U.S. patent application number 15/292597 was filed with the patent office on 2018-12-20 for multicast messaging within a wireless communication system.
The applicant listed for this patent is QUALCOMM Incorporated. Invention is credited to Arulmozhi Ananthanarayanan, Harleen Gill, Bongyong Song.
Application Number | 20180367956 15/292597 |
Document ID | / |
Family ID | 40471459 |
Filed Date | 2018-12-20 |
United States Patent
Application |
20180367956 |
Kind Code |
A9 |
Song; Bongyong ; et
al. |
December 20, 2018 |
MULTICAST MESSAGING WITHIN A WIRELESS COMMUNICATION SYSTEM
Abstract
Methods and systems for sending multicast messages are
disclosed. A multicast message is received to be transmitted to a
plurality of access terminals at a radio access network (RAN), the
received multicast message having a first format. The first format
may correspond to a conventional multicast message format. The RAN
determines whether the received multicast message requires special
handling. If the RAN determines the received multicast message
requires special handling, the radio access network converts the
received multicast message from the first format into a second
format. The RAN transmits the converted multicast message with the
second format (e.g., a data over signaling (DOS) message) on a
control channel to at least one of the plurality of access
terminals. The access terminals receiving the converted multicast
message interpret the message as a multicast message.
Inventors: |
Song; Bongyong; (San Diego,
CA) ; Gill; Harleen; (Los Altos, CA) ;
Ananthanarayanan; Arulmozhi; (San Diego, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
QUALCOMM Incorporated |
San Diego |
CA |
US |
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|
Prior
Publication: |
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Document Identifier |
Publication Date |
|
US 20170034671 A1 |
February 2, 2017 |
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|
Family ID: |
40471459 |
Appl. No.: |
15/292597 |
Filed: |
October 13, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14026128 |
Sep 13, 2013 |
9479350 |
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15292597 |
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|
12212462 |
Sep 17, 2008 |
8570911 |
|
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14026128 |
|
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60974833 |
Sep 24, 2007 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02N 2/183 20130101;
F03G 5/06 20130101; H04L 12/1881 20130101; H01L 41/082 20130101;
H02N 2/18 20130101; H04L 12/189 20130101; H04W 4/06 20130101; H04W
72/005 20130101; H01L 37/00 20130101 |
International
Class: |
H04W 4/06 20060101
H04W004/06; H04L 12/18 20060101 H04L012/18; H04W 72/00 20060101
H04W072/00 |
Claims
1. A method of receiving multicast messages within a wireless
communication system, comprising: receiving a first message in a
first message format on a first channel carrying both unicast and
multicast messages at an access terminal; determining whether the
first message includes a multicast message; extracting the
multicast message from the first message based on the determining;
and receiving a second message in a second message format on a
second channel.
2. The method of claim 1, wherein the first message is a data over
signaling (DOS) message.
3. The method of claim 2, wherein the multicast message includes a
multicast access terminal identifier (MATI) that identifies the
plurality of access terminals.
4. The method of claim 1, wherein the first channel is a control
channel, and wherein the first message is received on at least one
of a synchronous control channel capsule (SC) or a sub-synchronous
control channel capsule (SSC).
5. (canceled)
6. An access terminal, comprising: at least one transceiver
configured to receive a first message in a first message format on
a first channel carrying both unicast and multicast messages; and
at least one processor configured to determine whether the first
message includes a multicast message, and to extract the multicast
message from the first message based on the determination, wherein
the at least one transceiver is further configured to receive a
second message in a second message format on a second channel.
7. The method of claim 1, wherein the second channel is dedicated
for multicast and broadcast messages.
8. The method of claim 1, wherein the multicast message is targeted
to one particular multicast communication group.
9. The method of claim 8, wherein the second message is also
targeted to the particular multicast communication group.
10. The method of claim 9, the first message is received while a
multicast session associated with the particular multicast
communication group is inactive.
11. The method of claim 10, wherein the multicast message is
configured to announce the multicast session to the particular
multicast communication group.
12. The method of claim 1, wherein the first message format is a
unicast message format and the second message format is a broadcast
or multicast message format.
13. The access terminal of claim 6, wherein the second channel is
dedicated for multicast and broadcast messages.
14. The access terminal of claim 6, wherein the multicast message
is targeted to one particular multicast communication group.
15. The access terminal of claim 20, wherein the second message is
also targeted to the particular multicast communication group.
16. The access terminal of claim 21, wherein the first message is
received while a multicast session associated with the particular
multicast communication group is inactive.
17. The access terminal of claim 22, wherein the multicast message
is configured to announce the multicast session to the particular
multicast communication group.
18. The access terminal of claim 6, wherein the first message
format is a unicast message format and the second message format is
a broadcast or multicast message format.
19. A method of transmitting multicast messages within a wireless
communication system, comprising: transmitting, to at least one
group of access terminals, a first message in a first message
format on a first channel carrying both unicast and multicast
messages at a base station, wherein the first message includes a
multicast message; and transmitting, to the at least one group of
access terminals, a second message in a second message format on a
second channel.
20. The method of claim 19, wherein the second channel is dedicated
for multicast and broadcast messages.
21. The method of claim 19, wherein the multicast message is
targeted to one particular multicast communication group.
22. The method of claim 21, wherein the second message is also
targeted to the particular multicast communication group.
23. The method of claim 22, the first message is transmitted while
a multicast session associated with the particular multicast
communication group is inactive.
24. The method of claim 23, wherein the multicast message is
configured to announce the multicast session to the particular
multicast communication group.
25. The method of claim 32, wherein the first message format is a
unicast message format and the second message format is a broadcast
or multicast message format.
26. A base station, comprising: at least one transceiver configured
to: transmit, to at least one group of access terminals, a first
message in a first message format on a first channel carrying both
unicast and multicast messages at a base station, wherein the first
message includes a multicast message, and to transmit, to the at
least one group of access terminals, a second message in a second
message format on a second channel.
27. The base station of claim 26, wherein the second channel is
dedicated for multicast and broadcast messages.
28. The base station of claim 26, wherein the multicast message is
targeted to one particular multicast communication group.
29. The base station of claim 28, wherein the second message is
also targeted to the particular multicast communication group.
30. The base station of claim 29, the first message is transmitted
while a multicast session associated with the particular multicast
communication group is inactive.
31. The base station of claim 26, wherein the first message format
is a unicast message format and the second message format is a
broadcast or multicast message format.
Description
CLAIM OF PRIORITY
[0001] The present Application for Patent is a divisional of U.S.
patent application Ser. No. 14/026,126, entitled "MULTICAST
MESSAGING WITHIN A WIRELESS COMMUNICATION SYSTEM", filed Sep. 13,
2013, which in turn is a divisional of U.S. patent application Ser.
No. 12/212,462, entitled "MULTICAST MESSAGING WITHIN A WIRELESS
COMMUNICATION SYSTEM", filed Sep. 17, 2008, which in turn claims
priority to Provisional Application No. 60/974,833 entitled
"MULTICAST MESSAGING WITHIN A WIRELESS COMMUNICATION SYSTEM", filed
Sep. 24, 2007, each of which is assigned to the assignee hereof and
is hereby expressly incorporated by reference herein in its
entirety.
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 multicast
messaging within the wireless communication system.
[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 communication
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' 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 directed to methods and
systems for sending multicast messages. For example, a method
includes receiving a multicast message to be transmitted to a
plurality of access terminals at a radio access network (RAN), the
received multicast message having a first format. The first format
may correspond to a conventional multicast message format. The RAN
determines whether the received multicast message requires special
handling. If the RAN determines the received multicast message
requires special handling, the radio access network converts the
received multicast message from the first format into a second
format. The RAN transmits the converted multicast message with the
second format (e.g., a data over signaling (DOS) message) on a
control channel to at least one of the plurality of access
terminals. The access terminals receiving the converted multicast
message interpret the message as a multicast message.
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 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 using a broadcast multicast server (BCMCS) framework.
[0018] FIG. 5 illustrates a cycle of a downlink control channel
[0019] FIG. 6 illustrates a multicast messaging process according
to an embodiment of the present invention.
DETAILED DESCRIPTION
[0020] 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.
[0021] 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.
[0022] 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.
[0023] 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.
[0024] 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.
[0025] FIG. 1 illustrates a block diagram of one exemplary
embodiment of a wireless 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.
[0026] 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.
[0027] 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.
[0028] 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 (BSN) 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.
[0029] Referring to FIG. 2, the broadcast serving node (BSN) 165 is
typically 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. The PDSN and BSN may be integrated into a single network
node.
[0030] 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.
[0031] 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.
[0032] 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.
[0033] 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.
[0034] As discussed in the Background section, multicast messaging
may be performed in a number of ways. In order to better understand
embodiments of the present invention, a conventional multicast
messaging process will be described with respect to FIGS. 4 and 5,
respectively. Then, a multicast messaging process according to an
embodiment of the present invention will be described in greater
detail.
[0035] FIG. 4 illustrates a conventional multicast messaging
process using a broadcast multicast server (BCMCS) framework. The
multicast messaging process of FIG. 4 is described below as
performed within the wireless system 100 of FIGS. 1 and 2.
Referring to FIG. 4, in 400, the application server (or other
initiator) requests a multicast message be sent to a multicast
group including ATs (e.g., A, B and C). The multicast message from
400 is routed to the BSN 165. In 405, the BSN 165 forwards the
multicast message along with the associated multicast group
including the target destinations or ATs for the multicast message
over the BCA10 connection to the RAN 120. For example, the
multicast message is first forwarded to the BSC/PCF 122, and the
BSN/PCF 122 analyzes the multicast group members for the multicast
message and forwards the multicast message to each MPT/BS 124
serving one or more multicast group members.
[0036] After receiving the forwarded multicast message, the RAN 120
waits for a next available control channel capsule in 410. The
control channel referred to herein is a downlink control channel
which is assigned a different frequency, coding and/or bandwidth
than the broadcast channel (BCH). Generally, less bandwidth is
allocated to the control channel, which is conventionally intended
to include control messaging only, while more bandwidth is
allocated to the broadcast channel (BCH) which is conventionally
intended to include data.
[0037] Referring to FIG. 5, each control channel cycle includes a
total of 256 slots. Each control channel cycle includes a
synchronous control channel capsule (SC), an asynchronous control
channel capsule (AC), and a number of sub-synchronous control
channels (SSCs). One SC is regularly or periodically transmitted at
a given timeslot for each control channel cycle having a period of
256 slots, whereas the AC is transmitted at "random", or at
non-synchronous timeslots, within the control channel cycle. The SC
is first transmitted at a timeslot corresponding to "T mod
256=Offset", and then retransmitted at a timeslot corresponding to
"T mod 4=Offset", where T denotes a system time and an Offset
denotes a time value delayed from a fixed time, which are included
in the control channel header. Each SC may include a plurality of
control channel MAC layer packets, whereas each AC includes only
one control channel MAC layer packet. As each MPT/BS 124
periodically transmits one or more control channel MAC layer
packets, interference (e.g., inter-cell interference) may occur if
each MPT/BS 124 transmits at the same time. Accordingly, a
different offset is applied to the SC for each MPT/BS 124 to avoid
collisions. The MPT/BS may transmit as many as three SSC capsules
within one control channel period or 256 slot cycle. Each SSC
typically transmits only one control channel MAC layer packet.
Assuming an offset value of 2, the SSCs are transmitted at time
slots 66, 130 and 194. Control channel capsules (e.g., SCs, ACs,
SSCs, etc.) are generally well-known in the art within BCMCS
systems, and as such a further description thereof has been omitted
for the sake of brevity.
[0038] Returning back to FIG. 4, in 410, the RAN 120 may wait for
either a synchronous control channel capsule (SC) (e.g., timeslot 2
in a next control channel cycle assuming an offset of 2) or,
alternatively, a sub-synchronous control channel capsule (SSC)
(e.g., one of timeslots 66, 130, 194 of the control channel cycle
assuming an offset of 2), where the periodic BOM message is
scheduled. For example, one particular control channel capsule
within each control channel cycle may be reserved for a particular
BOM. Since other applications may be attempting to access the
control channel and other messages may be scheduled a delay of
multiple cycles may be incurred.
[0039] In 415, after waiting for the next available SC or SSC, the
RAN 120 transmits a broadcast overhead message (BOM) over the air
interface to one or more multicast group members (e.g., ATs A, B,
C). The BOM is a forward link control message defined by EV-DO
standards. The BOM is used to notify each multicast group member of
the BCMCS flows which are currently being carried in a sector. The
BOM also provides Interlaced Multiplexed Pair (IM-Pair) information
which is information regarding the forward link physical layer
timeslots that should be decoded to receive the desired packet
flows, and information on the number of physical layer slots per
broadcast physical layer packet and physical layer rate used to
transmit the flow. In 420, the RAN 120 waits a predetermined number
of slots (e.g., 8 to 16 slots) for the BOM to be decoded at the
target ATs. After the delay 420, the RAN 120 waits for the BCH slot
designated by the decoded BOM, 425. This creates another delay,
which may be further exacerbated based on the traffic on the
broadcast channel In 430, the RAN 120 transmits the announce
message to each multicast group member or target AT which it is
serving over the broadcast channel (BCH) on the designated BCH
slot.
[0040] As described above with respect to FIG. 4, conventional
BCMCS multicast messaging typically requires each target AT or
multicast group member to decode a broadcast overhead message (BOM)
before a multicast message is transmitted over a broadcast channel
(BCH) to the respective members of the multicast group. This
creates delays both for the scheduling of the BOM, delays for the
decoding, and potential subsequent delays for the scheduling the
announce message.
[0041] In the embodiment of FIG. 6, in 600, the application server
170 requests a multicast message be sent to a multicast group
including ATs A, B and C. The multicast message from 600 is routed
to the BSN 165. In 605, the BSN 165 forwards the multicast message
along with the associated multicast group including the target
destinations or ATs for the multicast message over the BCA10
connection to the RAN 120. For example, the BSN 165 may forward the
multicast message to the BSC/PCF 122, which may analyze the
multicast group members associated with the multicast message and
forwards the multicast message to each MPT/BS 124 serving one or
more multicast group members.
[0042] After receiving the forwarded multicast messages, the RAN
120 analyzes the received multicast message in 610. Based on the
analysis in 610, the RAN 120 determines whether to apply special
handling instructions or treatment to the multicast message in 615.
For example, the analyzing in 610 may evaluate the internet
protocol (IP) header of the multicast message. If a "flag" is
determined to be present within the IP header, for example, the
Difserv Code Point (DSCP) value of the IP header, the flag may be
interpreted as a trigger which requests special handling for the
multicast message. Alternatively, the flag may be provided within
the well-known BCA10 identifier (ID) or BCMCS flow ID (e.g.,
separate from the IP header). For example, before the multicast
session, the BSN 165 may be configured with the multicast sessions,
each identified by a multicast IP address and port number, which
are "reserved" or associated with special handling (e.g., multicast
sessions reserved for emergency communications, etc.). The BSN 165
may then share the corresponding BCMCS flow IDs with the RAN 120.
Accordingly, thereafter, during a multicast session, the RAN 120
may check, in 610, whether the received multicast message
corresponds to one of the reserved BCMCS flow IDs, and if so,
determines to apply special handling for the received multicast
message in 615.
[0043] In another alternative example, the flag may be provided via
both the IP header and BCMCS flow ID/BCA10 ID. Generally, a flag
represented by a BCMCS flow ID may be recognized by either portion
of the BSC/PCF 122 whereas a flag within the IP header (either a
DSCP or a multicast IP address and port number) may be
recognized/decoded by the PCF portion of the BSC/PCF 12 of the RAN
120. BCA10 identifiers and DSCP values are well-known in the art,
and will not be described further for the sake of brevity.
[0044] For example, the "flag" may be inserted into the multicast
message (e.g., via the IP header, the BCMCS flow ID or BCA10 ID,
etc.) at any higher-level position within the network architecture
relative to the RAN 120. The flag may be inserted into the IP
header by the application server 170, the BSN 165, etc. In another
example, the flag may be used to designate "higher priority"
multicast messages, such as announce messages that announce or
initiate a particular PTT session. In another example, multicast
messages associated with emergency alerts may be "flagged", whereas
multicast messages associated with product advertisements may not
necessarily be "flagged".
[0045] In 615, if the RAN 120 determines not to apply special
handling to the multicast message, the process advances to block
410 of FIG. 4 and conventional BCMCS multicast message protocols
can be used to transmit the multicast message to the multicast
message group. Otherwise, if the RAN 120 determines that special
handling has been requested for the multicast message in 615, the
process advances to 620.
[0046] In 620, the RAN 120 generates a data over signaling (DOS)
message which includes the multicast message. DOS messages are
well-known in the art within EV-DO protocols. DOS messages are
defined by EV-DO standards as a unicast message, and are not
associated with multicast messaging in the EV-DO standard. However,
embodiments of the invention generate a DOS message including the
multicast message. The DOS message may be reconfigured to support
multicast messaging protocols, as will now be described.
[0047] The CDMA2000 1x EV-DO defines, an access terminal identifier
(ATI) for identifying an access terminal, a broadcast ATI (BATI), a
multicast ATI (MATI), a unicast ATI (UATI), and a random ATI
(RATI). The BATI is defined as "00", the MATI is defined as "01",
the UATI is defined as "10", and the RATI is defined as "11". The
three ATI types excluding the BATI have a 32-bit field for
representing an ATI. The UATI is used in a 1:1 call processing
procedure.
[0048] As discussed above, DOS messages are defined by EV-DO
standards as being associated with unicast messaging, and not
multicast messaging. However, the DOS message generated in 620 is
addressed to the multicast access terminal identifier (MATI), where
the MATI is set to the BCMCSFlowID associated with the multicast
message. The BCMCSFlowID allows the ATs to identify the appropriate
stream on the broadcast channel for the group call. Generally, the
BCMCSFlowID is known at each respective AT which is monitoring a
particular BCMCS flow (e.g., the BCMCSFlowID may be designated by
the BOM, etc.). Accordingly, as will be described in greater detail
below, by tagging or addressing the DOS message of 620 to the MATI,
the target ATs receiving the DOS message may interpret the DOS
message as a multicast message associated with a particular BCMCS
flow, and directly receive the needed information to start the
group call. Alternatively, however, it will be appreciated that
other embodiments need not be limited to setting the MATI to the
BCMCSFlowID to distinguish the DOS as a multicast message. For
example, the MATI may be set to any value which multicast group
members or ATs may interpret as identifying the MATI to be a
multicast message for a particular multicast group.
[0049] In 625, the RAN 120 waits for a next available control
channel capsule on the control channel In 630, the RAN 120
transmits the DOS message to the multicast group members over the
control channel within the next available control channel capsule.
As discussed above, each synchronous channel (SC) (e.g., or
alternatively, each sub-synchronous channel) of the control channel
capsule may include a plurality of MAC layer packets. Accordingly,
in an example, the DOS message may be included in the first MAC
layer packet of the given control channel capsule.
[0050] In 635, each target AT receives the DOS message transmitted
in 630 over the control channel Because the DOS message is
addressed to the MATI, each target AT determines the DOS message to
include the associated multicast message (e.g., as opposed to a
unicast message). It will be appreciated that a DOS message
addressed to a MATI would likely be interpreted as an error in a
conventional handset or AT. In this embodiment, however, each
target AT may be configured to recognize a control message
addressed to the MATI (e.g., or otherwise identified as a multicast
message) as a multicast message, such that the AT configured in
accordance with this embodiment extracts the multicast message from
the received DOS message in 635. The respective target ATs may
acknowledge receipt of the multicast message included within the
DOS message subsequent to a successful receipt or "extracting" of
the multicast message. In another aspect of the invention, the RAN
120 may first confirm that one or more given target ATs is capable
of interpreting, for example, DOS messages using the MATI as
multicast messages, in order to ensure that the DOS multicast
messages are interpreted correctly by receiving ATs. In an example,
each AT receiving the DOS message may decode/extract the multicast
message in 635, irrespective of whether the AT is actually one of
the intended recipients of the multicast message. In another
example, only "target" ATs, or ATs interested in the multicast
session, may decode/extract the multicast message from the DOS
message in 635.
[0051] As will be appreciated from the forgoing description of the
exemplary multicast messaging process of FIG. 6, the delays and
potential loss of data associated with sending a BOM to the
multicast group members, waiting for BOM decoding, and sending an
announce message, may be avoided for DOS multicast messages by
allocating higher-priority status via an IP header flag and
transmitting the higher-priority multicast messages via the control
channel.
[0052] Further, it will be appreciated that the process of FIG. 6,
which has been described as being performed at the RAN 120 and/or
MPT/BS 124 may be performed at one or more RANs and/or MPT/BSs at
the same time in other embodiments of the invention, and the
description of FIG. 6 has been directed to a single-RAN and MPT/BS
implementation for the sake of convenience of description only. In
another example, if multicast group members are dispersed among
different MPT/BS 124's, procedures 610 through 635 may be performed
among the different MPT/BS 124's independently.
[0053] Further, while the embodiment of FIG. 6 is directed to a DOS
message in 1xEVDO being set to a MATI address or multicast bit
signature as opposed to a UATI address or unicast bit signature, it
will be appreciated that any control channel message adapted to
conform to a MATI-type message may alternatively be used to
transfer a multicast message on the control channel
[0054] 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.
[0055] 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.
[0056] 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.
[0057] Accordingly an embodiment of the invention can include an
apparatus including logic configured to detect a multicast message
associated with special handling instructions or higher priority
status (e.g., via an IP header flag). The apparatus can further
include logic configured to package the higher priority multicast
message into a DOS message, logic configured to transmit the DOS
message to ATs belonging to the multicast group members for the
multicast message at a next available SC or SSC. The various
logical elements can be integrated into one device or can be
distributed over several devices each operably couple to one
another. For example, the apparatus can be a radio access network,
a group communication system, or a wireless communication
network.
[0058] Further, aspects of embodiments of the invention can include
logical implementations of the functions described herein. For
example, embodiments of the invention can further include logic
configured to detect a multicast message associated with special
handling instructions or higher priority status (e.g., via an IP
header flag). The logic can further be configured to package the
higher priority multicast message into a DOS message, logic
configured to transmit the DOS message to ATs belonging to the
multicast group members for the multicast message at a next
available SC or SSC. Accordingly, those skilled in the art will
appreciate that embodiments of the invention are not limited to the
examples provided herein.
[0059] 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.
[0060] Accordingly, an embodiment of the invention can include a
computer-readable medium including code stored thereon for
detecting a multicast message associated with special handling
instructions or higher priority status (e.g., via an IP header
flag). The code can further package the higher priority multicast
message into a DOS message, and transmit the DOS message to ATs
belonging to the multicast group members for the multicast message
at a next available SC or SSC. Further, any of the functions
describe herein can be included in as additional code in further
embodiments of the invention.
[0061] 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.
* * * * *