U.S. patent application number 14/563301 was filed with the patent office on 2015-04-02 for method and apparatus for paging in machine to machine or mobile assisted deployments.
This patent application is currently assigned to InterDigital Patent Holdings, Inc.. The applicant listed for this patent is InterDigital Patent Holdings, Inc.. Invention is credited to Gregory S. Sternberg, Eldad M. Zeira.
Application Number | 20150092741 14/563301 |
Document ID | / |
Family ID | 45562438 |
Filed Date | 2015-04-02 |
United States Patent
Application |
20150092741 |
Kind Code |
A1 |
Zeira; Eldad M. ; et
al. |
April 2, 2015 |
METHOD AND APPARATUS FOR PAGING IN MACHINE TO MACHINE OR MOBILE
ASSISTED DEPLOYMENTS
Abstract
A WTRU may be configured to receive configuration information.
The received configuration information may be from a base station,
and may indicate one or more periodic resources. The periodic
resources may be used in peer to peer discovery, and may include
time and frequency resources. If the WTRU is a discoverable peer,
the WTRU may be configured to transmit an identification in the
periodic resources. The WTRU may transmit an identification that is
associated with a service. The WTRU may be configured to access a
wireless network in response to another WTRU desiring
communication.
Inventors: |
Zeira; Eldad M.;
(Huntington, NY) ; Sternberg; Gregory S.; (Mt.
Laurel, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
InterDigital Patent Holdings, Inc. |
Wilmington |
DE |
US |
|
|
Assignee: |
InterDigital Patent Holdings,
Inc.
Wilmington
DE
|
Family ID: |
45562438 |
Appl. No.: |
14/563301 |
Filed: |
December 8, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14167445 |
Jan 29, 2014 |
8909268 |
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14563301 |
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13347424 |
Jan 10, 2012 |
8644864 |
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14167445 |
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61431413 |
Jan 10, 2011 |
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61524948 |
Aug 18, 2011 |
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Current U.S.
Class: |
370/330 |
Current CPC
Class: |
H04W 68/00 20130101;
H04W 72/04 20130101; H04W 8/005 20130101; H04W 4/08 20130101; H04W
84/027 20130101; H04W 4/70 20180201; H04W 88/04 20130101 |
Class at
Publication: |
370/330 |
International
Class: |
H04W 8/00 20060101
H04W008/00; H04W 72/04 20060101 H04W072/04 |
Claims
1. A wireless transmit/receive unit (WTRU) comprising: circuitry
configured to receive configuration information from a base station
(BS) of a wireless network, wherein the configuration information
indicates a plurality of periodic resources for use in peer to peer
discovery, wherein the plurality of periodic resources are time and
frequency resources; circuitry configured to transmit an
identification in the plurality of periodic resources to other
WTRUs on a condition that the WTRU is a discoverable peer, wherein
the identification is associated with a service; and circuitry
configured to access the wireless network in response to one of the
other WTRUs desiring communication.
2. The WTRU of claim 1 further comprising circuitry configured to
receive a response from the one other WTRU in response to the
transmitted identification.
3. The WTRU of claim 1 further comprising circuitry configured to
transmit a preamble in the plurality of periodic resources.
4. The WTRU of claim 1 wherein the identification is associated
with a service characteristic.
5. A method for use by a wireless transmit/receive unit (WTRU), the
method comprising: receiving, by the WTRU, broadcast information
from a base station (BS) of a wireless network, wherein the
broadcast information indicates a plurality of periodic resources
for use in peer to peer discovery, wherein the periodic resources
are time and frequency resources; transmitting, by the WTRU, an
identification in the plurality of periodic resources to other
WTRUs on a condition that the WTRU is a discoverable peer, wherein
the identification is associated with a service; and accessing, by
the WTRU, the wireless network in response to one of the other
WTRUs desiring communication.
6. The method of claim 5 further comprising: receiving a response
from the one other WTRU in response to the transmitted
identification.
7. The method of claim 5 further comprising: transmitting a
preamble in the plurality of periodic resources.
8. The method of claim 5 wherein the identification is associated
with a service characteristic.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/167,445 filed Jan. 29, 2014, which issued
as U.S. Pat. No. 8,909,268 on Dec. 9, 2014, which is a continuation
of U.S. patent application Ser. No. 13/347,424 filed Jan. 10, 2012,
which issued as U.S. Pat. No. 8,644,864 on Feb. 4, 2014, which
claims the benefit of U.S. Provisional Application Ser. No.
61/431,413 filed on Jan. 10, 2011, and U.S. Provisional Application
No. 61/524,948 filed on Aug. 18, 2011, the contents of which are
hereby incorporated by reference.
BACKGROUND
[0002] Machine to machine (M2M) or machine type (MTC)
communications may be used synonymously, and may be defined as
communications initiated by the machine, to communicate with either
other machines or with humans. Applicable network topologies may
include wireless transmit/receive unit (WTRU)-WTRU direct
communications which may be used for coverage extension. WTRU-WTRU
direct communications may be referred to as peer-to-peer
communications. These communications may be used to increase
network robustness by providing an alternative path for
connectivity.
[0003] In typical cellular protocols, a WTRU that is either in
idle, disconnected or dormant state, may monitor the base station
(BS) or relay station (RS) infrequently to determine if the WTRU
needs to listen for a data transmission. This process may be
referred to as paging. In order to minimize battery consumption and
increase range, paging signals may be designed to be short.
[0004] M2M networks as defined above may differ from typical
cellular networks in two ways. First, some subscribers may not be
configured to decode, or may be out of range of BS or RS
transmissions. These subscribers, however, must still be reached.
Second, the number of subscribers in the cell could be very
large.
[0005] Typical M2M networks do not support paging for a group of
subscriber stations. Accordingly, it would be desirable to have a
method and apparatus to support paging for group subscriber
stations in M2M networks. It would also be desirable to extend the
page to a WTRU that is out of the range of the BS or RS. It would
also be desirable to reduce the relative overhead created by MAC
messaging for small amounts of data at a time. This overhead may
be, along with other signaling, associated with paging.
SUMMARY
[0006] A method and apparatus may be used to perform WTRU-WTRU
paging in wireless communications. For example, a wireless
transmit/receive unit (WTRU) may be configured to page another
WTRU. In this example, the paging WTRU may receive a first message
that indicates a group identification (ID). The WTRU may receive a
second message that may include an indicator that indicates one or
more other WTRUs that the paging WTRU may page. If the received
indicator matches a paging indicator of the paging WTRU, the paging
WTRU may transmit an access signal to one or more other WTRUs. The
paging indicator of the paging WTRU may be predetermined, and may
be received in a configuration message from a base station (BS).
The first message may be a secondary advanced (SA)-preamble.
[0007] A WTRU may be configured to receive a page from another
WTRU. For example, the paged WTRU may detect one or more of its
assigned paging indicators and transmit a message to one or more
other WTRUs. The one or more other WTRUs may belong to a group, and
the transmitted message may indicate the group. The one or more
assigned paging indicators may have been assigned by a BS at an
earlier time via a configuration message. The paged WTRU may use a
transmit power ramp up procedure for the transmitted message until
a response is received.
[0008] In response to the transmitted message, the paged WTRU may
receive an ACK from one or more other WTRUs. The ACK may be a
group-based ACK. The ACK may be followed by a plurality of messages
associated with a WTRU (WTRU-specific messages). The plurality of
WTRU-specific messages may each include an indicator that indicates
a WTRU ID. The paged WTRU may choose to associate with one of the
responding WTRUs. The choice may be based on a received indicator.
The paged WTRU may transmit a network access signal, and may
include an indicator that indicates the chosen WTRU ID.
[0009] A WTRU may be configured to receive configuration
information. The received configuration information may be from a
base station, and may indicate one or more periodic resources. The
periodic resources may be used in peer to peer discovery, and may
include time and frequency resources. If the WTRU is a discoverable
peer, the WTRU may be configured to transmit an identification in
the periodic resources. The WTRU may transmit an identification
that is associated with a service. The WTRU may be configured to
access a wireless network in response to another WTRU desiring
communication.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] A more detailed understanding may be had from the following
description, given by way of example in conjunction with the
accompanying drawings wherein:
[0011] FIG. 1A is a system diagram of an example communications
system in which one or more disclosed embodiments may be
implemented;
[0012] FIG. 1B is a system diagram of an example wireless
transmit/receive unit (WTRU) that may be used within the
communications system illustrated in FIG. 1A;
[0013] FIG. 1C is a system diagram of an example radio access
network and an example core network that may be used within the
communications system illustrated in FIG. 1A;
[0014] FIG. 2 is a flow diagram of an example method for performing
individual paging with a known WTRU location;
[0015] FIG. 3 is a flow diagram of an example method for reducing
overhead in group paging;
[0016] FIG. 4 is a flow diagram of example WTRU discovery
procedure;
[0017] FIG. 5 is a flow diagram of a paging example for a unicast
connection;
[0018] FIGS. 6A and 6B are flow diagrams of another example paging
procedure
[0019] FIG. 7 is a diagram of an example paging method for use in a
WTRU; and
[0020] FIG. 8 is a diagram of another example group paging
method.
DETAILED DESCRIPTION
[0021] When referred to hereafter, the terminology "wireless
transmit/receive unit (WTRU)" may include but is not limited to a
user equipment (UE), a mobile station (MS), and advanced mobile
station (AMS), high reliability (HR)-MS, a fixed or mobile
subscriber unit, a pager, a cellular telephone, a personal digital
assistant (PDA), a computer, or any other type of user device
capable of operating in a wireless environment. A WTRU may be a
non-infrastructure node. When referred to hereafter, the
terminology "seeking WTRU" includes but is not limited to a WTRU
attempting to discover and associate with peers. When referred to
hereafter, the terminology "discoverable WTRU" includes but is not
limited to a WTRU that may be discovered by the seeking WTRU.
[0022] When referred to hereafter, the terminology "base station
(BS)" may include but is not limited to a Node-B, an advanced base
station (ABS), an HR-BS, a site controller, an access point (AP),
or any other type of interfacing device capable of operating in a
wireless environment.
[0023] FIG. 1A shows an example 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 voice, data, video, messaging, broadcast,
and the like, to multiple wireless users. The communications system
100 may enable multiple wireless 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.
[0024] As shown in FIG. 1A, the communications system 100 may
include WTRUs 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 WTRUs, base stations (BSs), networks, and/or network elements.
Each of the WTRUs 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 WTRUs 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.
[0025] The communications 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 WTRUs 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 other networks
112. By way of example, the base stations 114a, 114b may be a base
transceiver station (BTS), a Node-B, an evolved Node-B (eNB), a
Home Node-B (HNB), a Home eNB (HeNB), 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.
[0026] 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, and the like. 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.
[0027] The base stations 114a, 114b may communicate with one or
more of the WTRUs 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, and the like). The air interface 116 may be established
using any suitable radio access technology (RAT). Each of WTRUs
102a, 102b, 102c, and 102d may be configured to page one or more
other WTRUs using paging messages 119.
[0028] More specifically, as noted above, the communications 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 WTRUs 102a, 102b, 102c may implement a radio technology such as
universal mobile telecommunications 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 (DL) packet access
(HSDPA) and/or high-speed uplink (UL) packet access (HSUPA).
[0029] In another embodiment, the base station 114a and the WTRUs
102a, 102b, 102c may implement a radio technology such as evolved
UTRA (E-UTRA), which may establish the air interface 116 using long
term evolution (LTE) and/or LTE-Advanced (LTE-A).
[0030] In other embodiments, the base station 114a and the WTRUs
102a, 102b, 102c may implement radio technologies such as IEEE
802.16 (i.e., worldwide interoperability for microwave access
(WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 evolution-data optimized
(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 RAN (GERAN), and the like.
[0031] The base station 114b in FIG. 1A may be a wireless router,
HNB, HeNB, or AP, 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 WTRUs 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 WTRUs 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 WTRUs 102c, 102d may utilize a cellular-based RAT,
(e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, and the like), to
establish a picocell or femtocell. As shown in FIG. 1A, 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.
[0032] 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 WTRUs 102a, 102b, 102c, 102d. For
example, the core network 106 may provide call control, billing
services, mobile location-based services, prepaid calling, Internet
connectivity, video distribution, and the like, and/or perform
high-level security functions, such as user authentication.
Although not shown in FIG. 1A, 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.
[0033] The core network 106 may also serve as a gateway for the
WTRUs 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 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.
[0034] Some or all of the WTRUs 102a, 102b, 102c, 102d in the
communications system 100 may include multi-mode capabilities,
i.e., the WTRUs 102a, 102b, 102c, 102d may include multiple
transceivers for communicating with different wireless networks
over different wireless links. For example, the WTRU 102c shown in
FIG. 1A 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.
[0035] FIG. 1B shows an example WTRU 102 that may be used within
the communications system 100 shown in FIG. 1A. As shown in FIG.
1B, the WTRU 102 may include a processor 118, a transceiver 120, a
transmit/receive element, (e.g., an antenna), 122, a
speaker/microphone 124, a keypad 126, a display/touchpad 128, a
non-removable memory 130, a removable memory 132, a power source
134, a global positioning system (GPS) chipset 136, and peripherals
138. It will be appreciated that the WTRU 102 may include any
sub-combination of the foregoing elements while remaining
consistent with an embodiment.
[0036] The processor 118 may be a general purpose processor, a
special purpose processor, a conventional processor, a digital
signal processor (DSP), a microprocessor, one or more
microprocessors in association with a DSP core, a controller, a
microcontroller, an application specific integrated circuit (ASIC),
a field programmable gate array (FPGA) circuit, an 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 WTRU
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. 1B depicts the processor
118 and the transceiver 120 as separate components, the processor
118 and the transceiver 120 may be integrated together in an
electronic package or chip.
[0037] 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. The transmit/receive element 122
may be configured to transmit and/or receive any combination of
wireless signals.
[0038] In addition, although the transmit/receive element 122 is
depicted in FIG. 1B as a single element, the WTRU 102 may include
any number of transmit/receive elements 122. More specifically, the
WTRU 102 may employ MIMO technology. Thus, in one embodiment, the
WTRU 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.
[0039] 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 WTRU 102 may have
multi-mode capabilities. Thus, the transceiver 120 may include
multiple transceivers for enabling the WTRU 102 to communicate via
multiple RATs, such as UTRA and IEEE 802.11, for example.
[0040] The processor 118 of the WTRU 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 130 and/or the removable memory 132. The
non-removable memory 130 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 WTRU 102, such as on a server or a home
computer (not shown).
[0041] 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 WTRU 102. The power source 134 may
be any suitable device for powering the WTRU 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), and the like), solar cells, fuel
cells, and the like.
[0042] 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 WTRU
102. In addition to, or in lieu of, the information from the GPS
chipset 136, the WTRU 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. The
WTRU 102 may acquire location information by way of any suitable
location-determination method while remaining consistent with an
embodiment.
[0043] 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.
[0044] FIG. 1C shows an example RAN 104 and an example core network
106 that may be used within the communications system 100 shown in
FIG. 1A. The RAN 104 may be an access service network (ASN) that
employs IEEE 802.16 radio technology to communicate with the WTRUs
102a, 102b, 102c over the air interface 116.
[0045] As shown in FIG. 1C, the RAN 104 may include base stations
140a, 140b, 140c, and an ASN gateway 142, 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 140a, 140b, 140c 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 WTRUs 102a, 102b, 102c over the air interface 116. In one
embodiment, the base stations 140a, 140b, 140c may implement MIMO
technology. Thus, the base station 140a, for example, may use
multiple antennas to transmit wireless signals to, and receive
wireless signals from, the WTRU 102a. The base stations 140a, 140b,
140c 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 142 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.
[0046] The air interface 116 between the WTRUs 102a, 102b, 102c and
the RAN 104 may implement the IEEE 802.16 specification. In
addition, each of the WTRUs 102a, 102b, 102c may establish a
logical interface (not shown) with the core network 106. The
logical interface between the WTRUs 102a, 102b, 102c and the core
network 106 may be used for authentication, authorization, IP host
configuration management, and/or mobility management. Each of WTRUs
102a, 102b, and 102c, may be configured to page one or more other
WTRUs using paging messages 119.
[0047] The communication link between each of the base stations
140a, 140b, 140c may include protocols for facilitating WTRU
handovers and the transfer of data between base stations. The
communication link between the base stations 140a, 140b, 140c and
the ASN gateway 142 may include protocols for facilitating mobility
management based on mobility events associated with each of the
WTRUs 102a, 102b, 102c.
[0048] As shown in FIG. 1C, the RAN 104 may be connected to the
core network 106. The communication link between the RAN 104 and
the core network 106 may include protocols for facilitating data
transfer and mobility management capabilities, for example. The
core network 106 may include a mobile IP home agent (MIP-HA) 144,
an authentication, authorization, accounting (AAA) server 146, and
a gateway 148. 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.
[0049] The MIP-HA 144 may be responsible for IP address management,
and may enable the WTRUs 102a, 102b, 102c to roam between different
ASNs and/or different core networks. The MIP-HA 144 may provide the
WTRUs 102a, 102b, 102c with access to packet-switched networks,
such as the Internet 110, to facilitate communications between the
WTRUs 102a, 102b, 102c and IP-enabled devices. The AAA server 146
may be responsible for user authentication and for supporting user
services. The gateway 148 may facilitate interworking with other
networks. For example, the gateway 148 may provide the WTRUs 102a,
102b, 102c with access to circuit-switched networks, such as the
PSTN 108, to facilitate communications between the WTRUs 102a,
102b, 102c and traditional land-line communications devices. In
addition, the gateway 148 may provide the WTRUs 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.
[0050] Although not shown in FIG. 1C, 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 include protocols for
coordinating the mobility of the WTRUs 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 include protocols for
facilitating interworking between home core networks and visited
core networks.
[0051] Various non-traditional applications for cellular networks
may be considered that involve communications not initiated by
humans and/or may not be strictly hierarchical topologies, such as
machine-to-machine (M2M) communications or machine type
communications (MTC). The M2M communications or MTC may be defined
as communications initiated by a machine to communicate with either
other machines or humans. The methods described herein may be
applicable to MTC communications, as well as other types of
communications.
[0052] Network topologies which include WTRU-to-WTRU direct
communications may be used for coverage extension, throughput
improvement, and the like. These network topologies may also
significantly increase network robustness by providing an
alternative path for connectivity, by discovering nodes when
necessary. However, the WTRUs may not be mobile at all, or have a
very low mobility.
[0053] Changes to the traditional behavior of a WTRU with respect
to the way it discovers and establishes a link with the network may
be necessary, including the functionality of node discovery,
routing, association and bandwidth request, as appropriate. A WTRU,
possibly assisted by the network, may identify and maintain an
association with a set of other WTRUs to either assist in relaying
data to/from the network, or communicate data locally without data
flows to/from a BS. Client collaboration, relaying and WTRU-to-WTRU
communication with or without a network may be implemented in any
type of wireless communication systems including, but not limited
to, IEEE 802.16 and any amendments thereof, long term evolution
(LTE), universal mobile telecommunication system (UMTS), and the
like.
[0054] In an 802.16m example, it may be assumed that the WTRU has
associated with the network prior to paging. In this example, the
WTRU may enter an IDLE state before it receives paging parameters.
Paging may use a deregistration indicator (DI). The paging function
may be updated in a ranging procedure using a Ranging Response
(RNG-RSP) medium access control (MAC) message.
[0055] Paging may be performed using a two sided grouping. For
example, a BS may be assigned to one or more groups, and a WTRU may
be assigned to multiple groups. The number of groups may be limited
to 4. Different paging cycles and/or offsets may be used within a
group. One of the WTRU groups may be designated as a primary group.
The primary group may have preference for detection, and may, for
example have the smallest offset. Paging may be performed using
primary and secondary groups, and there may be no need to
coordinate busy times. A location update procedure may be triggered
if there is no group present.
[0056] During paging unavailable intervals, the BS may not expect
to be able to page the WTRU. The WTRU may use this time for battery
savings or for making measurements. A re-synchronization and
detection of superframe header (SFH) may be performed towards the
end of a period to extract a superframe number to determine a
paging time. New paging parameters may be signaled using an
AAI-DREG-RSP message during an IDLE mode initiation and an
AAI-RNG-RSP during a location update.
[0057] A broadcast paging message, for example, an AAI-PAG-ADV
message, may be used to indicate the presence of DL traffic. The
broadcast paging message may be used to poll for a location update,
such as in ranging. The broadcast paging message may include an
emergency alert. Multiple WTRUs may be identified in the broadcast
paging message, therefore a true group may not exist. A paging
message without a WTRU ID may indicate that the WTRU return to a
sleep state. The broadcast paging message may be transmitted, for
example, within a frame including defined by N.sub.superframe
modulo PAGING_CYCLE=PAGING_OFFSET. The location within the frame
may be signaled in an A-field map (A-MAP) IE, and may continue in
the next frame. Paging by barred cells may be allowed, however
network entry may be restricted to preferred BSs.
[0058] Operation during a paging listening interval may be based on
a paging cycle and/or offset. Listening may be performed on a per
superframe basis. The WTRU may synchronize on a PA-preamble and may
decode a primary SFH (P-SFH). Paging ID information (PGID-Info) may
be transmitted regardless of the presence of paging to any WTRU,
and may signal which paging groups are supported by the BS. The
PGID-Info may be transmitted at a predetermined location in the
listening interval.
[0059] Machine to machine communications may involve a large number
of devices, where some, but not all devices may be of low or no
mobility. Data transmission may be infrequent and may tolerate
relatively high latency. M2M devices may share the network with
other types of devices.
[0060] Page groups may be used for the following reasons. Due to
device mobility, device location may never be certain. Several BSs
in the same area may be grouped together to cover the uncertainty.
As M2M mobility may be fairly low, the need for large groups of BSs
(and therefore a large group of WTRUs) may be reduced, but not
eliminated. The WTRU may belong to several groups to support
services with different latency requirements.
[0061] It may be assumed that there are a very large number of
devices for each sector. Most of these devices, however, may be
directly associated with the BS. Only a minority may need to be
relayed by another WTRU. The average number of WTRUs that may need
to be paged by any other WTRU is therefore small, however it is
possible that some WTRUs may need to page more than one WTRU. In
802.16, for example, paging a WTRU may be represented by its
Deregistration Information (DI). The DI for the WTRU may be 18
bits, for example. Paging as a whole, however, may require many
more bits since paging within a few WTRUs require a large overhead.
Note that while each paging WTRU may page only a few other WTRUs,
there could potentially be many paging WTRUs in the cell. If paging
is performed often, the impact of the overhead may be
significant.
[0062] M2M cases may present the need to page a group of users, for
example, devices of a similar type may be paged at the same time
for a specific task. Due to the possibility of some device
mobility, a long paging window and small coverage of a paging WTRU,
there may be some uncertainty in the paging WTRU, for example, the
WTRU may have changed location since a previous data exchange.
[0063] In one example of a Public Protection and Disaster Relief
(PPDR) case, the WTRUs are not associated unless they need to
communicate, and they may never be in an IDLE state. In this case,
there is no need for paging. In another PPDR case, the WTRU may be
associated with many other WTRUs, even when not in active
communication, and paging may be used.
[0064] In an example for throughput enhancement, all the WTRUs may
be associated directly with the BS and may be paged by the BS. In
M2M applications, three types of paging may be considered: 1)
individual paging with a known WTRU location, 2) group paging, and
3) individual paging with an unknown WTRU location. Individual
paging may be used for paging a specific WTRU for a specific
purpose. The attachment point of the WTRU to the network may be
known to a high degree of accuracy. Accordingly, the location of
the WTRU may be assumed to have not changed significantly from the
time of last communication with it. If the WTRU was recently
directly attached to a BS, then it may now be in the service area
of a small enough group of base stations adjacent to the original.
If the WTRU was recently attached through a paging WTRU, then it
may now be within range of a small group of WTRUs adjacent to
it.
[0065] Group paging may be used for paging a group of WTRUs to
perform a specific function. Examples of a specific function may
include, 1) network access of a group of WTRUs, for example, in
order to perform further communications, 2) ranging for a location
update, and 3) reception of data in broadcast mode, for example in
Smart Grid applications, some or all smart meters may be paged at
the same time to provide new operational parameters.
[0066] Individual paging with an unknown location may be used when
the location of the WTRU is not known. There may be several
mechanisms to perform that function, for example, a paged WTRU may
be instructed to range for a location update. As a result, the
location of the WTRU may be known, and the BS may use the
opportunity to transmit data to the WTRU. Alternatively, a paged
WTRU may be instructed to enter the network.
[0067] Paging may be performed on a group or on an individual
basis. Paging may be transmitted from an individual BS or from a
group of BSs. Paging may also be transmitted from an individual
paging WTRU or from a group of paging WTRUs. The latter may
increase the detection probability, and may overcome the location
uncertainty of the paged WTRU. A cause may be embedded in the
paging signal, and may provide an efficient signaling mechanism. If
paging is used to indicate a broadcast transmission, then the
information required to access the broadcast transmission may be
included in the paging signal.
[0068] For the following examples, it may be assumed that the paged
WTRU has maintained or re-acquired downlink (DL) synchronization,
and has updated its system information sufficiently to decode
paging messages or waveforms. FIG. 2 is a flow diagram of an
example method 200 for performing individual paging with a known
WTRU location by extending the transmission of a paging signal to
reach a WTRU that cannot decode the BS transmissions. In this
example, the paged WTRU may or may not need to implement a new
procedure in order to be paged by the paging WTRU.
[0069] Referring to FIG. 2, any WTRU, whether or not it has any
WTRU associated with it, may receive 210 a message that indicates
to the WTRU to act as a paging WTRU. The paging WTRU may be
assigned a WTRU ID that indicates one or more paging groups for its
paging function. These groups may or may not be the same as the
paging groups used for its normal operation as a WTRU. The WTRU ID
may indicate a single WTRU to page. A paged WTRU may be assigned
one or more groups that may or may not be the same as the paging
WTRU groups. The assignment may be made during an original
association or at any other time. Periodicity and time offset may
also be assigned during that time.
[0070] Paging messages to these paging groups may be transmitted at
a known periodicity and time offset. The paging WTRU may receive a
paging message 215, and if the paging message indicates a
previously assigned WTRU ID 220 the paging WTRU may transmit a
paging message to the WTRU as indicated by the received WTRU ID
230. Note that the received message may include multiple WTRU IDs,
and the paging WTRU may transmit a paging message to each of the
WTRUs indicated by the received WTRU IDs. If the received message
does not indicate an assigned WTRU ID, the paging WTRU may continue
to listen for a paging message 240.
[0071] A forwarding WTRU may have a WTRU attached to it. If a
paging WTRU is also a forwarding WTRU, the attached WTRUs may be
considered paged WTRUs. A mapping may be defined between the paging
WTRU groups and the paged WTRU groups. The groups used for the
paging message may be determined by this group mapping. A paging
WTRU may be assigned resources and transmit by the BS power for its
paging message.
[0072] In a multi-point transmission paging example, multiple
paging WTRUs may be assigned at least one common paging group and
one or more WTRU IDs to page. If, in addition, the same resources
are assigned and the paging WTRUs are sufficiently synchronized,
this example method may result in the transmission of the same
waveform from multiple sources to increase the probability of
paging success. BS paging messages may be CRC protected to prevent
erroneous decoding if multiple WTRU transmit dissimilar
information. Neither paging nor paged WTRU may be aware of the
multi-point transmission.
[0073] Joint transmission of pages by multiple WTRUs may provide
diversity gains over a single point transmission. Joint
transmission of pages by multiple BSs may also provide diversity
gains over a single point transmission. If joint transmission is
performed by WTRUs along with the BSs, additional performance gains
may be achieved. These diversity gains may combat short term fast
multi-path fading as well as longer term shadow fading. If multiple
WTRUs are used to transmit paging information, synchronization may
be achieved by triggering the BS paging message to the paging
WTRU.
[0074] Group paging may be performed by indicating a WTRU ID. by
transmitting a deregistration identifier (DI), transmitting a group
identifier (ID), or using WTRU IDs that may be separate from the DI
and may be assigned by the network. As a result, it may not be
necessary for the paged or paging WTRU to know whether an
individual or a group are paged.
[0075] In the examples above, a group paging message may be
transmitted for at least every single paged WTRU. Due to the
uncertainty in WTRU location and the short range of WTRU-WTRU
communications, the group paging message may need to be transmitted
by many paging WTRUs. It may be possible to group WTRUs to be paged
by location, however since grouping may be used for different
services, group management may become difficult.
[0076] In order to reduce overhead in group paging, transmission of
a group ID may be limited to the paging WTRU. Reception of the
group ID by the paged WTRU may result in the WTRU transmitting a
response signal with a possible transmit power ramp up procedure.
Reception of the response signal by the paging WTRU may trigger the
transmission of a full paging message.
[0077] FIG. 3 is a flow diagram of an example method 300 for
reducing overhead in group paging. Referring to FIG. 3, the BS may
transmit a preamble to establish a time reference 310. Establishing
a time reference may be combined with network synchronization. In
one example, a waveform similar to an 802.16m primary advanced
preamble (PA-preamble) may be transmitted to establish network time
and frequency synchronization. The PA-Preamble may define the
superframe and its location within the superframe may be
pre-determined and known.
[0078] A signal similar to an 802.16m secondary advanced preamble
(SA-preamble) may be used to transmit a paging group indicator 320
using a selection of code and time/frequency resources. This may be
possible as the SA-preamble, aside from being bandwidth dependent,
may have a signature that may denote an ID. Reception of the
SA-preamble may require an initial time synchronization obtained
from the PA-preamble.
[0079] The timing of transmission of the SA-preamble used to convey
paging may be fixed. Alternatively, the timing may be established
during association or broadcast. The SA-preamble may be transmitted
to a paged WTRU. The SA-preamble or another signal with similar
capabilities may include information related to the type of paging
device, for example a paging WTRU, and/or paging group information.
The paging group may be indicated in the SA-preamble signature and
timing element. The paging group may be expressed as a superframe
offset relative to the superframe periodicity. A paging group
indicator may be transmitted by any paging WTRU that has received a
paging message, for one of the paged WTRUs of the group. The BS may
arrange the paging messages such that the adjacent paging WTRU may
transmit the same paging indicator at the same time.
[0080] The paged WTRU, in response to the paging message, may then
transmit a signal indicating at least its presence. The paging WTRU
may listen for the response signal during an initial listening
phase 330. During the initial listening phase, listening resources
may be known and may either be fixed or established during an
initial association or by broadcast. The nature of the listening
resources may depend on the information and waveform used. For
example, the waveform may be a time domain waveform. In this
example, the listening resources may listen during one or more
listening time windows at times relative to the paging indicator
superframe. Note that in this example, the added interference
caused by the absence of a paged WTRU may be minimal.
[0081] The network in general, or the discoverable peer subscriber
station (DPSS), also known here as the paging WTRU, may not know at
this point that a paged WTRU is within range. The paging WTRU may
obtain information regarding a paged WTRU that is within range. In
addition, the paging WTRU may obtain a path loss estimate.
[0082] In order to minimize interference, the paged WTRU may start
transmission at a low power. The paged WTRU may determine whether
transmit power ramping will be used 340. If the paged WTRU
determines that transmit power ramping will be used, the paged WTRU
may perform an initial transmit power ramping 350.
[0083] To perform initial transmit power ramping, the paged WTRU
may transmit a waveform to make itself known to the paging WTRU. In
an example of multi-point transmission, the paged WTRU may transmit
a waveform to multiple paging WTRUs. For example, 802.16m ranging
preambles for either synchronized (S-RNG) or non-synchronized
devices (NS-RNG) may be used. The paging WTRU may receive a paging
response signal (PRS) from a paged WTRU 360, that may ramp up its
transmission power during a listening window 370. The paged WTRU
may ramp up its transmission power until a response is received or
an allowed maximum is reached, in which case the transmit power
ramping has failed. The initial power level and the transmit power
ramping steps may be predetermined. The listening windows may be
designed such that the paging WTRU knows how many transmit power
ramping steps have occurred. With knowledge of the step size an
initial power, the paging WTRU may estimate the path loss between
itself and the paged WTRU 380. The paging WTRU may then transmit a
paging message using a power based on the estimated path loss
390.
[0084] If the paged WTRU determines that transmit power ramping
will not be used, the paged WTRU may use a fixed power that may be
known to all devices 395. In this example, the PRS resources may be
provided in terms of the paging indicator or time reference. For
example, fixed resources may be used every n'th frame starting at a
predetermined time after the paging indicator.
[0085] Not all paging WTRUs that have received the PRS are required
to respond. Determining which paging WTRU responds may be based on
information estimated either in a distributed manner or under
direct BS control. For example, the paging-paged WTRU path loss
estimate or other criterion may be used to determine the best
paging WTRU. Note that the determination is not unique, and may
result in more than one best paging WTRU.
[0086] In a centralized control mode, all the paging WTRUs that
have received the PRS may send the path loss estimate information
or other information to the BS. The BS may then decide which paging
WTRU should respond based on the path loss estimate and other
parameters, for example, capabilities of the forwarding WTRU and
its own traffic load.
[0087] In one alternative, the responding paging WTRU may be
determined by the BS in a distributed manner by predetermining a
threshold on a function of the WTRU-BS and WTRU-WTRU path loss,
and/or or other criterion. The function may be signaled by the BS,
hard wired, or unspecified. Traffic load may be taking into account
in a similar manner, for example, by a threshold on buffer
occupancy.
[0088] Note that in itself the procedure does not absolutely
guarantee that at least one WTRU will respond. A high degree of
certainty may be achieved by BS control in the following manner.
Every WTRU that has received a PRS may signal that indication to
the BS. The BS may also know if the WTRU has responded and may
adjust the threshold as necessary. Transmission power for the
paging WTRU may be determined from the path loss estimate obtained
above. The response of the paging WTRU may contain the paging
messages, for example, as detailed in embodiments above.
[0089] In a WTRU/BS coordinated paging example, the BS may
initially attempt to directly page the paged WTRU. If a response is
not received within a specified time interval, the assistance of
one or more paging WTRUs may be requested. Requesting the
assistance of one or more paging WTRUs may improve the reliability
of paging while minimizing the battery drain impact on the paging
WTRU. Note that in this example, the attachment point may be either
the BS or the paging WTRU. The protocol of which node initiates the
first attempt, for example the WTRU, may be either established in
advance as part of a network association or signaled to the paging
WTRU by the BS at any other time. In this example, it is not
assumed that the paged WTRU may not be able to receive pages from
the BS. It may be assumed, however, that there may be a non-trivial
probability of success. The probability of success may not be high
enough to provide the desired reliability of successful paging.
[0090] An example autonomous paging WTRU triggering may be used in
conjunction with the WTRU/BS coordinated paging example to reduce
the signaling overhead. The paging WTRU may monitor the medium for
paging responses to the BS pages. If no response is signaled, the
WTRU may autonomously initiate assistance to the BS paging. While
this may be autonomous, it may be coordinated with the BS in
advance either at a network attachment time or any other time.
While this example may reduce the signaling overhead, it may
require that the paging WTRU be made aware of and monitor the
common channel that may be used for paging response messages. This
monitoring may offset the battery consumption advantage of the
WTRU/BS coordinated paging example.
[0091] Reduced overhead multi-point paging may be used in
conjunction with, for example, 802.16n discovery procedures.
Multi-point paging may be used when one or more WTRUs are out of
the coverage area of the BS, and they are moving in the cell such
that there is some uncertainty regarding which associated WTRU may
best page them.
[0092] Paging for a unicast connection may be performed using the
following example WTRU discovery procedure shown in FIG. 4. FIG. 4
shows a plurality of associated WTRUs 410-430, and one
non-associated WTRU 440. One or more associated WTRUs may be
designated as discoverable. These discoverable WTRUs may transmit
preambles that contain information regarding network timing,
bandwidth, one or more WTRU group IDs, and the type of device or
its ownership, if applicable. The discoverable WTRUs may transmit a
single preamble or a pair of primary and secondary preambles.
[0093] Referring to FIG. 4, WTRU 430 may transmit a preamble 445
and network connection information (NCI), using known resources or
resources derived from the cell-ID in the SA-preamble for the NCI.
The transmitted NCI may contain parameters required for initial
access. The parameters may include, for example, resources, codes,
etc. In this procedure, all discoverable WTRUs that are members of
a group may transmit the same preamble and NCI on the same
resources. This may result in the paged WTRU transmitting a group
response to all WTRUs which have transmitted their ID as explained
below.
[0094] The non-associated WTRU 440 may derive ranging parameters
from the NCI. Alternatively, if the NCI is not used, the
non-associated WTRU 440 may derive the ranging parameters 450 from
the WTRU ID or group WTRU ID, as indicated by the preamble. The
non-associated WTRU 440 may transmit an access signal 455 and ramp
up its transmit power 460. The code for ranging may be specified in
the NCI.
[0095] An associated WTRU, for example WTRU 430, may be designated
as a paging WTRU, and may receive the access signal 455. If the
received access signal 455 matches the access parameters of the
paging WTRU 430 and crosses a threshold, the paging WTRU 430 may
respond with an ACK 465. Upon receiving the ACK 465, the
non-associated WTRU 440 may stop transmit power ramping 470. The
paging WTRU 430 may transmit a specific NCI 475 that includes
specific access parameters. The non-associated WTRU 440 may then
access one or more of the responding associated WTRUs.
[0096] FIG. 5 is a flow diagram of a paging example 500 for a
unicast connection. The cell shown in FIG. 5 includes a BS 510, a
WTRU 520, and a WTRU 530. The WTRU 520 may be referred to as a
paging WTRU, and the WTRU 530 may be referred to as a paged WTRU.
In this example, WTRU 520 and WTRU 530 belong to group 1 540. Group
1 540 is shown with two WTRUs for simplicity, and it is understood
that each group may include more than two WTRUs. It is also
understood that each cell may include more than one BS.
[0097] Referring to FIG. 5, the BS 510 may transmit a paging ID
message 550 to one or more WTRUs. In this example, the BS 510 is
transmitting the paging ID message 550 to WTRU 520. The paging ID
message 550 may include the contents of a paging indication
information element (IE). The paging ID message 550 may also
include a one or more paged WTRU IDs, one or more paged group IDs,
and/or for example, a Synchronized ranging channel (S-RCH) resource
indicator. The paging ID message 550 may include an assigned paging
indicator (PI) for a single IDLE state WTRU or a group of IDLE
state WTRUs. One or more PIs may be assigned to each WTRU. A WTRU
in an IDLE state may be assigned a wakeup pattern that may match
the preamble or NCI epochs of a discoverable WTRU.
[0098] In response to receiving the paging ID message 550, the WTRU
520 may transmit a paging indicator IE 560 to WTRU 530. One or more
WTRUs may be instructed to transmit a paging indicator IE 560 that
indicates that an associated WTRU or group of WTRUs is paged. The
paging indicator IE 560 may be embedded in an NCI message.
Alternatively, the NCI message may indicate the resources where a
separate paging indicator message (PIM) may be found. The paging
indicator IE 560 may include a group preamble, a group NCI, and/or
a group paging indicator message, and may be transmitted using a
procedure similar to the discovery procedure above.
[0099] Each paging indicator or group of paging indicators may have
a code group associated with it from which a ranging code may be
selected randomly. If this group is distinct from those used for
initial network entry, then it may indicate to the paging WTRU that
the access is a response to a page. It may also indicate the group
to which the paged WTRU belongs.
[0100] Since all the members of a discoverable group may transmit
the same NCI, they may transmit the same PIM on the same resources,
therefore paging the same WTRU. Alternatively, in a group that uses
a separate PIM, some discoverable WTRUs may be instructed to omit
this message. If the message is omitted, then no other transmission
may occur on the same resources.
[0101] Referring again to FIG. 5, in response to the paging
indicator IE 560, the WTRU 530 may transmit an access signal 570
via an S-RCH resource. The access signal 570 may be a ranging
preamble transmitted using a transmit power ramp up procedure. The
WTRU 520, in response, may transmit an acknowledgement (ACK) 580
and a WTRU-specific SA-preamble and NCI 585. The WTRU 530 may then
transmit an additional access signal 590 and follow the normal cell
access procedure.
[0102] FIGS. 6A and 6B are flow diagrams of another example paging
procedure 600. Referring to FIG. 6A, a BS 610 may assign a PI
and/or a wakeup pattern to each IDLE state WTRU 620, 630 in the
cell. The PI may refer to a single WTRU or a group of WTRUs. One or
more PIs may be assigned to each WTRU. The assigned wakeup patterns
may match the preamble and/or NCI epochs of a discoverable WTRU.
The PI may also indicate that a WTRU is designated as a paging
WTRU.
[0103] Referring to FIG. 6B, WTRU 620 may be designated as a paging
WTRU. The paging WTRU 620 may transmit a group preamble, a group
NCI, and/or a group PIM 640 to the paged WTRU 630. The paging WTRU
620 may use a distinct code group to limit the number of WTRU
responses. The paged WTRU 630 may be in an idle state, and may
listen 650 for paging information embedded in the NCI or PIM. If
the paged WTRU 630 receives a paging indicator that was assigned to
it, the paged WTRU 630 may transmit an access signal 660 for
network entry. If a code group is associated with the PIM, the
paged WTRU 630 may select a code from the associated code group. In
response, the paging WTRU 620 may transmit a preamble associated
with a WTRU (WTRU-specific preamble) and NCI 670 to the paged WTRU
630.
[0104] Paging indicators may be included in the WTRU-specific NCI.
In addition, if a PIM is used, paging indicators may be added to
the PIM. The paging indicators may include an ID associated with a
WTRU that indicates, to a paging WTRU, which WTRU to page. Each
paging indicator may include one or more IDs associated with one or
more WTRUs, respectively. The paging indicators may also belong to
a group or may be specific to a paged WTRU. The paging indicators
may be different than those used in the preliminary stage. Any ID
that may have been assigned to a WTRU when it was previously
connected and retained by the network may be used as a paging ID.
An idle state WTRU may see a paging indicator assigned to it and
continue the network access procedure, including its ID in the
access message as normally used when answering a page.
[0105] FIG. 7 is a diagram of an example paging method 700 for use
in a WTRU. The WTRU may receive a configuration message 710 from
the BS indicating that the WTRU is designated as a paging WTRU. The
paging WTRU may transmit a group preamble, a group NCI, and/or a
group PIM 720. The paging WTRU may listen for an access signal 730.
If an access signal is received, the paging WTRU may transmit a
WTRU-specific preamble, NCI, and/or a PIM 740. The paging WTRU may
then initiate a network access procedure 750 and continue to
transmit a group preamble, a group NCI, and/or a group PIM 720. If
an access signal is not received, the paging WTRU may continue to
transmit a group preamble, a group NCI, and/or a group PIM 720.
[0106] The examples above may allow increased flexibility in the
paging process. For example, discoverable WTRUs may be grouped by a
combination of their service characteristics and rough geographical
location in the cell, such as groups that correspond to a
contiguous fraction of a cell area. As a result, the BS may base
the size of the paging area in the cell based on its uncertainty
regarding the location of the paged WTRU.
[0107] The paged WTRUs may be grouped based on one or a combination
of their service characteristics and location. For example, all the
WTRUs that provide a certain service may belong to a group and may
be paged so that they may receive a message. How the location
information is used may be determined by the BS. If the WTRU
density is below a threshold, the whole group in a certain
geographical area may be polled. Otherwise, if the density is over
a threshold, then sub-groups may be set up such that the paged
WTRUs are dispersed throughout the cell to prevent overloading
forwarding WTRUs with access attempts.
[0108] A two-stage procedure may be used with different paging
groups. This two-stage procedure may be used in conjunction with
code use to prioritize between accesses from different code
groups.
[0109] FIG. 8 is a diagram of another example group paging method
800. The wireless communication system shown in FIG. 8 includes a
plurality of WTRUs associated with a BS, and a non-associated WTRU,
WTRU G 810. The BS is not shown for simplicity. Of the associated
WTRUs, WTRU A 801, WTRU B 803, and WTRU C 805 belong to a first
group, for example, Group 1, and WTRU D 802, WTRU E 804, and WTRU F
806 belong to a second group, for example, Group 2.
[0110] Referring to FIG. 8, the WTRUs that belong to Group 1 may
each transmit a PA-preamble 821, an SA-preamble 823, and an NCI
825. The SA-preamble 823 may include a group ID 827 that indicates
which group the WTRU belongs, for example, Group 1. The group ID
827 may be based on service characteristics. The NCI 825 may
include paging indicators 829, or indicate where a separate paging
indicator may be transmitted, for example, the paging indicator may
be transmitted in a separate message. The NCI 825 may also be
group-based and include a group ID.
[0111] The WTRUs that belong to Group 2 may each transmit a
PA-preamble 831, an SA-preamble 833, and an NCI 835. The
SA-preamble 833 may include a group ID 837 that indicates which
group the WTRU belongs, for example, Group 2. The group ID 837 may
be based on service characteristics. The NCI 835 may include paging
indicators 839, or indicate where a separate paging indicator may
be transmitted, for example, the paging indicator may be
transmitted in a separate message. The NCI 835 may also be
group-based and include a group ID.
[0112] The non-associated WTRU, WTRU G 810, may detect one or more
of its paging indicators and transmit a ranging preamble 840 to a
group of its choice, for example, Group 2. The one or more paging
indicators may have been assigned by a BS at an earlier time via a
configuration message. The ranging preamble 840 may include an
indicator 845 or a field that indicates the chosen group. In this
example, the chosen group may be Group 2. WTRU G 810 may continue
to transmit the ranging preamble 840 using a transmit power ramp up
procedure until a response is received. Due to the transmit power
ramping, associated WTRUs that are nearby may tend to respond
first.
[0113] In this example, WTRU E 804 and WTRU F 806 may respond first
with a group-based acknowledgement (ACK) 850 that may include an
indicator 852 that indicates the WTRU group, for example, Group 2.
The group-based ACK 850 may be followed by a PA preamble associated
with a WTRU (WTRU-specific PA-preamble) 851, 853, an SA-preamble
associated with a WTRU (WTRU-specific SA-preamble) 854, 856, and an
NCI associated with a WTRU (WTRU-specific NCI) 855, 857. The
WTRU-specific SA preamble 854, 856 may include an indicator that
indicates a WTRU ID 861, 863, for example, WTRUs E and F,
respectively. The WTRU-specific NCI 855, 857 may include an
indicator that indicates a WTRU ID 862, 864, for example, WTRUs E
and F, respectively.
[0114] The non-associated WTRU G 810 may transmit a new network
access signal 870, for example a ranging preamble. The network
access signal 870 may be transmitted on resources determined from
the NCI 857, and may include an indicator 875 that indicates the
chosen WTRU ID 864. At this point, a normal access procedure may be
followed.
[0115] The examples shown in FIGS. 5-8 may be modified to indicate
the start or availability of a multicast transmission. In this
multi-point paging procedure, the paging indicators may be mapped
to multicast channel descriptors. The mapping may be established
during a previous connected state. The paging indicators may be
embedded in the NCI or a separate message indicated by the NCI.
Alternatively, the multicast channel descriptors may be explicitly
transmitted and may be either embedded in an NCI or in a separate
message. A WTRU that receives a paging indicator for its multicast
service or multicast channel descriptors may begin receiving
multicast transmission.
[0116] In some cases, the number of paged and paging WTRUs may be
low, and the latency requirements may be tight. To accommodate
these cases, the examples in FIGS. 5-8 may be adapted to perform
single point paging. In an example single point paging procedure,
the discoverable WTRU may transmit locally individual preambles and
NCI. A non-associated WTRU may access an associated WTRU using
signaled ranging parameters. This may be a single stage approach
similar to BS access by a WTRU. The NCI and PIM messages may be
used to indicate paging in this example.
[0117] An example transmission of NCI may include PIM transmission.
In this example, NCI partitioning may be performed. The NCI may be
divided into two subpackets, for example, an Initial Network
Configuration Information (I-NCI) and a Supplemental Network
Configuration Information (S-NCI).
[0118] The I-NCI may be transmitted first, with its location
determinable from the SA-preamble index, (Idx), and subcarrier set
index, (n) of the SA-preamble transmitted by the forwarding WTRU.
An example of the content of the I-NCI is shown in Table 1. An
example of the content of the S-NCI is shown in Table 2. The
location of the S-NCI may be specified in the I-NCI.
TABLE-US-00001 TABLE 1 Example for I-NCI contents and format Size
Syntax (bits) Notes BS IDcell 10 Frame Configuration 6 The mapping
between value of Index this index and frame configura- tion is
listed in Table 806, Table 807, and Table 808 If (WirelessMAN-OFDMA
True if Frame configuration with index is equal to -5, 7, FDM-based
UL PUSC 9, 11, 13, 15, 20, 21, 22, Zone 23, 24, 25, 26, 27, 28, 29
or 30 Support){ for 5/10 MHz channel band- width according to Table
806; -4, 6, 8 or 10 for 8.75 MHz channel bandwidth accord- ing to
Table 807; -3 or 5 (with CP = 1/8) for 7 MHz channel bandwidth
according to Table 808. False if Frame configura- tion index is
something else UL_Permbase 7 May indicate UL_Permbase used in
WirelessMAN-OFDMA system with FDM-based UL PUSC Zone. Reserved for
example, 1 to round up to integer bytes }else{ USAC 5/4/3 May
indicate the number of subbands K.sub.SB For 2048 FFT size, 5 bits
For 1024 FFT size, 4 bits For 512 FFT size, 3 bits UFPC 4/3/3 May
indicate the frequency partition configuration For 2048 FFT size, 4
bits For 1024 FFT size, 3 bits For 512 FFT size, 3 bits UFPSC 3/2/1
May indicate the number of subbands allocated to FPi (i > 0) in
16.3.7.2.3 For 2048 FFT size, 3 bits For 1024 FFT size, 2 bits For
512 FFT size, 1 bits UCAS.sub.SB0 5/4/3 May indicate the number of
subband-based CRUs in FP0 in 16.3.7.3.1 For 2048 FFT size, 5 bits
For 1024 FFT size, 4 bits For 512 FFT size, 3 bits UCAS.sub.MB0
5/4/3 May indicate the number of miniband-based CRUs in FP0 in
16.3.7.3.1 For 2048 FFT size, 5 bits For 1024 FFT size, 4 bits For
512 FFT size, 3 bits Resource Index for S-NCI for example, 6
Reserved rounding to integer bytes, for example }
TABLE-US-00002 TABLE 2 Contents and format for S-NCI Size Syntax
(bits) Notes If (Support of WirelessMANOFDMA with FDM-based UL PUSC
Zone){ Subframe offset of the RCH 2 May indicate the subframe
offset (O.sub.SF) of the RCH allocation. The range of values may be
0 .ltoreq. O.sub.SF .ltoreq. 3 Start RP code information 4 May
indicate the k.sub.ns, which may be the of the parameter for start
of the RP code group RCH (r.sub.ns0). r.sub.ns0(k.sub.ns) = 16
.times. k.sub.ns + 1, k.sub.ns = 0, 1, . . . , 15 Number of RP
codes 2 May indicate the number of RP codes and allocated for
coverage the particular codes that may be used for extension
ranging ranging with the forwarding WTRU. }else{ Subframe offset of
the S- 2 May indicate the subframe offset (O.sub.SF) of RCH the
S-RCH allocation Start RP code information May indicate the ks that
may be the of the parameter controlling the start root index S-RCH
of the RP codes (r.sub.s0). r.sub.s0 = 6 .times. k.sub.s + 1 The
range of values may be 0 .ltoreq. k.sub.s .ltoreq. 15 Transmission
timing offset 3 Indicates N.sub.RTO, which may be the of SRCH
parameter used for the calculation of the sample number, T.sub.RTO,
which may be applied to advance the ranging signal transmission
timing relative to the defined uplink transmission timing point
based on the frame structure from WTRU perspective when WTRU
conducts initial or handover ranging in a femtocell. T.sub.RTO =
floor(N.sub.RTO .times. (T.sub.g - 2) .times. F.sub.S)(samples)
where N.sub.RTO = min(RTD/(T.sub.g - 2), 7), and RTD may be the
round trip delay from the femto-BS to the overlay macro-BS. The
range of values is 0 .ltoreq. N.sub.RTO .ltoreq. 7. } UCASi 3/2/1
May Indicate the number of total allocated CRUs, in a unit of a
subband, for FPi (i .gtoreq. 0) in 16.3.7.3.1 For 2048 FFT size, 3
bits For 1024 FFT size, 2 bits For 512 FFT size, 1 bits Forwarding
EIRP 5 Unsigned integer from 1 to 31 in units of 1 dBm, where
0b00000 = 1 dBm and 0b11111 = 31 dBm. WTRU Transmit Power 5
Unsigned 5-bit integer. May specify the Limitation Level maximum
allowed WTRU transmit power. Values may indicate power levels in 1
dB steps starting from 0 dBm. EIRxPIR, min 5 Unsigned integer from
-133 to -102 in units of 1 dBm, where 0b00000 = -133 dBm and
0b11111 = -102 dBm. Pre-access S-NCI Indicator 1 May indicate
whether this is a pre-access S-NCI that may be used for Group
Discovery mode 0b0: not a pre-access S-NCI 0b1: pre-access S-NCI
Resource Index for PIM for example, 6
[0119] The I-NCI may be transmitted in the NI-NCI Distributed
Logical Resource Units (DLRUs) in the first subframe of a
superframe. The particular resource index may be determinable from
the SA-preamble transmitted by the forwarding WTRU. Within the
selected subframe, the I-NCI may occupy the last 5 OFDM symbols,
therefore effectively forming a Type-3 subframe.
[0120] An resource allocation for the S-NCI may be defined in the
I-NCI, as shown in Table 1, and the allocation may depend on the
IDCell and the frame configuration of the serving BS/RS. Paging
indicators may be included in the I-NCI, the S-NCI, or in a
separate PIM message. The location of the PIM may be indicated in
the I-NCI or in the S-NCI. Tables 1 and 2 show an example in which
the location is advertised in the S-NCI. In this example, specific
code groups may be assigned to each PI.
[0121] Table 3 illustrates an example format for a PIM message.
TABLE-US-00003 TABLE 3 Contents and format for PIM Size Syntax
(bits) Notes N_PI for May indicate the number of distinct example,
paging indicators in this message 8 For (i=0; i<N_PI; i++) { PI
for Paging indicator example, 16 Start RP code 4 May indicate the
ks that may be the information of the parameter controlling the
start root S-RCH index of the RP codes (r.sub.s0). r.sub.s0 = 6
.times. k.sub.s + 1 The range of values may be 0 .ltoreq. k.sub.s
.ltoreq. 15 }
[0122] 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
computer-readable media include electronic signals (transmitted
over wired or wireless connections) and computer-readable storage
media. Examples of computer-readable storage media include, but are
not limited to, a read only memory (ROM), a 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 WTRU, UE, terminal, base station, RNC, or any host
computer.
* * * * *