U.S. patent application number 16/405145 was filed with the patent office on 2019-08-22 for maximizing channel capacity for common downlink channels.
The applicant listed for this patent is TELEFONAKTIEBOLAGET LM ERICSSON (PUBL). Invention is credited to Sajal Kumar Das, John Walter Diachina, Nicklas Johansson, Olof Liberg, Marten Sundberg.
Application Number | 20190261410 16/405145 |
Document ID | / |
Family ID | 55181569 |
Filed Date | 2019-08-22 |
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United States Patent
Application |
20190261410 |
Kind Code |
A1 |
Johansson; Nicklas ; et
al. |
August 22, 2019 |
MAXIMIZING CHANNEL CAPACITY FOR COMMON DOWNLINK CHANNELS
Abstract
A wireless access node and method are described herein for
improving a bandwidth utilization efficiency of a common downlink
(DL) channel when transmitting device-related information included
in one or more messages to a wireless device or a group of wireless
devices, wherein the one or more messages have one or more
transport block formats that meet a coverage class need of the
wireless device or the group of wireless devices. In addition, a
wireless device and method are described herein for improving a
bandwidth utilization efficiency of the common DL channel by
receiving one or more messages including device-related information
on the common DL channel from the wireless access node, wherein the
one or more messages have one or more transport block formats that
meet a coverage class need of the wireless device.
Inventors: |
Johansson; Nicklas;
(Brokind, SE) ; Sundberg; Marten; ( rsta, SE)
; Liberg; Olof; (Stockholm, SE) ; Das; Sajal
Kumar; (Bangalore, IN) ; Diachina; John Walter;
(Garner, NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TELEFONAKTIEBOLAGET LM ERICSSON (PUBL) |
Stockholm |
|
SE |
|
|
Family ID: |
55181569 |
Appl. No.: |
16/405145 |
Filed: |
May 7, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15837268 |
Dec 11, 2017 |
10285198 |
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16405145 |
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14809987 |
Jul 27, 2015 |
9844074 |
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15837268 |
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62050517 |
Sep 15, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 68/005 20130101;
H04L 1/0007 20130101; H04W 74/006 20130101; H04L 1/00 20130101;
H04L 1/0003 20130101; H04L 1/0009 20130101 |
International
Class: |
H04W 74/00 20060101
H04W074/00; H04L 1/00 20060101 H04L001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 31, 2014 |
IN |
2161/DEL/2014 |
Claims
1. A wireless access node configured to improve a bandwidth
utilization efficiency on a common downlink (DL) channel when
transmitting device-related information to a wireless device or a
group of wireless devices, the wireless access node comprising: a
processor; and, a memory that stores processor-executable
instructions, wherein the processor interfaces with the memory to
execute the processor-executable instructions, whereby the wireless
access node is operable to determine one or more transport block
formats to be utilized for transmitting the device-related
information on the common DL channel to the wireless device or the
group of wireless devices, wherein the one or more transport block
formats requiring a number of repeated transmissions of the
device-related information on the common DL channel to meet a
current coverage class of the wireless device or a coverage class
common to the group of wireless devices.
2. The wireless access node of claim 1, wherein the wireless access
node is further operable to: transmit a message including the
device-related information to the wireless device or the group of
wireless devices utilizing one of the one or more transport block
formats.
3. The wireless access node of claim 1, wherein a plurality of
transport block formats is determined to be utilized for
transmitting the device-related information on the common DL
channel to the group of wireless devices, and wherein the wireless
access node is further operable to: identify common information
included in the device-related information applicable to the group
of wireless devices, and transmit a message including the common
information to the group of wireless devices utilizing one of the
plurality of transport block formats that is decodable by the group
of wireless devices; and, identify device-specific information
included in the device-related information applicable to each
individual wireless device in the group of wireless devices, and
transmit individual messages including the device-specific
information to the respective individual wireless devices utilizing
more than one of the plurality of transport block formats that are
applicable to the respective individual wireless devices.
4. The wireless access node of claim 3, wherein the one of the
plurality of transport block formats utilized to transmit the
message including the common information to the group of wireless
devices is the same as at least one of the more than one of the
plurality of transport block formats utilized to transmit the
individual messages including the device-specific information to
the respective individual wireless devices.
5. The wireless access node of claim 3, wherein the wireless access
node, before transmitting the message including the common
information and before transmitting the individual messages
including the device-specific information, is further operable to:
add information in the message including the common information and
in each of the individual messages including the device-specific
information, wherein the added information enables each of the
individual wireless devices to uniquely identify the message
including the common information that corresponds to its respective
individual message including the device-specific information.
6. A method in a wireless access node for improving a bandwidth
utilization efficiency on a common downlink (DL) channel when
transmitting device-related information to a wireless device or a
group of wireless devices, the method comprising: determining one
or more transport block formats to be utilized for transmitting the
device-related information on the common DL channel to the wireless
device or the group of wireless devices, wherein the one or more
transport block formats requiring a number of repeated
transmissions of the device-related information on the common DL
channel to meet a current coverage class of the wireless device or
a coverage class common to the group of wireless devices.
7. The method of claim 6, further comprising: transmitting a
message including the device-related information to the wireless
device or the group of wireless devices utilizing one of the one or
more transport block formats.
8. The method of claim 6, wherein a plurality of transport block
formats is determined to be utilized for transmitting the
device-related information on the common DL channel to the group of
wireless devices, and the method further comprises: identifying
common information included in the device-related information
applicable to the group of wireless devices, and transmitting a
message including the common information to the group of wireless
devices utilizing one of the plurality of transport block formats
that is decodable by the group of wireless devices; and,
identifying device-specific information included in the
device-related information applicable to each individual wireless
device in the group of wireless devices, and transmitting
individual messages including the device-specific information to
the respective individual wireless devices utilizing more than one
of the plurality of transport block formats that are applicable to
the respective individual wireless devices.
9. The method of claim 8, wherein the one of the plurality of
transport block formats utilized to transmit the message including
the common information to the group of wireless devices is the same
as at least one of the more than one of the plurality of transport
block formats utilized to transmit the individual messages
including the device-specific information to the respective
individual wireless devices.
10. The method of claim 8, wherein before transmitting the message
including the common information and the individual messages
including the device-specific information, the method further
comprises: adding information in the message including the common
information and in each of the individual messages including the
device-specific information, wherein the added information enables
each of the individual wireless devices to uniquely identify the
message including the common information that corresponds to its
respective individual including containing the device-specific
information.
11. A wireless device configured to improve a bandwidth utilization
efficiency on a common downlink (DL) channel when receiving
device-related information from a wireless access node, the
wireless device comprising: a processor; and, a memory that stores
processor-executable instructions, wherein the processor interfaces
with the memory to execute the processor-executable instructions,
whereby the wireless device is operable to receive one or more
messages including the device-related information on the common DL
channel from the wireless access node, wherein the one or more
messages being received a repeated number of times on the common DL
channel as required by one or more transport block formats defined
to meet a current coverage class of the wireless device.
12. The wireless device of claim 11, wherein the wireless device is
further operable to: receive the device-related information
included in one of the one or more messages having one of the one
or more transport block formats.
13. The wireless device of claim 11, wherein a plurality of
messages including the device-related information is received,
wherein the plurality of messages has a plurality of transport
block formats, wherein the device-related information includes (1)
common information applicable to the wireless device and one or
more other wireless devices, and (2) device-specific information
applicable to the wireless device, and wherein the wireless device
is further operable to: receive the common information included in
one of the plurality of messages having one of the plurality of
transport block formats; and receive the device-specific
information included in another one of the plurality of messages
having one of the plurality of transport block formats.
14. The wireless device of claim 13, wherein the one of the
plurality of transport block formats utilized to transmit the one
of the plurality of messages including the common information is
the same as the one of the plurality of transport block formats
utilized to transmit the one of the plurality of messages including
the device-specific information.
15. The wireless device of claim 13, wherein the wireless device is
further operable to: identify information in the one of the
plurality of messages including the common information and the one
of the plurality of messages including the device-specific
information, where the identified information uniquely identifies
the one of the plurality of messages including the common
information that corresponds to the one of the plurality of
messages including the device-specific information.
16. A method in a wireless device for improving a bandwidth
utilization efficiency on a common downlink (DL) channel when
receiving device-related information from a wireless access node,
the method comprising: receiving one or more messages including the
device-related information on the common DL channel from the
wireless access node, wherein the one or more messages being
received a repeated number of times on the common DL channel as
required by one or more transport block formats defined to meet a
current coverage class of the wireless device.
17. The method of claim 16, further comprising: receiving the
device-related information included in one of the one or more
messages having one of the one or more transport block formats.
18. The method of claim 16, wherein a plurality of messages
including the device-related information is received, wherein the
plurality of messages has a plurality of transport block formats,
wherein the device-related information includes (1) common
information applicable to the wireless device and one or more other
wireless devices, and (2) device-specific information applicable to
the wireless device, and the method further comprises: receiving
the common information included in one of the plurality of messages
having one of the plurality of transport block formats; and
receiving the device-specific information included in another one
of the plurality of messages having one of the plurality of
transport block formats.
19. The method of claim 18, wherein the one of the plurality of
transport block formats utilized to transmit the one of the
plurality of messages including the common information is the same
as the one of the plurality of transport block formats utilized to
transmit the one of the plurality of messages including the
device-specific information.
20. The method of claim 18, further comprising: identifying
information in the one of the plurality of messages including the
common information and the one of the plurality of messages
including the device-specific information, where the identified
information uniquely identifies the one of the plurality of
messages including the common information that corresponds to the
one of the plurality of messages including the device-specific
information.
Description
CLAIM OF PRIORITY
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/837,268, filed on Dec. 11, 2017, issued on
May 7, 2019 as U.S. Pat. No. 10,285,198, which is a continuation of
U.S. patent application Ser. No. 14/809,987, filed on Jul. 27,
2015, issued on Dec. 12, 2017 as U.S. Pat. No. 9,844,074, which
claims the benefit of priority to Indian Application No.
2161/DEL/2014, filed on Jul. 31, 2014, and to U.S. Provisional
Application Ser. No. 62/050,517, filed on Sep. 15, 2014. The entire
contents of each of these applications are hereby incorporated by
reference for all purposes.
TECHNICAL FIELD
[0002] The present disclosure relates generally to common downlink
channels in wireless communication networks and, more particularly,
to techniques for increasing or maximizing channel capacity of a
common downlink channel by utilizing different transport block
formats in the common downlink channel to meet the coverage class
needs of a specific wireless device or a group of wireless
devices.
BACKGROUND
[0003] The following abbreviations and terms are herewith defined,
at least some of which are referred to within the following
description of the present disclosure. [0004] 3GPP 3rd-Generation
Partnership Project [0005] AGCH Access Grant Channel [0006] ASIC
Application Specific Integrated Circuit [0007] BCCH Broadcast
Control Channel [0008] BLER Block Error Rate [0009] BS Base Station
[0010] CC Coverage Class [0011] CCCH Common Control Channel [0012]
CN Core Network [0013] CRC Cyclic Redundancy Check [0014] CS Coding
Scheme [0015] DL Downlink [0016] DRX Discontinuous Reception [0017]
DSP Digital Signal Processor [0018] EDGE Enhanced Data rates for
GSM Evolution [0019] EGPRS Enhanced General Packet Radio Service
[0020] eNB evolved Node B [0021] ETWS Earthquake and Tsunami
Warning System [0022] E-UTRA Evolved Universal Terrestrial Radio
Access [0023] GSM Global System for Mobile Communications [0024]
GERAN GSM/EDGE Radio Access Network [0025] GMSK Gaussian Minimum
Shift Keying [0026] GPRS General Packet Radio Service [0027] HARQ
Hybrid Automatic Repeat Request [0028] LTE Long-Term Evolution
[0029] MTC Machine Type Communications [0030] MS Mobile Station
[0031] PCH Paging Channel [0032] PDN Packet Data Network [0033] PG
Paging Group [0034] P-TMSI Packet Temporary Mobile Station Identity
[0035] PTCCH/D Packet Timing Control Channel/Downlink [0036] RAN
Radio Access Node [0037] RACH Random Access Channel [0038] RLC
Radio Link Control [0039] TA Timing Advance [0040] TDMA Time
Division Multiple Access [0041] TMSI Temporary Mobile Station
Identity [0042] UE User Equipment [0043] UL Uplink [0044] UMTS
Universal Mobile Telecommunications System [0045] WCDMA Wideband
Code Division Multiple Access [0046] WiMAX Worldwide
Interoperability for Microwave Access
[0047] In existing wireless communication networks, the
communication between wireless devices and wireless access nodes in
the network are typically handled by the use of different logical
channels. Each logical channel has its own purpose(s) and is
typically mapped onto a physical channel following a certain frame
structure in time and frequency.
[0048] One type of logical channel on the downlink (DL) is one that
is monitored by a multiplicity of wireless devices, and is also
used for addressing a multiplicity (i.e., not necessarily all
wireless devices monitoring the channel, but at least a subset) of
wireless devices with a message sent by the wireless access node
using a single radio block transmitted on the channel. This type of
logical channel is referred to herein as a "common DL channel" and
could include, for example, in Global System for Mobile (GSM), the
Common Control Channel (CCCH).
[0049] In the existing wireless communication networks, the
wireless access node typically uses the same transport block format
(e.g., channel coding rate and error detection capability) for
transmitting a message on a common DL channel irrespective of the
type of wireless device or channel conditions applicable to any
given wireless device. In particular, the wireless access node uses
the same transport block format for each of the radio blocks used
to send a message on the common DL channel, where the transport
block format has a generic format that can be received by all of
the wireless devices that are addressed by the message.
[0050] For example, one possible system implementation of the
transport block format would be to have the wireless access node
choose a channel coding rate that is sufficiently robust to ensure
that all of the addressed wireless devices can correctly receive
the corresponding transmitted radio block (message) with a certain
minimum level of probability (i.e., regardless of the radio channel
conditions experienced by any of the addressed wireless devices).
In particular, to realize a sufficiently high probability of radio
block (message) reception by all of the addressed wireless devices,
the wireless access node may use a robust transmit block coding
rate in combination with repeated transmissions of that transport
radio block (message).
[0051] However, the wireless access node's configuration of the
transport block format according to a worst case scenario regarding
the channel conditions (for example) would typically result in a
waste of radio resources. This waste of radio resources could, for
example, occur when the wireless access node makes repeated
transmissions (i.e., multiple repetitions) of a message on a common
DL channel according to the number of repetitions that is needed by
the wireless device with the worst radio channel conditions that is
addressed by the message while many or all of the other wireless
devices addressed by the same message may, for example, only need a
single transmission. This waste of radio resources and other
shortcomings are addressed in the present disclosure.
SUMMARY
[0052] A wireless access node, a wireless device, and various
methods for addressing at least the aforementioned shortcoming and
other shortcomings are described in the independent claims.
Advantageous embodiments of the wireless access node, the wireless
device, and the various methods are further described in the
dependent claims.
[0053] In one aspect, the present disclosure provides a wireless
access node configured to improve a bandwidth utilization
efficiency on a common downlink (DL) channel when transmitting
device-related information to a wireless device or a group of
wireless devices. The wireless access node comprises a processor
and a memory that stores processor-executable instructions, wherein
the processor interfaces with the memory to execute the
processor-executable instructions, whereby the wireless access node
is operable to perform a determine operation. In the determine
operation, the wireless access node determines one or more
transport block formats to be utilized for transmitting the
device-related information on the common DL channel to the wireless
device or the group of wireless devices, wherein the one or more
transport block formats meet a coverage class need of the wireless
device or the group of wireless devices. The wireless access node,
by determining one or more transport block formats to be utilized
in this manner, has an advantage in that it helps to maximize the
use of radio resources when transmitting device-related information
on the common downlink DL channel to the wireless device or the
group of wireless devices.
[0054] In another aspect, the present disclosure provides a method
in a wireless access node for improving a bandwidth utilization
efficiency on a common downlink (DL) channel when transmitting
device-related information to a wireless device or a group of
wireless devices. The method comprises a determining step. In the
determining step, the wireless access node determines one or more
transport block formats to be utilized for transmitting the
device-related information on the common DL channel to the wireless
device or the group of wireless devices, wherein the one or more
transport block formats meet a coverage class need of the wireless
device or the group of wireless devices. The method has an
advantage in that it helps to maximize the use of radio resources
when transmitting device-related information on the common downlink
DL channel to the wireless device or the group of wireless
devices.
[0055] In yet another aspect, the present disclosure provides a
wireless device configured to improve a bandwidth utilization
efficiency on a common downlink (DL) channel when receiving
device-related information from a wireless access node. The
wireless device comprises a processor and a memory that stores
processor-executable instructions, wherein the processor interfaces
with the memory to execute the processor-executable instructions,
whereby the wireless device is operable to perform a receiving
operation. In the receiving operation, the wireless device receives
one or more messages including the device-related information on
the common DL channel from the wireless access node, wherein the
one or more messages have one or more transport block formats that
meet a coverage class need of the wireless device. The wireless
device, by adopting one or more transport block formats in this
manner, has an advantage in that it helps to maximize the use of
radio resources when receiving device-related information on the
common downlink DL channel from the wireless access node.
[0056] In still yet another aspect, the present disclosure provides
a method in a wireless device for improving a bandwidth utilization
efficiency on a common downlink (DL) channel when receiving
device-related information from a wireless access node. The method
comprises a receiving step. In the receiving step, the wireless
device receives one or more messages including the device-related
information on the common DL channel from the wireless access node,
wherein the one or more messages have one or more transport block
formats that meet a coverage class need of the wireless device. The
method has an advantage in that it helps to maximize the use of
radio resources when receiving device-related information on the
common downlink DL channel from the wireless access node.
[0057] Additional aspects of the invention will be set forth, in
part, in the detailed description, figures and any claims which
follow, and in part will be derived from the detailed description,
or can be learned by practice of the invention. It is to be
understood that both the foregoing general description and the
following detailed description are exemplary and explanatory only
and are not restrictive of the invention as disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0058] A more complete understanding of the present invention may
be obtained by reference to the following detailed description when
taken in conjunction with the accompanying drawings:
[0059] FIG. 1 is a diagram of an exemplary wireless communication
network in accordance with an embodiment of the present
disclosure;
[0060] FIG. 2 is a flowchart of a method implemented in a wireless
access node to improve a bandwidth utilization efficiency on a
common DL channel when transmitting device-related information to a
wireless device or a group of wireless devices in accordance with
an embodiment of the present disclosure;
[0061] FIG. 3 is a block diagram illustrating structures of an
exemplary wireless access node configured in accordance with an
embodiment of the present disclosure;
[0062] FIG. 4 is a flowchart of a method implemented in a wireless
device to improve a bandwidth utilization efficiency on a common DL
channel when receiving device-related information from a wireless
access node in accordance with an embodiment of the present
disclosure;
[0063] FIG. 5 is a block diagram illustrating structures of an
exemplary wireless device configured in accordance with an
embodiment of the present disclosure; and,
[0064] FIG. 6 is a graph illustrating the simulation results of a
performance of a four burst radio block carrying 184 information
bits compared to a one burst radio block carrying different amounts
of information bits.
DETAILED DESCRIPTION
[0065] To describe the technical features of the present
disclosure, a discussion is provided first to describe an exemplary
wireless communication network which includes multiple wireless
access nodes and multiple wireless devices, each of which are
configured in accordance with the present disclosure (illustrated
in FIG. 1). Then, a discussion is provided to explain in more
detail how the wireless access node and the wireless device each
implement the technical features of the present disclosure
(illustrated in FIGS. 2-5). Finally, a discussion is provided to
explain the technical features of the present disclosure when
applied to a GSM wireless communication network (illustrated in
FIG. 6).
Exemplary Wireless Communication Network 100
[0066] Referring to FIG. 1, there is illustrated an exemplary
wireless communication network 100 in accordance with the present
disclosure. The wireless communication network 100 includes
multiple wireless access nodes 102.sub.1 and 102.sub.2 (only two
shown), multiple wireless devices 104.sub.1, 104.sub.2, 104.sub.3,
104.sub.4. . . 104.sub.n, and a core network 106 (e.g., EGPRS core
network 106). The wireless communication network 100 includes many
other well-known components, but for clarity, only the components
needed to describe the technical features of the present disclosure
are described herein. Further, the wireless communication network
100 is described herein as being an GSM/EGPRS wireless
communication network 100 which is also known as an EDGE wireless
communication network 100. However, those skilled in the art will
readily appreciate that the techniques of the present disclosure,
which are applied to the GSM/EGPRS wireless communication network
100, are generally applicable to other types of wireless
communication systems, including, for example, WCDMA, LTE, and
WiMAX systems.
[0067] The wireless communication network 100 includes the wireless
access nodes 102.sub.1 and 102.sub.2 (only two shown) which provide
network access to the wireless devices 104.sub.1, 104.sub.2,
104.sub.3, 104.sub.4. . . 104.sub.n. In this example, the wireless
access node 102.sub.1 is providing network access to wireless
device 1041 while the wireless access node 102.sub.2 is providing
network access to wireless devices 104.sub.2, 104.sub.3, 104.sub.4.
. . 104.sub.n. The wireless access nodes 102.sub.1 and 102.sub.2
are connected to the core network 106 (e.g., EGPRS core network
106). The core network 106 is connected to an external packet data
network (PDN) 108, such as the Internet, and a server 110 (only one
shown). The wireless devices 104.sub.1, 104.sub.2, 104.sub.3,
104.sub.4. . . 104n may communicate with one or more servers 110
(only one shown) connected to the core network 106 or the PDN
108.
[0068] The wireless devices 104.sub.1, 104.sub.2, 104.sub.3,
104.sub.4. . . 104n may refer generally to an end terminal (user)
that attaches to the wireless communication network 100, and may
refer to either a MTC device or a non-MTC device. Further, the term
"wireless device" is generally intended to be synonymous with the
term "User Equipment," or UE, as that term is used by the
3rd-Generation Partnership Project (3GPP), and includes standalone
wireless devices, such as terminals, cell phones, smart phones,
tablets, and wireless-equipped personal digital assistants, as well
as wireless cards or modules that are designed for attachment to or
insertion into another electronic device, such as a personal
computer, electrical meter, etc.
[0069] Likewise, the wireless access nodes 102.sub.1 and 102.sub.2
may refer in general to a base station or central node in the
wireless communication network 100, and may refer to wireless
access nodes 102.sub.1 and 102.sub.2 that are controlled by a
physically distinct radio network controller as well as to more
autonomous access points, such as the so-called evolved Node Bs
(eNBs or eNodeBs) in Long-Term Evolution (LTE) networks.
Accordingly, the term "wireless access node" may also refer to
Radio Network Controllers (RNCs) and Node Bs (NBs) in 3G, or Base
Station Controllers (BSCs) or Base Transceiver Stations (BTSs) in
2G.
[0070] Each wireless device 104.sub.1, 104.sub.2, 104.sub.3,
104.sub.4. . . 104n may include a transceiver circuit 110.sub.1,
110.sub.2, 110.sub.3, 110.sub.4. . . 110n for communicating with
the wireless access nodes 102.sub.1 and 102.sub.2, and a processing
circuit 112.sub.1, 112.sub.2, 112.sub.3, 112.sub.4. . . 112n for
processing signals transmitted from and received by the transceiver
circuit 110.sub.1, 110.sub.2, 110.sub.3, 110.sub.4. . . 110n and
for controlling the operation of the corresponding wireless device
104.sub.1, 104.sub.2, 104.sub.3, 104.sub.4. . . 104.sub.n. The
transceiver circuit 110.sub.1, 110.sub.2, 110.sub.3, 110.sub.4. . .
110n may include a transmitter 114.sub.1, 114.sub.2, 114.sub.3,
114.sub.4. . . 114n and a receiver 116.sub.1, 116.sub.2, 116.sub.3,
116.sub.4. . . 116.sub.n, which may operate according to any
standard, e.g., the GSM/EDGE standard. The processing circuit
112.sub.1, 112.sub.2, 112.sub.3, 112.sub.4. . . 112n may include a
processor 118.sub.1, 118.sub.2, 118.sub.3, 118.sub.4. . . 118.sub.n
and a memory 120.sub.1, 120.sub.2, 120.sub.3, 120.sub.4. . .
120.sub.n for storing program code for controlling the operation of
the corresponding wireless device 104.sub.1, 104.sub.2, 104.sub.3,
104.sub.4. . . 104.sub.n. The program code may include code for
performing the procedures (e.g., identifying a transport block
format of multiple transport block formats included in a common
downlink channel; determining values for properties of a transport
block format; receiving information common to multiple wireless
devices; receiving device-specific information; and identifying,
from a transport block format, information allowing unique
identification of common information corresponding to
device-specific information) as described hereinafter.
[0071] Each wireless access node 102.sub.1 and 102.sub.2 may
include a transceiver circuit 122.sub.1 and 122.sub.2 for
communicating with wireless devices 104.sub.1, 104.sub.2,
104.sub.3, 104.sub.4. . . 104.sub.n, a processing circuit 124.sub.1
and 124.sub.2 for processing signals transmitted from and received
by the transceiver circuit 122.sub.1 and 122.sub.2 and for
controlling the operation of the corresponding wireless access node
102.sub.1 and 102.sub.2, and a network interface 126.sub.1 and
126.sub.2 for communicating with the core network 106 (e.g., via
core network nodes such as Serving GPRS Support Nodes (SGSNs) in
GPRS or Mobility Management Entity (MMEs) in LTE). The transceiver
circuit 122.sub.1 and 122.sub.2 may include a transmitter 128.sub.1
and 128.sub.2 and a receiver 130.sub.1 and 130.sub.2, which may
operate according to any standard, e.g., the GSM/EDGE standard. The
processing circuit 124.sub.1 and 124.sub.2 may include a processor
132.sub.1 and 132.sub.2 and a memory 134.sub.1 and 134.sub.2 for
storing program code for controlling the operation of the
corresponding wireless access node 102.sub.1 and 102.sub.2. The
program code may include code for performing the procedures (e.g.,
determining coverage class for one or more wireless devices;
determining respective values for properties of different transport
block formats; determining different transport block formats for
including in a common downlink channel; formatting a common
downlink channel to include different transport block formats;
identifying/extracting/sending information common to multiple
wireless devices; identifying/extracting/sending wireless
device-specific information; adding to or formatting transport
block formats to include information that allows each of multiple
wireless devices to uniquely identify which common information
corresponds to its device-specific information; and determining a
number of repetitions for transmitting information to a particular
wireless device or group of wireless devices) as described
hereinafter.
Technical Features of Present Disclosure
[0072] In the present disclosure, a scenario of interest is where N
wireless devices 104.sub.2, 104.sub.3, 104.sub.4(for example) are
performing procedures during which they are attempting to read
information (e.g., messages) on the DL of a common DL channel
within the same time interval. It is proposed herein for the
wireless access node 102.sub.2 (for example) to determine and
utilize/adopt different transport block formats in a common DL
control channel to meet the coverage class need of each specific
user (e.g., wireless device 104.sub.2) or a group of users (e.g.,
wireless devices 104.sub.3 and 104.sub.4with the same coverage
class) attempting to read messages on the common DL control channel
utilizing the determined different transport block formats, thereby
improving bandwidth utilization efficiency on the common DL control
channel when compared to the case where the wireless access node
simply assumes the wireless devices are in the worst coverage class
when utilizing/adopting transport block formats.
[0073] The term "transport block format" used herein refers to the
way in which device-related information (e.g., messages) in the
common DL channel is transmitted including, but not limited to:
[0074] the number of payload bits (i.e., message information bits)
per transport block; [0075] transport block modulation type; [0076]
transport block coding rate, which affects the number of payload
bits per transport block; [0077] time duration of the transport
block (i.e., time interval spanned by the transmitted block); and
[0078] if repetitions are used to achieve a lower transport block
coding rate (i.e., allowing more payload bits per transport block),
the number of transport block repetitions of a pre-defined
format.
[0079] The term "coverage class" as used herein can be defined as
follows: The coverage class of any given wireless device is
essentially a measure of its current radio environment such that a
wireless device in the worst coverage class supported by the
network will need to make use of the most robust transport block
format to help ensure that the wireless device remains operational.
Conversely, wireless devices in the best coverage class will remain
operational when the least robust transport block format is used.
Additional transport block formats can be used for wireless devices
that experience radio conditions worse than those of wireless
devices in the best coverage class. At any point in time a wireless
device belongs to a specific coverage class which determines the
total number of blind transmissions to be used when receiving radio
blocks. A coverage class applicable at any point in time can differ
between different logical channels. Upon initiating a system
access, a wireless access node determines the coverage class
applicable to the RACH/AGCH based on estimating the number of blind
repetitions of a radio block needed by the wireless device's
receiver to experience a BLER (block error rate) of approximately
10%. The wireless access node determines the coverage class to be
used by a wireless device on its assigned packet channel resources
based on estimating the number of blind repetitions of a radio
block needed to satisfy a target BLER and considering the number of
HARQ retransmissions (of a radio block) that will, on average,
result from using that target BLER.
[0080] Furthermore, in accordance with an alternative technical
feature of the present disclosure, if a message normally sent on
the common DL channel includes information common to a multiplicity
of the wireless devices 104.sub.3 and 104.sub.4(for example)
monitoring that channel and addressed by that same message, it is
proposed that the following alternative approach can be used by the
wireless access node 102.sub.2 (for example) for delivering the
message content to the group of wireless devices 104.sub.3 and
104.sub.4(for example): [0081] extract the common information 213
that is applicable to the group of wireless devices 104.sub.3 and
104.sub.4(for example) from the device-related information 209 and
transmit the common information 213 included in a message 215 using
a transport block format that all of the addressed wireless devices
104.sub.3 and 104.sub.4(for example) can decode; [0082] extract the
device-specific information 217a and 217b from the device-related
information 209 and transmit the device-specific information 217a
and 217b included in messages 219a and 219b respectively using a
transport block format applicable to that respective wireless
device 104.sub.3 or 104.sub.4(for example) alone; and [0083]
include information 221 in each transport block (message 219a and
219b ) including the device-specific information 217a and 217b and
in the transport block(s) (messages(s) 215) including the common
information 213 that allows each wireless device 104.sub.3 and
104.sub.4(for example) to uniquely identify the transport block(s)
(message(s) 215) including the common information 213 that
corresponds to the transport block (message 219a and 219b )
including its device-specific information.
[0084] Using this alternative technical feature of sending
information to N wireless devices 104.sub.3 and 104.sub.4(for
example) on a common DL channel allows for the use of fewer radio
resources when compared to what would be required without such a
separation of device-related information.
[0085] The following are some advantages associated with using the
first technical feature (one embodiment) and the alternative
technical feature (alternative embodiment) of the present
disclosure: [0086] Efficient usage of common DL channel in the
wireless communication network 100. [0087] Increased number of
wireless devices addressable by the same common DL channel per unit
of time. [0088] Ensuring a Block Error Rate (BLER) performance
similar to that of a legacy coding scheme CS-1 coded radio block
for information received using the new transport block formats.
[0089] Improved wireless device power saving when receiving
information addressed to the wireless device on the common DL
channel. [0090] The technical features of the present disclosure
help to exploit these advantages in various ways, as described in
the following examples: [0091] (a) Optimum resource utilization: as
each instance of information transmission consumes some available
radio resources (e.g., time slot and frequency), transmitting the
needed information using more radio resources than necessary is a
waste of these scarce radio resources. As such, transmitting the
needed information using device-appropriate transport blocks
(messages) per the present disclosure is a preferred way of
information transmission. This can be realized, for example, by
introducing transport blocks (messages) that have a reduced number
of information (i.e., payload) bits per burst compared to legacy
operation, wherein for legacy operation the number of information
bits per burst is determined based on the assumption that multiple
instances of these bursts will be repeated and potentially include
information addressing multiple devices. If transport blocks
(messages) are instead realized using a single burst (which may be
sufficient for cases where a small volume of payload information
needs to be sent to a given wireless device) with the intent of the
information carried therein only addressing a single wireless
device, then better common DL control channel resource usage and
capacity improvement becomes possible. This will be especially true
for systems where transport block (message) repetitions will range
from a single repetition for wireless devices in the best coverage
class to X repetitions (e.g., 16) for wireless devices in the worst
coverage class. [0092] (b) Wireless device power saving: the
disclosed techniques provide a clear advantage of wireless device
power saving. For receiving a transport block in GSM, which is
referred to as a radio block and transmitted over four bursts
(spread over four Time Division Multiple Access (TDMA) frames, each
consisting of eight timeslots), a wireless device will typically
consume: V.sub.cc*I.sub.avg*T=(3.3 V) * (50,000 .mu.A) * (4*577
.mu.s)+(3.3V)*(1000 .mu.A) * (28*577 .mu.s)=434.13 .mu.J. Whereas,
for receiving a transport block that is transmitted over a single
burst, a wireless device will typically consume:
V.sub.cc*I.sub.avg*T=(3.3 V) * (50,000 .mu.A) * (1*577 .mu.s)=95.2
.mu.J. Thus, the power saving ratio per transport block will be
approximately 4:1.
[0093] The term "radio block" is used herein and can be defined as
follows: a message is sent using one or more radio blocks where
each radio block may be transmitted using multiple repetitions at
the physical layer (e.g., a legacy RLC data block is a radio block
sent using four bursts). One or more radio blocks are used to send
a message where each radio block in the set makes use of the same
transport block format (e.g. same modulation scheme, same channel
coding scheme, and the same number of repetitions per radio block).
The radio resources are shared but are typically used to send a
message to one wireless device at a time by including unique
information in each radio block header to indicate the intended
wireless device. However, the concept of group messaging also
exists where information in each radio block header indicates the
group of wireless devices for which the message is intended. The
case where several messages (each message sent using a set of one
or more radio blocks) are addressed to different wireless devices
using the group messaging concept is possible but is not very
typical, i.e., the more typical concept involves sending a single
message to a single wireless device or to a group of wireless
devices using a corresponding set of radio blocks.
[0094] Referring to FIG. 2, there is a flowchart of a method 200
implemented in a wireless access node 102.sub.2 (for example) for
improving a bandwidth utilization efficiency on a common DL channel
when transmitting device-related information to a wireless device
104.sub.2 (for example) or a group of wireless devices 104.sub.3
and 104.sub.4(for example) in accordance with an embodiment of the
present disclosure. At step 202, the wireless access node 102.sub.2
determines one or more transport block formats to be utilized for
transmitting the device-related information on the common DL
channel to the wireless device 104.sub.2 or the group of wireless
devices 104.sub.3 and 104.sub.4, wherein the one or more transport
block formats meet a coverage class need of the wireless device
104.sub.2 or the group of wireless devices 104.sub.3 and
104.sub.4(e.g., the wireless devices 104.sub.3 and 104.sub.4 have
the same coverage class).
[0095] In one embodiment, the wireless access node 102.sub.2 has
device-related information 205 for the wireless device 1042. In
this case, the wireless access node 102.sub.2 at step 204 transmits
a message 207 including the device-related information 205 to the
wireless device 104.sub.2 utilizing one of the one or more
transport block formats specifically determined based at least in
part on the coverage class need of the wireless device 104.sub.2
(illustrated in FIG. 1). As an example, if the wireless device
104.sub.2 has a coverage class of "1" then the wireless access node
102.sub.2 would determine a transport block format to be utilized
specifically for the wireless device 104.sub.2 that has a specific
number of payload bits, modulation type, coding rate, time duration
etc . . . and no repetitions based at least in part on the coverage
class "1" (e.g., the coverage class "1" corresponds to an initial
transmission and no repetitions). The wireless access node
102.sub.2 then transmits the message 207 including the
device-related information 205 to the wireless device 104.sub.2
utilizing the determined transport block format (illustrated in
FIG. 1).
[0096] In the same embodiment, the wireless access node 102.sub.2
has device-related information 209 for the group of wireless
devices 104.sub.3 and 104.sub.4. In this case, the wireless access
node 102.sub.2 at step 204 transmits a message 211 including the
device-related information 209 to the group of wireless devices
104.sub.3 and 104.sub.4 utilizing one of the one or more transport
block formats specifically determined based at least in part on the
coverage class need of the group of wireless devices 1043 and
104.sub.4 (illustrated in FIG. 1). As an example, if the group of
wireless devices 104.sub.3 and 104.sub.4 have a coverage class of
"2" then the wireless access node 102.sub.2 would determine a
transport block format to be utilized specifically for the the
group of wireless devices 104.sub.3 and 104.sub.4 that has a
specific number of payload bits, modulation type, coding rate, time
duration etc . . . and one repetition based at least in part on the
coverage class "2" (e.g., the coverage class "2" corresponds to an
initial transmission and one repetition). The wireless access node
102.sub.2 then transmits the message 211 including the
device-related information 209 to the group of wireless devices
104.sub.3 and 104.sub.4 utilizing the determined transport block
format (illustrated in FIG. 1).
[0097] In an alternative embodiment, the wireless access node
102.sub.2 has device-related information 209 for the group of
wireless devices 104.sub.3 and 104.sub.4, and the wireless access
node 102.sub.2 instead of performing step 204 could perform steps
206, 208, 210, 212 and 214. More specifically, in this alternative
embodiment, the wireless access node 102.sub.2 at step 202
determines a plurality of transport block formats to be utilized
for transmitting the device-related information 209 on the common
DL channel to the group of wireless devices 104.sub.3 and
104.sub.4. The wireless access node 102.sub.2 at step 206 would
identify common information 213 included in the device-related
information 209 applicable to the group of wireless devices
104.sub.3 and 104.sub.4, and transmit at step 208 a message 215
including the common information 213 to the group of wireless
devices 104.sub.3 and 104.sub.4 utilizing one of the plurality of
transport block formats that is decodable by the group of wireless
devices 104.sub.3 and 104.sub.4 (illustrated in FIG. 1). Further,
the wireless access node 102.sub.2 would identify at step 210
device-specific information 217a and 217b included in the
device-related information 209 applicable to each individual
wireless device 104.sub.3 and 104.sub.4 in the group of wireless
devices 104.sub.3 and 104.sub.4, and transmit at step 212
individual messages 219a and 219b including the device-specific
information 217a and 217b to the respective individual wireless
devices 104.sub.3 and 104.sub.4 utilizing more than one of the
plurality of transport block formats that are applicable to the
respective individual wireless devices 104.sub.3 and 104.sub.4
(illustrated in FIG. 1). It is to be noted that the transport block
format utilized to transmit the message 215 including the common
information 213 to the group of wireless devices 104.sub.3 and
104.sub.4 can be the same as or different from at least one of the
transport block formats utilized to transmit the individual
messages 219a and 219b including the device-specific information
217a and 217b to the respective individual wireless devices
104.sub.3 and 104.sub.4. If desired, the wireless access node
102.sub.2 at step 214 can add information 221 in the message 215
including the common information 213 and in each of the individual
messages 219a and 219b including the device-specific information
217a and 217b that enables each of the individual wireless devices
104.sub.3 and 104.sub.4 to uniquely identify the message 215
including the common information 213 that corresponds to its
respective individual message 219a and 219b including the
device-specific information 217a and 217b.
[0098] As an example, if the wireless devices 104.sub.3 and
104.sub.4 each have a coverage class of "2" then the wireless
access node 102.sub.2 would determine a transport block format to
be utilized specifically for the wireless devices 104.sub.3 and
104.sub.4 that has a specific number of payload bits for the common
information 213, modulation type, coding rate, time duration etc .
. . and one repetition based at least in part on the coverage class
"2" (e.g., the coverage class "2" corresponds to an initial
transmission and one repetition). In addition, the wireless access
node 102.sub.2 would determine a transport block format to be
utilized specifically for the wireless device 104.sub.3 that has a
specific number of payload bits for the device-specific information
217a, modulation type, coding rate, time duration etc . . . and one
repetition based at least in part on the coverage class "2". Plus,
the wireless access node 102.sub.2 would determine a transport
block format to be utilized specifically for the wireless device
104.sub.4 that has a specific number of payload bits for the
device-specific information 217b, modulation type, coding rate,
time duration etc . . . and one repetition based at least in part
on the coverage class "2". The wireless access node 102.sub.2 then
transmits the message 215 including the common information 213
(possibly including the added information 221) to the wireless
devices 104.sub.3 and 104.sub.4 utilizing the specially determined
transport block format (illustrated in FIG. 1). Plus, the wireless
access node 102.sub.2 would transmit the message 219a including the
device-specific information 217a (possibly including the added
information 221) to the wireless device 104.sub.3 utilizing the
specially determined transport block format (illustrated in FIG.
1). It is to be noted that the transport block formats used to
transmit the messages 215 and 219a can be the same or different.
Finally, the wireless access node 102.sub.2 would transmit the
message 219b including the device-specific information 217b
(possibly including the added information 221) to the wireless
device 104.sub.4 utilizing the specially determined transport block
format (illustrated in FIG. 1). It is to be noted that the
transport block formats used to transmit the messages 215 and 219b
can be the same or different.
[0099] Referring to FIG. 3, there is a block diagram illustrating
structures of an exemplary wireless access node 102.sub.2 (for
example) for improving a bandwidth utilization efficiency on a
common DL channel when transmitting device-related information to a
wireless device 104.sub.2 (for example) or a group of wireless
devices 104.sub.3 and 104.sub.4 (for example) in accordance with an
embodiment of the present disclosure. The wireless access node
102.sub.2 may comprise a determine module 302, a first transmit
module 304, a first identify module 306, a second transmit module
308, a second identify module 310, a third transmit module 312, and
an add module 314. The determine module 302 is configured to
determine one or more transport block formats to be utilized for
transmitting the device-related information on the common DL
channel to the wireless device 104.sub.2 or the group of wireless
devices 104.sub.3 and 104.sub.4, wherein the one or more transport
block formats meet a coverage class need of the wireless device
104.sub.2 or the group of wireless devices 104.sub.3 and 104.sub.4.
In one embodiment, if the wireless access node 102.sub.2 has
device-related information 205 for the wireless device 104.sub.2,
then the first transmit module 304 is configured to transmit a
message 207 including the device-related information 205 to the
wireless device 104.sub.2 utilizing one of the one or more
transport block formats specifically determined based at least in
part on the coverage class need of the wireless device 1042
(illustrated in FIG. 1). In the same embodiment, if the wireless
access node 102.sub.2 has device-related information 209 for the
group of wireless devices 104.sub.3 and 104.sub.4 (e.g., having the
same coverage class), then the first transmit module 304 is
configured to transmit a message 211 including the device-related
information 209 to the group of wireless devices 104.sub.3 and
104.sub.4 utilizing one of the one or more transport block formats
specifically determined based at least in part on the coverage
class need of the group of wireless devices 104.sub.3 and 104.sub.4
(illustrated in FIG. 1).
[0100] The determine module 302 may determine a plurality of
transport block formats to be utilized for transmitting the
device-related information 209 on the common DL channel to the
group of wireless devices 104.sub.3 and 104.sub.4. In an
alternative embodiment, if the wireless access node 102.sub.2 has
device-related information 209 for the group of wireless
devices104.sub.3 and 104.sub.4, then the first identify module 306
is configured to identify common information 213 included in the
device-related information 209 for the group of wireless devices
104.sub.3 and 104.sub.4, and the second transmit module 308 is
configured to transmit a message 215 including the common
information 213 to the group of wireless devices 104.sub.3 and
104.sub.4 utilizing one of the plurality of transport block formats
that is decodable by the group of wireless devices 104.sub.3 and
104.sub.4 (illustrated in FIG. 1). Further, the second identify
module 310 is configured to identify device-specific information
217a and 217b included in the device-related information 209
applicable to each individual wireless device 104.sub.3 and
104.sub.4 in the group of wireless devices 104.sub.3 and 104.sub.4,
and the third transmit module 312 is configured to transmit
individual messages 219a and 219b including the device-specific
information 217a and 217b to the respective individual wireless
devices 104.sub.3 and 104.sub.4 utilizing more than one of the
plurality of transport block formats that are applicable to the
respective individual wireless devices 104.sub.3 and 104.sub.4
(illustrated in FIG. 1). It is to be noted that the transport block
format utilized to transmit the message 215 including the common
information 213 to the group of wireless devices 104.sub.3 and
104.sub.4 can be the same as or different from the transport block
formats utilized to transmit the individual messages 219a and 219b
including the device-specific information 217a and 217b to the
respective individual wireless devices 104.sub.3 and 104.sub.4. The
add module 314 is configured to add information 221 in the message
215 including the common information 213 and in each of the
individual messages 219a and 219b including the device-specific
information 217a and 217b that enables each of the individual
wireless devices 104.sub.3 and 104.sub.4 to uniquely identify the
message 215 including the common information 213 that corresponds
to its respective individual message 219a and 219b including the
device-specific information 217a and 217b.
[0101] As those skilled in the art will appreciate, the
above-described modules 302, 304, 306, 308, 310, 312, and 314 of
the wireless access node 102.sub.2 may be implemented separately as
suitable dedicated circuits. Further, the modules 302, 304, 306,
308, 310, 312, and 314 can also be implemented using any number of
dedicated circuits through functional combination or separation. In
some embodiments, the modules 302, 304, 306, 308, 310, 312, and 314
may be even combined in a single application specific integrated
circuit (ASIC). As an alternative software-based implementation,
the wireless access node 102.sub.2 may comprise a memory 134.sub.2,
a processor 132.sub.2 (including but not limited to a
microprocessor, a microcontroller or a Digital Signal Processor
(DSP), etc.) and a transmitter128.sub.2. The memory 1342 stores
machine-readable program code executable by the processor 132.sub.2
that cause the wireless access node 102.sub.2 to perform the steps
of the above-described method 200. It is to be noted that the
wireless access nodes 102.sub.1 and 102.sub.2 and other wireless
access nodes can be configured to implement the above-described
method 200.
[0102] Referring to FIG. 4, there is a flowchart of a method 400
implemented in a wireless device 104.sub.2, 104.sub.3 or 104.sub.4
(for example) for improving a bandwidth utilization efficiency on a
common DL channel when receiving device-related information from a
wireless access node 102.sub.2 (for example) in accordance with an
embodiment of the present disclosure. At step 402, the wireless
device 104.sub.2, 104.sub.3 or 104.sub.4 receives one or more
messages 207, 211, 215, 219a and 219b including the device-related
information on the common DL channel from the wireless access node
102.sub.2, wherein the one or more messages 207, 211, 215, 219a and
219b have one or more transport block formats that meet a coverage
class need of the wireless device 104.sub.2, 104.sub.3 or
104.sub.4. In one embodiment, the wireless device 104.sub.2
receives at step 402a the device-related information 205 included
in message 207 having one transport block format based at least in
part on the coverage class of the wireless device 1042. In the same
embodiment, the wireless device 104.sub.3 receives at step 402a the
device-related information 209 included in message 211 having one
transport block format based at least in part on the coverage class
of the wireless device 104.sub.3.
[0103] At step 402, the wireless device 104.sub.2, 104.sub.3 or
104.sub.4 may receive a plurality of messages including the
device-related information, wherein the plurality of messages has a
plurality of transport block formats. In an alternative embodiment,
the wireless device 104.sub.3 receives at step 402b the common
information 213 included in message 215 having one of the plurality
of transport block formats based at least in part on the coverage
class of the wireless device 104.sub.3. In addition, the wireless
device 104.sub.3 receives at step 402c the device-specific
information 217a included in message 219a having one of the
plurality of transport block formats based at least in part on the
coverage class of the wireless device 1043. It is to be noted that
the transport block formats used for messages 215 and 219a can be
the same or different. Plus, the wireless device 104.sub.3 at step
402d identifies information 221 in the message 215 including the
common information 213 and the message 219a including the
device-specific information 217a that enables the wireless device
104.sub.3 to uniquely identify the message 215 including the common
information 213 that corresponds to the message 219a including the
device-specific information 217a. In one embodiment, the wireless
devices 104.sub.4 receives at step 402a the device-related
information 209 included in message 211 having one transport block
format based at least in part on the coverage class of the wireless
device 104.sub.4. In an alternative embodiment, the wireless device
104.sub.4 receives at step 402b the common information 213 included
in message 215 having one of the plurality of transport block
formats based at least in part on the coverage class of the
wireless device 104.sub.4. In addition, the wireless device
104.sub.4 receives at step 402c the device-specific information
217b included in message 219b having one of the plurality of
transport block formats based at least in part on the coverage
class of the wireless device 104.sub.4. It is to be noted that the
transport block formats used for messages 215 and 219b can be the
same or different. Plus, the wireless device 104.sub.4 at step 402d
identifies information 221 in the message 215 including the common
information 213 and the message 219b including the device-specific
information 217b that enables the wireless device 104.sub.4 to
uniquely identify the message 215 including the common information
213 that corresponds to the message 219b including the
device-specific information 217b.
[0104] Referring to FIG. 5, there is a block diagram illustrating
structures of an exemplary wireless device 104.sub.2, 104.sub.3 or
104.sub.4 (for example) for improving a bandwidth utilization
efficiency on a common DL channel when receiving device-related
information from the wireless access node 102.sub.2 (for example)
in accordance with an embodiment of the present disclosure. The
wireless device 104.sub.2, 104.sub.3 or 104.sub.4 (for example) may
comprise a receive module 502, a first receive module 502a, a
second receive module 502b, a third receive module 502c, and an
identify module 502d. The receive module 502 is configured to
receive one or more messages 207, 211, 215, 219a and 219b including
the device-related information on the common DL channel from the
wireless access node 102.sub.2, wherein the one or more messages
207, 211, 215, 219a and 219b have one or more transport block
formats that meet a coverage class need of the wireless device
104.sub.2, 104.sub.3 or 104.sub.4. In one embodiment, the wireless
device 104.sub.2 comprises the first receive module 502a that is
configured to receive the device-related information 205 included
in message 207 having one transport block format based at least in
part on the coverage class of the wireless device 104.sub.2. In one
embodiment, the wireless device 104.sub.3 comprises the first
receive module 502a that is configured to receive the
device-related information 209 included in message 211 having one
transport block format based at least in part on the coverage class
of the wireless device 104.sub.3.
[0105] The receive module 502 may receive a plurality of messages
including the device-related information, wherein the plurality of
messages has a plurality of transport block formats. In an
alternative embodiment, the wireless device 104.sub.3 comprises the
second receive module 502b that is configured to receive the common
information 213 included in message 215 having one of the plurality
of transport block formats based at least in part on the coverage
class of the wireless device 104.sub.3. In addition, the wireless
device 104.sub.3 comprises the third receive module 502c that is
configured to receive the device-specific information 217a included
in message 219a having one of the plurality of transport block
formats based at least in part on the coverage class of the
wireless device 104.sub.3. It is to be noted that the transport
block formats used for messages 215 and 219a can be the same or
different. Plus, the wireless device 104.sub.3 comprises the
identify module 502d that is configured to identify information 221
in the message 215 including the common information 213 and the
message 219a including the device-specific information 217a that
enables the wireless device 104.sub.3 to uniquely identify the
message 215 including the common information 213 that corresponds
to the message 219a including the device-specific information
217a.
[0106] In one embodiment, the wireless device 104.sub.4 comprises
the first receive module 502a that is configured to receive the
device-related information 209 included in message 211 having one
transport block format based at least in part on the coverage class
of the wireless device 1043. In an alternative embodiment, the
wireless device 104.sub.4 comprises the second receive module 502b
that is configured to receive the common information 213 included
in message 215 having one of the plurality of transport block
formats based at least in part on the coverage class of the
wireless device 104.sub.4. In addition, the wireless device
104.sub.4 comprises the third receive module 502c that is
configured to receive the device-specific information 217b included
in message 219b having one of the plurality of transport block
formats based at least in part on the coverage class of the
wireless device 104.sub.4. It is to be noted that the transport
block formats used for messages 215 and 219b can be the same or
different. Plus, the wireless device 104.sub.4 comprises the
identify module 502d that is configured to identify information 221
in the message 215 including the common information 213 and the
message 219b including the device-specific information 217b that
enables the wireless device 104.sub.4 to uniquely identify the
message 215 including the common information 213 that corresponds
to the message 219b including the device-specific information
217b.
[0107] As those skilled in the art will appreciate, the
above-described modules 502, 502a, 502b, 502c and 502d of the
wireless device 104.sub.2, 104.sub.3 or 104.sub.4 (for example) may
be implemented separately as suitable dedicated circuits. Further,
the modules 502, 502a, 502b, 502c and 502d can also be implemented
using any number of dedicated circuits through functional
combination or separation. In some embodiments, the modules 502,
502a, 502b, 502c and 502d may be even combined in a single
application specific integrated circuit (ASIC). As an alternative
software-based implementation, the wireless device 104.sub.2,
104.sub.3 or 104.sub.4 (for example) may comprise a memory
120.sub.2, 120.sub.3 and 120.sub.4, a processor 118.sub.2,
118.sub.3 and 118.sub.4 (including but not limited to a
microprocessor, a microcontroller or a Digital Signal Processor
(DSP), etc.) and receiver 116.sub.2, 116.sub.3 and 116.sub.4. The
memory 120.sub.2, 120.sub.3 and 120.sub.4 stores machine-readable
program code executable by the processor 118.sub.2, 118.sub.3 and
118.sub.4 that cause the wireless device 104.sub.2, 104.sub.3 or
104.sub.4 (for example) to perform the steps of the above-described
method 400. It is to be noted that the wireless devices 104.sub.1,
104.sub.2, 104.sub.3, 104.sub.4. . . 104n and other wireless
devices can be configured to implement the above-described method
400.
Application to GSM Wireless Communication Network
1. Paging Channel (PCH)
[0108] In one embodiment, the above techniques are applied to the
GSM wireless communication network and the PCH channel, part of the
CCCH in the DL. The current PCH can at most carry paging-related
information to four wireless devices addressed within a PCH
message. The default transport block format used by GSM today for
sending PCH messages is known as a radio block, containing 23
octets of payload space (mapped into 456 bits after cyclic
redundancy check (CRC) addition and encoding). A radio block
consists of four normal bursts, each occupying one timeslot in the
TDMA frame structure in GSM. Furthermore, the transport block
format consists of using Gaussian Minimum Shift Keying (GMSK)
modulation and a code rate provided by coding scheme CS-1 to convey
the information to the wireless devices.
[0109] In the following discussion, it is assumed that the changes
to the legacy transport block format needed for the new transport
block format proposed pursuant to the present disclosure involves:
[0110] 1. Reduced time duration from a four burst radio block to as
little as a single burst radio block. [0111] 2. Reduced payload
information per transport block. Different mechanisms may be used
to reduce the size of PCH messages. For example, the `type of
identity` in a paging message may be fixed to a Packet Temporary
Mobile Station Identity (P-TMSI). As Temporary Mobile Station
Identity (TMSI) is 32 bits only, only 32 bits will be needed in the
Mobile Identity information element field (e.g., `MS identity` in
paging message) to address the MS using P-TMSI. Thus, using P-TMSI
will help to reduce the total number of information bits that need
to be carried within the transport block. [0112] 3. Allowing for a
variable number of transport block repetitions to reflect the radio
channel conditions specific to each of the N wireless devices to be
paged. It is to be noted that it is possible to adapt the number of
transport block repetitions dynamically, for example, according to
device-specific radio channel quality (e.g., detected or based on
ongoing device-specific feedback received) or according to a fixed
coverage class associated with a given wireless device.
2. PCH Example
[0113] The following properties of the transport block format are
assumed to be the same for this example as for the current (i.e.,
legacy) PCH: [0114] 1. Modulation used (i.e., GMSK) [0115] 2. Code
rate used (i.e., around 1/2). It is assumed that a one burst radio
block and a four burst radio block of roughly the same code rate
provide roughly the same performance. This is supported by the
simulation results illustrated in the graph shown in FIG. 6 where
the performance of a four burst radio block carrying 184
information bits is compared to a one burst radio block carrying
different amounts of information bits. The results where simulated
over a slowly moving, non-hopping channel with a Doppler spread of
around 1 Hz.
[0116] Further, it is assumed that the four users (wireless
devices) multiplexed in the current PCH block need 1, 4, 8, and 2
repetitions, respectively, for user 1, 2, 3, and 4.
[0117] Hence, the current PCH consisting of 4 bursts per radio
block transmitted needs to be transmitted 8 times to ensure the
decoding (i.e., reception performance) of user 3 (i.e., the user
with the worst radio channel conditions, in this example), and
hence, in total 8*4=32 normal bursts need to be transmitted. If
instead, the modulation and code rate above are followed, but
within the context of the new device-specific transport block
format techniques described in the present disclosure, then the
same information could be carried with 1+4+8+2=15 bursts. Hence, a
bandwidth reduction of 53% is achieved.
[0118] More detailed simulations have also been performed where the
probability of a wireless device needing extended coverage (i.e.,
more than a single repetition) is assumed to be 20%, and within
that 20%, the number of repetitions needed for different levels of
extended coverage is: [0119] 10%: 2 transmissions [0120] 5%: 4
transmissions [0121] 3%: 8 transmissions [0122] 2%: 16
transmissions
[0123] In the case of using the disclosed techniques proposed in
the present disclosure, the average resource utilization is: (0.8*1
burst)+[(0.1*2 bursts)+(0.05*4 bursts)+(0.03*8 bursts)+(0.02*16
bursts)]=1.76 bursts. However, if assuming multiplexing of four
users (wireless devices) in the same paging block as per current
operation (i.e., the Broadcast Control Channel (BCCH) makes no
attempt to address wireless devices of the same or similar coverage
class within the same paging block), then the corresponding
resource utilization, when using the current 4 burst PCH block, is
3.7 bursts. Even though users (wireless devices) needing 16
repetitions are rare in the system, these users will, when paired
with three other users in the same block, most probably be paired
with users needing only a single repetition. For those users
needing only a single repetition, the number of repetitions used is
a vast waste of radio resources. In this example, the bandwidth
saving with the new transport block formats of the present
disclosure is around 53%.
[0124] The use of the new transport block formats pursuant to the
present disclosure will effectively generate a quadrupling of the
number of paging groups associated with any given coverage class
for any given Discontinuous Reception (DRX) cycle, since
repetitions will be performed on the burst level instead of at the
radio block level. For example, a wireless device needing eight
repetitions and using a DRX cycle of approximately one minute will
result in the following: [0125] DRX cycle=256 51-multiframes
.about.60 sec (208 DRX cycles within the overall frame number (FN)
space). [0126] PCH blocks (4 bursts each) per DRX
cycle=PB_DRX_CYCLE=256* 8=2048. [0127] Paging groups per DRX
cycle=PG_DRX_CYCLE=(PB_DRX_CYCLE*4)/8=1024. [0128] No inherent
difficulty is seen to arise from a paging group perspective when
using the new burst based transport block format described
herein.
3. Managing Common Information on the PCH
[0129] PCH messages currently contain information common to all
wireless devices including the set of N wireless devices to be
paged within that PCH message (e.g., implicit reject information
and Earthquake and Tsunami Warning System (ETWS) information) as
well as device-specific information (e.g., MS identification such
as P-TMSI). If the common information is not sent separately from
the device-specific information, then together their payload space
could be large enough to need a reduced channel coding rate for the
transport blocks used to send them, and thereby result in a reduced
BLER performance for these transport blocks, as illustrated in FIG.
6. As such, from a transport block BLER perspective, it may be
beneficial if the common information is sent using transport blocks
separate from transport blocks used to send the N instances of
device-specific information as described in the present disclosure.
This can be realized, for example, using one or more of the
technical features of the present disclosure as follows: [0130]
Identify the common information applicable to a set of N wireless
devices that need to be paged and send the common information using
a transport block format that all N devices can decode; [0131] Send
each of the N instances of device-specific information using an
applicable transport block format. The device-specific information
could also include, for example, a flag indicating whether or not
the wireless device needs to still acquire common information,
since the common information could be semi-static and therefore may
not have changed since the last time the common information was
read by the wireless device; and [0132] Include information in each
of the transport block formats used to send the device-specific
information and in the transport block format used to send the
common information that enables each of the N wireless devices to
uniquely identify which common information corresponds to its
device-specific information.
[0133] Using the previous example where four users (wireless
devices) are to be paged and respectively need 1, 4, 8, and 2
repetitions, there will be 15 transport blocks including
device-specific information and 8 transport blocks including the
common information, where all 23 transport blocks (bursts) maintain
payload space specific transport block BLER performance, as
illustrated in FIG. 6. This is still a large improvement (i.e., 28%
fewer bursts needed) compared to the 32 bursts that would need to
be transmitted using the legacy transport block format, wherein
each PCH block consists of 4 bursts and is repeated 8 times.
3.1 Management of PCH Resources
[0134] In today's GSM wireless communication network, the base
station (BS) needs to send valid layer 3 messages continuously on
all paging sub-channels on the CCCH. However, when wireless devices
of different coverage classes monitor the same physical resource
for layer 3 messages, it might turn out that wireless device B of a
device class experiencing better coverage than the corresponding
class for wireless device A (i.e., implying, for example, that less
repetitions are needed to reach the wireless device B) is sent a
layer 3 message using one or more radio blocks that include radio
block(s) of wireless device A's paging group. Although these paging
messages will not include a layer 3 message addressing wireless
device A, it is of interest for wireless device A to decode the
radio block sent from the BS to get a confirmation that wireless
device A is still connected to a suitable cell and that wireless
device A is still monitoring a correct CCCH. However, wireless
device A will not be able to correctly decode the radio block
unless the radio block is transmitted using a sufficiently high
number of repetitions.
3.2 Overload Control Management Using PCH Resources
[0135] In addition, wireless devices may still need to be subject
to an overload control mechanism, e.g., the legacy Implicit Reject
feature, in which the wireless devices first need to read a
PCH/Access Grant Channel (AGCH) message (sent to any wireless
device) to obtain access permission related information prior to
attempting a system access.
[0136] When sending information on a CCCH, the network takes into
account wireless devices associated with the highest coverage class
(e.g., needing 16 repetitions) since these wireless devices may be
monitoring the channel. This can be realized by ensuring a certain
minimum periodicity with which this information (e.g., overload
control, valid Layer 3 header) is sent using the transport formats
needed by these wireless devices. For example, the network can
periodically send Implicit Reject information as common information
using a transport block format appropriate for 16 repetitions
regardless of whether or not the network needs to send information
to any specific high coverage class wireless device at that point
in time.
4. Access Grant Channel (AGCH)
[0137] Support for new transport block formats used for sending
messages on the AGCH per the present disclosure can be realized in
the same manner as described above for PCH messages, since the same
payload volume dependent BLER performance applies as illustrated in
FIG. 6. One difference may be that the volume of common information
associated with an AGCH message sent using legacy procedures can be
expected to be significantly larger than for a PCH message. As
such, for the AGCH case, there may be an even greater incentive for
sending common information (i.e., information applicable to a set
of N wireless devices looking for an AGCH message) using a
transport block format that all N wireless devices can decode per
the present disclosure.
5. Packet Timing Control Channel/Downlink (PTCCH/D)
[0138] In one embodiment, the above techniques of the present
disclosure can be applied to the PTCCH/D channel, which is used to
support the Continuous Timing Advance (TA) procedure in GSM for all
wireless devices (MSs) in packet transfer mode, as described in
3GPP TS 45.010 V11.0.0, entitled "Technical Specification Group
GSM/EDGE Radio Access Network; Radio subsystem synchronization
(Release 11)." The contents of this document are hereby
incorporated by reference.
[0139] The PTCCH/D can at most carry eight bits of TA related
information to 16 wireless devices (users) addressed by the same
radio block. The default transport block format used by GSM today
is to transmit the PTCCH/D over a radio block consisting of four
normal bursts, each occupying one timeslot distributed evenly over
two 52-multi-frames. The transport block format consists of using
GMSK modulation and a code rate provided by coding scheme CS-1 to
convey the information to the wireless device's receiver.
[0140] However, per the present disclosure, the transmit time
duration of the PTCCH/D is reduced from a four burst radio block to
a single burst radio block. In the single burst format, at least
four wireless devices (users) using eight bits of TA information
can be addressed. Over four bursts, the numbers of addressed
wireless devices (users) are at least 16, as today.
[0141] In another embodiment of the present disclosure, up to six
users using eight bits of TA information can be supported per
burst, with the same code rate as today (i.e., as defined by coding
scheme CS-1). The simulation results illustrated in FIG. 6 for the
PCH are applicable also to the PTCCH/D.
[0142] In another embodiment of the present disclosure, where less
than eight bits of TA information are transmitted per wireless
device (user), the code rate can be made more robust than coding
scheme CS-1 to improve link level performance, and/or to lower the
number of repetitions needed in an extended coverage scenario.
Alternatively, the number of wireless devices (users) supported by
a single burst can be extended beyond six.
[0143] In yet another embodiment of the present disclosure, the
number of repetitions for the single burst format used in an
extended coverage scenario is adapted, e.g., according to the need
of the wireless devices (users) addressed in the single burst
format. Groupings of wireless devices (users) with similar or the
same coverage class needs will minimize the total number of burst
transmissions in the Continuous TA procedure. In contrast to the
PTCCH/D block multiplexing scheme used today, where each wireless
device assigned the same physical channel (i.e., where the PTCCH/D
is mapped) monitors each PTCCH/D block on that channel, the PTCCH/D
channel when mixing wireless devices (users) of different coverage
classes will have to be assigned such that wireless devices know or
can determine which radio resources are applicable and with which
periodicity the radio resources should be read.
[0144] An alternative approach to realizing PTCCH/D for extended
coverage in accordance with the present disclosure is to provide an
update interval of the TA information, for example, according to
the worst coverage class wireless devices. In one example, the
worst coverage class needs 16 repetitions. In this case, each PTCCH
block (addressing all wireless devices as per current operation)
may only change TA information every 16th PTCCH/D block
interval.
SUMMARY
[0145] A scenario addressed by the present disclosure is where N
wireless devices are performing procedures during which the N
wireless devices are attempting to read information (e.g.,
messages) on the DL of a common channel within the same time
interval and the network introduces new transport block formats in
the DL of a common channel to send the N wireless devices
information (e.g., messages) in a way that satisfies the specific
coverage class needs of these N wireless devices and that will
result in the ability to realize a significantly improved
utilization of the bandwidth available on the common DL channel
when compared to the case where the wireless devices are simply
assumed to be in the worst coverage class. In addition, another
scenario discussed herein considers the case where information that
is common to all N wireless devices is identified and sent using
transport blocks that are separate from transport blocks used to
send device-specific information, thereby allowing the use of fewer
radio resources when compared to what would be required without
such separation of information. Finally, an improved power saving
for wireless devices reading the common channel can be realized
since the use of these new transport formats results in fewer
bursts being read and processed, especially for the wireless
devices in the best coverage class (e.g., coverage class 1 wherein
only a single initial transmission/reception is needed).
[0146] Those skilled in the art will appreciate that the use of the
term "exemplary" is used herein to mean "illustrative," or "serving
as an example," and is not intended to imply that a particular
embodiment is preferred over another or that a particular feature
is essential. Likewise, the terms "first" and "second," and similar
terms, are used simply to distinguish one particular instance of an
item or feature from another, and do not indicate a particular
order or arrangement, unless the context clearly indicates
otherwise. Further, the term "step," as used herein, is meant to be
synonymous with "operation" or "action." Any description herein of
a sequence of steps does not imply that these operations must be
carried out in a particular order, or even that these operations
are carried out in any order at all, unless the context or the
details of the described operation clearly indicates otherwise.
[0147] Of course, the present disclosure may be carried out in
other specific ways than those herein set forth without departing
from the scope and essential characteristics of the invention. One
or more of the specific processes discussed above may be carried
out in a cellular phone or other communications transceiver
comprising one or more appropriately configured processing
circuits, which may in some embodiments be embodied in one or more
application-specific integrated circuits (ASICs). In some
embodiments, these processing circuits may comprise one or more
microprocessors, microcontrollers, and/or digital signal processors
programmed with appropriate software and/or firmware to carry out
one or more of the operations described above, or variants thereof.
In some embodiments, these processing circuits may comprise
customized hardware to carry out one or more of the functions
described above. The present embodiments are, therefore, to be
considered in all respects as illustrative and not restrictive.
[0148] Although multiple embodiments of the present disclosure have
been illustrated in the accompanying Drawings and described in the
foregoing Detailed Description, it should be understood that the
invention is not limited to the disclosed embodiments, but instead
is also capable of numerous rearrangements, modifications and
substitutions without departing from the present disclosure that as
has been set forth and defined within the following claims.
* * * * *