U.S. patent application number 14/947899 was filed with the patent office on 2016-06-02 for operating a wireless system in an unlicensed band.
This patent application is currently assigned to BROADCOM CORPORATION. The applicant listed for this patent is BROADCOM CORPORATION. Invention is credited to Wei BAI, Chunyan GAO, Jing HAN, Wei HONG, Haiming WANG, Na WEI.
Application Number | 20160157233 14/947899 |
Document ID | / |
Family ID | 46757349 |
Filed Date | 2016-06-02 |
United States Patent
Application |
20160157233 |
Kind Code |
A1 |
BAI; Wei ; et al. |
June 2, 2016 |
OPERATING A WIRELESS SYSTEM IN AN UNLICENSED BAND
Abstract
A network access node identifies a component carrier within an
unlicensed radio spectrum, determines whether or not to configure
the component carrier for use as a secondary component carrier, and
based on the determining configures the component carrier for use
as a secondary component carrier companion to a primary component
carrier within a licensed radio spectrum. In various non-limiting
embodiments the network node senses the component carrier within
the unlicensed radio spectrum, and as more data is needed to make
the determination employs a mobile device to also sense and further
to measure the component carrier within the unlicensed radio
spectrum. Specific procedures are detailed for both the network
node and the mobile device.
Inventors: |
BAI; Wei; (Beijing, CN)
; GAO; Chunyan; (Beijing, CN) ; WANG; Haiming;
(Beijing, CN) ; WEI; Na; (Beijing, CN) ;
HAN; Jing; (Beijing, CN) ; HONG; Wei;
(Beijing, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BROADCOM CORPORATION |
Irvine |
CA |
US |
|
|
Assignee: |
BROADCOM CORPORATION
Irvine
CA
|
Family ID: |
46757349 |
Appl. No.: |
14/947899 |
Filed: |
November 20, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14002407 |
Aug 30, 2013 |
9198188 |
|
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PCT/CN11/71429 |
Mar 1, 2011 |
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14947899 |
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Current U.S.
Class: |
370/329 |
Current CPC
Class: |
H04L 5/001 20130101;
H04L 5/0091 20130101; H04W 72/085 20130101; H04L 27/2032 20130101;
H04W 72/0453 20130101; H04W 16/14 20130101 |
International
Class: |
H04W 72/04 20060101
H04W072/04 |
Claims
1. An apparatus, comprising: at least one processor; and at least
one computer-readable memory storing at least one computer program;
in which the at least one memory with the at least one computer
program is configured with the at least one processor to cause the
apparatus to at least: identify a component carrier within an
unlicensed radio spectrum; based on the identifying, determine
whether or not to configure the component carrier for use as a
secondary component carrier; and based on the determining,
configure the component carrier for use as a secondary component
carrier companion to a primary component carrier within a licensed
radio spectrum.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of and claims
the benefit of priority under 35 U.S.C. .sctn.120 from U.S. Ser.
No. 14/002,407, filed Aug. 30, 2015, the entire contents of which
is incorporated herein by reference and which is a national stage
application of International Application No. PCT/CN11/71429, filed
Mar. 1, 2011.
TECHNICAL FIELD
[0002] The exemplary and non-limiting embodiments of this invention
relate generally to wireless communication systems, methods,
devices and computer programs and, more specifically, relate to
procedures for component carriers of a carrier aggregation system
which utilize unlicensed spectrum.
BACKGROUND
[0003] The following abbreviations that may be found in the
specification and/or the drawing figures are defined as
follows:
[0004] 3GPP third generation partnership project
[0005] CA carrier aggregation
[0006] CC component carrier
[0007] CE control element
[0008] CQI channel quality indicator
[0009] CRS cell specific reference signal
[0010] DL downlink (node B towards UE)
[0011] eNB node B/base station in an E-UTRAN system
[0012] E-UTRAN evolved UTRAN (LTE)
[0013] GERAN GSM EDGE Radio Access Network
[0014] GSM global system for mobile communications
[0015] ISM industrial, scientific and medical
[0016] LTE long term evolution
[0017] LTE-A LTE-Advanced
[0018] MAC medium access control
[0019] MME mobility management entity
[0020] PCC primary component carrier
[0021] PRACH physical random access channel
[0022] PSTN public switched telephone network
[0023] RACH random access channel
[0024] RRC radio resource control
[0025] RRM radio resource management
[0026] RS reference signal
[0027] RSRP reference signal received power
[0028] RSRQ reference signal received quality
[0029] RSSI received signal strength indicator
[0030] Scell secondary component carrier
[0031] SGW serving gateway
[0032] SIB system information block
[0033] TDM time division multiplex
[0034] UE user equipment
[0035] UL uplink (UE towards node B/eNB)
[0036] UTRAN universal terrestrial radio access network
[0037] WLAN wireless local area network
[0038] The LTE-Advanced wireless system is designed to provide
enhanced services by means of higher data rates and lower latency
with reduced cost. Carrier Aggregation (CA) is one technology to
improve data rates. FIG. 1 illustrates the CA concept: the whole
bandwidth of the wireless system is divided into two or more
component carriers (CCs), of which FIG. 1 shows five CCs by
example. At least one CC is configured to serve legacy UEs. Release
10 and later UEs are to be capable of monitoring/using multiple
CCs, and so the wireless network is able to assign two or more CCs
simultaneously as active for a single UE. This enables the network
greater scheduling flexibility by giving it the ability to allocate
channels to the same UE on any of the one or more CCs assigned to
the UE. For the case that multiple CCs are assigned and active for
a UE, one of the assigned CCs will be the UE's primary CC and the
other(s) will be secondary CC(s). The UE's secondary CC(s) is/are
also sometimes termed an extension carrier.
[0039] 3GPP LTE Rel-10 uses CCs designated on a licensed band. In
an LTE-A system an eNB will configure RRM measurement for a UE in a
licensed band, and the UE will report related results used to
decide which cell/carrier on the licensed band is good enough to be
configured. An RRM measurement is based on a cell specific
reference signal (CRS) measurement, but the CRS is transmitted only
in the carriers already configured in an LTE system, these carriers
being of the licensed band.
[0040] For at least this reason, there is no support in the LTE
system for carrier aggregation using an unlicensed band. What is
needed in the art is a way to intelligently deploy unlicensed
spectrum for use in a CA type system. Such a deployment has the
potential to reduce operator's cost, improve system throughput,
off-load traffic from a licensed band, and improve spectrum
efficiency overall. However, it is understood that new efficient
measurement and sensing mechanisms, as well as configurations,
would be required in order to achieve such potential.
[0041] Some discussion for developing the LTE-A standard for shared
band access may be seen at a presentation by M-A Phan, H. Wiemann
and J. Sachs entitled FLEXIBLE SPECTRUM USAGE-- HOW LTE CAN MEET
FUTURE CAPACITY DEMANDS (Ericsson; Jul. 8, 2010) and another by Rui
Yang entitled OVERVIEW OF RESEARCH PROJECTS WITH NYU-POLY
(InterDigital Communications; Nov. 12, 2010).
SUMMARY
[0042] The foregoing and other problems are overcome, and other
advantages are realized, by the use of the exemplary embodiments of
this invention.
[0043] In a first exemplary embodiment of the invention there is an
apparatus, comprising at least one processor, and at least one
computer-readable memory storing at least one computer program. In
this embodiment the at least one memory with the at least one
computer program is configured with the at least one processor to
cause the apparatus to at least identify a component carrier within
an unlicensed radio spectrum, based on the identifying, determine
whether or not to configure the component carrier for use as a
secondary component carrier, and based on the determining,
configure the component carrier for use as a secondary component
carrier companion to a primary component carrier within a licensed
radio spectrum.
[0044] In a second exemplary embodiment of the invention there is
an apparatus, comprising: means for identifying a component carrier
within an unlicensed radio spectrum, means for determining whether
or not to configure the component carrier for use as a secondary
component carrier based on the means for identifying, and means for
configuring the component carrier for use as a secondary component
carrier companion to a primary component carrier within a licensed
radio spectrum based on the means for determining.
[0045] In a third exemplary embodiment of the invention there is a
method, comprising: identifying by a network access node a
component carrier within an unlicensed radio spectrum, based on the
identifying, determining whether or not to configure the component
carrier for use as a secondary component carrier, and based on the
determining, configuring the component carrier for use as a
secondary component carrier companion to a primary component
carrier within a licensed radio spectrum.
[0046] In a fourth exemplary embodiment of the invention there is
an apparatus, comprising: at least one processor, and at least one
computer-readable memory storing at least one computer program, in
which the at least one memory with the at least one computer
program is configured, with the at least one processor, to cause
the apparatus at least to: sense at least one component carrier
within an unlicensed radio spectrum and/or measure a measurement
reference signal received on a component carrier within an
unlicensed radio spectrum from a network access node, send to the
network access node results of the sensing and/or measuring, and
thereafter receive from the network access node an indication to
take the component carrier within the unlicensed radio spectrum
into use as a secondary component carrier companion to a primary
component carrier within a licensed radio spectrum.
[0047] In a fifth exemplary embodiment of the invention there is a
method, comprising: performing by a mobile device at least one of
sensing a component carrier within an unlicensed radio spectrum and
measuring a measurement reference signal received on a component
carrier within an unlicensed radio spectrum from a network access
node, sending to the network access node results of the at least
one of sensing and measuring, and thereafter receiving from the
network access node an indication to take the component carrier
within the unlicensed radio spectrum into use as a secondary
component carrier companion to a primary component carrier within a
licensed radio spectrum.
[0048] In a sixth exemplary embodiment of the invention there is an
apparatus, comprising: at least one of means for sensing a
component carrier within an unlicensed radio spectrum and means for
measuring a measurement reference signal on a component carrier
within an unlicensed radio spectrum from a network access node,
means for sending to the network access node results of the at
least one of means for sensing and means for measuring, and means
for receiving from the network access node an indication to take
the component carrier within the unlicensed radio spectrum into use
as a secondary component carrier companion to a primary component
carrier within a licensed radio spectrum.
[0049] These and other embodiments and aspects are detailed below
with particularity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] FIG. 1 is a schematic diagram illustrating a wireless system
utilizing carrier aggregation, in which there are five component
carriers or cells shown for which user equipment might be allocated
multiple component carriers/cells simultaneously.
[0051] FIG. 2A is a simplified block diagram of a procedure for
sensing and measurement of component carriers within an unlicensed
band in accordance with the exemplary embodiments of the
invention
[0052] FIG. 2B illustrates simplified operations performed during
Phases 0-3 by devices such as a base station and/or user equipment,
in accordance with the exemplary embodiments of the invention.
[0053] FIG. 3 illustrates simplified procedures using different
combinations of the Phases 0-3, in accordance with non-limiting
embodiments of the invention.
[0054] FIGS. 4a-4e illustrated non-limiting examples of coding
which are related to information elements (IE) for RRC messaging
and reporting trigger events in accordance with the embodiments of
the invention.
[0055] FIGS. 5 and 6 are logic flow diagrams which illustrate the
operation of a method, and a result of execution of computer
program instructions embodied on a computer readable memory, in
accordance with the exemplary embodiments of this invention.
[0056] FIG. 7 is a simplified block diagram of the UE in
communication with a wireless network illustrated as an eNB and a
serving gateway SGW, which are an example of exemplary electronic
devices suitable for use in practicing the exemplary embodiments of
this invention.
DETAILED DESCRIPTION
[0057] Exemplary embodiments of the invention detailed herein
provide solutions and address problems in adapting a CA
communication system for usability with an unlicensed spectrum
band.
[0058] Unlicensed spectrum bands may also be termed shared bands.
As an example, the shared bands include the ISM band and the TV
white spaces which the US Federal Communications Committee FCC is
considering for this use.
[0059] Shared bands may be controlled by licensed spectrum systems,
and may be used by a stand-alone cell such as a LTE-A femto cell
which provides fast access to the Internet in a similar manner to
the WLAN specifications at IEEE 802.11. One advantage of using an
LTE-A femto cell over a traditional WLAN is the improved spectrum
efficiency in LTE-A. This improved spectrum efficiency is realized
through such concepts as LTE's flexibility in managing the
deployment bandwidth and the number of utilized carriers, and even
the LTE's flexibility in reconfiguration of a center frequency.
[0060] However, at least one challenge in adopting this shared band
concept is the need to manage on communications devices, such as
network access nodes (e.g., base stations, relay stations and the
like) and/or mobile devices, the increased discovery burden which
would be required. Since there are already some local networks
deployed in unlicensed bands, for example WiFi, Bluetooth, and
Zigbee, the interference in the unlicensed bands can be more
variable than interference in a licensed band, such as an LTE
licensed band. As the interference situation in these shared bands
can change quickly, an access node (e.g., eNB in LTE-A) using a
shared band channel would necessarily be required to dynamically
avoid the interference.
[0061] The related requirements of a communications device to use a
shared channel can include avoiding channel interference and in
some cases re-deploying the device to a more suitable channel of a
shared band. This is especially important during an access node
discovery phase. As similarly stated above, these required
operations for deploying in the unlicensed band will cause
additional operations and processing by the communications device.
Further, it is reasonable to expect that a device performing a
cellular operation using a shared band, such as an ISM band, would
be required to react especially quickly to a changing interference
environment of the shared band so as not to allow the cellular
communications to be interrupted or a call to drop. For at least
these reasons, aggregation of carriers on a licensed band as a PCC
is seen to be a more attractive alternative than deploying LTE in a
stand alone unlicensed band directly.
[0062] Control signaling for unlicensed bands can be sent via a
licensed band. To achieve satisfactory data transmission
performance and real gain from a carrier aggregation deployment in
unlicensed radio spectrums, some interference avoidance and
reduction schemes are necessary. One such technique is to evaluate
the usability of the band before attempting a data transmission in
the unlicensed band. In addition, considering the additional
processing required, it would be desirable that such an evaluation
be implemented with low complexity.
[0063] In accordance with the exemplary embodiments of the
invention, one implementation to achieve this preferred low
complexity includes reusing the existing mechanisms of an existing
communication system as much as possible for assessing the
usability of the unlicensed band.
[0064] The eNB of an LTE-A system operating in a licensed band will
configure RRM measurement to a UE and let the UE report related
results so that the eNB can determine which cell/carrier is good
enough to be configured. RRM measurement is based on cell specific
reference signal (CRS) measurement. Conventionally the CRS is
transmitted only in the carriers already configured in an LTE
system. Therefore, new efficient measurement and sensing mechanisms
are necessary to evaluate the usability of an unlicensed band
before the unlicensed band can be used by the LTE system. The
exemplary embodiments of the invention address at least these
requirements.
[0065] FIG. 2A illustrates a simplified block diagram of a sensing
and measurement procedure, in accordance with the exemplary
embodiments of the invention, to find a carrier on an unlicensed
band and determine whether the carrier could be used to operate an
LTE-A system.
[0066] In FIG. 2A the dashed vertical line divides the operations
related to the eNB from those of the UE. In certain embodiments at
least some of the operations occurring across this line may be
performed, at least in part, with one or both of the eNB and the
UE. Further, the UE is not limited to a single UE, and the
operations in FIG. 2A which are performed may represent operations
performed in one or more of a plurality of eNBs and/or UEs.
[0067] For clarity of description FIG. 2A is explained with
reference to phases 0-3. At block 210 in a Phase 0 of the
operations, there is detecting by an eNB that more resources are
needed to support data transmission and there are no available or
suitable radio resources on the licensed band. At block 215 there
is determining whether there is a running CC(s) on the unlicensed
band and whether the running CC(s) is sufficient. A running CC
means a CC already configured as a primary or a secondary CC for at
least one mobile device. If block 215 finds that there is a
sufficient running CC(s) on the unlicensed band, then at block 220
the UE(s) is configured to perform measurements on the detected
running unlicensed band CC(s). If block 215 concludes that there is
not a sufficient running CC(s) on the unlicensed band then the
process moves to Phase 1 of the operations. At block 225 the eNB
performs its own sensing in the unlicensed band to detect possible
component carriers and the eNB pre-selects at least one of these
CCs of the unlicensed band. If block 225 is performed then in Phase
2 of the process at block 230 there is determining of whether UE(s)
sensing on the detected and/or pre-selected CCs is needed. If at
block 230 it is determined that UE sensing on the detected and/or
pre-selected CCs is needed then the process proceeds to block 235
where a new measurement object and trigger is defined and sent to
the UE for reporting. The reporting by the UE is based on at least
one new trigger event such that reporting by a particular UE is
"on" when that particular UE senses that a particular carrier
becomes better than a "threshold;" and the reporting by that
particular UE is "off" when that particular UE senses that that
particular carrier becomes worse than the "threshold". In an
embodiment, the UE reports an "on" or "off" flag based on comparing
the sensed condition of the CC to the threshold it received from
the eNB. Further, it is noted that an additional timer, such as a
"TimerToTrigger" timer is set upon any change in condition due to a
trigger event. The additional timer sets a minimum duration for
which the condition remains. Then at block 240 the eNB receives
reports from the UE(s) which carry results from the UE sensing of
the carrier(s). If at block 230 sensing by the UE is not needed, or
if the sensing results the eNB receives at block 240 are still
insufficient to determine whether the CC in the unlicensed band is
suitable, then optionally the operations continue at Phase 3. At
block 245 there is a determining by the eNB whether more accurate
reporting is needed for measured, detected, and/or pre-selected CCs
of the unlicensed band. If more accurate reporting is needed then
at block 255 the eNB sends a measurement type preamble on the
configured carrier(s) that is within the unlicensed band. At block
260 the UE reads the measurement preamble on the CC(s), takes
measurements on that CC and reports back to the eNB. Blocks
245/255/260 may be repeated at the eNB's discretion as needed to
gather sufficient information about the CC to make a decision
whether or not to take it into use. Once the decision is made at
any one of blocks 225, 230, 240 or 245 that the CC is suitable,
then at block 265 the eNB configures the CC in the unlicensed band
as a Scell (i.e., secondary CC(s)) for the UE.
[0068] FIG. 2B illustrates additional details the exemplary
embodiments of the invention related to Phases 0-3 of the
operations, as described above in FIG. 2A.
[0069] Firstly, if the eNB detected that an additional resource is
needed to support data transmission, such as between UEs and/or
between an eNB and UE(s), and there is no available resource on a
licensed band, the eNB would check whether there is already a
running CC for other UEs on the unlicensed band. If there is a
carrier already running on the unlicensed band, the eNB should
first configure the UE to do measurements on this unlicensed CC and
report the measurements to the eNB. This measurement process is
identified as being associated with Phase 0 in FIG. 2B.
[0070] Secondly, if there is no running carrier on the unlicensed
band or the carrier running on the unlicensed band is not good
enough, then as identified as a Phase 1 operation, the eNB itself
should sense and/or pre-select at least one carrier from the
unlicensed band. It is noted that this pre-selecting can be
performed using information stored in an internal or external
database, such information can include white space information
and/or sensing results.
[0071] If the number of CCs pre-selected is larger than a
pre-determined amount and/or if eNB requires information regarding
interference conditions of these CCs, such as a DL interference
condition at the UE side, the eNB may configure the UE to perform
sensing and or measuring. This sensing and/or measuring is being
performed on particular pre-selected carriers in the unlicensed
band. Then, as identified as being associated with Phase 2 in FIG.
2B, when the sensing is complete the UE should report the sensing
results to the eNB to be used by the eNB to decide which carrier(s)
are sufficiently available for the UE.
[0072] Finally, if the eNB wants to get a more accurate report for
some of the CCs in the unlicensed band which have may have been
sensed by the UE in Phase 2, the eNB could send a measurement type
preamble on at least one of the carriers on the unlicensed band.
The sending is identified as being associated with Phase 3 in FIG.
2B, and is configuring the UE to do measurement and reporting using
the measurement type preamble. Based on at least a measurement
report from the UE, the eNB ascertains with enhanced certainty
whether the identified CC(s) in the unlicensed band is/are
sufficiently available or not. Note that sensing in Phase 2 and
measuring in Phase 3 are distinct; sensing may be for example the
UE sensing transmit power or signal level on the CC and comparing
to the threshold noted above with respect to FIG. 2A, whereas
measuring gives more detailed information such as measuring the
specific DL interference seen by the UE by reading a measurement
preamble on the CC.
[0073] The operations of FIGS. 2A and 2B, as described above, may
be fully controlled by the eNB. Therefore, in accordance with the
exemplary embodiments of the invention, the eNB may decide to skip
at least one step. For example, phases 2 and 3 are both optional in
certain embodiments. That is to say, there is the possibility to
enter block 240 or phase 3 directly from block 220 or phase 1.
Further, the eNB can configure an unlicensed carrier right after
block 230, or in one of Phase 1 or Phase 2 of the operations as at
least illustrated in FIGS. 2A and 2B. In a non-limiting embodiment
of the invention the decision regarding the skipping and/or
ordering of these blocks can be made in consideration of the
capabilities of either or both of the UE and the eNB.
[0074] In addition, the operations associated with Phases 0-3, as
at least with regards to FIGS. 2A and 2B, are further detailed as
follows: [0075] Phase 0: the eNB configures the UE to do
measurements on carrier(s) which are already running on unlicensed
band: [0076] Since CRS is already transmitted, the conventional LTE
measurement mechanism can be re-used for this purpose, as adapted
for the unlicensed band. [0077] The inventors propose three options
to decide whether the carrier in question is available: [0078]
Pre-define a fixed threshold and let the UE decide. The UE then
reports an On-Off flag to the eNB to indicate its decision whether
the carrier is available or not. [0079] The eNB semi-statically
configures the threshold, but still lets the UE decide and report
its On-Off flag as noted above. [0080] Fully reuse the LTE-A
mechanism, in which the UE reports RSRP/RSRQ to the eNB and the eNB
decides whether the carrier is available or not. [0081] For the
first two options above in which the UE decides the carrier
availability, there is also a need to define some report trigger
event to let the UE report the On-Off flag of Phase 2 described
with reference to the sensing of block 235 of FIG. 2A. In an
exemplary embodiment: [0082] For the "on" flag, the reporting
trigger is the event A4 defined in [TS 36.331] re-used for this
purpose, such as, "neighbor becomes better than threshold"; [0083]
For the "off" flag, the reporting trigger is a newly defined event
A7, such as "neighbor becomes worse than threshold" [0084] The
inventors also present two options to report the measurement result
in Phase 3 described with reference to the measuring at block 260
of FIG. 2A: [0085] Reporting the result via RRC message on the
PUSCH on the cell with the RRC link, and/or [0086] Reporting the
result via the PUCCH which is explicitly configured on the Pcell.
Below are two options for this PUCCH report. [0087] Option I: The
report for each carrier can be defined by reusing the periodic CQI
report, and the report for each carrier is sent using TDM [0088]
Option II: Only use 1 or 2 bits to report for each carrier, and
reports for all the carriers are jointly coded and send in PUCCH
format II. [0089] Phase 1: the eNB does its own measurements and/or
sensing itself and chooses some carriers which have potential to be
used; these are candidate carriers. [0090] This phase is fully
implemented only by the eNB side with no measurements from the UEs.
[0091] Phase 2: the eNB configures the UE to do the measurements
and/or sensing and lets the UE report the results [0092] In this
embodiment there is defined a new sensing object, and a new trigger
event for reporting: [0093] i. For the "on" flag, there is defined
the new event A8 "sensing carrier becomes better than threshold."
[0094] ii. For the "off" flag, there is defined a new event A9,
such as "sensing carrier becomes worse than threshold." [0095] The
inventors further present two options for the UE to do the sensing,
which may be UE-spccific implementations: [0096] i. Measuring
common RSSI and comparing with the threshold to report the sensing
result. [0097] This requires the UE to introduce a new measurement
capability of "common RSSI", such as measure all the power received
from the carrier. [0098] ii. Use an ISM technique to get the
sensing result if there is an ISM module deployed at the UE
already. [0099] The reporting mechanism is the same as phase 1.
[0100] Phase 3: the eNB sends a measurement preamble on the carrier
in question, and lets the UE do the measurement on that
carrier/preamble and report the measurement result [0101] a
conventional CRS can be used as the measurement preamble. [0102]
The procedure of phase 3 may be similar with phase 0 but with some
differences in the parameters being utilized.
[0103] In accordance with the exemplary embodiments, sensing can be
explained as at least one of: no running LTE system or LTE
reference signal is transmitted in the unlicensed band.
Additionally, sensing can be based on power detection of radio
signals, regardless of whether the detected power is from
transmissions within some wireless system(s) or just from white
noise. In addition, in accordance with the embodiments, measuring
can refer to a base station/eNB transmitting CRS, and a mobile
device/UE measuring RSRP/RSRQ.
[0104] FIG. 3 illustrates procedures using different combinations
of Phases, in accordance with non-limiting embodiments of the
invention. These procedures P1-P4, as illustrated in FIG. 3, are
described as follows:
[0105] In the procedure identified as P1, it can be seen that
operations of Phase 0 are first performed including measuring CCs
running in the unlicensed band and/or a reusing of R10's
measurements. Thereafter in P1 there is configuring a secondary CC
(Scell) on the selected carriers.
[0106] In the procedure identified as P2, operations of Phase 0 are
first performed including measuring CCs running in the unlicensed
band and/or a reusing of R10's measurements. Then operations of
Phase 1 are performed including the eNB sensing and/or measuring an
unlicensed band to determine one or more CCs of the unlicensed
band. Thereafter, in P1 there is configuring a secondary CC (Scell)
on selected carriers of the one or more CCs.
[0107] In the procedure P3, operations of Phase 0 are first
performed including measuring CCs running in the unlicensed band
and/or a reusing of R10's measurements. Then operations of Phase 1
are performed including the eNB sensing and/or measuring an
unlicensed band to determine one or more CCs of the unlicensed
band. Then there is configuring the UE to measure and/or sense a
pre-determined set of CCs of the unlicensed band and report back to
the eNB the CCs which are acceptable and/or available. These
operations are further associated with Phase 2 in that, if needed,
the UE can be sensing CCs sensed and/or measured by the eNB in
Phase 1. Thereafter, in P3 a secondary CC (Scell) is configured on
selected carriers of the one or more CCs.
[0108] In P4 operations of Phase 0 are first performed including
measuring CCs running in the unlicensed band and/or a reusing of
R10's measurements. Then operations of Phase 1 are performed
including the eNB sensing and/or measuring an unlicensed band to
determine one or more CCs of the unlicensed band. Then there is
sending a signal including a measuring type preamble on at least
one CC of the one or more CCs of the unlicensed band. The sending
is configuring the UE to do measurement and reporting based on the
signal including the measurement type preamble. These operations
are further associated with Phase 3 in that, if needed, the UE can
be sensing CCs sensed and/or measured by the eNB in Phase 1.
Thereafter, in P4 a secondary CC (Scell) is configured on selected
carriers of the one or more CCs.
[0109] It is noted that although a Phase and its procedures may be
controlled by the eNB, the order in which the implemented Phases
are performed is in an exemplary embodiment be based on the above
numerical order of the Phases. In this embodiment it would be
allowable for the eNB to use only Phases 0, 1, and 3, in that
order, as illustrated in FIG. 3 as the P4 operations. However, if
the eNB also uses phase 2 in this embodiment it follows that the
eNB uses phase 2 and thereafter phase 3 so the operations include
Phases 0, 1, 2, and 3 in numerical order.
[0110] Further, the exemplary embodiments of the invention can be
summarized as follows: [0111] Embodiment #1: The overall procedure
(especially the signaling part of phase2 and phase3) for sensing
and measurement, as at least described in FIGS. 2A and 2B, which
may be specifically defined in 3GPP standards if this embodiment is
accepted as such. [0112] Embodiment #2: for phase 0 [0113] i. #2a:
this comprises a new trigger event A7 "neighbor becomes worse than
threshold" [0114] ii. #2b: this comprises a new report format, such
as a one data bit identifying availability of an unlicensed band.
If by example the one data bit may be defined so that value "1"
stands for "available" and value "0" stands for "un-available", or
vice versa. The one data bit may be disposed in an RRC message
based on a trigger or periodic report on a PUCCH to report the
measurement result. It is noted that a report for each carrier can
be sent using TDM or jointly coded in this case. [0115] Embodiment
#3: for phase 2 [0116] i. #3a: in this embodiment there is defined
the new measurement capability "common RSSI" for Rel-11 and beyond
UE in PHY spec and define new quantity configuration in RRC spec.
[0117] ii. #3b: in this embodiment the UE uses its ISM module to
obtain its measurement and the UE generates the sensing report if
there is interference from another ISM device. [0118] iii. #3c:
this embodiment introduces the new trigger event A8: "sensing
carrier becomes better than threshold" and new trigger event A9:
"sensing carrier becomes worse than threshold". For more easy
adoption these events should be defined for Rel-11 and beyond for
the UE side.
[0119] In the overall procedures, other than in Phase 1, each phase
can reuse existing LTE measurement configuration procedures.
However, it is noted that new measurement object(s), reporting
trigger event(s), and reporting formats may still need to be
defined.
[0120] In FIGS. 4a-e there are illustrated coding which is related
to information elements (IE) for RRC messaging and reporting
trigger events as in accordance with the embodiments of the
invention.
[0121] For example, as illustrated in FIG. 4a there is a
MeasObjectUnlicensedBand information element. In FIG. 4a the IE
MeasObjectUnlicensedBand specifies information applicable for
measurement/sensing on unlicensed band. Here, "carrierFreq" stands
for the central frequency of the sensing carrier on the unlicensed
band, and "allowcdMeasBandwidth" stands for the bandwidth of the
sensing carrier.
[0122] The IE MeasObjectUnlicensedBand information element, as
illustrated in FIG. 4a, comprises code as follows:
TABLE-US-00001 -- ASN1START MeasObjectUnlicensdBand ::= SEQUENCE {
carrierFreq ARFCN-ValueUnlicensedBand, allowedMeasBandwidth
AllowedMeasBandwidth,
[0123] As illustrated in FIG. 4b, there is a QuantityConfig
information element. In FIG. 4b the IE QuantityConfig specifies the
measurement quantities and layer 3 filtering coefficients for
E-UTRA and inter-RAT measurements.
[0124] The IE 1.1.1.1 QuantityConfig, as illustrated in FIG. 4b,
comprises code as follows:
TABLE-US-00002 -- ASN1START quantityConfigUnLicensedBand
QuantityConfigUnlicenseBand OPTIONAL, -- Need ON
QuantityConfigUnlicensedBand ::=SEQUENCE {
MeasQuantityUnlicensedBand ENUMERATED {common-rssi}
[0125] Further, FIG. 4c illustrates a trigger event A7 at a
threshold in accordance with the exemplary embodiments of the
invention. In this case, the reporting trigger event A7 is when
"neighbor becomes worse as identified with the threshold.
[0126] The "1.1.1.2 Event A7 (Neighbour becomes worse than
threshold)," as illustrated in FIG. 4c, can comprise coding as
follows:
The UE shall: [0127] 1> consider the entering condition for this
event to be satisfied when condition A8-1, as specified below, is
fulfilled; [0128] 1> consider the leaving condition for this
event to be satisfied when condition A8-2, as specified below, is
fulfilled;
[0128] Mn+Ofn+Ocn-Hys<Thresh Inequality A7-1 (Entering
condition)
Mn+Ofn+Ocn+Hys>Thresh Inequality A7-2 (Leaving condition)
The variables in the formula are defined as follows: [0129] Mn is
the measurement result of the neighbouring cell, not taking into
account any offsets. [0130] Ofn is the frequency specific offset of
the frequency of the neighbour cell (i.e. offsetFreq as defined
within measObjectEUTRA corresponding to the frequency of the
neighbour cell). [0131] Ocn is the cell specific offset of the
neighbour cell (i.e. cellIndividualOffset as defined within
measObjectEUTRA corresponding to the frequency of the neighbour
cell), and set to zero if not configured for the neighbour cell.
[0132] Hys is the hysteresis parameter for this event (i.e.
hysteresis as defined within reportConfigEUTRA for this event).
[0133] In addition, FIG. 4d illustrates a trigger event A8 at a
threshold in accordance with the exemplary embodiments of the
invention. In this case the reporting trigger event A8 identifies
that a carrier of an unlicensed band has become better than a
threshold, such as an absolute threshold.
[0134] The "1.1.1.3 Event A8 (measured and/or sensed carrier on
unlicensed band becomes better than absolute threshold)" as
illustrated in FIG. 4d comprises coding as follows:
The UE shall: [0135] 1> consider the entering condition for this
event to be satisfied when condition A9-1, as specified below, is
fulfilled; [0136] 1> consider the leaving condition for this
event to be satisfied when condition A9-2, as specified below, is
fulfilled;
Inequality A8-1 (Entering Condition)
[0137] Then, FIG. 4e illustrates a trigger event A9 at a threshold
in accordance with an exemplary embodiment of the invention. Here,
the reporting trigger event A9 identifies that a carrier of an
unlicensed band has become worse than a threshold, such as an
absolute threshold.
[0138] The "1.1.1.4 Event A9 (measured and/or sensed carrier on
unlicensed band becomes worse than absolute threshold)" as
illustrated in FIG. 4e can comprise coding as follows:
The UE shall: [0139] 1> consider the entering condition for this
event to be satisfied when condition A9-1, as specified below, is
fulfilled; [0140] 1> consider the leaving condition for this
event to be satisfied when condition A9-2, as specified below, is
fulfilled;
[0140] Mn-Hys<Thresh Inequality A9-1 (Entering condition)
Mn+Hys>Thresh Inequality A9-2 (Leaving condition)
[0141] In FIG. 5 there is illustrated a logic flow diagram which
describes an exemplary embodiment of the invention in a manner
which may be from the perspective of the eNB. FIG. 5 may be
considered to illustrate the operation of a method, and a result of
execution of a computer program stored in a computer readable
memory, and a specific manner in which components of an electronic
device are configured to cause that electronic device to operate.
The various blocks shown in FIG. 5 may also be considered as a
plurality of coupled logic circuit elements constructed to carry
out the associated function(s), or specific result of strings of
computer program code stored in a memory.
[0142] In block 510 of FIG. 5 a component carrier within an
unlicensed radio spectrum is identified. In block 520 of FIG. 5
based on the identifying, it is determined whether or not to
configure the component carrier for use as a secondary component
carrier. Then in block 530 of FIG. 5, based on the determining, the
component carrier is configured for use as a secondary component
carrier. This secondary component carrier is then companion to a
primary component carrier which is within a licensed radio
spectrum.
[0143] Further, in accordance with the paragraph above, sending a
measurement reference on the selected at least one component
carrier to a mobile device, where the determining is based on a
reply from the mobile device according to the measurement
reference.
[0144] In accordance with the paragraph above, the measurement
reference is one of a cell specific reference identified in a phase
0 of the operations or a measurement preamble sent to the mobile
device in a phase 3 of the operations.
[0145] Additionally, in accordance with the preceding paragraphs,
the reply comprises a common received signal strength indicator
which is the power detection results of all the radio power
collected in the configured sensing frequency.
[0146] Further, in accordance with the preceding paragraph, the
selected at least one component carrier is one of at least one
component carrier running on the unlicensed radio spectrum for a
phase 1 of the operations or a pre-selected subset of at least one
component carrier on the unlicensed radio spectrum in a phase 2 and
a phase 3 of the operations, where the pre-selected subset is
identified using a database associated with the base station.
[0147] Additionally, in accordance with the preceding paragraph,
the selecting the at least one component carrier within the
unlicensed radio spectrum comprises sensing at least one component
carrier within the unlicensed radio spectrum by the base station in
a phase 1 of the operations.
[0148] Furthermore, in accordance with the preceding claims, the
phase 2 and the phase 3 of the operations are optional, and a
device performing the method as stated above is caused to perform
phases of the operations in a numerical order of the phases.
[0149] The operations in any one of the preceding claims performed
by a network node of a long term evolution advanced network.
[0150] In accordance with the preceding paragraphs, at least one of
the identifying and the determining comprises: sensing, by the
network access node, an available component carrier within the
unlicensed radio spectrum; configuring at least one mobile device
to report measurements results on an available component carrier
within the unlicensed radio spectrum; and configuring at least one
mobile device to report measurements results on an available
component carrier within the unlicensed radio spectrum.
[0151] Further, in accordance with the preceding paragraph, the
configuring the at least one mobile device comprises one of:
sending on a configured component carrier within an unlicensed
radio spectrum a message comprising a preamble used to pre-define
one or more of a fixed or semi-statically configured threshold to
prompt a mobile device to report measurements on the available
component carrier, and reusing, with a cell specific reference
signal, a mechanism of the long term evolution network to configure
the mobile device to report measurements on the available component
carrier.
[0152] In accordance with the preceding paragraph, the pre-defining
the one or more threshold comprises a defined trigger reporting
event such that reporting by a mobile device is "on" when sensing
that the component carrier becomes better than the "threshold," and
last for a certain time and reporting by a mobile device is "off"
when sensing that the component carrier becomes worse than the
"threshold." and last for a certain time
[0153] In accordance with the preceding paragraph, the trigger
reporting event remains in the "on" or the "off" condition for at
least a duration determined by a separate trigger timer.
[0154] Additionally, in accordance with the preceding paragraphs,
the reporting is receive via one of a radio resource control
message over the component carrier or channel quality indicator
report signaling.
[0155] In accordance with the preceding paragraphs, the channel
quality indicator report signaling uses data fields comprising one
or two bits to identify component carriers within the unlicensed
radio spectrum to which the report is applicable.
[0156] In accordance with the preceding paragraphs, the
measurements comprise a common received signal strength indicator
to indicate all power received from the component carrier within
the unlicensed radio spectrum.
[0157] FIG. 6 similarly illustrates a logic flow diagram. The logic
flow illustrated in FIG. 6 describes an exemplary embodiment of the
invention in a manner which may be from the perspective of a mobile
device, such as a user equipment. FIG. 6 may be considered to
illustrate the operation of a method, and a result of execution of
a computer program stored in a computer readable memory, and a
specific manner in which components of an electronic device are
configured to cause that electronic device to operate. The various
blocks shown in FIG. 6 may also be considered as a plurality of
coupled logic circuit elements constructed to carry out the
associated function(s), or specific result of strings of computer
program code stored in a memory.
[0158] In block 610 of FIG. 6 there is performed at least one of
sensing a component carrier within an unlicensed radio spectrum,
and measuring a measurement reference signal received from a
network access node on a component carrier within the unlicensed
radio spectrum. In block 620 of FIG. 6 there is sent to the network
access node results of the at least one of sensing and measuring.
Then in block 630 of FIG. 6, there is received from the network
access node an indication to take the component carrier within the
unlicensed radio spectrum into use as a secondary component carrier
by the mobile device. In this embodiment the secondary component
carrier is taken into use companion to a primary component carrier
which is itself within licensed radio spectrum.
[0159] In accordance with the preceding paragraph, comprising
receiving from the network access node a preamble used to
pre-define one of a fixed or semi-statically configured at least
one threshold to prompt the mobile device to report measurements on
the available component carrier.
[0160] In accordance with the preceding paragraphs, the message to
the network access node comprises channel quality indicator report
signaling which uses data fields comprising one or two bits to
identify component carriers within the unlicensed radio spectrum to
which the report is applicable.
[0161] Further, in accordance with the preceding paragraphs, the
message to the network access node is sent in response to a
reporting event trigger of the mobile device being set to "on" due
to a threshold trigger indicating that a component carrier has
become better than a predefined threshold.
[0162] In addition, in accordance with the preceding paragraphs,
the message to the network access node comprises a common received
signal strength indicator to indicate all power received from the
component carrier within the unlicensed radio spectrum.
[0163] In accordance with the preceding paragraphs, the mobile
device comprises a module which is capable of transmitting in the
industrial, scientific and medical band, which is unlicensed radio
spectrum; the method further comprising using the industrial,
scientific and medical module to at least one of sense and measure
a component carrier within the unlicensed radio spectrum.
[0164] Reference is now made to FIG. 7 for illustrating a
simplified block diagram of various electronic devices and
apparatus that are suitable for use in practicing the exemplary
embodiments of this invention. In FIG. 7 a wireless network (eNB 22
and mobility management entity MME/serving gateway SGW 24) is
adapted for communication over a wireless link 21 with an
apparatus, such as a mobile terminal or UE 20, via a network access
node, such as a base or relay station or more specifically an eNB
22. The network may include a network control element MME/SGW 24,
which provides connectivity with further networks (e.g., publicly
switched telephone network (PSTN) and/or a data communications
network/Internet).
[0165] The UE 20 includes processing means such as at least one
data processor (DP) 20A, storing means such as at least one
computer-readable memory (MEM) 20B storing at least one computer
program (PROG) 20C, communicating means such as a transmitter TX
20D and a receiver RX 20E for bidirectional wireless communications
with the eNB 22 via one or more antennas 20F. Also stored in the
MEM 20B at reference 20G is at least one algorithm which the UE 20
utilizes to perform operations including, but not limited to,
sensing, measuring, reporting on and using component carriers of an
unlicensed radio spectrum or band.
[0166] The eNB 22 also includes processing means such as at least
one data processor (DP) 22A, storing means such as at least one
computer-readable memory (MEM) 22B storing at least one computer
program (PROG) 22C, and communicating means such as a transmitter
TX 22D and a receiver RX 22E for bidirectional wireless
communications with the UE 20 via one or more antennas 22F. There
is a data and/or control path 25 coupling the eNB 22 with the
MME/SGW 24, and another data and/or control path 23 coupling the
eNB 22 to other eNB's/access nodes. Also stored in the MEM 22B at
reference 22G is at least one algorithm which the eNB 22 utilizes
to perform operations including, but not limited to, sensing,
measuring, identifying, setting thresholds, and creating
measurement type preambles for utilization of, such as by itself or
other network nodes, component carriers of an unlicensed radio
spectrum or band.
[0167] Similarly, the MME/SGW 24 includes processing means such as
at least one data processor (DP) 24A, storing means such as at
least one computer-readable memory (MEM) 24B storing at least one
computer program (PROG) 24C, and communicating means such as a
modem 24H for bidirectional wireless communications with the eNB 22
via the data/control path 25. While not particularly illustrated
for the UE 20 or eNB 22, those devices are also assumed to include
as part of their wireless communicating means a modem which may be
inbuilt on an RF front end chip within those devices 20, 22 and
which also carries the TX 20D/22D and the RX 20E/22E.
[0168] At least one of the PROGs 20C in the UE 20 is assumed to
include program instructions that, when executed by the associated
DP 20A, enable the device to operate in accordance with the
exemplary embodiments of this invention, as detailed above. The eNB
22 and MME/SGW 24 may also have software to implement certain
aspects of these teachings. In these regards the exemplary
embodiments of this invention may be implemented at least in part
by computer software stored on the MEM 20B, 22B which is executable
by the DP 20A of the UE 20 and/or by the DP 22A of the eNB 22, or
by hardware, or by a combination of tangibly stored software and
hardware (and tangibly stored firmware). Electronic devices
implementing these aspects of the invention need not be the entire
UE 20 or eNB 22, but exemplary embodiments may be implemented by
one or more components of same such as the above described tangibly
stored software, hardware, firmware and DP, or a system on a chip
SOC or an application specific integrated circuit (ASIC).
[0169] In general, the various embodiments of the UE 20 can
include, but are not limited to personal portable digital devices
having wireless communication capabilities, including but not
limited to cellular telephones, navigation devices,
laptop/palmtop/tablet computers, digital cameras and music devices,
and Internet appliances.
[0170] Various embodiments of the computer readable MEMs 20B and
22B include any data storage technology type which is suitable to
the local technical environment, including but not limited to
semiconductor based memory devices, magnetic memory devices and
systems, optical memory devices and systems, fixed memory,
removable memory, disc memory, flash memory, DRAM, SRAM, EEPROM and
the like. Various embodiments of the DPs 20A and 22A include but
are not limited to general purpose computers, special purpose
computers, microprocessors, digital signal processors (DSPs) and
multi-core processors.
[0171] The exemplary embodiments of the invention as stated above
at least provide at the advantages of defining practical
measurement and sensing procedures for utilizing unlicensed bands
in a communications system, such as an LTE system, the measurement
and sensing procedures being aligned with the current 3GPP LTE
release. In addition, the embodiments as described above provide
robust results for use in the sensing and measurement and minimize
signaling overhead by limiting reporting to on-off flag
indications. Further, the ENB has enough flexibility to control the
whole procedure in order to reduce delay and/or increase
robustness, and the UE has the flexibility regarding generating a
report based on its own capability.
[0172] Various modifications and adaptations to the foregoing
exemplary embodiments of this invention may become apparent to
those skilled in the relevant arts in view of the foregoing
description. While the exemplary embodiments have been described
above in the context of the E-UTRAN system, it should be
appreciated that the exemplary embodiments of this invention are
not limited for use with only this one particular type of wireless
communication system, and that they may be used to advantage in
other wireless communication systems such as for example UTRAN,
GERAN and GSM and others so long as there are different carriers
operating on different timing which might be assigned to a UE.
[0173] Further, some of the various features of the above
non-limiting embodiments may be used to advantage without the
corresponding use of other described features. The foregoing
description should therefore be considered as merely illustrative
of the principles, teachings and exemplary embodiments of this
invention, and not in limitation thereof.
* * * * *