the different functional entities of
the WRTUs 102a, 102b, 102c, the RAN 104, and the core network 106
may be defined as reference points.
As shown in FIG. 2E, the RAN 104 may include base stations 170a,
170b, 170c, and an ASN gateway 172, though it will be appreciated
that the RAN 104 may include any number of base stations and ASN
gateways while remaining consistent with an embodiment. The base
stations 170a, 170b, 170c may each be associated with a particular
cell (not shown) in the RAN 104 and may each include one or more
transceivers for communicating with the WRTUs 102a, 102b, 102c over
the air interface 116. In one embodiment, the base stations 170a,
170b, 170c may implement MIMO technology. Thus, the base station
170a, for example, may use multiple antennas to transmit wireless
signals to, and receive wireless signals from, the WRTU 102a. The
base stations 170a, 170b, 170c may also provide mobility management
functions, such as handoff triggering, tunnel establishment, radio
resource management, traffic classification, quality of service
(QoS) policy enforcement, and the like. The ASN gateway 172 may
serve as a traffic aggregation point and may be responsible for
paging, caching of subscriber profiles, routing to the core network
106, and the like.
The air interface 116 between the WRTUs 102a, 102b, 102c and the
RAN 104 may be defined as an R1 reference point that implements the
IEEE 802.16 specification. In addition, each of the WRTUs 102a,
102b, and 102c may establish a logical interface (not shown) with
the core network 106. The logical interface between the WRTUs 102a,
102b, 102c and the core network 106 may be defined as an R2
reference point, which may be used for authentication,
authorization, IP host configuration management, and/or mobility
management.
The communication link between each of the base stations 170a,
170b, and 170c may be defined as an R8 reference point that
includes protocols for facilitating WRTU handovers and the transfer
of data between base stations. The communication link between the
base stations 170a, 170b, 170c and the ASN gateway 172 may be
defined as an R6 reference point. The R6 reference point may
include protocols for facilitating mobility management based on
mobility events associated with each of the WRTUs 102a, 102b,
100c.
As shown in FIG. 2E, the RAN 104 may be connected to the core
network 106. The communication link between the RAN 104 and the
core network 106 may defined as an R3 reference point that includes
protocols for facilitating data transfer and mobility management
capabilities, for example. The core network 106 may include a
mobile IP home agent (MIP-HA) 174, an authentication,
authorization, accounting (AAA) server 176, and a gateway 178.
While each of the foregoing elements are depicted as part of the
core network 106, it will be appreciated that any one of these
elements may be owned and/or operated by an entity other than the
core network operator.
The MIP-HA 174 may be responsible for IP address management, and
may enable the WRTUs 102a, 102b, and 102c to roam between different
ASNs and/or different core networks. The MIP-HA 174 may provide the
WRTUs 102a, 102b, 102c with access to packet-switched networks,
such as the Internet 110, to facilitate communications between the
WRTUs 102a, 102b, and 102c and IP-enabled devices. The AAA server
176 may be responsible for user authentication and for supporting
user services. The gateway 178 may facilitate interworking with
other networks. For example, the gateway 178 may provide the WRTUs
102a, 102b, 102c with access to circuit-switched networks, such as
the PSTN 108, to facilitate communications between the WRTUs 102a,
102b, and 102c and traditional land-line communications devices. In
addition, the gateway 178 may provide the WRTUs 102a, 102b, 102c
with access to the networks 112, which may include other wired or
wireless networks that are owned and/or operated by other service
providers.
Although not shown in FIG. 2E, it will be appreciated that the RAN
104 may be connected to other ASNs and the core network 106 may be
connected to other core networks. The communication link between
the RAN 104 the other ASNs may be defined as an R4 reference point,
which may include protocols for coordinating the mobility of the
WRTUs 102a, 102b, 102c between the RAN 104 and the other ASNs. The
communication link between the core network 106 and the other core
networks may be defined as an R5 reference, which may include
protocols for facilitating interworking between home core networks
and visited core networks.
A mobile user may choose from a wide range of technologies to
access networks such as GPRS, EDGE, 3G and/or 4G for wide area
access, and/or WiFi for local area access. Mobile hosts may be
multi-homed (e.g., connected via multiple access technologies
and/or multi-access points) and may possess two or more
heterogeneous interfaces. Internet content may be distributed
(e.g., over a "cloud") such that content delivery may become more
complex (e.g., to get the right content from the right
location).
In one or more embodiments, a multi-homed wireless device (e.g., a
mobile host, mobile device, netbook and/or UE, among others) may
access or receive (e.g., efficiently access or receive) content
(e.g., internet-based content).
In one or more embodiments, a multi-homed mobile host may use
(e.g., may fully utilize) a subset or all of the available
interfaces (e.g., wireless and/or wired) to send content or to
receive content (e.g., efficiently receive content).
Although the receiver is described in FIGS. 2A-2E as a wireless
terminal, it is contemplated that in one or more embodiments that
such a terminal may use wired communication interfaces with the
communication network.
FIG. 3A is a diagram that illustrates a representative system
deploying core network based access technologies and Internet-based
access technologies.
Referring to FIG. 3A, representative system 100 may include RAN
104, internet access network (IAN) 105, core network 106, PSTN 108,
Internet 110, and other networks 112. System 100 may communicate
with WRTU 102 via communications links (e.g., wireless interfaces
or wired interfaces) through the RAN 104 to the core network 106 or
the IAN 105 to the Internet 110. The RAN 104 may include one or
more core network based radio access technologies (e.g., with one
or a plurality of core network based radio access points CNBRAP-1,
CNRBRAP-2, . . . CNBRAP-N). The IAN 104 may include one or more
internet based access technologies (e.g., with one or a plurality
of internet based access points IBAP-1, IBAP-2, . . . IBAP-N). The
core network 106 may also interface with the PSTN 108, the Internet
110 and/or the other networks 112. System 100 may enable carrier
aggregation of supplementary carriers with, for example, a WiFi, an
802.11 or WLAN anchor carrier in, for example, the ISM band.
In one or more embodiments, one or more of the CNBRAPs may be
access points using the TVWS band and/or one or more of the IBAPs
may be WiFi, 802.11 or WLAN access points using the ISM band.
In one or more embodiments, channels associated with license exempt
frequencies or licensed frequencies may be aggregated with
frequencies used for operation of WiFi, 802.11 or WLAN access
points.
FIG. 3B shows an exemplary system 200 deploying supplementary
carriers in an opportunistic fashion to use Licensed Exempt (LE)
bands (e.g., TVWS and ISM) contemplated by embodiments. The system
may use heterogeneous network deployments that may make use of
advanced LE carrier aggregation solutions to provide hot-spot
coverage. The heterogeneous network architecture may include, for
example an LTE macro cell 210 and underlay of pico/femto/RRH cells
220-1, 220-2 . . . 220-N that may aggregate licensed and LE bands.
The macro cells 210 may provide service continuity. The pico/femto
cells 220-1, 220-2 . . . 220-N may be used to provide hot spot
coverage. A coexistence database 230 and mechanisms to coordinate
operation with other secondary networks/users operating in LE bands
may be implemented. A TVWS database 240 may be used to protect
incumbent users operating in the TVWS band. There may be
infrastructure to support dynamic spectrum trading across both
licensed and LE bands. The infrastructure may include IBAPs 250
(e.g., HeNBs, WiFi APs, 802.11 APs and/or WLAN APs) communicating
via the Internet to enable carrier aggregation of spectrum from
licensed exempt bands and the bands associated with the IBAPs 250
using, for example, the ISM band. For example, channels in the ISM
bands and/or licensed frequency bands may be aggregated with
channels in another frequency band (e.g., a licensed exempt TVWS
band) for carrier aggregation.
Although carrier aggregation has been discussed with respect to
license exempt TVWS bands, it is contemplated that other frequency
bands (e.g., licensed band) may also be aggregated with ISM bands
for carrier aggregation.
Wireless systems following the 802.11 standards may use a carrier
sense multiple access with collision avoidance (CSMA/CA) scheme.
The CSMA/CA may be enhanced with a virtual carrier sense mechanism
that may use Request to Send (RTS) and Clear to Send (CTS) control
frames to reserve the channel for a period of time. Successfully
received packets may be acknowledged through an ACK control frame.
A station (STA) or access point (AP) may maintain a timer for each
transmitted frame. If the ACK is not received before expiration of
the timer, among other contemplated conditions, the frame may be
retransmitted, and the retransmissions may continue until a maximum
number of retransmissions is exceeded, after which the frame may be
discarded.
APs (e.g., 802.11 APs) may broadcast beacons that may be used for
discovery, and may provide network information to the STAs (or UEs
or WTRUs). The STAs (or UEs or WTRUs) may passively scan for
broadcast beacons. After broadcasted beacons are found, the STAs
(or UEs or WTRUs) may associate with the AP, and adjust their
timing to the timing of the beacon signal. For example, in 802.11
based networks, frame synchronization at the STAs may be achieved
by monitoring the beacons transmitted by the APs. The beacons may
be sent periodically (e.g., at a nominal rate), and may include a
timestamp information element, which may be used by the STAs to
update their local clocks. In one or more embodiments described
herein, the term beacon may refer to an 802.11 beacon, a modified
802.11 beacon to support supplementary channels, and/or more
generally to a special management frame that may include
information to allow operation over supplementary channels.
The beacons may be used to support devices in one or more power
save modes. An AP may periodically or at predetermined times send a
Traffic Indication Map (TIM), for example within a beacon, to
identify which STAs using a power saving mode have data frames
waiting for them (cached) in the AP's buffer. The TIM may identify
each respective STA by an association ID that the AP assigned
during the association procedure.
Anchor channels generally refer to channels that may support
existing or legacy communication. One or more supplementary
channels in the same or other frequency bands, using the same or
different underlying radio access technology, may be aggregated to
a respective anchor channel. The supplementary channel may increase
system capacity, address potential bottlenecks, and/or reduce
latency. The supplementary channel may not be a fully-backward
compatible channel, and as a result may not be in operation alone
without a corresponding anchor channel. For example, the
supplementary channel may be linked to an anchor carrier such that:
(1) a wireless transmit/receive device (WTRU or user equipment
(UE)) or cellular device may not be able to camp on a cell using
(or perhaps in some embodiments only using) a supplementary
channel; and/or (2) the WLAN STAs may not be able to associate with
an AP using (or perhaps in some embodiments only using) a
supplementary channel.
Although an anchor channel is shown using an 802.11 WiFi radio
access technology (RAT), it is contemplated that other RATs may be
implemented. In one or more embodiments, the anchor channel and the
supplementary channel may be associated with a number of different
frequency or spectrum bands including an anchor carrier that may
use TVWS.
In one or more embodiments, a WLAN may include: (1) an anchor
channel using an ISM band and a supplementary channel using a TVWS
band; (2) the anchor channel using the TVWS band and the
supplementary channel using the ISM band or the same or a different
TVWS band.
A legacy STA (LS) may generally refer to an 802.11 or other STA
that may not or perhaps does not support inter-band carrier
aggregation.
An inter-band (IB) STA may general refer to an 802.11 STA that may
or does support inter-band carrier aggregation.
An anchor channel may generally refer to a channel that may support
communication with one or more legacy STAs.
A supplementary channel may generally refer to a channel that may
be aggregated with a corresponding anchor channel, and that in one
or more embodiments may rely on the anchor channel for one or more
procedures (e.g. discovery procedures, association procedures,
and/or beaconing procedures) and/or may provide optimized data
transfer on the supplementary channel.
An uplink (UL) transmission may generally refer to a transmission
from the STAs to or towards the AP and a downlink (DL) transmission
may generally refer to a transmission from the AP to or towards the
STAs.
One or more embodiments contemplate inter-band aggregation or band
aggregation of non-contiguous bands, for example, interband
aggregation between ISM channels and/or one or more non-contiguous
TVWS channels.
In one or more embodiments, the inter-band aggregation may include
the TVWS band having particular operating procedures and may
include: (1) scheduling procedures (e.g., that schedule traffic
across the aggregated bands); (2) discovery procedures (e.g., that
run in both bands); beaconing procedures (that run in both bands);
and/or (3) adaptation procedures (that provide for a fast changing
environment), among others.
In one or more embodiments, an anchor channel using 802.11
technologies may be used to support one or more supplementary
channels in the LE band.
In one or more embodiments, the anchor channel in one band (e.g. LE
spectrum) may be deployed or used to support supplementary channels
in the same or a different band. The anchor channel may carry: (1)
common scheduling information; (2) frame synchronization
information; (3) transmission feedback information; (4) channel
change reconfiguration information; (5) mobility management related
procedures or information; and/or (6) supplementary channel
configuration information, for example pertinent to channels
operating over multiple bands. The LE spectrum may be any LE band,
for example ISM bands, the TVWS band, sub 1 GHz bands that may be
used for 802.11ah deployments or may be any licensed band which may
be leased out (e.g., brokered) for a pre-specified duration for
secondary use by other technologies such as 802.11.
The 802.11 STAs may operate using multiple channels across one or
multiple bands and may use the anchor channel to send or to
receive: (1) configuration information; (2) synchronization
information; (3) scheduling information; and/or (4) feedback
information associated with the supplementary channels.
FIG. 4 is a diagram illustrating carrier aggregation using a
representative anchor channel and multiple supplementary
channels.
Referring to FIG. 4, the anchor carrier may use or be within the
ISM bands and the supplementary carrier may use or be within the
TVWS band. The bandwidth of the supplementary carriers may or may
not be the same and the rate supported by the supplementary
carriers may be the same or different between or among
supplementary carriers. It is contemplated that the technology used
in the supplementary channel may or may not be the same as that
used in the anchor channel.
Although a single supplementary channel is generally described, it
is contemplated that any number of supplementary channels may be
used and may extend the bandwidth available relative to a single
supplementary channel. For example, in one or more embodiments, a
plurality of supplementary channels may be aggregated with one or
more anchor channels.
FIG. 5 is an exemplary timing diagram illustrating communication
over the anchor channel and supplementary channels of FIG. 4
contemplated by one or more embodiments.
Referring to FIG. 5, an AP may send or transmit, via an anchor
channel (e.g., in the anchor band), management frames or beacons
b1, b2 and b3 that may be used for both the anchor channel and one
or more supplementary channels. The STA may use or continue to use
the anchor channel for the signaling (e.g., management and/or
control information from the STA) related to, for example: (1)
association procedures; (2) disassociation procedures; (3)
reassociation procedures; (4) authentication procedures; (5)
deauthentication procedures; and/or (6) discovery procedures (e.g.,
beaconing and/or probing), among others. For example, the control
information may be provided over the anchor channel from the AP in
a granted time slot after a corresponding set of beacons in a
beacon interval. After the supplementary channel 1 and
supplementary channel 2 are established or aggregated with the
anchor channel, the STA may exchange data with the AP over the
anchor channel, the supplementary channel 1 and/or the
supplementary channel 2. For example, as shown in FIG. 5, data may
be split between the anchor channel and the supplementary channel
1.
In one or more embodiments, the anchor channel may repeat the
beacons B1, B2 and B3 at some or at each beacon interval. The
supplementary channels may not include some or any beacons and may
include frames of data (or perhaps in some embodiments may only
include such frames) (e.g., exclusive of management and/or control
information). In some embodiments, the management and/or control
information may instead be sent over the anchor channel.
In one or more embodiments, the STA may provide this management
and/or control signaling on a primary supplementary channel.
The beacons B1, B2 and B3 may include operating details,
information and/or parameters of the channels, and may be
configured for or tailored to different types of channels or
individual channels (e.g., first and second types of channels may
have different beacons or beacon structures, for example TVWS
channels may have a first beacon structure and ISM channels may
have a second, different beacon structure). The beacons may be
adapted to the capability of the AP associated with the
channels.
In one or more embodiments, the AP may periodically or at
designated periods send beacons (e.g., k beacons such as B1, B2, Bk
where some or each beacon may correspond to a supplementary
channel) at or after the Target Beacon Transmission Times (TBTTs)
or beacon interval. Beacon B1 associated with the primary or anchor
channel may be transmitted to a broadcast address, whereas the
beacons B2 and B3 associated with or for the supplementary channels
may be transmitted to pre-defined multicast-group addresses. By
sending the beacons B2 and B3 to pre-defined multicast-group
addresses, among other contemplated techniques, legacy STAs may
avoid unnecessarily dealing with such beacon frames. The
periodicity or timing of the beacon transmissions for the
supplementary channels may not be the same as the periodicity or
timing for the anchor channel. For instance, if the operating
conditions of the supplementary channel 1 do not change frequently
(within a threshold period), beacon B2 may be sent once each N TBTT
or beacon interval, where N may be an integer number.
FIG. 6 is a diagram illustrating an exemplary frame structure sent
from an AP.
Referring to FIG. 6, the beacon frame structure may include a MAC
header portion, frame body, and/or a frame check sequence (FCS).
The beacon may include a frame control field, a duration field, an
address field (e.g., destination address field), a source address
field, a basic service set identifier (BSSID) field, and/or a
sequence control field, among others. The frame body may include
control/management type information including a timestamp, the
beacon interval, a capabilities field, a service set identifier
(SSID), supported rates, a QoS capability, and/or the information
for the supplementary channels (e.g., supplementary channel 1 and
supplementary channel 2), among others.
For example, the operating details or information for the
supplementary channels may be carried as additional information
elements (IEs) in the anchor channel beacon. The beacon may use the
broadcast address and be received by both legacy STAs and
inter-band STAs. In one or more embodiments, the new information
elements may be ignored by legacy STAs. In some embodiments, the
use of the additional supplementary channel operating details or
information may increase the size of the beacon.
In either one or more contemplated beacon structures associated
with each supplementary channel or one or more contemplated
information elements in the anchor channel beacon that may be
associated with the supplementary channels, the supplementary
channel operating details or information may be provided to the
inter-band UEs and may include one or more of: (1) the usage mode
of the supplementary channel such as details or information of how
the UE may use the supplementary channel; (For example, various
alternatives are described in subsequent embodiments. For some or
each of the usage modes, the AP may provide details or information
related to: (i) the duration of the usage mode; (ii) where and/or
how acknowledgements may to be transmitted for data sent on the
supplementary channel; and/or (iii) inter-frame spacing to be used
on the supplementary channel, among others.) (2)
Activation/Deactivation of the supplementary channel; (For example,
this mechanism may allow the AP to activate and deactivate a
supplementary channel at the granularity of a beacon interval.) (3)
Traffic Indication Map (TIM) associated with the supplementary
channels such that the TIM may be modified to signal future
activity on the supplementary channels; (For example, the AP may
signal the STAs that may be scheduled (e.g., for uplink
transmission or for downlink transmission) on the supplementary
channel before the next TBTT. Upon reception of the TIM that
indicates that a STA may not be scheduled, the STA may deactivate
the supplementary channel until the next TBTT. For instance, the
STA may stop monitoring the channel for any downlink traffic. In
one implementation, the STA may receive both the TIM from the
anchor channel (used to indicate to STAs in power save mode that
there is traffic pending at the AP) as well as a TIM for each of
the supplementary channels. The TIM for a supplementary channel may
carry scheduling activity until the next beacon. If no activity is
scheduled, the STA may deactivate the supplementary channel.) (4)
Resource Sharing Map (RSM); and/or (The format of the RSM may be
similar to the TIM and may provide an indication of the STAs that
may be allowed to use the supplementary channel for the current
beacon interval. For example, new beacon information may indicate a
list or table of association IDs that may use a given supplementary
channel. STAs which are not part of the list or table may or may
not be allowed to contend for access via the respective
supplementary channel until the next beacon interval (e.g., at
least the next beacon interval, and may use the indication to
deactivate the channel.) (5) Dynamic Spectrum Management (DSM)
information. For example, the DSM information may include
information particular to the band carrying the supplementary
channel. For example, for the TVWS band, the AP may provide
information related to: (i) measurements (type and/or frequency of
measurements, and/or reporting of the measurements); (ii) quieting
periods (e.g., one or more periods during which the STA may not
transmit over the supplementary channel to allow sensing by the AP
(e.g., to potentially detect the arrival of a primary user of the
channel); (iii) channel information (such as the frequency and/or
bandwidth of the supplementary channel). If the bandwidth or
channel aggregation uses a set of supplementary channels, the
channel information may refer to a set of carriers; (iv)
transmitted power regulation and/or limits for one or more
supplementary channels; (v) coexistence information such as
information to allow coexistence across systems. For example, TVWS
database information regarding primary usage information and/or
location information associated with the primary usage; (vi) a
channel switch announcement; (vii) beacon interval numbers (BINs).
For example, the AP may send a BIN to identify a particular beacon
interval. The BIN may be in addition to or in lieu of a sequence
number that may be carried in the header of the beacon frames.
Unlike the sequence number which may be incremented for management
frames (e.g., all management frames), QoS data frames (e.g., with a
broadcast/multicast address in the Address 1 field), and/or non-QoS
data frames (e.g., all non-QoS data frames), the BIN may be
incremented (e.g., only incremented) for beacon frames to allow the
AP to schedule specific actions to occur in a specific future
beacon interval. For instance, the BINs may be used for certain
types of usage modes. In one or more embodiments, the beacon
interval number may be set by a modulo-K counter (e.g.,
K=4096).
FIG. 7 is a diagram illustrating an example carrier aggregation
technique. Referring to FIG. 7, in one or more embodiments, the AP
may send one or more beacons that may be modified to include
control information for the supplementary channel. The one or more
beacons may be sent over the anchor channel. STA 1 may discover the
AP by searching for beacons. The STA 1 may determine from the
beacons the capability of the AP, the SSID of the AP, and/or the
beacon interval or Target Beacon Transmit Time (TBTT). The AP may
send a second beacon at the next TBTT. The STA 1 may synchronize
with the AP by adjusting its timing synchronization function (TSF)
timer. The STA 1 may send an Association Request to the AP to
initiate an Association between the STA 1 and AP. The AP may send
an Association Response including the AP's capabilities and its
association identifier (AID). The STA1 may configure its anchor
channel and supplementary channel or channels. The STA 1 may
communicate over the anchor channel (e.g., send data over the
anchor channel to the AP using a legacy protocol). The AP may send
an acknowledgment message to the STA 1 regarding the data
communicated. A further beacon may be sent from the AP after a
second beacon interval. The further beacon may also be modified for
the supplementary channel or channels and may provide the same or a
different allocation of supplementary channels to the STA 1. The AP
may also send or exchange data with the STA 1. The exchange of data
between the AP and STA 1 may be based on the usage mode of the
supplementary channels 1 and 2. For example, the supplementary
channels may be used in a DL only, UL only or bidirectional mode.
The STA 1 may also send data on the anchor channel and may receive
an acknowledgment message from the AP. The procedure for
associating the supplementary channels with the anchor channel may
be dynamic and may occur during each beacon or set of beacons that
are associated with a respective beacon interval.
The STA may use (or perhaps in some embodiments perhaps rely on)
the anchor channel beacon for discovery and/or synchronization. A
STA may search for the anchor channel beacon (or send a probe
request on the anchor channel). After discovery of the AP, the
inter-band STAs may synchronize with the beacon and/or may read the
beacon information to determine the AP capability over the anchor
channel and over any aggregated supplementary channels. The
inter-band STAs may associate with the AP, providing details or
information of its own capabilities.
In one or more embodiments, the Association Request (AR) frame may
be modified to include a new Information field "Supplementary
Channel Capability," which may provide an indication of the
supplementary channels supported by the STA, the measurement
capabilities of the STA, and/or any specific usage modes supported
by the STA. The AP may respond with an AR frame that may assign the
STA a unique Association Identifier (AID). The STA may communicate
with the AP using the anchor channel and/or the agreed usage mode
on the supplementary channels.
In one or more embodiments, if the anchor channel uses its own
timing, among other contemplated conditions, the anchor channel may
assist the supplementary channel by including a scaling factor in
the supplementary channel information element (IE) and/or in the
supplementary channel beacon.
FIG. 8 is a diagram illustrating an exemplary SuppChan sync sent on
the anchor channel.
Referring to FIG. 8, the anchor channel may transmit one or more
secondary channel sync (e.g., SuppChan Sync) signals as specified
management frames, for example, on the anchor channel. These
specified management frames may have a higher priority to reduce
their transmission latency and provide synchronization timing
information for the allocated supplementary channels.
In one or more embodiments, the AP may relax its segregation of
management frames to the anchor channel by allowing certain
management frames (e.g., ACTION management frames) to be
transmitted on both the anchor channel and the supplementary
channel or channels.
It is contemplated in one or more embodiments that if the
supplementary channel is shared with competing systems (e.g.,
802.11, LTE, and/or WPAN, among others) then a coexistence
mechanism may be used. In one or more embodiments, a coexistence
management frame (CMF) may periodically or at pre-established times
be transmitted (e.g., similar to or the same as a beacon) using or
over the supplementary channel. The CMF may have a very long period
(e.g., greater than a threshold time period) in the order of K
beacon intervals (K>1) and may include limited information
(e.g., service set identifier (SSID) and/or usage mode). Other
802.11 networks may be able to identify and interpret the CMF and
execute a coexistence procedure to allow a sharing of the
supplementary channel or to enable the other 802.11 networks to use
an alternate channel.
In one or more embodiments, if the system uses communication over
one or more supplementary channels, the AP may send beamforming
vector identifier information and/or beamforming sector identifier
information to the STA's. It is contemplated in one or more
embodiments that the AP may determine or know the STA's location
information or sector ID in which the STA is located. When the
supplementary channel is allocated for UL transmission, among other
contemplated conditions, the allocation information may allow the
STA to avoid scanning the spatial region to look for or detect
appropriate beam pattern to communicate with the AP. When the
supplementary channel is allocated for DL transmission, among other
contemplated conditions, the AP may communicate the spatial
precoding information to the STA. The spatial precoding information
may be carried in the Association Response message sent to the STA
using or over the anchor channel.
In one or more embodiments, the supplementary channel and anchor
channel may maintain the same frame synchronization and/or may rely
on or may continue to rely on the beacon transmissions on the
anchor channel. The STA operating in both bands may maintain
timestamps (e.g., a single series of timestamps for synchronizing
both the anchor channel and the supplementary channel). Respective
timestamps or each timestamp may be derived from the information
carried in an anchor channel beacon.
In one or more embodiments, beacon information may not be carried
in the supplementary channels. The STAs communicating using or over
the supplementary carriers may communicate or continue to
communicate during the target beacon transmission times (TBTTs). A
STA may determine whether to delay acting on any information
included in the beacon carried on the anchor carrier, until after
completion of any ongoing transmission or transmission opportunity
(TXOP) on the supplementary channel.
In one or more embodiments, the STA may terminate the ongoing
transmission or TXOP if the anchor frame beacon requests a specific
action. Representative examples of different types of specific
action may include those that may affect the TVWS band channels
(e.g., a channel switch announcement or start of a quiet period).
In other representative embodiments, the STA may send messages
indicating when (e.g., may specifically be told when) to act on
information included in the anchor carrier beacon (for instance,
act on such information in K TBTTs).
FIG. 9 is a diagram illustrating an exemplary transmission
operation on an anchor channel and a supplementary channel.
Referring to FIG. 9, transmission operations on the anchor channel
may include acknowledgment messages while transmission operations
on the supplementary channel may use the anchor channel for those
acknowledgments. For example, the anchor channel may have, in a
first timing sequence, a first anchor transmission of data/control
information from the AP to station A, a second anchor transmission
of an acknowledgment message from station A to the AP, the third
anchor transmission of data/control information from the AP to
station B, a fourth anchor transmission of an acknowledgment
message from station B to the AP, a fifth anchor transmission of
data/control information from station C to the AP, a sixth anchor
transmission of acknowledgment message from the AP to station C, a
seventh anchor transmission of data/control information from
station B to the AP, and an eighth anchor transmission of an
acknowledgment message from the AP to station B. Each
acknowledgment message may indicate whether the previous message
was successfully received, for example. Since the supplementary
channel may be allocated as a downlink only channel, any
acknowledgment of transmissions over the supplementary channel may
occur using the anchor channel.
A second timing sequence that may occur on the supplementary
channel at the same time as (e.g., while) the first timing sequence
is occurring on the anchor channel may include a first
supplementary transmission (e.g., of data) from the AP to station
A, a second supplementary transmission (e.g., of data) from the AP
to station D, a third supplementary transmission (e.g., of data)
from the AP to station B, a fourth supplementary transmission
(e.g., of data) from the AP to station A, a fifth transmission
(e.g., of data) from the AP to station C, a sixth supplementary
transmission (e.g., of data) from the AP to station E, a seventh
supplementary transmission (e.g., of data) from the AP to station
A, and an eighth supplementary transmission (e.g., of data) from
the AP to station D.
The supplementary channel may be used as added capacity that may be
managed (e.g., substantially managed and/or maintained) by
operations on the anchor channel. If operation in anchor channel
and supplementary channels are sufficiently far apart in the
frequency domain (e.g., as may be the case if the channels are in
different bands), among other contemplated conditions, the
operation on the supplementary channel may not have a duplex
restriction (e.g., the same duplex restrictions as the anchor
channels). A STA may receive or transmit (or in some embodiments
perhaps only receive or transmit) at any given time on a particular
channel or closely spaced adjacent channels. It is contemplated
that while the STA (or AP) may be transmitting on the supplementary
channel, it may be receiving on the anchor channel (or vice versa).
The supplementary channel may not be restricted to be half-duplex.
If the supplementary channel may be used as added capacity, the
channel may be used solely for: (1) AP-to-STA (e.g., downlink (DL))
transmissions; (2) STA-to-AP (e.g., uplink (UL)) transmissions,
and/or may be shared for both uplink and downlink transmissions
(i.e. shared UL/DL transmissions) as described in detail below.
In the DL only transmission mode (DLOTM), the supplementary channel
may be used for DL (e.g., entirely for DL) operations. For example,
when the AP becomes congested with DL traffic (for instance,
because of heavy load on the anchor channel or interference on the
anchor carrier), among other contemplated conditions, the DLOTM
mode may be used. The supplementary channel may be activated and
may be used (or perhaps in some embodiments may only be used) to
transport AP-to-STA traffic. As the transmissions may be controlled
by the AP, the DL traffic may be scheduled by the anchor carrier
(or in some embodiments perhaps entirely by the anchor carrier),
and the DL traffic may be transmitted without the RTS/CTS mechanism
and without CSMA. When operating in the DLOTM, the STAs may turn
off their transmit circuitry for the supplementary channels.
In one or more embodiments, the DL traffic on the supplementary
channel may be reserved for frames not using acknowledgments, or
for broadcast/multicast frames. The traffic may be packed (or in
some embodiments perhaps tightly packed) on the supplementary
carrier, with an insignificant amount or no amount of interframe
spacing.
In one or more embodiments, the supplementary channel may be used
to carry data frames (one, some, or all of the data frames)
including, for example, those that are to be acknowledged. If a
data frame is to be acknowledged, among other contemplated
conditions, the AP may space the DL frames to allow reception of an
acknowledgement frame from the destination STA (e.g., allowing the
destination STA) to: (1) process the DL frame, (2) generate an
acknowledgement frame and/or (3) transmit the acknowledgement frame
(e.g., with or without a delay caused by interframe spacing).
The AP may use or continue to use the anchor channel in half-duplex
mode. The AP may schedule the DL traffic on the supplementary
channels. If the STA is configured to monitor a DL-only
supplementary channel (for instance based on the TIM IE carried in
the supplementary channel operating details, parameters or
information), among other contemplated conditions, the STA may
monitor (e.g., continuously monitor) the supplementary channel for
scheduled data. If a frame is received with the correct destination
address, the frame may be recovered and may be forwarded to higher
layers of the STA protocol stack for further processing.
If the STA is in a Power Save (PS) mode, among other contemplated
conditions, the AP may be aware of the PS mode and may not schedule
DL traffic to the STA during the times associated with the PS mode.
In one or more embodiments, the supplementary channel may be used
(or perhaps in some embodiments only used) for frames not having to
be acknowledged (e.g., multicast and/or broadcast traffic, among
others). The AP may use a fair scheduling algorithm to share the
supplementary channel across STAs, and may send the traffic with an
insignificant or no interframe spacing. In one or more embodiments,
the supplementary channel may be used to carry data traffic (e.g.,
some or all data traffic including those that are to be
acknowledged).
FIG. 10 is a diagram illustrating another example transmission
operation on the anchor channel and supplementary channel.
Referring to FIG. 10, the timing sequence in FIG. 10 is the same as
that of FIG. 9 except for the transmission operation on the
supplementary channel. For frames on the supplementary channel that
are to be acknowledged, the AP may use one or a combination of the
following to substantially reduce or eliminate such
acknowledgements: (1) the AP may repeat a frame transmission K
times in order to increase reliability and the AP may no longer
expect the ACK from the STAs; (The number of repetitions may be
configured through the supplementary channel operating details (for
instance carried in the anchor channel beacon); and/or (2) The AP
may use a more robust modulation and coding scheme (MCS) (e.g., by
using QPSK instead of 64-QAM64, for example or BPSK instead of QPSK
or 64-QAM and/or a lower coding rate. The AP may no longer expect
the ACK from the STAs. One of skill understands such a selection of
a more robust modulation or coding scheme. In one or more
embodiments, the AP may segment frames and/or may limit (or
restrict) the maximum transmission times over the supplementary
channel.
In a first example, in a first set of K supplementary
transmissions, the AP may repeatedly send data and/or control
information to station A, in a second set of K supplementary
transmissions, the AP may repeatedly send data and/or control
information to station D, and in a third set of K supplementary
transmissions, the AP may repeatedly send data and/or control
information to station B. The reliability of the transmission to
each station may be increased by the repeated transmission K times.
In a second example, the robustness of the MCS for each
supplementary transmission on the supplementary channel may be
increased.
FIG. 11 is a diagram illustrating an exemplary acknowledgment
procedure. In FIGS. 11-15, successful reception is indicated by a
check mark while unsuccessful reception is indicated by an X.
Referring to FIG. 11, the AP may send (e.g., broadcast) to one or
more stations (e.g., STA 1). The traffic may include one or more
beacons modified to include information for allocation/control of
the supplementary channel. The traffic may be sent over the anchor
channel. The AP may send on the supplementary channel further
traffic destined for the STA 1 and having a unique frame identifier
(e.g., frame number). The frame (e.g., frame 1) may be successfully
received by STA 1. The STA 1 may start a timer (e.g., a block
acknowledgment timer).
One or more other frames may be sent on the supplementary channel
by the AP and may be destined for other stations. The AP may buffer
frames while waiting for an acknowledgment from the STA 1. The AP
may send on the primary and/or supplementary channel more traffic
destined for the STA 1 (e.g., frame 2). Frame 2, however may not be
successfully received by STA 1. The AP may send on the
supplementary channel additional traffic destined for the STA 1
(e.g., frame 3). STA 1, based on receiving frame 3 prior to
successful reception of frame 2, may begin to buffer incoming
frames while waiting for frame 2. In some embodiments, if frame 3
is sent on the primary channel, among other contemplated
conditions, the STA 1 may send an acknowledgment (ACK) to the AP
indicating successful reception of frame 3. The AP may send on the
supplementary channel more traffic (e.g., frames 4, 5 and 6).
Frames 4, 5, and 6 may be successfully received by STA 1. After
successful reception of frames 4, 5 and 6, the block acknowledgment
timer may expire. Responsive to the expiration of the block
acknowledgment timer, the STA 1 may send over the anchor channel a
block acknowledgment indicating successful reception of frames 1,
4, 5 and 6. Responsive to receipt of the block acknowledgment, the
AP may discard or erase frames 1, 4, 5 and 6 and may retransmit
frame 2 to the STA 1. The retransmission of frame 2 may be sent on
the anchor channel to increase reliability or resent over the
supplementary channel. The STA 1 may then forward the frames (e.g.,
frames 2-6) to higher layers in the STA 1's protocol stack.
For example, the STA may use a first type of acknowledgement
mechanism to transmit the acknowledgement to the AP. In one
representative ACK procedure (e.g., ACK procedure 1), the STA may
send a block acknowledgement for the frames (e.g. some or all
frames) received on the supplementary channel. A block ACK may be
sent by STAs (e.g., some or all STAs) having received frames on the
supplementary channel. The block ACK message may be sent on the
anchor channel. The block ACK message may have a higher priority
associated with it to reduce latency (e.g., overall latency). The
transmission of the block ACK may be tied to or may correspond with
the timing of the TBTT. For example, the transmission of the block
ACK (e.g., associated with data received after a beacon is
received) may be sent before the next TBTT. As a second example,
the block ACK transmission may be triggered based on a maximum
configured ACK latency is exceeded (e.g., using a timer). For
example, the STA may send a block ACK, if the time since reception
of the oldest un-ACKed frame exceeds a threshold. In order for the
AP to cross-reference the frame being ACKed, the AP may use a frame
identifier that may be included in the frames (e.g., some or all
frames) sent over the supplementary channel. The frame identifier
may be unique for each STA or may be global across STAs (e.g., some
or all STAs). In one or more embodiments, the AP may use the STA
identity (AID) and the frame identifier to uniquely identify the
frame being acknowledged.
FIG. 12 is a diagram illustrating another exemplary acknowledgment
procedure.
Referring to FIG. 12, the AP may send (e.g., broadcast) to one or
more stations (e.g., STA 1). The traffic may include one or more
beacons modified to include information for allocation/control of
the supplementary channel. The traffic may be sent over the anchor
channel. The AP may send on the supplementary channel further
traffic destined for the STA 1 and having a unique frame identifier
(e.g., frame number). The frame (e.g., frame 1) may be successfully
received by STA 1. The AP may start a timer (e.g., a block
acknowledgment timer).
One or more other frames may be sent on the supplementary channel
by the AP and destined for other stations. The AP may buffer frames
while waiting for an acknowledgment from the STA 1. The AP may send
on the supplementary channel and/or the primary channel more
traffic destined for the STA 1 (e.g., frame 2). Frame 2, however,
may not be successfully received by STA 1. The AP may send on the
supplementary channel additional traffic destined for the STA 1
(e.g., frame 3). STA 1, based on receiving frame 3 prior to
successful reception of frame 2, may begin to buffer incoming
frames while waiting for frame 2. In some embodiments, if frame 3
is sent on the primary channel, among other contemplated
conditions, the STA 1 may send an acknowledgment (ACK) to the AP
indicating successful reception of frame 3. The AP may send on the
supplementary channel more traffic (e.g., frames 4, 5 and 6).
Frames 4, 5, and 6 may be successfully received by STA 1. After
successful reception of frames 4, 5 and 6, the block acknowledgment
timer may expire. Responsive to the expiration of the block
acknowledgment timer, the AP may send a block acknowledgement
request over the anchor channel to the STA 1 and the STA 1 may send
over the anchor channel a block acknowledgment indicating
successful reception of frames 1, 4, 5, and 6. Responsive to
receipt of the block acknowledgment, the AP may discard or erase
frames 1, 4, 5 and 6 and may retransmit frame 2 to the STA 1. The
retransmission of frame 2 may be sent on the anchor channel to
increase reliability or resent over the supplementary channel. The
STA 1 may then forward the frames (e.g., frames 2-6) to higher
layers in the STA 1's protocol stack.
For example, the STA may use a second type of acknowledgement
mechanism to transmit an acknowledgment to the AP. In a second
representative ACK procedure (e.g., ACK procedure 2), the STAs may
be queried (or polled) on the anchor carrier. The query message may
be set with a high priority (e.g., higher than, for example, other
data messages). The AP may send a broadcast ACK query probe. The
STAs, responsive to receipt of the broadcast ACK query probe, as a
trigger, may commence Block ACK transmissions. In one or more
embodiments, the AP (e.g., which may know the STAs using or sent
traffic on the supplementary channel) may query those STAs
individually. The AP may send a query message based on the time
since the last unacknowledged frame. For example, a query message
may be sent if the time since the last unacknowledged frame exceeds
a threshold. A timer may be started for the first unacknowledged
frame. At expiration of the timer, among other conditions, the AP
may query the STA to send a block ACK. As a second example, the
query message may be sent based on a number of frames or
unacknowledged frames sent to each STA such that the query message
may be sent after the transmission of K frames or K unacknowledged
frames over the supplementary channel.
FIG. 13 is a diagram illustrating another example acknowledgment
procedure.
Referring to FIG. 13, the AP may send (e.g., broadcast) to one or
more stations (e.g., STA 1). The traffic may include one or more
beacons modified to include information for allocation/control of
the supplementary channel. The traffic may be sent over the anchor
channel. The AP may send on the supplementary channel further
traffic destined for the STA 1 and having a unique frame identifier
(e.g., frame number). The frame (e.g., frame 1) may be successfully
received by STA 1.
One or more other frames may be sent on the supplementary channel
by the AP and destined for other stations. The AP may buffer frames
while waiting for an acknowledgment from the STA 1. The AP may send
on the supplementary channel and/or the primary channel more
traffic destined for the STA 1 (e.g., frame 2). Frame 2, however
may not be successfully received by STA 1. The AP may send on the
supplementary channel additional traffic destined for the STA 1
(e.g., frame 3). STA 1, based on receiving frame 3 prior to
successful reception of frame 2, may begin to buffer incoming
frames while waiting for frame 2. In some embodiments, if frame 3
is sent on the primary channel, among other contemplated
conditions, the STA 1 may send an acknowledgment (ACK) to the AP
indicating successful reception of frame 3. The AP may send on the
supplementary channel more traffic (e.g., frames 4, 5 and 6).
Frames 4, 5, and 6 may be successfully received by STA 1. The AP
may send one or more additional beacons over the anchor channel
modified to include the information for allocation/control of the
supplementary channel. After sending the beacons, the AP may start
an Acknowledgement resolution period and may send a block
acknowledgement request over the anchor channel to the STA 1. The
STA 1 may send over the anchor channel a block acknowledgment
indicating successful reception of frames 1, 4, 5 and 6. Responsive
to receipt of the block acknowledgment, the AP may discard or erase
frames 1, 4, 5 and 6 and may retransmit frame 2 to the STA 1. The
retransmission of frame 2 may be sent on the anchor channel to
increase reliability or resent over the supplementary channel. The
STA 1 may then forward the frames (e.g., frames 2-6) to higher
layers in the STA 1's protocol stack.
For example, the STA may use a third type of acknowledgement
mechanism to transmit an acknowledgment to the AP. In a third
representative ACK procedure (e.g., ACK procedure 3), the AP may
establish or define an ACK resolution period, for instance after
(e.g., immediately after) the beacon. During the ACK resolution
period, the AP may query the individual STAs for which it expects
an acknowledgement.
Each of the ACK procedures (e.g., ACK procedures 1, 2 and/or 3) may
be enhanced such that the STAs may be configured to
opportunistically piggyback the ACK information in ongoing
communications in the anchor channel (e.g., in the frame header of
the STA to AP transmissions).
FIG. 14 is a diagram illustrating another exemplary acknowledgement
procedure.
Referring to FIG. 14, the AP may send (e.g., broadcast) beacons
over the anchor channel to one or more stations (e.g., STA 1 and
STA 5). The beacons in the traffic may be modified for
allocation/control information for allocating and/or controlling
the supplementary channel. At time t1, a frame (e.g., frame 1) may
be sent over the supplementary channel from the AP destined for STA
1 and may start an acknowledgment timer. Frame 1 is to have an
acknowledgment. Responsive to successful reception of frame 1 by
STA 1, STA 1 may send an acknowledgment message to the AP. Since
the acknowledgment message is received prior to the acknowledgment
timer expiring (e.g., prior to the response time exceeding a
threshold time), the acknowledgment timer may be stopped and the AP
may consider or determine that frame 1 successfully reached STA 1.
At time t2, a second frame (e.g., frame 2) may be sent over the
supplementary channel from the AP destined for STA 5. Frame 2 may
not have an acknowledgment and an acknowledgment timer may not be
started. At time t3, a frame (e.g., frame 3) may be sent over the
supplementary channel from the AP destined for STA 1 and may start
an acknowledgment timer. Frame 3 is to have an acknowledgment.
Since frame 3 is not successfully received by STA 1, STA 1 may not
send an acknowledgment message to the AP. Since the acknowledgment
message is not received prior to the acknowledgment timer expiring
(e.g., prior to the response time exceeding a threshold time, for
example T4-T3 exceeding a threshold), the AP may retransmit or
resend frame 3. The retransmitted or resent frame 3 may use the
same procedure as frame 1, may be successfully received by STA 1
and may be acknowledged before the acknowledgment timer
expires.
In one or more embodiments, the AP may schedule complete
transactions between itself and the stations. Both the DL
transmission and any potential UL acknowledgment frame associated
with each DL transmission may be scheduled by the AP. As a result,
the supplementary channel may have DL frames interspersed with UL
ACKs from the stations. In this mode, the AP may not contend for
the medium (e.g., no CSMA procedure may be undertaken) prior to
initiating a DL transmission. It is contemplated that the APs and
the stations may toggle between the reception mode (e.g., in which
the AP may receive acknowledgements and stations may receive
frames) and the transmission mode (e.g., in which the AP may send
frames and stations may send acknowledgements). The AP schedules DL
frames, and for those to be acknowledged, the AP may start a timer
waiting for the station ACK. If the timer expires before reception
of the ACK, the AP determines (by inference) a failed transmission
and may perform a frame retransmission.
In one or more embodiments, the AP may use the supplementary
channel to send Frame 1 to station 1. For example, as Frame 1 is to
have acknowledgement, the AP may start an ACK timer at time t1
(e.g., the end of Frame 1). The AP then may transition to reception
mode for the supplementary channel, in order to receive the
acknowledgement for Frame 1. During this time, the AP may not send
any new frames on the supplementary, although it may begin to
prepare and schedule a future frame. If an acknowledgement is
received, the AP may stop the timer, may switch to transmission
mode, and may send the new scheduled frame (Frame 2). In this case,
Frame 2 (which is destined to station 5) may not use
acknowledgement. As a result, at the end of the transmission (time
t2) the AP may schedule and may transmit another frame (Frame 3).
This frame (destined to Station 1) may use an acknowledgement. At
the end of transmission, the AP may switch mode (to reception mode)
and may restart the ACK timer (at t3). If the ACK is not received
before the expiry of the timer (at t4), the AP may know that the
frame was not received. It may change to transmission mode and
resends Frame 3. This frame may be successfully received at the
station.
From a STA perspective, the STAs (e.g., some or all of the STAs)
may be in reception mode for the supplementary channel and may be
controlled or dynamically changed each beacon interval by
information carried in the beacon. For instance, a STA may know
that it is not to be scheduled in the upcoming beacon interval and
may shut down its supplementary channel operation. For those STAs
that may be scheduled in a beacon interval, the STAs may be by
default in reception mode. During this mode, if the STAs correctly
receive a frame that is to be acknowledged (e.g. Frame 1 in FIG.
14), they may generate the ACK frame, may transition to
transmission mode, and after an appropriate inter-frame spacing,
may send the ACK to the AP. This interframe spacing may be the SIFS
or a newly defined inter-frame spacing. After transmission of the
ACK frame, the stations may return to reception mode.
In one or more embodiments, an uplink (UL) Only Transmission Mode
(ULOTM) may be used for the supplementary channel operations, for
example, where the system bottleneck may be the UL. The
supplementary channel may be activated and may be used (e.g., only
used) to transport STA-to-AP traffic. When operating in the ULOTM
mode, the STAs may turn off, power-off or power down their receive
circuitry for the supplementary channels.
In one or more embodiments, the supplementary channel may use a
fixed reservation-based access scheme, where the supplementary
channel may be shared (between or among STAs) in a round robin
(e.g., fixed round-robin) manner. A first STA (e.g., STA 1) may be
given ownership or control of the supplementary channel for a
certain fixed period (e.g., from time t0 to t1). A second STA
(e.g., STA 2) may be given ownership or control of the
supplementary channel for another fixed period (e.g., from time t1
to t2). Other STAs may be given control for other respective
periods. The ownership or control time may be tied to beacon
intervals. For instance, STA K may have ownership or control (e.g.,
for transmission of data in the UL) of the supplementary channel
for a certain time duration (T_K) each beacon interval or every L
beacon intervals. The fixed pattern may be included or indicated in
a RSM that may be controlled by the AP and may be signaled to the
STAs. The signaling may be carried in the anchor channel beacon, or
it may be signaled on the supplementary channel. The AP may modify
the schedule of the STAs associated with the AP, when a new STA
associates to the AP, or when a currently associated STA
disassociates from the AP. Depending on the synchronization, among
other conditions, the AP may determine whether to configure a guard
time between transmissions from different associated STAs.
In one or more embodiments, the supplementary channel may use a
demand reservation-based access scheme, and may use the anchor
channel as its reservation channel. Respective STAs may send
reservation requests (including, for example, their buffer state,
and/or queue size, among others) to the AP on the anchor carrier,
for instance, using a new MAC frame or by piggybacking the request
on an existing data frame transmission. The AP may store the
information for the STAs (e.g., some or all STAs or only the STA
requesting reservations) may implement a scheduler to distribute
the capacity on the supplementary channel, and may signal the
assignment to the STAs. The signaling for the assignments may be:
(1) carried in the anchor channel beacon; (2) carried in a new MAC
frame on the anchor channel; (3) piggybacked with a DL frame in the
anchor channel; and/or (4) carried in a new MAC frame on the
supplementary channel, among others.
In one or more embodiments, the supplementary channel may use a
contention based access scheme, and may use a CSMA type mechanism
in a CSMA contention based access mode (CCBAM). Each STA may follow
the rules for sensing the channel and transmit (or in some
embodiments perhaps only transmit) if the channel is sensed to be
free for an interframe spacing time. A new interframe spacing may
be established or defined for the supplementary channel, for
example, to allow for efficient sharing of the capacity. To reduce
the impact of hidden nodes, the supplementary channel operating in
a CCBAM may restrict the maximum frame size. The ACK feedback for
the UL frames may be carried in the anchor channel. The AP may send
the ACK to the UL STAs after the beacon, in an ACK resolution
period. The information may be coded in a single broadcast message
that may include the address of the STA being acknowledged and/or
an indication of the packet that is being acknowledged (for
instance, using a frame identifier).
FIG. 15 is a diagram illustrating an example acknowledgement
procedure for ULOTM, using the demand reservation-based access
scheme, as an example. It is contemplate that modifications of this
acknowledgement procedure may apply to other above-identified
schemes.
Referring to FIG. 15, the AP may send on the anchor channel
broadcast beacons to one or more STAs (e.g., STA 1 and STA 2 . . .
STA N) served by the AP. Each STA may monitor their respective
queue status (e.g., buffer occupancy or availability) and/or other
parameters indicating reservation priority by the STA. Each STA 1,
2, etc. N may send a reservation request frame to the AP over the
anchor channel. The reservation request frame may indicate the
respective STA's queue status and/or reservation priority. The AP
may receive the reservation request frames from each STA 1, 2, etc.
N and may evaluate or determine distribution/allocation of
supplementary channel resources for each station (e.g., STA 1, 2 .
. . N) during the upcoming beacon interval.
The AP may send or broadcast on the anchor channel beacons to the
STAs served by the AP. The beacons may include (e.g., may be
modified to include) control/allocation information for
controlling/allocating the supplementary channel (e.g., including
the assignments in the upcoming beacon interval). For example, STA
1 may have an allocation/assignment to transmit its frame numbers 1
and 2 on the supplementary channel during the upcoming beacon
interval and STA 2 may have an allocation/assignment to transmit
its frame numbers 3 and 4 on the supplementary channel during the
upcoming beacon interval. STA 1 and 2 may send traffic on the
supplementary channel at their assigned or allocated time slots.
For example, responsive to the traffic sent from STA 1 being
successfully received and frame 4 sent from STA 2 being
successfully received, but frame 3 sent from STA 2 not being
successfully received after the next beacon interval begins, an
acknowledgment resolution period is initiated by the AP. The AP may
first broadcast on the anchor channel the beacons with the
assignment information for the upcoming beacon interval and then
may send (e.g., broadcast) on the anchor channel a block
acknowledgment including acknowledgment of the successful receipt
of frame 1 and 2 sent from STA 1 and acknowledgment of successful
receipt of frame 4 sent from STA 2.
In one or more embodiments, the supplementary channel may use a
Bi-Directional transmission Mode (BiDTM) for both UL and DL
operations (e.g., where intra-LAN traffic may be higher than a
threshold amount). For example, the traffic may be mostly between
STAs in the network managed by the AP and may cause heavy traffic
in both the UL and DL.
In one or more embodiments, the supplementary channel may be tied
to the anchor channel transmissions. The STAs (e.g. some or each
STA) and the AP may use primary channel sensing, and may use the
anchor channel as the primary channel. If the AP or a particular
STA wins the contention on the anchor channel (e.g., controls the
transmission on the anchor channel), it may transmit on both the
anchor and supplementary channel. The AP and STAs may rely on or
use predetermined or dynamically established aggregation rules.
In one or more embodiments, the AP and/or STAs may obtain access to
the supplementary channel or channels independently from access to
the anchor channel. The AP and/or STA may use aggregation rules
that may allow 2 or more independent TXOPs across the anchor
channel and the supplementary channels. For example, a STA that
desires to send some MAC packets to the AP may perform CSMA
procedure concurrently on both the anchor channel and the primary
channel of the supplementary channels and may send the MAC packets
on the channels it has win access to first. A STA may not have the
capability to perform concurrent CSMA operation and may
autonomously or by the AP configure itself to perform CSMA access
on the supplementary channel or channels (or in some embodiments
perhaps only the supplementary channels) or on the anchor channel
(or perhaps in some embodiments perhaps only the anchor channel)
for a given period (e.g., the configuration or reconfiguration may
be dynamic and based on measurements, traffic monitoring, and/or a
congestion threshold, among others. The AP may select and may send
information to the STAs about the CSMA access procedure it is
allowed to use including which channel is the primary channel for a
set of supplementary channels. The information may be sent over a
management frame or beacon on the anchor channel.
The anchor channel may include information for the scheduled TXOPs
for the supplementary channels. The signaling may be carried: (1)
in the anchor channel beacon, or (2) in a new MAC management
message on the anchor channel.
In one or more embodiments, the supplementary channel may use a
spatial reuse mode (SReM) in which either DL or UL direction may be
allocated independently by individual STA using beamforming
techniques (e.g., which may be useful when the supplementary
channel may be in a higher frequency band (exceeding a threshold
frequency) or in a frequency band above the anchor channel
frequency).
The same supplementary channel can be used simultaneously over
multiple AP-STA links using beamforming on each link to mitigate
interference in the spatial domain. For example, each link may be
operated independently in the UL or DL direction (e.g., a
particular supplementary channel may be operated in DL mode for a
link between the AP and STA1 while the supplementary channel may be
operated in UL mode between the AP and STA2).
In one or more embodiments, on each AP-STA link, multiple
supplementary carriers may be supported such that a first portion
of the supplementary carriers may be in DL beamforming mode while a
second portion of the supplementary carriers may be in UL
beamforming mode.
In one or more embodiments, multiple supplementary channels may use
a variable duplex spacing mode (VDSM) such that the multiple
supplementary channels may be spaced arbitrarily apart in frequency
from each other and the individual channels may be assigned to
operate in the either of the DLTOM or ULTOM. Any self-interference
due to leakage of signals from one the transmit chains into the
receive chains may be minimized using either one or both of the
following: (1) self-interference cancellation at the radio front
end so that the leaked signals from the transmit chain into the
receive chain may be cancelled using adaptive filtering (e.g.,
Normalized Least Mean Squares (NLMS) and/or Recursive Least Squares
(RLS) equalizers, among others; and/or (2) tuneable filters (e.g.,
either in analog or digital domain) with high out-of-band rejection
may be used to effectively filter signals leaked from adjacent
bands.
FIG. 16 is a diagram illustrating an exemplary AP coverage area
using a plurality of supplementary channels/carriers.
Referring to FIG. 16, the AP may be in communication with a TVWS
database to inform the AP of available TVWS supplementary channels.
Based on the TVWS information from the TVWS database or
measurements from the STAs, supplementary carriers/channels A, B, C
and D may be available in the APs coverage area (e.g., the entire
coverage area). Supplementary carriers/channels A, B and D may use
beamforming to provide coverage in non-overlapping portions of the
APs anchor carrier coverage area. Supplementary carrier/channel C
may use beamforming to provide coverage that overlaps supplementary
carriers/channels A, B and D. The anchor carrier/channel may cover
the AP's entire coverage area. Beamforming by the AP on the
supplementary carriers/channels may enable joint coverage of the
STAs while enhancing capacity between the AP and the STAs. For
example, certain STAs may be allocated channels on more than one
supplementary carrier (e.g., in overlapping supplementary
carrier/channel areas).
In one or more embodiments, the TVWS band may be used to carry the
anchor channel. Lower frequency bands may be better suited to
support large coverage areas by the AP. The higher frequency bands
may be better suited for providing high throughput in close
proximity to the AP because larger swaths of spectrum are available
for use and/or because of the ease of achieving high spatial
beamforming gains using antenna arrays. In one example, joint
coverage and capacity enhancements may be enabled via inter band
carrier aggregation using the lower frequency band, as the anchor
carrier, to enable robust connectivity with the AP across a large
coverage area while the high frequency bands are aggregated with
the anchor carrier, as a supplementary carrier, to provide capacity
enhancements. It is contemplated that the anchor carrier may
implement the CSMA approach for channel access by the STAs and the
supplementary carrier may be used in DLTOM, ULTOM and/or BiDTM.
It is contemplated that the AP may dynamically switch between or
among the operating modes, for example, based on: (1) buffer
conditions or states of the AP or STAs, (2) capacity of the links;
(3) congestion measurements of the links; and/or (3) estimated
throughput for the links, among others.
In one or more embodiments, a tuneable filter (e.g., analog or
digital) may be used on the supplementary band. For example, one or
more tuneable filters may be used in the radio front-end for the
supplementary bands (e.g., the higher frequency bands) to
dynamically adjust the bandwidth and carrier frequency based on
capacity requirements. The tunable filters may also maintain the
in-band noise to a minimum.
In one or more embodiments, spatial multiplexing may be used on the
supplementary band. For example, the anchor carrier may use
traditional CSMA, (e.g., in the TVWS band), and the supplementary
carrier may be allocated to users (e.g., and may use beamforming).
The supplementary carrier may provide capacity enhancements while
the primary carrier may provide a large coverage area, for example,
to enable efficient spatial reuse of the supplementary channels
while providing significant capacity gains to the STAs. The STAs
closer to the AP (e.g., with a location determined to be within a
threshold distance or a signal level above a threshold amount) may
use the anchor carrier (or in some embodiments perhaps exclusively)
for control plane signaling while the supplementary channel or
channels may be used for data plane communication. The remaining
STAs (e.g., not meeting such a criteria and/or further away from
the AP) may use the physical resources on the anchor carrier for
data and control plane signaling.
In one or more embodiments, the system (e.g., the AP and/or STA)
may initiate a swap of the anchor channel and the supplementary
channel, such that the current anchor channel may become the new
supplementary channel and the current supplementary channel may
become the new anchor channel. The swap, for example, may be based
on the supplementary channel quality exceeding that of the anchor
channel, or when the anchor channel becomes unavailable. In such
cases, the system may choose the best available supplementary
channel as the new anchor channel. The new anchor channel may be,
for example, in the TVWS or in the ISM bands. The system may
determine when the existing anchor channel becomes unavailable,
e.g., by using the beacons. For example, if a certain number of
consecutive beacons or the ratio of lost beacons to overall beacon
in a period of time exceeds a threshold ratio (e.g., 5 beacons may
be lost or 50% of the beacons may be lost), the STA may know or
determine that the anchor channel is to be changed. Since different
STAs may undergo different interference, and their observation of
the beacon receptions may be different, the AP may receive
different STAs report of different quality for the anchor channel.
It is contemplated that there may be no alternative channel which
is perceived to or is better for all or a majority of the STAs
served by the AP. In at least one example embodiment, if the beacon
loss threshold is 5 and the actual beacon losses are as follows in
Table 1:
TABLE-US-00001 TABLE 1 Current anchor channel Alternative channel
STA 1 6 beacon losses 4 beacon losses STA 2 7 beacon losses 8
beacon losses STA 3 3 beacon losses 1 beacon loss
The AP may count the number of STAs whose beacon losses are greater
than the threshold for each channel, may select the channel with
the minimum count as the new anchor channel, and may disseminate
the information on the new anchor channel (e.g., if there is a
change to the anchor channel) to the STAs (e.g., some or all of the
STAs served by the AP).
For example, in this representative example, two STAs have beacon
losses greater than the threshold (e.g., STA1 and STA2) for the
current anchor channel, while one STA (e.g., STA2) has a beacon
loss greater than the threshold for the alternative channel. And
the AP may switch the anchor to the alternative channel.
Other mechanisms may be used for selection of the anchor channel
including selection based on: (1) a count of the total number of
lost beacons for the channels involved; and/or (2) a count of the
total number of lost beacons for the channels involved with any
outlier STAs excluded (e.g., the highest and/or lowest beacon loss
counts from the STAs excluded).
Although the determination to swap or switch the anchor channel is
disclosed to be based on beacon losses, it is contemplated that it
may be based on other parameters including successful beacon
receipt by the STAs. In cases where the supplementary channel is
not broadcasting a beacon, the AP may use other measures or
parameters to determine channel quality, for example, Bit Error
Rate, retransmission frequency, Signal-to-Inference Ratio and/or
Signal-to-Noise Ratio, among others.
FIG. 17A is a diagram illustrating an exemplary coverage area
change when changing channels from TVWS to ISM band (e.g., while
keeping the same channel bandwidth and TX power) and FIG. 17B is a
diagram illustrating a coverage area change when changing channels
from ISM band to TVWS (e.g., while keeping the same channel
bandwidth and TX power).
Referring to FIGS. 17A and 17B, a procedure (e.g., a mobility
procedure) may be used for handovers between supplementary channels
in different bands, for example, when radios switch channels
between two bands from one band to another band, and the two bands
have different carrier frequencies and/or bandwidths. With the same
configuration after the switch over (e.g., the same transmission
power and modulation and coding scheme (MCS)), the communication
ranges may be different (e.g., very different), and the impacts of
interference may be different (e.g., very different) as discussed
below.
In some embodiments, the lower the carrier frequency, the larger
the communication range. For example, using a free space radio
propagation model, the received power may be proportional to the
square of the wavelength. The carrier frequency for the TVWS is in
the range between 512 MHz and 698 MHz (excluding channel 37),
whereas the carrier frequency for the ISM band used by IEEE
802.11/b/g is much higher at 2.4 GHz. Under the free space radio
propagation model, a radio operating in the TVWS may have a
communication range approximately 4 times as great as a radio
operating in the 2.4 GHz ISM band with the same configuration.
When the bandwidth changes, among other conditions, the power
spectrum density may change in the opposite direction. When the
transmission power is fixed, among other contemplate conditions, if
the bandwidth increases, the power spectrum density may decrease,
and if the bandwidth decreases, the power spectrum density may
increase. A reduction of channel bandwidth with the transmission
power fixed may result in a sudden increase in the out-of-band
emission (OOBE), which may lead to potential violation of the
interference limit imposed by spectrum access policies. As an
example, if the bandwidth of a channel in the 2.4 GHz ISM band is
20 MHz, and the bandwidth of a channel in the TVWS in the U.S. is 6
MHz. when a radio switches between channels of different
bandwidths, the impact of the change in bandwidth may be considered
or determined to ensure service continuity. Without communication
range matching, the service continuity may not be guaranteed, or
inefficiency may occur. In one or more embodiments, the
communication ranges for the channels or frequency bands being
switched may be matched, for example, to make the capacity of the
communication link remain approximately the same when the radios
switch among different bands.
The capacity of the communication link may depend on a number of
factors including, for example: (1) channel bandwidth; (2) SNR; (3)
attenuation; (4) carrier frequency or bands; and/or (5) MCS, among
others. The capacity generally refers to the raw throughput that is
achievable under the constraint of available configurations of the
radios. The TX power may be estimated as shown in Equation 1:
P.sub.RX=.alpha.(f)P.sub.TX/r.sup.n (1) where .alpha.(f) is a
function of carrier frequency f, P.sub.TX is the TX power, r is the
distance between the transmitter and the receiver, and n.gtoreq.2
is the attenuation exponent.
A representative procedure for range matching two channels Channel
1 and Channel 2, which are in Band 1 and Band 2, respectively, may
include: (1) for the change from Channel 1 to Channel 2, estimate
the channel capacity of Channel 1 (e.g., using C1=B1
log.sub.2(1+SINR1), where B1 is the bandwidth of Channel 1, SINR1
is the Signal to Interference and Noise Ratio. (2) for each TX
power level (e.g., quantized TX power which is quantized into a
number of levels), a set of channels (called Channel 2) in Band 2
may be determined such that |C2-C1| is minimized where C2=B2
log.sub.2(1+SINR2). B2 is the total bandwidth to be used in Band 2,
and itself may consist of a number of channels. For example, in the
TVWS, B2 may be equal to the bandwidth of multiple TV channels. The
SINR2 may be affected by the choice of Channel 2, the TX power,
and/or the carrier frequency; and (3) find the minimum TX power and
the MCS scheme for Channel 2 such that |T2-T1|<.gamma.T1, where
T1 is the raw throughput of Channel 1, T2 is the raw throughput of
Channel 2, and .gamma. is a constant between 0 and 1. The minimum
TX power may be chosen that satisfies the above constraint to
alleviate interference (e.g., unnecessary interference).
Another procedure may generate policies and create look-up tables
for fast implementation based on the above algorithm or other range
matching algorithms.
In one or more embodiments, a single master clock may be used to
control both the anchor channel and the one or more supplementary
channels.
It is contemplated in one or more embodiments that two channels of
different bandwidths may be controlled using a master clock. In one
representative embodiment, a first channel may be 5 MHz wide, and a
second channel may be 20 MHz wide. If the modulation and coding,
for example, are common between the channels, when the radio
switches from the second channel at 20 MHz width to the first
channel at 5 MHz width, among other contemplated conditions, the
master clock may be slow down to 1/4 of the original clock rate. If
the modulation and coding, for example, are common between the
channels, when the radio switches from the first channel to the
second channel, the master clock may be sped up by a factor of 4
(e.g., 4 times as fast as the clock rate before the switching). In
one or more embodiments, the changing of the clock rate may be
dynamic depending on the spectrum availability and the channel
qualities. The parameters related to timing, such as Short
Interframe Space (SIFS) and/or DCF Interframe Space (DIFS), may be
controlled by the master clock to maintain the proper behavior at
the protocol level. For example, the clock counters may be adjusted
for these parameters so that the values of the parameters comply
with any standards.
FIG. 18 is a block diagram illustrating an exemplary transceiver
architecture for inter-band MAC-layer aggregation (e.g., using
multiple radio front-ends).
Referring to FIG. 18, the transceiver architecture may include a
first radio front-end and a second radio front-end, a filter
module, a digital baseband (DBB) module, a plurality of PHY
layers/modules, a MAC layer and an IP layer. The transceiver may
realize inter-band MAC-layer aggregation using the two radio front
ends including the first radio front end (e.g., for the ISM band)
and the second radio front end (e.g., for the TVWS band). In FIG.
18, the transceiver is shown for a 5-band aggregation scheme, but
aggregation scheme of any number of bands is possible. The 5-band
aggregation scheme may include 5 independent PHY chains mapped to
the two RF front ends. A first flow may include three 22 MHz ISM
channels aggregated with two 5 MHz TVWS channels. A second flow may
include one 22 MHz ISM channel aggregated with four 22 MHz TVWS
channels. One of the bands (e.g., ISM or TVWS) may act, as an
anchor carrier, while the other band or bands may act, as a
supplementary or secondary carrier. The anchor channel may carry
the control information for channel allocation, and/or link
establishment and removal on the supplementary or secondary carrier
or carriers. The aggregation of the first and second flows may
occur at the MAC layer from the lower PHY layers.
The MAC layer (e.g., a single common MAC layer) may schedule the IP
packets to different PHY flows using a joint scheduler. The flow
control mechanism may be implemented based on the channel quality
feedback received from the individual PHY layers back to the MAC
layer.
The filter module may include a tunable RF filter bank having a
bandwidth that may be set dynamically based on the availability of
spectrum on the band. For example, each filter in the filter bank
may be set to either 22 MHz on the ISM band or 5 MHz on the TVWS
band. The DBB module may be configured for dynamic up conversion
from baseband to passband of a signal or dynamic down conversion
from passband to baseband of the signal. The DDB may be used to
collect raw digital samples from the RF front end to provide to a
sensing module or processor.
The sensing module may communicate with the CMF, which may in turn
communicate with the TVWS database.
The channels on the ISM band and the TVWS band may be allocated
based on channel availability and/or channel quality results from
the sensing module. In one or more embodiments, the allocation may
be based additionally on information from the TVWS database for the
TVWS band) indicating allowable and/or restricted channel
availability.
FIG. 19 is a block diagram illustrating another representative
transceiver architecture.
Referring to FIG. 19, the transceiver may be configured similar to
that of FIG. 18 except that the PHY layers may be mapped directly
to either the ISM or TVWS radio front ends. For example, three of
the PHY layers may be mapped to the TVWS radio front end and two
other PHY layers may be mapped to the ISM radio font-end.
In one or more embodiments, multiple bands may be aggregated using
interband aggregation at the IP layer and intraband aggregation at
the MAC layer. A thin layer above the MAC layer and below the IP
layer may be configured for IP packet aggregation/segregation of UL
and DL traffic. Individual MACs (e.g., one for each of the ISM and
TVWS bands) may be configured for intra-band aggregation.
FIG. 20 is a block diagram illustrating another representative
transceiver architecture.
Referring to FIG. 20, the transceiver may be configured similar to
that of FIG. 19 except that a single wideband radio front-end
(e.g., a single ISM/TVWS band radio front end) may be included and
each PHY layer may be mapped directly to the single radio-front end
to enable a flexible/tunable architecture may be used to achieve
inter and intra band aggregation at the MAC layer and/or the IP
layer. The tunability control may be managed using a control plane
module. The control plane module may control the selection of one
or both of: (1) IP layer aggregation, or (2) MAC layer aggregation
and may also control the number of PHY flows, filter bank tuning,
and/or RF band(s).
In view of the description herein and FIGS. 1-20, embodiments
contemplate one or more techniques and/or wireless transmit/receive
units (WTRU) for managing aggregation between an access point (AP)
and a Wireless Receiver/Transmitter Unit (WRTU) using an anchor
channel over a first frequency band between the AP and the WRTU,
where the first frequency band may be an anchor band. The
techniques and/or WTRU configuration may include wirelessly
receiving, by the WRTU, one or more beacons via the anchor channel,
where the one or more beacons may provide allocation information
for allocating a supplementary channel on a second frequency band,
as a supplementary band, that may be different from the first
frequency band.
The techniques and/or WTRU configuration may also include
establishing the supplementary channel over the supplementary band
using the allocation information provided in the one or more
beacons and/or wirelessly exchanging, by the WRTU, data over the
established supplementary channel on the supplementary band.
The techniques and/or WTRU configuration may be such that the
wirelessly exchanging of the data over the established
supplementary channel may include one or more of: (1) wirelessly
sending the data over the established supplementary channel; (2)
wirelessly receiving the data over the established supplementary
channel; and/or (3) wirelessly sending and receiving data over the
established supplementary channel.
The techniques and/or WTRU configuration may be such that the
wirelessly receiving of the one or more beacons via the anchor
channel may include receiving a series of beacons, where each
beacon may include control information for the anchor channel and
control information for the supplementary channel.
The techniques and/or WTRU configuration may be such that the
wirelessly receiving of the one or more beacons via the anchor
channel may include receiving a series of beacons, where a first
portion of the series of beacons may include control information
for the anchor channel and a second portion of the series of
beacons may include control information for the supplementary
channel.
The techniques and/or WTRU configuration may be such that the
series of beacons may be received in each beacon transmission
interval such that the first beacon in each beacon transmission
interval may be broadcast and other respective beacons in each
beacon transmission interval may be multicast.
The techniques and/or WTRU configuration may be such that the
series of beacons may be periodically received such that the first
beacon associated with the anchor channel may be broadcast and
other respective beacons associated with the supplementary channels
may be multicast.
The techniques and/or WTRU configuration may also include
determining, by the WRTU, which of the series of beacons are the
beacons that include the control information for the supplementary
channel based on a predetermined number of beacon intervals, and/or
searching, by the WRTU, for the control information in the
determined beacons.
The techniques and/or WTRU configuration may be such that the
wirelessly receiving of the one or more beacons via the anchor
channel may include providing allocation information for allocating
at least one further supplementary channel on the second frequency
band or a further frequency band. The techniques and/or WTRU
configuration may also include establishing the further
supplementary channel using the allocation information provided by
the one or more beacons and/or wirelessly exchanging, by the WRTU,
further data over the further supplementary channel.
The techniques and/or WTRU configuration may be such that the
wirelessly exchanging of the data over the established
supplementary channel and the further data over the further
supplementary channel may include one or more of: (1) wirelessly
sending the data over the established supplementary channel and
wirelessly receiving the further data over the established further
supplementary channel; (2) wirelessly receiving the data over the
established supplementary channel and wireless sending the further
data over the established further supplementary channel; (3)
wirelessly sending the data and the further data over the
established supplementary channel and the established further
supplementary channel; and/or (4) wirelessly receiving the data and
the further data over the established supplementary channel and the
established further supplementary channel.
The techniques and/or WTRU configuration may be such that the
wirelessly receiving of the one or more beacons via the anchor
channel may include receiving a series of beacons, where a first
portion of the series of beacons may include control information
for the anchor channel and a second portion of the series of
beacons may include control information for the supplementary
channel.
The techniques and/or WTRU configuration may also include
determining, by the WRTU from the control information in the second
portion of the series of beacons, whether to modify channel
allocation for sending/receiving data on at least one of: (1) the
supplementary channel; and/or (2) the further supplementary
channel. The techniques and/or WTRU configuration may also include
changing, based on the control information in each beacon of the
second portion of beacons, an allocation on the supplementary
channel to provide one or more of: (1) an uplink only channel on
the supplementary channel; and/or (2) a downlink only channel on
the supplementary channel.
The techniques and/or WTRU configuration may also include changing,
based on the control information in each beacon of the second
portion of the beacons, an allocation on the further supplementary
channel to provide one or more of: (1) an uplink only channel on
the further supplementary channel; and/or (2) a downlink only
channel on the further supplementary channel.
The techniques and/or WTRU configuration may also include switching
the anchor channel and one channel of the supplementary channel and
further supplementary channel, responsive to the one channel having
less beacon losses relative to the anchor channel such that the one
channel may become a new anchor channel and the previous anchor
channel may become one of the supplementary channels.
The techniques and/or WTRU configuration may be such that the
anchor channel may be in an ISM band and the supplementary band may
be in a TVWS band.
The techniques and/or WTRU configuration may be such that the
beacons that include the allocation information for the
supplementary channel may further include quieting information
indicating one or more quiet periods for quieting the WRTU.
The techniques and/or WTRU configuration may also include
determining, by the WRTU, from the quieting information of the
quiet periods and/or restricting, by the WRTU, transmissions during
the quiet periods that may enable a search for other transmissions
on the TVWS band.
The techniques and/or WTRU configuration may also include
responsive to finding other transmissions on the TVWS band,
receiving, by the WRTU, one or more beacons indicating updated
allocation information to move the WRTU from the supplementary
channel.
The techniques and/or WTRU configuration may be such that the
allocation information in the beacons sent over on the anchor
channel may include operating information regarding the
supplementary channel associated with at least one of: (1) an
association procedure; and/or (2) a discovery procedure.
The techniques and/or WTRU configuration may be such that the
wirelessly receiving of the one or more beacons via the anchor
channel may include one or more of: detecting at least one beacon
in a beacon portion of a frame that is associated with control
information indicating the allocation information for the anchor
channel; and/or detecting a beacon in a payload portion of the
frame used for data exchange on the anchor channel, where the
beacons detected in the payload portion may indicate the allocation
information for the supplementary channel.
The techniques and/or WTRU configuration may include detecting the
allocation information from the received one or more beacons
including determining at least one of: (1) a usage mode of the
supplementary channel; (2) activation or deactivation of the
supplementary channel; (3) a traffic indication map indicating
whether the WRTU is scheduled for uplink or downlink transmission
on the supplementary channel before the next beacon interval; (4) a
resource sharing map indicating whether the WRTU is restricted from
using the supplementary channel for the current beacon interval;
(5) dynamic spectrum management information indicating at least one
of (i) a quieting period during which the WRTU is restricted from
transmitting over the supplementary channel, (ii) transmitted power
limits for the supplementary channel, or (iii) coexistence
information; (6) a channel switch announcement; and/or (7) a beacon
interval number identifying a particular beacon interval.
The techniques and/or WTRU configuration may also include sending,
by the WRTU, a request including capability information indicating
the capability of the WRTU to use the supplementary channel or
further supplementary channels.
The techniques and/or WTRU configuration may also include
receiving, by the WRTU via the anchor channel, at least one of: a
scaling factor indicating a channel synchronization relative to the
anchor channel and/or a secondary channel sync signal in a
management frame on the anchor channel.
The techniques and/or WTRU configuration may also include
receiving, by the WRTU via the supplementary channel, frames
including data; and/or sending, by the WRTU via the anchor channel,
a block acknowledgement for the frames received on the
supplementary channel.
The techniques and/or WTRU configuration may be such that the
sending of the block acknowledgement for the frames received on the
supplementary channel may be sent responsive to expiration of a
timer or the initiation of a subsequent beacon interval.
The techniques and/or WTRU configuration may be such that the
sending of the block acknowledgement for the frames received on the
supplementary channel may be sent when a time since reception of
the oldest unacknowledged frame exceeds a threshold.
The techniques and/or WTRU configuration may also include
receiving, by the WRTU, a broadcast acknowledgement query on the
anchor channel to initiate a block acknowledgment response, wherein
responsive to reception of the broadcast acknowledgement query, the
block acknowledgement on the anchor channel for the frames received
on the supplementary channel may be sent.
The techniques and/or WTRU configuration may also include
receiving, by the WRTU, a broadcast acknowledgement query on the
anchor channel to initiate a block acknowledgment response, wherein
responsive to reception of the broadcast acknowledgement query, the
block acknowledgement on the anchor channel for the frames received
on the supplementary channel may be sent.
The techniques and/or WTRU configuration may also include
determining, by the WRTU whether predetermined portions used for
data exchange on the anchor channel may be available for
acknowledgements; and/or inserting, by the WRTU, the block
acknowledgment into one of the predetermined portions that is
available for acknowledgements, where the sending of the block
acknowledgement for the frames received on the supplementary
channel may include sending the frame that includes the inserted
block acknowledgment.
The techniques and/or WTRU configuration may be such that the WRTU
may be a plurality of WRTUs. The techniques and/or WTRU
configuration(s) may also include: allocating the supplementary
channel based on one or more of: (1) a fixed reservation-access
scheme in which supplementary channel is shared between or among
the plurality of WRTUs in a fixed round-robin manner; (2) a demand
reservation-based access scheme in which the anchor channel is used
as a reservation channel; and/or (3) a contention access scheme in
which each WRTU follows pre-existing rules for sensing the
supplementary channel and transmits if the channel is sensed free
for a threshold period.
Embodiments contemplate techniques and/or access point (AP)
configuration for managing aggregation between an access point (AP)
and a Wireless Receiver/Transmitter Unit (WRTU) using an anchor
channel over a first frequency band between the AP and the WRTU,
where the first frequency band may be an anchor band. The
techniques and/or AP configuration may include wirelessly
transmitting, by the AP, one or more beacons via the anchor
channel, where the one or more beacons may provide allocation
information for allocating a supplementary channel on a second
frequency band, as a supplementary band, different from the first
frequency band.
The techniques and/or AP configuration may include establishing the
supplementary channel over the supplementary band using the
allocation information provided by the one or more beacons, and/or
wirelessly exchanging, by the AP, data over the established
supplementary channel on the supplementary band.
The techniques and/or AP configuration may be such that the
wirelessly exchanging of the data over the established
supplementary channel may include one of: (1) wirelessly sending
the data over the established supplementary channel; (2) wirelessly
receiving the data over the established supplementary channel;
and/or (3) wirelessly sending and receiving data over the
established supplementary channel.
The techniques and/or AP configuration may be such that the
wirelessly sending of the one or more beacons via the anchor
channel may include sending a series of beacons, where each beacon
may include control information for the anchor channel and control
information for the supplementary channel.
The techniques and/or AP configuration may be such that the
wirelessly sending of the one or more beacons via the anchor
channel may include sending a series of beacons, where a first
portion of the series of beacons may include control information
for the anchor channel and a second portion of the series of
beacons may include control information for the supplementary
channel.
The techniques and/or AP configuration may also include
determining, by the AP, which of the series of beacons may be the
beacons that are to include the control information for the
supplementary channel based on a predetermined number of beacon
intervals, and/or inserting, by the AP, the control information in
the determined beacons.
The techniques and/or AP configuration may be such that the series
of beacons may be sent in each beacon transmission interval such
that the first beacon in each beacon transmission interval may be
broadcast and other respective beacons in each interval may be
multicast.
The techniques and/or AP configuration may be such that the series
of beacons may be periodically sent such that the first beacon
associated with the anchor channel may be broadcast and other
respective beacons associated with the supplementary channels may
be multicast.
The techniques and/or AP configuration may be such that the
wirelessly sending of the one or more beacons via the anchor
channel may include providing allocation information for allocating
at least one further supplementary channel on a further frequency
band, as a further supplementary band, different from the anchor or
supplementary bands. The techniques and/or AP configuration may
also include establishing the further supplementary channel over
the further supplementary band using the allocation information
provided by the one or more beacons, and/or wirelessly exchanging,
by the WRTU, further data over the further supplementary channel on
the further supplementary band.
The techniques and/or AP configuration may be such that the
wirelessly exchanging of the data over the established
supplementary channel and the further data over the further
supplementary channel includes one or more of: (1) wirelessly
sending the data over the established supplementary channel and
wirelessly receiving the further data over the established further
supplementary channel; (2) wirelessly receiving the data over the
established supplementary channel and wireless sending the further
data over the established further supplementary channel; (3)
wirelessly sending the data and the further data over the
established supplementary channel and the established further
supplementary channel; and/or (4) wirelessly receiving the data and
the further data over the established supplementary channel and the
established further supplementary channel.
The techniques and/or AP configuration may be such that the
wirelessly sending of the one or more beacons via the anchor
channel may include sending a series of beacons, a first portion of
the series of beacons that may include control information for the
anchor channel and a second portion of the series of beacons that
may include control information for the supplementary channel.
The techniques and/or AP configuration may also include
determining, by the AP, whether to modify one or more channel
allocations for exchanging data on the supplementary and further
supplementary channels, and/or inserting, by the AP into the second
portion of the series of beacons, control information to allocate
the supplementary channel as one or more of: (1) as an uplink only
channel; and/or (2) a downlink only channel. The techniques and/or
AP configuration may also include inserting, by the AP into the
second portion of the series of beacons, control information to
allocate the further supplementary channel as one of: (1) as an
uplink only channel; or (2) a downlink only channel; and/or
sending, by the AP, the series of beacons on the anchor
channel.
The techniques and/or AP configuration may also include switching,
by the AP, the anchor channel and one channel of the supplementary
channel and the further supplementary channel, responsive to the
one channel having less beacon losses relative to the anchor
channel such that the one channel may become a new anchor channel
and the previous anchor channel may become one of the supplementary
channels.
The techniques and/or AP configuration may be such that the anchor
channel may be in an ISM band and the supplementary band may be in
a TVWS band.
The techniques and/or AP configuration may be such that the beacons
that include the allocation information of the supplementary
channel may further include quieting information indicating one or
more quiet periods for quieting the WRTU. The techniques and/or AP
configuration may also include determining, by the AP during the
one or more quiet periods, whether transmissions are present on the
TVWS band, as a determined result, and/or sending, by the AP to the
WRTU, updated allocation information, responsive to the determined
result.
The techniques and/or AP configuration may be such that the
allocation information in the beacons on the anchor channel may
include operating information regarding the supplementary channel
associated with at least one of: (1) an association procedure;
and/or (2) a discovery procedure.
The techniques and/or AP configuration may be such that the
wirelessly sending of the one or more beacons via the anchor
channel may include: sending at least one beacon in a beacon
portion that is associated with control information indicating the
allocation information for the anchor channel; and/or sending one
or more beacons in a payload portion used for data exchange on the
anchor channel, where the beacons sent in the payload portion may
indicate the allocation information for the supplementary
channel.
The techniques and/or AP configuration may also include: inserting
the allocation information into the one or more beacons to be sent
including determining at least one of: (1) a usage mode of the
supplementary channel; (2) activation or deactivation of the
supplementary channel; (3) a traffic indication map indicating
whether the WRTU is scheduled for uplink or downlink transmission
on the supplementary channel before the next beacon interval; (4) a
resource sharing map indicating whether the WRTU is restricted from
using the supplementary channel for the current beacon interval;
(5) dynamic spectrum management information indicating at least one
of (i) a quieting period during which the WRTU is restricted from
transmitting over the supplementary channel, (ii) transmitted power
limits for the supplementary channel, or (iii) coexistence
information; (6) a channel switch announcement; and/or (7) a beacon
interval number identifying a particular beacon interval, as the
allocation information.
The techniques and/or AP configuration may also include receiving,
by the AP, a message including capability information indicating
the capability of the WRTU to use the supplementary channel or
further supplementary channels; determining, by the AP, an
allocation of at least one of: (1) the supplementary channel and/or
(2) the further supplementary channels for the WRTU in accordance
with the received capability information; and/or inserting the
allocation information corresponding to the determined allocation
for the WRTU in the series of beacons destined for the WRTU.
The techniques and/or AP configuration may also include sending, by
the WRTU via the anchor channel, at least one of: a scaling factor
indicating channel synchronization relative to the anchor channel,
and/or a secondary channel sync signal in a management frame on the
anchor channel.
The techniques and/or AP configuration may also include sending, by
the AP via the supplementary channel, frames including data; and/or
receiving, by the AP via the anchor channel, a block
acknowledgement for the frames received on the supplementary
channel.
The techniques and/or AP configuration may be such that the
receiving of the block acknowledgement for the frames sent on the
supplementary channel may be received in a same or a next beacon
interval as the allocation of the supplementary channel for the
data sent.
The techniques and/or AP configuration may be such that the
receiving of the block acknowledgement for the frames sent on the
supplementary channel may be received after a time since reception
of the oldest unacknowledged frame exceeds a threshold.
The techniques and/or AP configuration may also include sending, by
the AP, a broadcast acknowledgement query on the anchor channel to
initiate a block acknowledgment response; and/or receiving, by the
AP, the block acknowledgement in response to the broadcast
acknowledgement query.
The techniques and/or AP configuration may also include detecting,
by the AP, the block acknowledgement from one or more predetermined
portions used for data exchange on the anchor channel; and/or
resending one or more frames using a frame identify when the block
acknowledgement indicates that the one or more frames were not
properly received.
The techniques and/or AP configuration may be such that the WRTU is
a plurality of WRTUs. The techniques and/or AP configuration may
also include allocating, by the AP, the supplementary channel based
on at least one of: (1) a fixed reservation-access scheme in which
the supplementary channel is shared between or among the plurality
of WRTUs in a fixed round-robin manner; (2) a demand
reservation-based access scheme in which the anchor channel is used
as a reservation channel; and/or (3) a contention access scheme in
which each WRTU follows pre-existing rules for sensing the
supplementary channel and transmits if the channel is sensed free
for threshold period.
Embodiments contemplate techniques and/or WTRU configuration for
managing band aggregation with an access point (AP) using an anchor
channel over a first frequency band with the AP, where the first
frequency band may be an anchor band. The techniques and/or WTRU
configuration may include a wireless receiver/transmitter
configured to wirelessly receive one or more beacons via the anchor
channel, where the one or more beacons may provide allocation
information for allocating of a supplementary channel on a second
frequency band, as a supplementary band, different from the first
frequency band; and/or a processor in communication with the
wireless receiver/transmitter configured to establish the
supplementary channel over the supplementary band using the
allocation information provided by the one or more beacons.
The techniques and/or WTRU configuration may be such that the
wireless receiver/transmitter may wirelessly exchange data over the
established supplementary channel on the supplementary band.
The techniques and/or WTRU configuration may be such that a MAC
layer may aggregate the flows over the anchor and supplementary
channels.
Embodiments contemplate techniques and/or AP configuration that for
managing band aggregation with a Wireless Receiver/Transmitter Unit
(WRTU) using an anchor channel over a first frequency band with the
WRTU, where the first frequency band being an anchor band. The
techniques and/or AP configuration may include a wireless
receiver/transmitter configured to wirelessly transmit one or more
beacons via the anchor channel, the one or more beacons providing
allocation information for allocating a supplementary channel on a
second frequency band, as a supplementary band, different from the
first frequency band; and/or a processor in conjunction with the
wireless receiver/transmitter configured to establish the
supplementary channel over the supplementary band using the
allocation information provided by the one or more beacons.
The techniques and/or AP configuration may be such that the
wireless receiver/transmitter may wirelessly exchange data over the
established supplementary channel on the supplementary band.
Throughout the disclosure, one of skill understands that certain
representative embodiments may be used in the alternative or in
combination with other representative embodiments.
Although features and elements are described above in particular
combinations, one of ordinary skill in the art will appreciate that
each feature or element can be used alone or in any combination
with the other features and elements. In addition, the methods
described herein may be implemented in a computer program,
software, or firmware incorporated in a computer readable medium
for execution by a computer or processor. Examples of
non-transitory computer-readable storage media include, but are not
limited to, a read only memory (ROM), random access memory (RAM), a
register, cache memory, semiconductor memory devices, magnetic
media such as internal hard disks and removable disks,
magneto-optical media, and optical media such as CD-ROM disks, and
digital versatile disks (DVDs). A processor in association with
software may be used to implement a radio frequency transceiver for
use in a WRTU, UE, terminal, base station, RNC, or any host
computer.
Moreover, in the embodiments described above, processing platforms,
computing systems, controllers, and other devices containing
processors are noted. These devices may contain at least one
Central Processing Unit ("CPU") and memory. In accordance with the
practices of persons skilled in the art of computer programming,
reference to acts and symbolic representations of operations or
instructions may be performed by the various CPUs and memories.
Such acts and operations or instructions may be referred to as
being "executed," "computer executed" or "CPU executed."
Suitable processors include, by way of example, a general purpose
processor, a special purpose processor, a conventional processor, a
digital signal processor (DSP), a plurality of microprocessors, one
or more microprocessors in association with a DSP core, a
controller, a microcontroller, Application Specific Integrated
Circuits (ASICs), Application Specific Standard Products (ASSPs);
Field Programmable Gate Arrays (FPGAs) circuits, any other type of
integrated circuit (IC), and/or a state machine.
A processor in association with software may be used to implement a
radio frequency transceiver for use in a wireless transmit receive
unit (WRTU), user equipment (UE), terminal, base station, Mobility
Management Entity (MME) or Evolved Packet Core (EPC), or any host
computer. The WRTU may be used m conjunction with modules,
implemented in hardware and/or software including a Software
Defined Radio (SDR), and other components such as a camera, a video
camera module, a videophone, a speakerphone, a vibration device, a
speaker, a microphone, a television transceiver, a hands free
headset, a keyboard, a Bluetooth.RTM. module, a frequency modulated
(FM) radio unit, a Near Field Communication (NFC) Module, a liquid
crystal display (LCD) display unit, an organic light-emitting diode
(OLED) display unit, a digital music player, a media player, a
video game player module, an Internet browser, and/or any Wireless
Local Area Network (WLAN) or Ultra Wide Band (UWB) module.
Although the invention has been described in terms of communication
systems, it is contemplated that the systems may be implemented in
software on microprocessors/general purpose computers (not shown).
In certain embodiments, one or more of the functions of the various
components may be implemented in software that controls a
general-purpose computer.
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