U.S. patent application number 12/212423 was filed with the patent office on 2009-03-26 for managing acknowledgment transmissions from multicast group members of a multicast group within a wireless communications network.
This patent application is currently assigned to QUALCOMM INCORPORATED. Invention is credited to Harleen GILL, Bongyong SONG.
Application Number | 20090080356 12/212423 |
Document ID | / |
Family ID | 40471458 |
Filed Date | 2009-03-26 |
United States Patent
Application |
20090080356 |
Kind Code |
A1 |
SONG; Bongyong ; et
al. |
March 26, 2009 |
MANAGING ACKNOWLEDGMENT TRANSMISSIONS FROM MULTICAST GROUP MEMBERS
OF A MULTICAST GROUP WITHIN A WIRELESS COMMUNICATIONS NETWORK
Abstract
Aspects of managing acknowledgment transmissions from multicast
group members of a multicast group within a wireless communications
network are disclosed. An access network transmits an announce
message announcing a multicast session to a plurality of access
terminals. One of the plurality of access terminals (i.e., a first
responder) sends a BCMCSFlowRegistration message and an announce
acknowledgment (ACK) message to the access network. In an example,
the BCMCSFlowRegistration message and announce ACK message are sent
within the same access probe on a reverse link access channel.
Next, the access network sends, in response to the received
BCMCSFlowRegistration message, a suppression message to request
access terminals not to send announce acknowledgment messages for
the announced multicast session. Alternatively, an application
server sends the suppression message in response to the received
announce ACK message. In either scenario, the access terminals
receiving the suppression message suppress transmission of
subsequent announce ACK messages.
Inventors: |
SONG; Bongyong; (San Diego,
CA) ; GILL; Harleen; (San Diego, CA) |
Correspondence
Address: |
QUALCOMM INCORPORATED
5775 MOREHOUSE DR.
SAN DIEGO
CA
92121
US
|
Assignee: |
QUALCOMM INCORPORATED
San Diego
CA
|
Family ID: |
40471458 |
Appl. No.: |
12/212423 |
Filed: |
September 17, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60974831 |
Sep 24, 2007 |
|
|
|
60974796 |
Sep 24, 2007 |
|
|
|
Current U.S.
Class: |
370/312 |
Current CPC
Class: |
H04L 47/12 20130101;
H04W 4/06 20130101; H04L 47/32 20130101; H04L 12/1872 20130101;
H04W 4/10 20130101; H04W 28/02 20130101; H04W 60/00 20130101; H04W
76/40 20180201; H04L 47/15 20130101; H04W 72/005 20130101; H04L
47/14 20130101; H04L 47/10 20130101; H04L 47/323 20130101; H04L
12/189 20130101 |
Class at
Publication: |
370/312 |
International
Class: |
H04H 20/71 20080101
H04H020/71 |
Claims
1. A method of suppressing acknowledgments to multicast announce
messages within a wireless communications network, comprising:
sending an announce message announcing a multicast session to a
plurality of access terminals; receiving, from one of the plurality
of access terminals, at least one response message responsive to
the announce message; and sending, in response to the received at
least one response message, a suppression message to request access
terminals not to send announce acknowledgment messages for the
announced multicast session.
2. The method of claim 1, wherein the receiving step receives the
at least one response message in accordance with an access control
message (ACM) that indicates a manner in which access terminals are
to attempt to send response messages to the announce message.
3. The method of claim 2, wherein the ACM designates, for the
access terminal from which the at least one response message is
received, a first position in a response order indicated by the
ACM.
4. The method of claim 1, wherein the at least one response message
includes an announce acknowledgment message acknowledging that the
transmitted announce message has been received.
5. The method of claim 1, wherein the at least one response message
includes a multicast registration message requesting registration
to the announced multicast session.
6. The method of claim 5, wherein the multicast registration
message is a BCMCSFlowRegistration message.
7. The method of claim 1, wherein the at least one response message
includes (i) an announce acknowledgment message acknowledging that
the transmitted announce message has been received and (ii) a
multicast registration message requesting registration to the
announced multicast session.
8. The method of claim 7, wherein the announce acknowledgment
message and the multicast registration message are bundled together
within a single access probe on a reverse link channel.
9. The method of claim 1, wherein the sending steps and receiving
step are performed at an application server.
10. The method of claim 1, wherein the suppression message has a
proprietary message format that is not defined by 1x EV-DO
standards.
11. The method of claim 1, wherein the sending steps and receiving
steps are performed at an access network.
12. The method of claim 11, wherein the suppression message
corresponds to a broadcast overhead message (BOM) or a proprietary
message having a format that is not defined by 1x EV-DO
standards.
13. The method of claim 12 wherein the BOM is either sent in at
least one reserved slot of a downlink control channel that is
reserved for BOMs, or is sent in at least one slot being earlier
than the at least one reserved slot of the downlink control
channel.
14. The method of claim 13, wherein the at least one earlier slot
is a first available slot on the downlink control channel
subsequent to receiving the at least one response message.
15. The method of claim 1, further comprising: determining whether
sufficient resources are available to support the multicast session
in one or more sectors of the wireless communication system,
wherein the sending step sends the suppression message in sectors
that are determined not to have sufficient resources to support the
multicast session.
16. The method of claim 15, wherein the suppression message further
informs the access terminals to ignore the announced multicast
session.
17. The method of claim 1, wherein the suppression message is a
broadcast reject message (BRM).
18. The method of claim 1, wherein the sending step sends the
suppression message within a sector including the access terminal
that sent the at least one response message.
19. The method of claim 18, wherein the sending step sends the
suppression message in each sector where the announce message has
announced the given multicast session.
20. The method of claim 1, wherein the sending step sends the
suppression message in a given cluster within the wireless
communications network, the cluster being a subset of sectors where
the announce message has announced the given multicast session.
21. The method of claim 20, wherein the cluster includes a
contiguous set of sectors carrying the multicast flow on a given
interlace-multiplex pair of a downlink broadcast channel.
22. The method of claim 20, wherein the cluster wherein the cluster
includes at least one target sector that is expected to include one
or more access terminals participating in the given multicast
session, and at least one supporting sector that is not expected to
include any access terminals participating in the given multicast
session.
23. A method of suppressing acknowledgments to multicast announce
messages within a wireless communications network, comprising:
receiving, at an access terminal, an announce message announcing a
multicast session, the announced multicast session being a
multicast session that the access terminal wishes to monitor;
receiving, at the access terminal, a suppression message requesting
the access terminal not to transmit an announce acknowledgment
message for the announced multicast session; and suppressing
transmission of the announce acknowledgment message in response to
the received suppression message.
24. The method of claim 23, further comprising: receiving an access
control message (ACM) that indicates a manner in which the access
terminal is to attempt to send the announce acknowledgment message,
wherein the access terminal receives the suppression message before
the access terminal makes the attempt in accordance with the
ACM.
25. The method of claim 23, wherein the suppression message
originates at an application server.
26. The method of claim 23, wherein the access terminal is
configured to recognize the suppression message as a request not to
send the announce acknowledgment message for the announced
multicast session.
27. The method of claim 23, wherein the suppression message
originates at an access network.
28. The method of claim 27, wherein the suppression message
corresponds to one of a broadcast overhead message (BOM) and a
proprietary message having a format that is not defined by 1x EV-DO
standards.
29. The method of claim 28, wherein the BOM is either sent in at
least one reserved slot of a downlink control channel that is
reserved for BOMs, or is sent in at least one slot being earlier
than the at least one reserved slot of the downlink control
channel.
30. The method of claim 29, wherein the at least one earlier slot
is a first available slot on the downlink control channel
subsequent to receiving the announce acknowledgment message.
31. The method of claim 29, further comprising: monitoring, at the
access terminal, the downlink control channel after receiving the
announce message, to determine whether a suppression message has
been received.
32. The method of claim 31, wherein the monitoring step includes
monitoring the at least one reserved slot of the downlink control
channel and the at least one earlier slot of the downlink control
channel.
33. The method of claim 31, wherein the monitoring step includes
monitoring each synchronous control channel of the downlink control
channel after receiving the announce message.
34. The method of claim 31, wherein the monitoring step includes
monitoring each synchronous and sub-synchronous control channel
capsule of the downlink control channel after receiving the
announce message.
35. The method of claim 33, wherein the monitoring step monitors
each synchronous, sub-synchronous and asynchronous control channel
capsule of the downlink control channel after receiving the
announce message.
36. The method of claim 23, wherein the suppression message informs
the access terminal to ignore the announced multicast session.
37. The method of claim 36, wherein the suppression message is a
broadcast reject message (BRM).
38. The method of claim 37, wherein the BRM is received if
sufficient resources are not available at a serving base station to
support the announced multicast session.
39. A method of sending acknowledgments to multicast announce
messages within a wireless communications network, comprising:
receiving, at an access terminal, an announce message announcing a
multicast session, the announced multicast session being a
multicast session that the access terminal wishes to monitor; and
sending, from the access terminal, a multicast registration message
requesting registration to the announced multicast session for the
access terminal and an announce acknowledgment message
acknowledging that the announce message has been received, the
multicast registration message and announce acknowledgment message
being sent to an access network within the same access probe on a
reverse link channel.
40. The method of claim 39, further comprising: receiving an access
control message (ACM) that indicates a manner in which the access
terminal is to attempt to send response messages to the announce
message; selecting the access probe upon which to send the
multicast registration message and the announce acknowledgment
message based on the ACM.
41. The method of claim 39, wherein the multicast registration
message is a BCMCSFlowRegistration message.
42. The method of claim 39, wherein the sending step delays a
transmission of at least one of the multicast registration message
and the announce acknowledgment message such that the multicast
registration message and the announce acknowledgment message are
sent together on the same access probe on the reverse link
channel.
43. A wireless communication system, comprising: logic configured
to send an announce message announcing a multicast session to a
plurality of access terminals; logic configured to receive, from
one of the plurality of access terminals, at least one response
message responsive to the announce message; and logic configured to
send, in response to the received at least one response message, a
suppression message to request access terminals not to send
announce acknowledgment messages for the announced multicast
session.
44. The wireless communication system of claim 43, wherein the
logic configured to receive receives the at least one response
message in accordance with an access control message (ACM) that
indicates a manner in which access terminals are to attempt to send
response messages to the announce message.
45. The wireless communication system of claim 43, wherein the at
least one response message includes at least one of (i) an announce
acknowledgment message acknowledging that the transmitted announce
message has been received and (ii) a multicast registration message
requesting registration to the announced multicast session.
46. The wireless communication system of claim 45, wherein the
announce acknowledgment message and the multicast registration
message are bundled together within a single access probe on a
reverse link channel.
47. The wireless communication system of claim 46, wherein the
suppression message corresponds to a broadcast overhead message
(BOM) or a proprietary message having a format that is not defined
by 1x EV-DO standards.
48. The wireless communication system of claim 47, wherein the BOM
is either sent in at least one reserved slot of a downlink control
channel that is reserved for BOMs, or is sent in at least one slot
being earlier than the at least one reserved slot of the downlink
control channel.
49. The wireless communication system of claim 43, further
comprising: logic configured to determine whether sufficient
resources are available to support the multicast session in one or
more sectors of the wireless communication system, wherein the
logic configured to send the suppression message sends the
suppression message in sectors that are determined not to have
sufficient resources to support the multicast session.
50. The wireless communication system of claim 43, wherein the
suppression message is a broadcast reject message (BRM).
51. An access terminal, comprising: logic configured to receive an
announce message announcing a multicast session, the announced
multicast session being a multicast session that the access
terminal wishes to monitor; logic configured to receive a
suppression message requesting the access terminal not to transmit
an announce acknowledgment message for the announced multicast
session; and logic configured to suppress transmission of the
announce acknowledgment message in response to the received
suppression message.
52. The access terminal of claim 51, further comprising: logic
configured to receive an access control message (ACM) that
indicates a manner in which the access terminal is to attempt to
send the announce acknowledgment message, wherein the access
terminal receives the suppression message before the access
terminal makes the attempt in accordance with the ACM.
53. The access terminal of claim 51, wherein the suppression
message corresponds to one of a broadcast overhead message (BOM)
and a proprietary message having a format that is not defined by 1x
EV-DO standards.
54. The access terminal of claim 53, wherein the BOM is either sent
in at least one reserved slot of a downlink control channel that is
reserved for BOMs, or is sent in at least one slot being earlier
than the at least one reserved slot of the downlink control
channel.
55. The access terminal of claim 54, further comprising: logic
configured to monitor the downlink control channel after receiving
the announce message, to determine whether a suppression message
has been received.
56. The access terminal of claim 51, wherein the suppression
message is a broadcast reject message (BRM).
57. An access terminal, comprising: logic configured to receive an
announce message announcing a multicast session, the announced
multicast session being a multicast session that the access
terminal wishes to monitor; and logic configured to send a
multicast registration message requesting registration to the
announced multicast session for the access terminal and an announce
acknowledgment message acknowledging that the announce message has
been received, the multicast registration message and announce
acknowledgment message being sent to an access network within the
same access probe on a reverse link channel.
58. The access terminal of claim 57, further comprising: logic
configured to receive an access control message (ACM) that
indicates a manner in which the access terminal is to attempt to
send response messages to the announce message; logic configured to
select the access probe upon which to send the multicast
registration message and the announce acknowledgment message based
on the ACM.
59. The access terminal of claim 57, wherein the logic configured
to send delays a transmission of at least one of the multicast
registration message and the announce acknowledgment message such
that the multicast registration message and the announce
acknowledgment message are sent together on the same access probe
on the reverse link channel.
60. A wireless communication system, comprising: means for sending
an announce message announcing a multicast session to a plurality
of access terminals; means for receiving, from one of the plurality
of access terminals, at least one response message responsive to
the announce message; and means for sending, in response to the
received at least one response message, a suppression message to
request access terminals not to send announce acknowledgment
messages for the announced multicast session.
61. The wireless communication system of claim 60, wherein the
means for receiving receives the at least one response message in
accordance with an access control message (ACM) that indicates a
manner in which access terminals are to attempt to send response
messages to the announce message.
62. The wireless communication system of claim 60, wherein the at
least one response message includes at least one of (i) an announce
acknowledgment message acknowledging that the transmitted announce
message has been received and (ii) a multicast registration message
requesting registration to the announced multicast session.
63. The wireless communication system of claim 62, wherein the
announce acknowledgment message and the multicast registration
message are bundled together within a single access probe on a
reverse link channel.
64. The wireless communication system of claim 63, wherein the
suppression message corresponds to a broadcast overhead message
(BOM) or a proprietary message having a format that is not defined
by 1x EV-DO standards.
65. The wireless communication system of claim 64, wherein the BOM
is either sent in at least one reserved slot of a downlink control
channel that is reserved for BOMs, or is sent in at least one slot
being earlier than the at least one reserved slot of the downlink
control channel.
66. The wireless communication system of claim 60, further
comprising: means for determining whether sufficient resources are
available to support the multicast session in one or more sectors
of the wireless communication system, wherein the means for sending
the suppression message sends the suppression message in sectors
that are determined not to have sufficient resources to support the
multicast session.
67. The wireless communication system of claim 60, wherein the
suppression message is a broadcast reject message (BRM).
68. An access terminal, comprising: means for receiving an announce
message announcing a multicast session, the announced multicast
session being a multicast session that the access terminal wishes
to monitor; means for receiving a suppression message requesting
the access terminal not to transmit an announce acknowledgment
message for the announced multicast session; and means for
suppressing transmission of the announce acknowledgment message in
response to the received suppression message.
69. The access terminal of claim 68, further comprising: means for
receiving an access control message (ACM) that indicates a manner
in which the access terminal is to attempt to send the announce
acknowledgment message, wherein the access terminal receives the
suppression message before the access terminal makes the attempt in
accordance with the ACM.
70. The access terminal of claim 68, wherein the suppression
message corresponds to one of a broadcast overhead message (BOM)
and a proprietary message having a format that is not defined by 1x
EV-DO standards.
71. The access terminal of claim 70, wherein the BOM is either sent
in at least one reserved slot of a downlink control channel that is
reserved for BOMs, or is sent in at least one slot being earlier
than the at least one reserved slot of the downlink control
channel.
72. The access terminal of claim 71, further comprising: means for
monitoring the downlink control channel after receiving the
announce message, to determine whether a suppression message has
been received.
73. The access terminal of claim 68, wherein the suppression
message is a broadcast reject message (BRM).
74. An access terminal, comprising: means for receiving an announce
message announcing a multicast session, the announced multicast
session being a multicast session that the access terminal wishes
to monitor; and means for sending a multicast registration message
requesting registration to the announced multicast session for the
access terminal and an announce acknowledgment message
acknowledging that the announce message has been received, the
multicast registration message and announce acknowledgment message
being sent to an access network within the same access probe on a
reverse link channel.
75. The access terminal of claim 74, further comprising: means for
receiving an access control message (ACM) that indicates a manner
in which the access terminal is to attempt to send response
messages to the announce message; means for selecting the access
probe upon which to send the multicast registration message and the
announce acknowledgment message based on the ACM.
76. The access terminal of claim 74, wherein the means for sending
delays a transmission of at least one of the multicast registration
message and the announce acknowledgment message such that the
multicast registration message and the announce acknowledgment
message are sent together on the same access probe on the reverse
link channel.
77. A computer-readable medium including program code stored
thereon, the program code configured to operate within a wireless
communications system including a plurality of sectors, comprising:
program code to send an announce message announcing a multicast
session to a plurality of access terminals; program code to
receive, from one of the plurality of access terminals, at least
one response message responsive to the announce message; and
program code to send, in response to the received at least one
response message, a suppression message to request access terminals
not to send announce acknowledgment messages for the announced
multicast session.
78. The computer-readable medium of claim 77, wherein the program
code to receive receives the at least one response message in
accordance with an access control message (ACM) that indicates a
manner in which access terminals are to attempt to send response
messages to the announce message.
79. The computer-readable medium of claim 77, wherein the at least
one response message includes at least one of (i) an announce
acknowledgment message acknowledging that the transmitted announce
message has been received and (ii) a multicast registration message
requesting registration to the announced multicast session.
80. The computer-readable medium of claim 79, wherein the announce
acknowledgment message and the multicast registration message are
bundled together within a single access probe on a reverse link
channel.
81. The computer-readable medium of claim 80, wherein the
suppression message corresponds to a broadcast overhead message
(BOM) or a proprietary message having a format that is not defined
by 1x EV-DO standards.
82. The computer-readable medium of claim 81, wherein the BOM is
either sent in at least one reserved slot of a downlink control
channel that is reserved for BOMs, or is sent in at least one slot
being earlier than the at least one reserved slot of the downlink
control channel.
83. The computer-readable medium of claim 77, further comprising:
program code to determine whether sufficient resources are
available to support the multicast session in one or more sectors
of the wireless communication system, wherein the program code to
send the suppression message sends the suppression message in
sectors that are determined not to have sufficient resources to
support the multicast session.
84. The computer-readable medium of claim 77, wherein the
suppression message is a broadcast reject message (BRM).
85. A computer-readable medium including program code stored
thereon, the program code configured to operate within an access
terminal, comprising: program code to receive an announce message
announcing a multicast session, the announced multicast session
being a multicast session that the access terminal wishes to
monitor; program code to receive a suppression message requesting
the access terminal not to transmit an announce acknowledgment
message for the announced multicast session; and program code to
suppress transmission of the announce acknowledgment message in
response to the received suppression message.
86. The computer-readable medium of claim 85, further comprising:
program code to receive an access control message (ACM) that
indicates a manner in which the access terminal is to attempt to
send the announce acknowledgment message, wherein the access
terminal receives the suppression message before the access
terminal makes the attempt in accordance with the ACM.
87. The computer-readable medium of claim 85, wherein the
suppression message corresponds to one of a broadcast overhead
message (BOM) and a proprietary message having a format that is not
defined by 1x EV-DO standards.
88. The computer-readable medium of claim 87, wherein the BOM is
either sent in at least one reserved slot of a downlink control
channel that is reserved for BOMs, or is sent in at least one slot
being earlier than the at least one reserved slot of the downlink
control channel.
89. The computer-readable medium of claim 88, further comprising:
program code to monitor the downlink control channel after
receiving the announce message, to determine whether a suppression
message has been received.
90. The computer-readable medium of claim 85, wherein the
suppression message is a broadcast reject message (BRM).
91. A computer-readable medium including program code stored
thereon, the program code configured to operate within an access
terminal, comprising: program code to receive an announce message
announcing a multicast session, the announced multicast session
being a multicast session that the access terminal wishes to
monitor; and program code to send a multicast registration message
requesting registration to the announced multicast session for the
access terminal and an announce acknowledgment message
acknowledging that the announce message has been received, the
multicast registration message and announce acknowledgment message
being sent to an access network within the same access probe on a
reverse link channel.
92. The computer-readable medium of claim 91, further comprising:
logic configured to receive an access control message (ACM) that
indicates a manner in which the access terminal is to attempt to
send response messages to the announce message; logic configured to
select the access probe upon which to send the multicast
registration message and the announce acknowledgment message based
on the ACM.
93. The computer-readable medium of claim 91, wherein the program
code to send delays a transmission of at least one of the multicast
registration message and the announce acknowledgment message such
that the multicast registration message and the announce
acknowledgment message are sent together on the same access probe
on the reverse link channel.
Description
CLAIM OF PRIORITY UNDER 35 U.S.C. .sctn.119
[0001] The present Application for Patent claims priority to
Provisional Application No. 60/974,796 entitled "Methods of
Responding to an Interactive Multicast Message Within a Wireless
Communication System" filed Sep. 24, 2007, and to Provisional
Application No. 60/974,831 entitled "Methods of Managing
Acknowledgment Transmissions From Multicast Group Members of a
Multicast Group within a Wireless Communications Network" filed
Sep. 24, 2007, each of which are assigned to the assignee hereof
and hereby expressly incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to communications in a wireless
telecommunication system and, more particularly to methods of
managing acknowledgment transmissions from multicast group members
of a multicast group within a wireless communications network.
[0004] 2. Description of the Related Art
[0005] Wireless communication systems have developed through
various generations, including a first-generation analog wireless
phone service (1G), a second-generation (2G) digital wireless phone
service (including interim 2.5G and 2.75G networks) and a
third-generation (3G) high speed data/Internet-capable wireless
service. There are presently many different types of wireless
communication systems in use, including Cellular and Personal
Communications Service (PCS) systems. Examples of known cellular
systems include the cellular Analog Advanced Mobile Phone System
(AMPS), and digital cellular systems based on Code Division
Multiple Access (CDMA), Frequency Division Multiple Access (FDMA),
Time Division Multiple Access (TDMA), the Global System for Mobile
access (GSM) variation of TDMA, and newer hybrid digital
communication systems using both TDMA and CDMA technologies.
[0006] The method for providing CDMA mobile communications was
standardized in the United States by the Telecommunications
Industry Association/Electronic Industries Association in
TIA/EIA/IS-95-A entitled "Mobile Station-Base Station Compatibility
Standard for Dual-Mode Wideband Spread Spectrum Cellular System,"
referred to herein as IS-95. Combined AMPS & CDMA systems are
described in TIA/EIA Standard IS-98. Other communications systems
are described in the IMT-2000/UM, or International Mobile
Telecommunications System 2000/Universal Mobile Telecommunications
System, standards covering what are referred to as wideband CDMA
(WCDMA), CDMA2000 (such as CDMA2000 1xEV-DO standards, for example)
or TD-SCDMA.
[0007] In wireless communication systems, mobile stations,
handsets, or access terminals (AT) receive signals from fixed
position base stations (also referred to as cell sites or cells)
that support communication links or service within particular
geographic regions adjacent to or surrounding the base stations.
Base stations provide entry points to an access network (AN)/radio
access network (RAN), which is generally a packet data network
using standard Internet Engineering Task Force (IETF) based
protocols that support methods for differentiating traffic based on
Quality of Service (QoS) requirements. Therefore, the base stations
generally interact with ATs through an over the air interface and
with the AN through Internet Protocol (IP) network data
packets.
[0008] In wireless telecommunication systems, Push-to-talk (PTT)
capabilities are becoming popular with service sectors and
consumers. PTT can support a "dispatch" voice service that operates
over standard commercial wireless infrastructures, such as CDMA,
FDMA, TDMA, GSM, etc. In a dispatch model, communication between
endpoints (ATs) occurs within virtual groups, wherein the voice of
one "talker" is transmitted to one or more "listeners." A single
instance of this type of communication is commonly referred to as a
dispatch call, or simply a PTT call. A PTT call is an instantiation
of a group, which defines the characteristics of a call. A group in
essence is defined by a member list and associated information,
such as group name or group identification.
[0009] Conventionally, data packets within a wireless
communications network have been configured to be sent to a single
destination or access terminal. A transmission of data to a single
destination is referred to as "unicast". As mobile communications
have increased, the ability to transmit given data concurrently to
multiple access terminals has become more important. Accordingly,
protocols have been adopted to support concurrent data
transmissions of the same packet or message to multiple
destinations or target access terminals. A "broadcast" refers to a
transmission of data packets to all destinations or access
terminals (e.g., within a given cell, served by a given service
provider, etc.), while a "multicast" refers to a transmission of
data packets to a given group of destinations or access terminals.
In an example, the given group of destinations or "multicast group"
may include more than one and less than all of possible
destinations or access terminals (e.g., within a given group,
served by a given service provider, etc.). However, it is at least
possible in certain situations that the multicast group comprises
only one access terminal, similar to a unicast, or alternatively
that the multicast group comprises all access terminals (e.g.,
within a cell or sector), similar to a broadcast.
[0010] Broadcasts and/or multicasts may be performed within
wireless communication systems in a number of ways, such as
performing a plurality of sequential unicast operations to
accommodate the multicast group, allocating a unique
broadcast/multicast channel (BCH) for handling multiple data
transmissions at the same time and the like. A conventional system
using a broadcast channel for push-to-talk communications is
described in United States Patent Application Publication No.
2007/0049314 dated Mar. 1, 2007 and entitled "Push-To-Talk Group
Call System Using CDMA 1x-EVDO Cellular Network", the contents of
which are incorporated herein by reference in its entirety. As
described in Publication No. 2007/0049314, a broadcast channel can
be used for push-to-talk calls using conventional signaling
techniques. Although the use of a broadcast channel may improve
bandwidth requirements over conventional unicast techniques, the
conventional signaling of the broadcast channel can still result in
additional overhead and/or delay and may degrade system
performance.
[0011] The 3.sup.rd Generation Partnership Project 2 ("3GPP2")
defines a broadcast-multicast service (BCMCS) specification for
supporting multicast communications in CDMA2000 networks.
Accordingly, a version of 3GPP2's BCMCS specification, entitled
"CDMA2000 High Rate Broadcast-Multicast Packet Data Air Interface
Specification", dated Feb. 14, 2006, Version 1.0 C.S0054-A, is
hereby incorporated by reference in its entirety.
SUMMARY
[0012] Embodiments of the invention are related to Managing
acknowledgment transmissions from multicast group members of a
multicast group within a wireless communications network. For
example, an access network transmits an announce message announcing
a multicast session to a plurality of access terminals. One of the
plurality of access terminals (i.e., a first responder) sends a
BCMCSFlowRegistration message and an announce acknowledgment (ACK)
message to the access network. In an example, the
BCMCSFlowRegistration message and announce ACK message are sent
within the same access probe on a reverse link access channel.
Next, the access network sends, in response to the received
BCMCSFlowRegistration message, a suppression message to request
access terminals not to send announce acknowledgment messages for
the announced multicast session. Alternatively, an application
server sends the suppression message in response to the received
announce ACK message. In either scenario, the access terminals
receiving the suppression message suppress transmission of
subsequent announce ACK messages.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] A more complete appreciation of embodiments of the invention
and many of the attendant advantages thereof will be readily
obtained as the same becomes better understood by reference to the
following detailed description when considered in connection with
the accompanying drawings which are presented solely for
illustration and not limitation of the invention, and in which:
[0014] FIG. 1 is a diagram of a wireless network architecture that
supports access terminals and access networks in accordance with at
least one embodiment of the invention.
[0015] FIG. 2 illustrates the carrier network 126 according to an
embodiment of the present invention.
[0016] FIG. 3 is an illustration of an access terminal in
accordance with at least one embodiment of the invention.
[0017] FIG. 4 illustrates a conventional multicast messaging
process.
[0018] FIG. 5 illustrates a sector of the wireless communication
system according to an embodiment of the present invention.
[0019] FIG. 6 illustrates a multicast messaging process according
to an embodiment of the present invention.
[0020] FIG. 7 illustrates a continuation of the process of FIG. 6
or the process of FIG. 8.
[0021] FIG. 8 illustrates a multicast messaging process according
to another embodiment of the present invention.
DETAILED DESCRIPTION
[0022] Aspects of the invention are disclosed in the following
description and related drawings directed to specific embodiments
of the invention. Alternate embodiments may be devised without
departing from the scope of the invention. Additionally, well-known
elements of the invention will not be described in detail or will
be omitted so as not to obscure the relevant details of the
invention.
[0023] The words "exemplary" and/or "example" are used herein to
mean "serving as an example, instance, or illustration." Any
embodiment described herein as "exemplary" and/or "example" is not
necessarily to be construed as preferred or advantageous over other
embodiments. Likewise, the term "embodiments of the invention" does
not require that all embodiments of the invention include the
discussed feature, advantage or mode of operation.
[0024] Further, many embodiments are described in terms of
sequences of actions to be performed by, for example, elements of a
computing device. It will be recognized that various actions
described herein can be performed by specific circuits (e.g.,
application specific integrated circuits (ASICs)), by program
instructions being executed by one or more processors, or by a
combination of both. Additionally, these sequence of actions
described herein can be considered to be embodied entirely within
any form of computer readable storage medium having stored therein
a corresponding set of computer instructions that upon execution
would cause an associated processor to perform the functionality
described herein. Thus, the various aspects of the invention may be
embodied in a number of different forms, all of which have been
contemplated to be within the scope of the claimed subject matter.
In addition, for each of the embodiments described herein, the
corresponding form of any such embodiments may be described herein
as, for example, "logic configured to" perform the described
action.
[0025] A High Data Rate (HDR) subscriber station, referred to
herein as an access terminal (AT), may be mobile or stationary, and
may communicate with one or more HDR base stations, referred to
herein as modem pool transceivers (MPTs) or base stations (BS). An
access terminal transmits and receives data packets through one or
more modem pool transceivers to an HDR base station controller,
referred to as a modem pool controller (MPC), base station
controller (BSC) and/or packet control function (PCF). Modem pool
transceivers and modem pool controllers are parts of a network
called an access network. An access network transports data packets
between multiple access terminals.
[0026] The access network may be further connected to additional
networks outside the access network, such as a corporate intranet
or the Internet, and may transport data packets between each access
terminal and such outside networks. An access terminal that has
established an active traffic channel connection with one or more
modem pool transceivers is called an active access terminal, and is
said to be in a traffic state. An access terminal that is in the
process of establishing an active traffic channel connection with
one or more modem pool transceivers is said to be in a connection
setup state. An access terminal may be any data device that
communicates through a wireless channel or through a wired channel,
for example using fiber optic or coaxial cables. An access terminal
may further be any of a number of types of devices including but
not limited to PC card, compact flash, external or internal modem,
or wireless or wireline phone. The communication link through which
the access terminal sends signals to the modem pool transceiver is
called a reverse link or traffic channel. The communication link
through which a modem pool transceiver sends signals to an access
terminal is called a forward link or traffic channel. As used
herein the term traffic channel can refer to either a forward or
reverse traffic channel.
[0027] FIG. 1 illustrates a block diagram of one exemplary
embodiment of a wireless communication system 100 in accordance
with at least one embodiment of the invention. System 100 can
contain access terminals, such as cellular telephone 102, in
communication across an air interface 104 with an access network or
radio access network (RAN) 120 that can connect the access terminal
102 to network equipment providing data connectivity between a
packet switched data network (e.g., an intranet, the Internet,
and/or carrier network 126) and the access terminals 102, 108, 110,
112. As shown here, the access terminal can be a cellular telephone
102, a personal digital assistant 108, a pager 110, which is shown
here as a two-way text pager, or even a separate computer platform
112 that has a wireless communication portal. Embodiments of the
invention can thus be realized on any form of access terminal
including a wireless communication portal or having wireless
communication capabilities, including without limitation, wireless
modems, PCMCIA cards, personal computers, telephones, or any
combination or sub-combination thereof. Further, as used herein,
the terms "access terminal", "wireless device", "client device",
"mobile terminal" and variations thereof may be used
interchangeably.
[0028] Referring back to FIG. 1, the components of the wireless
network 100 and interrelation of the elements of the exemplary
embodiments of the invention are not limited to the configuration
illustrated. System 100 is merely exemplary and can include any
system that allows remote access terminals, such as wireless client
computing devices 102, 108, 110, 112 to communicate over-the-air
between and among each other and/or between and among components
connected via the air interface 104 and RAN 120, including, without
limitation, carrier network 126, the Internet, and/or other remote
servers.
[0029] The RAN 120 controls messages (typically sent as data
packets) sent to a base station controller/packet control function
(BSC/PCF) 122. The BSC/PCF 122 is responsible for signaling,
establishing, and tearing down bearer channels (i.e., data
channels) between a packet data service node 100 ("PDSN") and the
access terminals 102/108/110/112. If link layer encryption is
enabled, the BSC/PCF 122 also encrypts the content before
forwarding it over the air interface 104. The function of the
BSC/PCF 122 is well-known in the art and will not be discussed
further for the sake of brevity. The carrier network 126 may
communicate with the BSC/PCF 122 by a network, the Internet and/or
a public switched telephone network (PSTN). Alternatively, the
BSC/PCF 122 may connect directly to the Internet or external
network. Typically, the network or Internet connection between the
carrier network 126 and the BSC/PCF 122 transfers data, and the
PSTN transfers voice information. The BSC/PCF 122 can be connected
to multiple base stations (BS) or modem pool transceivers (MPT)
124. In a similar manner to the carrier network, the BSC/PCF 122 is
typically connected to the MPT/BS 124 by a network, the Internet
and/or PSTN for data transfer and/or voice information. The MPT/BS
124 can broadcast data messages wirelessly to the access terminals,
such as cellular telephone 102. The MPT/BS 124, BSC/PCF 122 and
other components may form the RAN 120, as is known in the art.
However, alternate configurations may also be used and the
invention is not limited to the configuration illustrated. For
example, in another embodiment the functionality of the BSC/PCF 122
and one or more of the MPT/BS 124 may be collapsed into a single
"hybrid" module having the functionality of both the BSC/PCF 122
and the MPT/BS 124.
[0030] FIG. 2 illustrates the carrier network 126 according to an
embodiment of the present invention. In the embodiment of FIG. 2,
the carrier network 126 includes a packet data serving node (PDSN)
160, a broadcast serving node 165, an application server 170 and an
Internet 175. However, application server 170 and other components
may be located outside the carrier network in alternative
embodiments. The PDSN 160 provides access to the Internet 175,
intranets and/or remote servers (e.g., application server 170) for
mobile stations (e.g., access terminals, such as 102, 108, 110, 112
from FIG. 1) utilizing, for example, a cdma2000 Radio Access
Network (RAN) (e.g., RAN 120 of FIG. 1). Acting as an access
gateway, the PDSN 160 may provide simple IP and mobile IP access,
foreign agent support, and packet transport. The PDSN 160 can act
as a client for Authentication, Authorization, and Accounting (AAA)
servers and other supporting infrastructure and provides mobile
stations with a gateway to the IP network as is known in the art.
As shown in FIG. 2, the PDSN 160 may communicate with the RAN 120
(e.g., the BSC/PCF 122) via a conventional A10 connection. The A10
connection is well-known in the art and will not be described
further for the sake of brevity.
[0031] Referring to FIG. 2, the broadcast serving node (BSN) 165
may be configured to support multicast and broadcast services. The
BSN 165 will be described in greater detail below. The BSN 165
communicates with the RAN 120 (e.g., the BSC/PCF 122) via a
broadcast (BC) A10 connection, and with the application server 170
via the Internet 175. The BCA10 connection is used to transfer
multicast and/or broadcast messaging. Accordingly, the application
server 170 sends unicast messaging to the PDSN 160 via the Internet
175, and sends multicast messaging to the BSN 165 via the Internet
175.
[0032] Generally, as will be described in greater detail below, the
RAN 120 transmits multicast messages, received from the BSN 165 via
the BCA10 connection, over a broadcast channel (BCH) of the air
interface 104 to one or more access terminals 200.
[0033] Referring to FIG. 3, an access terminal 200, (here a
wireless device), such as a cellular telephone, has a platform 202
that can receive and execute software applications, data and/or
commands transmitted from the RAN 120 that may ultimately come from
the carrier network 126, the Internet and/or other remote servers
and networks. The platform 202 can include a transceiver 206
operably coupled to an application specific integrated circuit
("ASIC" 208), or other processor, microprocessor, logic circuit, or
other data processing device. The ASIC 208 or other processor
executes the application programming interface ("API`) 210 layer
that interfaces with any resident programs in the memory 212 of the
wireless device. The memory 212 can be comprised of read-only or
random-access memory (RAM and ROM), EEPROM, flash cards, or any
memory common to computer platforms. The platform 202 also can
include a local database 214 that can hold applications not
actively used in memory 212. The local database 214 is typically a
flash memory cell, but can be any secondary storage device as known
in the art, such as magnetic media, EEPROM, optical media, tape,
soft or hard disk, or the like. The internal platform 202
components can also be operably coupled to external devices such as
antenna 222, display 224, push-to-talk button 228 and keypad 226
among other components, as is known in the art.
[0034] Accordingly, an embodiment of the invention can include an
access terminal including the ability to perform the functions
described herein. As will be appreciated by those skilled in the
art, the various logic elements can be embodied in discrete
elements, software modules executed on a processor or any
combination of software and hardware to achieve the functionality
disclosed herein. For example, ASIC 208, memory 212, API 210 and
local database 214 may all be used cooperatively to load, store and
execute the various functions disclosed herein and thus the logic
to perform these functions may be distributed over various
elements. Alternatively, the functionality could be incorporated
into one discrete component. Therefore, the features of the access
terminal in FIG. 3 are to be considered merely illustrative and the
invention is not limited to the illustrated features or
arrangement.
[0035] The wireless communication between the access terminal 102
and the RAN 120 can be based on different technologies, such as
code division multiple access (CDMA), WCDMA, time division multiple
access (TDMA), frequency division multiple access (FDMA),
Orthogonal Frequency Division Multiplexing (OFDM), the Global
System for Mobile Communications (GSM), or other protocols that may
be used in a wireless communications network or a data
communications network. The data communication is typically between
the client device 102, MPT/BS 124, and BSC/PCF 122. The BSC/PCF 122
can be connected to multiple data networks such as the carrier
network 126, PSTN, the Internet, a virtual private network, and the
like, thus allowing the access terminal 102 access to a broader
communication network. As discussed in the foregoing and known in
the art, voice transmission and/or data can be transmitted to the
access terminals from the RAN using a variety of networks and
configurations. Accordingly, the illustrations provided herein are
not intended to limit the embodiments of the invention and are
merely to aid in the description of aspects of embodiments of the
invention.
[0036] FIG. 4 illustrates a conventional multicast messaging
process. In particular, FIG. 4 illustrates a broadcast and
multicast service (BCMCS) messaging process supporting a
push-to-talk (PTT) or multicast session.
[0037] In 400, one of a plurality of access terminals in
communication with the RAN 120 ("PTT initiator") requests to
initiate a PTT session, or multicast session. Accordingly, the PTT
initiator sends a PTT call request to the application server 170
(e.g., a PTT server). Next, in 405, the application server 170
announces the PTT session to each multicast group member for the
PTT session. For example, the application server 170 forwards the
announce message to the RAN 120 via the PDSN 160 and/or BSN 165,
and the RAN 120 transmits the announce message over the air
interface 104 to a plurality of ATs. The announce message is
transmitted in multiple sectors within the wireless communication
system 100.
[0038] FIG. 5 illustrates a sector 500 of the wireless
communication system 100 according to an embodiment of the present
invention. The sector 500 includes a base station or MPT/BS 505.
The sector 500, which corresponds to a region wherein ATs can be
served by the base station 505, further includes ATs A through E.
The PTT initiator discussed above with respect to 400 can be one of
ATs A through E, or alternatively may correspond to an AT within
another sector (not shown). For convenience of explanation, it will
be assumed hereinafter that the PTT initiator is not present within
sector 500 of FIG. 5.
[0039] Returning to FIG. 4, each of ATs A through E receives the
announce message sent at 405. In 410, AT A responds to the announce
message by sending an announce acknowledgment (ACK) message on a
reverse link access channel to the base station 505 of the RAN 120.
Also, in 415, AT A sends a BCMCSFlowRegistration message to the RAN
120 to register for the BCMCS flow associated with the announce
message. While not shown explicitly within FIG. 4, the RAN 120
forwards the announce ACK message to the application or PTT server
170, and the RAN 120 adds AT A to a multicast group for the
announced PTT session after receiving the BCMCSFlowRegistration
message.
[0040] 1x EV-DO standards provide the BCMCSFlowRegistration message
for AT registration to multicast groups. Conventional
BCMCSFlowRegistration messages include a listing of one or more
BCMCS flows that a given AT is requesting to monitor. For example,
if the announce message in 405 announces a PTT call associated with
BCMCS Flow FLOW_1, then the BCMCSFlowRegistration messages sent in
response to the announce message includes FLOW_1.
BCMCSFlowRegistration messages may be sent to the RAN 120 at
different times during a multicast or PTT session, and not merely
in response to an announce message.
[0041] The first AT to respond to the announce message from 405 can
be referred to as a "first responder". Accordingly, in FIG. 4, it
may be assumed that AT A is the first responder (i.e., the first AT
to respond in any sector). Next, each of ATs B through E responds
to the announce message by sending an announce ACK message, 420.
Each of ATs B through E also sends the BCMCSFlowRegistration
message to register for the BCMCS flow announced in 425. It will be
appreciated that while the announce ACK message transmission of 420
and the BCMCSFlowRegistration message transmission of 425 are shown
as single steps, the announce ACK messages and
BCMCSFlowRegistration messages may each be sent from different of
the ATs B through E at different times, and 420 and 425 have been
condensed into single blocks in FIG. 4 for convenience of
explanation.
[0042] At some point after the first responder AT A sends the
announce ACK message, in 430, the application server 170 begins the
PTT session or call by providing the RAN 120 with multicast
messages to be forwarded to base stations serving sectors including
one or more ATs that have registered for the announced PTT session
(e.g., ATs A through E in sector 500). Accordingly, in 435 and 440,
respectively, ATs A through E monitor the multicast messages sent
in 430 associated with the announced PTT session.
[0043] As discussed above with respect to FIGS. 4 and 5, an
announce ACK message and BCMCSFlowRegistration message are sent
from each AT that receives the announce message from 405. However,
the application server 170 need only receive a single announce ACK
message in order to determine to initiate the PTT session. In other
words, the PTT session or call can begin (e.g., the PTT initiator
can begin speaking or multicasting to at least one recipient) once
the application server 170 receives an announce ACK message from
the first responder. Thus, subsequent announce ACK messages can be
redundant, and can increase interference on the reverse link access
channel.
[0044] As discussed above, redundant announce ACK messages received
at the application or PTT server 170 can increase interference on
the reverse link access channel. Accordingly, embodiments of the
present invention, which will now be described in greater detail,
are directed to reducing or "suppressing" the number of announce
ACK messages sent in response to an announce message announcing a
PTT session.
[0045] FIG. 6 illustrates a multicast messaging process according
to an embodiment of the present invention. In 600, one of a
plurality of access terminals in communication with the RAN 120
("PTT initiator") requests to initiate a PTT session, or multicast
session. Accordingly, the PTT initiator sends a PTT call request to
the application server 170 (e.g., a PTT server). Next, in 605, the
application server 170 announces the PTT session to each multicast
group member for the PTT session. For example, the application
server 170 forwards the announce message to the RAN 120 via the
PDSN 160 and/or BSN 165, and the RAN 120 transmits the announce
message over the air interface 104 (e.g., over a downlink broadcast
channel (BCH), over a downlink control channel, etc.) to a
plurality of ATs. The announce message is transmitted in multiple
sectors, including sector 500, within the wireless communication
system 100.
[0046] In an example, the announce message sent in 605 may be
bundled with an access control message (ACM), with the ACM
providing feedback protocols for ATs. In other words, the ACM
determines a manner in which ATs can respond to the announce
message. For a further discussion of ACMs and feedback scheduling
protocols, see U.S. Provisional Patent Application No. 60/974,796,
entitled "METHODS OF RESPONDING TO AN INTERACTIVE MULTICAST MESSAGE
WITHIN A WIRELESS COMMUNICATION SYSTEM", filed on Sep. 24, 2007,
assigned by the assignee hereof, and expressly incorporated by
reference herein in its entirety.
[0047] Below, the process of FIG. 6 is described as performed at
sector 500 within the RAN 120. However, it will be appreciated that
the process of FIG. 6 may concurrently be performed at other
sectors (not shown) within the RAN 120.
[0048] In 610, AT A responds to the announce message by sending an
announce ACK message on the reverse link access channel to the base
station 505 of the RAN 120. In 610, the announce ACK message is
"bundled" with a BCMCSFlowRegistration message within a single
access probe to register for the BCMCS flow associated with the
announce message. In contrast, as shown in FIG. 4, announce ACKs
and BCMCSFlowRegistration messages sent in response to announce
messages are not necessarily bundled together, and are rather
typically sent independently on different access probes.
Accordingly, it will be appreciated that synchronizing the
transmission of the announce ACK and the BCMCSFlowRegistration
message within a single access probe reduces the traffic load on
the reverse link access channel. Further, while not shown
explicitly within FIG. 4, the RAN 120 forwards the announce ACK
message to the application or PTT server 170. In an example, the
announce ACK message can be sent in accordance with an ACM that was
previously sent to AT A (e.g., and other ATs). In this example, AT
A may be the first to respond because the ACM designates AT A a
first slot in which to respond to the announce message, while other
ATs wait at least until AT A attempts to respond to the announce
message before initiating their own attempt to respond.
Alternatively, AT A may simply be the first AT to successfully
respond irrespective of whether an AT response order is indicate
via an ACM.
[0049] In 615, the RAN 120 determines whether the base station 505
has sufficient resources to handle the requested PTT session. For
example, if the base station 505 of the RAN 120 is already
participating in a number of PTT sessions, the amount of downlink
bandwidth on the downlink broadcast channel (BCH) may be relatively
limited, and the RAN 120 may determine that the base station 505
does not have sufficient resources to handle the announced PTT
session. If the RAN 120 determines that sufficient resources are
not available, the process advances to 700 of FIG. 7, which will be
described in greater detail below. Otherwise, the process advances
to 620 of FIG. 6.
[0050] In 620, the RAN 120/base station 505 transmits an announce
ACK suppression message (e.g., over the downlink control channel,
the downlink BCH, etc.). The announce ACK suppression message is
sent to discourage ATs that have not yet responded to the announce
message within the sector 500 from sending the announce ACK
message. The announce ACK suppression message is sent by the RAN
120 at least at base station 505 within sector 500. However, the
announce ACK suppression message can also be sent by the RAN 120
within each sector within which the announce message was announced
in 605.
[0051] In an example, the announce ACK suppression message is a
broadcast overhead message (BOM) that is sent in response to a
first BCMCSFlowRegistration message received for the announced PTT
session within a given sector. BOMs are well-known in the art, and
include a listing of one or more BCMCS flow IDs for BCMCS flows
carried within a given sector. BOMs also include information that
instruct ATs with regard to how to "tune" to an advertised BCMCS
flow on the downlink broadcast channel (BCH). Accordingly, in this
example, the BOM sent in 620 includes the BCMCS flow ID for the
announced PTT session.
[0052] Conventionally, BOMs are sent on the downlink control
channel within reserved slots of the downlink control cycle. In
this example, however, the BOM is sent at the first available or
earliest slot of the downlink control channel cycle, and need not
wait for the scheduled/reserved BOM slot(s). By sending the BOM,
which in this example functions as an announce ACK suppression
message, as early as possible, the chances of reaching ATs before
transmission of an announce ACK message (and the
BCMCSFlowRegistration message) increase.
[0053] However, in another embodiment, the BOM can be sent at its
normal, reserved slot(s) on the downlink BCH in 620. In this
alternative embodiment, the BOM still functions as an announce ACK
suppression message because the ATs are configured to interpret any
BOM for the announced PTT session as a request not to send an
announce ACK message for the announced PTT session.
[0054] In another alternative embodiment, the announce ACK
suppression message sent in 620 need not be a BOM (e.g., either an
"immediate" BOM or a BOM sent on reserved downlink channel slots),
but can be configured as a proprietary downlink message sent on the
control channel. For example, the proprietary downlink message may
correspond to a message that is not specified within 1x EV-DO
protocols. In this example, in order to interpret the proprietary
message as a request not to send announce ACK messages, the ATs may
be specially configured to recognize the proprietary message as
such.
[0055] In any of the above examples, it will be appreciated that
not all ATs within the sector 500 need be specially configured to
recognize either an immediate BOM, a conventional BOM, or a
proprietary message as an announce ACK suppression message for
proper operation. It will be appreciated that if more ATs can
recognize announce ACK suppression messages within the sector 500,
fewer announce ACK messages and/or BCMCSFlowRegistration messages
need be sent.
[0056] In 625, ATs B through E, which received the announce message
from 605 but have not yet sent announce ACK messages, receive the
announce ACK suppression message. For purposes of explanation,
assume each of ATs B through E have been configured to recognize
announce ACK suppression messages (e.g., an immediate BOM for the
announced PTT session, a conventional BOM for the announced PTT
session, a proprietary announce ACK suppression message, etc.).
Instead of sending the announce ACK message, ATs B through E
suppress the announce ACK message transmission. For example, if the
announce ACK suppression message is an "immediate" BOM for the
announced PTT session (e.g., a BOM transmitted in a slot earlier
than that of the reserved BOM slot of the downlink control channel
cycle), each of ATs B through E can be configured to interpret the
immediate BOM associated with the announced PTT session as a
request not to send the announce ACK message, and so on.
[0057] Next, at some point after the first responder AT A sends the
announce ACK message, the application server 170 begins the PTT
session or call by providing the RAN 120 with multicast messages to
be transmitted, in 630, on the downlink broadcast channel (BCH).
Accordingly, in 635 and 640, respectively, ATs A through E monitor
the multicast messages sent in 630 associated with the announced
PTT session.
[0058] It will be appreciated that even though ATs B through E do
not send announce ACK messages, ATs B through E are not precluded
from monitoring the PTT session, and can monitor the periodic BOMs
sent on the downlink control channel, and tune to multicast
messages on the BCH, which collectively comprise the multicast
messaging of the PTT session, in the same manner as ATA.
[0059] Further, it will be appreciated that only announce ACK
messages need be suppressed in response to the announce ACK
suppression message, and not necessarily BCMCSFlowRegistration
messages. While BCMCSFlowRegistration messages may be bundled with
announce ACK messages, BCMCSFlowRegistration messages may also be
sent separately. For example, whether a given AT sends a
BCMCSFlowRegistration message can be based on a BOM field
parameter. BOMs typically include a register for paging (RFP) field
and a register for dynamic broadcast (RFDB) field. If the RFP field
and/or the RFDB field is set to a first logic level (e.g., a higher
logic level or logic "1"), ATs receiving the BOM may be prompted to
send a BCMCSFlowRegistration message. Otherwise, if the RFP field
and/or the RFDB field is set to a second logic level (e.g., a lower
logic level or logic "0"), ATs receiving the BOM may not be
prompted to send a BCMCSFlowRegistration message. Thus, if the
announce ACK suppression message is a BOM and RFDB=0 or RFP=0, ATs
B through E do not send an announce ACK message or a
BCMCSFlowRegistration message, and if the announce ACK suppression
message is a BOM and RFDB=1 or RFP=1, ATs B through E do not send
an announce ACK message, but do send a BCMCSFlowRegistration
message. For a further discussion of triggering
BCMCSFlowRegistration messages via BOM field parameters, see U.S.
Provisional Patent Application No. 60/974,808, entitled "METHODS OF
SUPPORTING MULTICAST COMMUNICATIONS ASSOCIATED WITH OVERLAPPING
CLUSTERS WITHIN A WIRELESS COMMUNICATIONS NETWORK", having attorney
docket no. 072340P1, filed on Sep. 24, 2007, assigned by the
assignee hereof, and expressly incorporated by reference herein in
its entirety.
[0060] Returning to FIG. 6, in 615, if the RAN 120 determines that
the base station 505 does not have sufficient resources to support
the PTT session, the process advances to 700 of FIG. 7. In 700 of
FIG. 7, the RAN 120 (e.g., via base station 505) transmits a
broadcast reject message (BRM) to ATs A through E. BRMs are
well-known in the art and defined by 1x EV-DO standards. The RAN
120 may also notify the application server 170 that the base
station 505 cannot support the PTT session in 705. In 710, AT A
receives the BRM and interprets the BRM as a request to ignore the
announce message. In other words, AT A ignores the announce message
by not attempting to monitor the announced PTT session (e.g., even
though AT A previously attempted to register for the announced PTT
session by sending the announce ACK message including the
BCMCSFlowRegistration message in 610). Likewise, in 715, ATs B
through E also receive the BRM and interpret the BRM as a request
to ignore the announce message. In other words, similar to AT A,
ATs B through E ignore the announce message by not attempting to
monitor and/or register for the announced PTT session.
[0061] While FIGS. 6 and 7 are directed to "RAN implemented"
announce ACK suppression processes, in an alternative embodiment,
the application or PTT server 170 may generate the announce ACK
suppression message.
[0062] FIG. 8 illustrates a multicast messaging process according
to another embodiment of the present invention. In FIG. 8, 800, 805
and 810 correspond to 600, 605 and 610, respectively, of FIG. 6,
and as such will not be described further for the sake of
brevity.
[0063] In 815, after the application server 170 receives the
announce ACK from the first responder AT A, the application server
170 sends an announce ACK suppression message to the RAN 120, which
transmits the announce ACK suppression message at the base station
505 within sector 500 of FIG. 5 (e.g., on a downlink control
channel, a downlink broadcast channel (BCH), etc.). While not shown
explicitly within FIG. 8, the announce ACK suppression message sent
from the application server 170 can also be sent to each sector
that transmitted the announce message at 805. In another example,
the announce ACK suppression message sent from the application
server can be sent within a given "cluster" of the wireless
communication system. For example, a cluster corresponds to a
contiguous set of sectors carrying the multicast flow on a given
interlace-multiplex pair of the downlink broadcast channel, wherein
the contiguous set of sectors includes both (i) target sectors that
are expected to include one or more multicast group members and
(ii) supporting sectors that satisfy a given relationship with the
target sectors, are not expected to include any multicast group
members and are configured to carry the multicast flow as well in
order to "support" the target sectors. Clusters, target sectors and
supporting sectors are described in more detail within U.S.
Provisional Patent Application No. 60/974,808, entitled "METHODS OF
SUPPORTING MULTICAST COMMUNICATIONS ASSOCIATED WITH OVERLAPPING
CLUSTERS WITHIN A WIRELESS COMMUNICATIONS NETWORK", having attorney
docket no. 072340P1, filed on Sep. 24, 2007, assigned by the
assignee hereof, and expressly incorporated by reference herein in
its entirety. Thus, the announce ACK suppression message may be
sent in one (or more) clusters of the wireless communication
system. In this example, the announce ACK suppression message may
be a proprietary message, and the respective multicast group
members or ATs may be configured to recognize the announce ACK
suppression message and interpret the announce ACK suppression
message as a request not to send an announce ACK for a particular
announced PTT session. For convenience of explanation, the process
of FIG. 8 is described below assuming that all ATs are configured
to recognize announce ACK suppression messages.
[0064] In 820, the RAN 120 determines whether the base station 505
has sufficient resources to handle the requested PTT session. For
example, if the base station 505 of the RAN 120 is already
participating in a number of PTT sessions, the amount of downlink
bandwidth may be relatively limited and the RAN 120 may determine
that the base station 505 does not have sufficient resources to
handle the announced PTT session. If the RAN 120 determines that
sufficient resources are not available, the process advances to 700
of FIG. 7.
[0065] In 825, ATs B through E, which received the announce message
from 805 but have not yet sent announce ACK messages, receive the
announce ACK suppression message generated at the application
server 170. Instead of sending the announce ACK message, ATs B
through E suppress the announce ACK message transmission. For
example, if the announce ACK suppression message embodied as a
proprietary downlink control message, each of ATs B through E is
configured to interpret the proprietary downlink control message as
a request not to send the announce ACK message for the announced
PTT session.
[0066] Next, at some point after the first responder AT A sends the
announce ACK message, the application server 170 begins the PTT
session or call by providing the RAN 120 with multicast messages to
be transmitted in 830 on the downlink broadcast channel (BCH).
Accordingly, in 835 and 840, respectively, ATs A through E monitor
the multicast messages sent in 830 associated with the announced
PTT session.
[0067] It will be appreciated that even though ATs B through E do
not send announce ACK messages, ATs B through E are not precluded
from monitoring the PTT session, and can monitor the BOMs on the
downlink control channel and multicast messages on the BCH, which
collectively comprise the multicast messaging of the PTT session,
in the same manner as AT A. Further, it will be appreciated that
only announce ACK messages need be suppressed, and not necessarily
BCMCSFlowRegistration messages. This concept is discussed above in
the description of FIG. 6 in greater detail with respect to RFDB
and RFP fields within the BOM used to either trigger or suppress
BCMCSFlowRegistration messaging.
[0068] While above-described embodiments of the present invention
are directed to specific implementations wherein an announce ACK
suppression message is sent to ATs within a given sector either
from a base station serving the sector or from a centralized PTT
server, it will be appreciated that any communication entity
recognizing a first responder to an announced PTT session may be
capable of initiating the transmission of the announce ACK
suppression message. Thus, other embodiments of the present
invention may be directed to any implementation wherein an announce
ACK suppression message is transmitted to one or more sectors
responsive to a first responder to a PTT session.
[0069] Those of skill in the art will appreciate that information
and signals may be represented using any of a variety of different
technologies and techniques. For example, data, instructions,
commands, information, signals, bits, symbols, and chips that may
be referenced throughout the above description may be represented
by voltages, currents, electromagnetic waves, magnetic fields or
particles, optical fields or particles, or any combination
thereof.
[0070] Further, those of skill in the art will appreciate that the
various illustrative logical blocks, modules, circuits, and
algorithm steps described in connection with the embodiments
disclosed herein may be implemented as electronic hardware,
computer software, or combinations of both. To clearly illustrate
this interchangeability of hardware and software, various
illustrative components, blocks, modules, circuits, and steps have
been described above generally in terms of their functionality.
Whether such functionality is implemented as hardware or software
depends upon the particular application and design constraints
imposed on the overall system. Skilled artisans may implement the
described functionality in varying ways for each particular
application, but such implementation decisions should not be
interpreted as causing a departure from the scope of the present
invention.
[0071] The various illustrative logical blocks, modules, and
circuits described in connection with the embodiments disclosed
herein may be implemented or performed with a general purpose
processor, a digital signal processor (DSP), an application
specific integrated circuit (ASIC), a field programmable gate array
(FPGA) or other programmable logic device, discrete gate or
transistor logic, discrete hardware components, or any combination
thereof designed to perform the functions described herein. A
general purpose processor may be a microprocessor, but in the
alternative, the processor may be any conventional processor,
controller, microcontroller, or state machine. A processor may also
be implemented as a combination of computing devices, e.g., a
combination of a DSP and a microprocessor, a plurality of
microprocessors, one or more microprocessors in conjunction with a
DSP core, or any other such configuration.
[0072] The methods, sequences and/or algorithms described in
connection with the embodiments disclosed herein may be embodied
directly in hardware, in a software module executed by a processor,
or in a combination of the two. If implemented in software, the
functions may be stored on or transmitted over as one or more
instructions or code on a computer-readable medium.
Computer-readable media includes both computer storage media and
communication media including any medium that facilitates transfer
of a computer program from one place to another. A storage media
may be any available media that can be accessed by a computer. By
way of example, and not limitation, such computer-readable media
can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk
storage, magnetic disk storage or other magnetic storage devices,
or any other medium that can be used to carry or store desired
program code in the form of instructions or data structures and
that can be accessed by a computer. Also, any connection is
properly termed a computer-readable medium. For example, if the
software is transmitted from a website, server, or other remote
source using a coaxial cable, fiber optic cable, twisted pair,
digital subscriber line (DSL), or wireless technologies such as
infrared, radio, and microwave, then the coaxial cable, fiber optic
cable, twisted pair, DSL, or wireless technologies such as
infrared, radio, and microwave are included in the definition of
medium. Disk and disc, as used herein, includes compact disc (CD),
laser disc, optical disc, digital versatile disc (DVD), floppy disk
and blu-ray disc where disks usually reproduce data magnetically,
while discs reproduce data optically with lasers. Combinations of
the above should also be included within the scope of
computer-readable media.
[0073] While the foregoing disclosure shows illustrative
embodiments of the invention, it should be noted that various
changes and modifications could be made herein without departing
from the scope of the invention as defined by the appended claims.
The functions, steps and/or actions of the method claims in
accordance with the embodiments of the invention described herein
need not be performed in any particular order. Furthermore,
although elements of the invention may be described or claimed in
the singular, the plural is contemplated unless limitation to the
singular is explicitly stated.
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