Subject: [NEXTEL-1] Efficient CDMA one-to-many service (Q-Com)

From: Marcel <[email-masked]>
Date: Wed, 22 Jan 2003 04:30:04 -0500

Vassilovski, Dan
                                                                                 January
16, 2003

Efficient CDMA one-to-many service

                                             Abstract

A one-to-many wireless telephone communication system includes a transmitting telephone
that transmits voice packets in, e.g.,
CDMA to a base station in an IP-based infrastructure. The base station converts the CDMA
packets to IP and sends them
through the infrastructure to a communication manager, which copies the packets as many
times as necessary for the recipient
telephones in the group and sends the IP packets back through the infrastructure using the
IP addresses of the recipients. The
base stations receiving the IP packets transform them to voice packets and transmit the
voice packets to the recipient
telephones, thereby relieving the telephones from having to support IP.

Name  Qualcomm
                                             Claims

What is claimed is:

1. A one-to-many wireless telephone system, comprising: at least one infrastructure
component; at least one wireless
transmitting telephone using a wireless telephone over-the-air (OTA) protocol not
encapsulated in an Internet protocol (IP) to
communicate with the infrastructure component, the infrastructure component transforming
OTA information to IP information
and sending the IP information through an infrastructure to a communication manager
accessing a database of user groups, the
communication manager sending copies of the IP information to recipient wireless
telephones in a group of at least three
telephones including the transmitting telephone; the infrastructure component or another
like infrastructure component
transforming the IP information to OTA information and sending the OTA information to the
recipient wireless telephones.

2. The system of claim 1, wherein the OTA protocol is a code division multiple access
(CDMA) air interface protocol.

3. The system of claim 1, wherein the infrastructure component is a base station (BTS).

4. The system of claim 1, wherein the infrastructure component converts OTA protocol
packets to IP packets.

5. The system of claim 1, wherein the infrastructure component converts IP packets to OTA
protocol packets.

6. The system of claim 4, wherein the infrastructure component converts IP packets to OTA
protocol packets.

7. A method for permitting one-to-many communication between at least a transmitting
wireless telephone and at least two
recipient wireless telephones, comprising: sending voice packets unencapsulated in an
IP-based protocol from the transmitting
telephone to an infrastructure; encapsulating the voice packets in at least one IP-based
protocol at the infrastructure to render
IP-based protocol packets; sending at least two sets of the IP-based protocol packets
through the infrastructure; extracting
voice packets from the sets of the IP-based protocol packets; and transmitting the voice
packets unencapsulated in an
IP-based protocol to the recipient telephones.

8. The method of claim 7, wherein the voice packets are code division multiple access
(CDMA) voice packets.

9. The method of claim 7, wherein the act of encapsulating is undertaken by a base station
(BTS) in the infrastructure.

10. The method of claim 7, wherein the act of extracting is undertaken by a base station
(BTS) in the infrastructure.

11. The method of claim 7, comprising copying the IP-based protocol packets.

12. The method of claim 11, wherein the act of copying is undertaken by a communication
manager.

13. The method of claim 7, comprising establishing half duplex communication between the
telephones.

14. A telephone system for use in a one-to-many communication session, comprising: at
least one over-the-air (OTA)
transmitting endpoint indicating a group of OTA recipient endpoints and generating OTA
voice packets intended therefor; at
least one IP endpoint receiving the OTA voice packets and outputting IP-based protocol
packets in response thereto; and at
least one communication manager receiving the IP-based protocol packets and duplicating
them for the OTA recipient
endpoints, the IP-based protocol packets being sent to at least one IP endpoint which
receives the IP-based protocol packets
and outputs OTA voice packets in response thereto for transmission thereof to the OTA
recipient endpoints.

15. The system of claim 14, wherein the OTA voice packets are code division multiple
access (CDMA) packets.

16. The system of claim 14, further comprising an infrastructure transmitting packets
between the IP endpoint and the
communication manager.

17. The system of claim 14, wherein the IP endpoint is a base station (BTS).

18. The system of claim 14, wherein half duplex communication is established by the
communication manager.

                                           Description

I. FIELD OF THE INVENTION

[0001] The present invention relates generally to enabling a one-to-many communication
service using a wireless telephone.

II. BACKGROUND OF THE INVENTION

[0002] Wireless telephones, such as but not limited to wireless telephones that
communicate using Code Division Multiple
Access (CDMA) spread spectrum modulation techniques, can be used to provide one-to-many
communication capability (also
referred to as "dispatch" or "net broadcast"). An example of such a service is the present
assignee's QChat.RTM. service,
disclosed in, e.g., U.S. patent application Ser. Nos. 09/518,622, filed Mar. 3, 2000,
09/518,776, filed Mar. 3, 2000, and
09/518,985, filed Mar. 3, 2000, all of which are incorporated herein by reference. Using
the QChat service, a user of a
CDMA telephone can press a button on the phone to automatically invoke what amounts to a
private, half-duplex network to
speak to one or more other CDMA telephone users on the network. By "half duplex" is meant
that only one speaker at a time
can talk when the button is held down. When the button is released, other speakers in the
network can depress their talk
buttons and speak to the other phones.

[0003] The above-mentioned service is based on transmitting voice packets that are
encapsulated within standard Internet
Protocol (IP)-based protocols, including UDP, IP, PPP, RTP, and RLP, which are designed to
carry non-voice data (i.e.,
computer data) in a CDMA data service. In a data service, as opposed to a voice service,
the wireless telephone essentially
functions as a data conduit for a computer that is plugged into the phone. In any event,
it is to be appreciated that the
one-to-many communication capability of QChat is implemented using an IP-based service
originally designed to carry
computer data.

[0004] In the one-to-many voice service field to which the present invention is directed,
a component within the CDMA
infrastructure known as a communication manager arbitrates speaker and listener privileges
and processes the IP packets
carrying the voice data by replicating and transmitting the voice packets to the IP
addresses of other wireless telephones
participating in the network. While the QChat service is an effective one-to-many
communication service, the present invention
recognizes that it is possible to improve the latency and voice quality of the service.

[0005] Specifically, IP-related protocols increase over-the-air reliability by introducing
certain communication overhead that
increases latency (communication time delay), with the increased latency ordinarily not
representing much if any drawback
when computer data is being transmitted, but affecting the telephone's ability to transmit
voice data. More specifically, since the
overhead of a single IP-based data protocol unit exceeds the capacity of a single CDMA
over-the-air frame, the IP-based data
protocol overhead must be amortized by aggregating multiple voice frames in a single
IP-based data protocol unit, resulting in
added latency for voice transmission. Moreover, to maintain the added latency at a
user-tolerable level, the voice packets must
be reduced in size by restricting the CDMA vocoder (compression component) to encode data
at rates other than its peak
rate. This adversely affects voice quality.

[0006] Still further, by requiring the QChat service to use IP, increased processing
requirements are imposed on the wireless
telephone by requiring encapsulation of voice frames within the IP-based protocols. For
instance, the wireless telephone must
exercise the IP-based data protocol unit with a frequency that is dictated by the number
of voice frames aggregated in the unit.
With the above critical observations in mind, the present invention provides the solutions
disclosed herein.

SUMMARY OF THE INVENTION

[0007] A method for permitting one-to-many communication between a transmitting wireless
telephone and at least two
recipient wireless telephones includes sending voice packets unencapsulated in an IP-based
protocol from the transmitting
telephone to an infrastructure. The method then includes encapsulating the voice packets
in an IP-based protocol at the
infrastructure to render IP-based protocol packets, at least two copies of which are sent
through the infrastructure. By "sending
copies" is meant not only sending separate copies to individual addresses, but also
sending a single copy to a multicast address
that is monitored by two or more entities. Voice packets are extracted from the copies of
the IP-based protocol packets and
sent unencapsulated in an IP-based protocol to the recipient telephones.

[0008] In another aspect, a telephone system for use in a one-to-many communication
session includes an over-the-air (OTA)
transmitting endpoint indicating a group of OTA recipient endpoints and generating OTA
voice packets intended for the
recipients. An IP endpoint receives the OTA voice packets and outputs IP-based protocol
packets in response thereto. A
communication manager receives the IP-based protocol packets and duplicates them for the
OTA recipient endpoints, with the
IP-based protocol packets then being sent to one or more other IP endpoints. These other
IP endpoints receive the IP-based
protocol packets and output OTA voice packets in response thereto for transmission of the
voice packets to the OTA recipient
endpoints.

[0009] In yet another aspect, a one-to-many wireless telephone system includes an
infrastructure component, preferably a base
station, and a wireless transmitting telephone that uses a wireless telephone over-the-air
(OTA) protocol such as CDMA which
is not encapsulated in an Internet protocol (IP) to communicate with the infrastructure
component. The infrastructure
component transforms OTA information to IP information and sends the IP information
through an infrastructure to a
communication manager. In turn, the communication manager accesses a database of user
groups to ascertain recipients in the
group. As set forth below, the communication manager sends copies of the IP information to
the recipient wireless telephones in
the group, which includes at least three telephones including the transmitting telephone.
The infrastructure component or another
like infrastructure component transforms the IP information to OTA information and sends
the OTA information to the recipient
wireless telephones.

[0010] The details of the present invention, both as to its structure and operation, can
best be understood in reference to the
accompanying drawings, in which like reference numerals refer to like parts, and in which:

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 is a block diagram of a presently preferred one-to-many wireless
communication system; and

[0012] FIG. 2 is a flow chart of the present logic.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0013] Referring initially to FIG. 1, a system is shown, generally designated 10, for
effecting one-to-many communication
between a transmitting wireless communication device 12 that does not support voice over
Internet Protocols (VOIP) and
plural group member telephones 13 that likewise do not support VOIP, via a telephony
infrastructure 14 that supports IP. By
"does not support VOIP" or "does not support IP" is meant that the devices 12, 13 either
have no IP or VOIP capability, or
that they have such capability but for improved voice performance use a standard over the
air (OTA) voice protocol such as a
spread spectrum scheme like CDMA or WCDMA or other wireless protocol such as but not
limited to TDMA, UMTS,
TD-SCDMA, etc. to communicate with the infrastructure 14. In one non-limiting embodiment
the devices 12, 13 are mobile
telephones made by Kyocera, Samsung, or other manufacturer that use Code Division Multiple
Access (CDMA) principles
and CDMA over-the-air (OTA) communication air interface protocols such as defined in but
not limited to IS-95A, IS-95B,
UCDMA, IS-2000, and others to communicate with the infrastructure 14.

[0014] For instance, the wireless communication systems to which the present invention can
apply, in amplification to those
noted above, include Personal Communications Service (PCS) and cellular systems, such as
Analog Advanced Mobile Phone
System (AMPS) and the following digital systems: CDMA, Time Division Multiple Access
(TDMA), and hybrid systems that
use both TDMA and CDMA technologies. A CDMA cellular system is described in the
Telecommunications Industry
Association/Electronic Industries Association (TIA/EIA) Standard IS-95. Combined AMPS and
CDMA systems are
described in TLA/EIA Standard IS-98. Other communications systems are described in the
International Mobile
Telecommunications System 2000/Universal Mobile Telecommunications Systems (IMT-2000/UM),
standards covering what
are referred to as wideband CDMA (WCDMA), cdma2000 (such as cdma2000 1.times. or 3.times.
standards, for example)
or TD-SCDMA.

[0015] The present invention applies to any wireless communication device 12; for
illustration it will be assumed that the device
12 is a telephone. In general, wireless communication devices to which the present
invention applies may include but are not
limited to a wireless handset or telephone, a cellular phone, a data transceiver, or a
paging and position determination receiver,
and can be hand-held, or portable as in vehicle-mounted (including cars, trucks, boats,
planes, trains), as desired. However,
while wireless communication devices are generally viewed as being mobile, it is to be
understood that the present invention can
be applied to "fixed" units in some implementations. Also, the present invention applies
to data modules or modems used to
transfer voice and/or data information including digitized video information, and may
communicate with other devices using
wired or wireless links. Further, commands might be used to cause modems or modules to
work in a predetermined
coordinated or associated manner to transfer information over multiple communication
channels. Wireless communication
devices are also sometimes referred to as user terminals, mobile stations, mobile units,
subscriber units, mobile radios or
radiotelephones, wireless units, or simply as "users" and "mobiles" in some communication
systems.

[0016] As shown in FIG. 1, the wireless telephone 12 communicates, using one or more of
the above-mentioned systems, with
at least one first infrastructure component 16 that accesses a logic module to execute the
logic of the present invention. The first
component 16 preferably is a base station (BTS), but it can also be implemented by base
station controller (BSC), mobile
switching center (MSC), gateway to a satellite system, or other infrastructure component.
In any case, the first component 16
not only supports the necessary protocols and systems to communicate with the wireless
device 12, but also supports IP
(which includes attendant protocols or stack of IP protocols), and accordingly the
component 16 communicates with the
infrastructure 14.

[0017] The infrastructure 14 can include a BSC or other BTS using IP. Preferably,
conventional BSC functions are undertaken
by the BTS, so that no BSC need be provided. It is to be understood that while FIG. 1
shows a single BTS 16 communicating
with the telephones 12, 13, each telephone 12, 13 can communicate through the
infrastructure 14 via separate respective BTS.

[0018] The infrastructure component 16 thus communicates with the wireless telephones 12,
13 using OTA protocol but
communicates internally to the infrastructure 14 using IP, thereby relieving the wireless
telephones 12, 13 from having to
support IP and attendant suite of voice over Internet protocols or from having to support
any processing, use of resources, etc.
related to implementing IP. Also, by using IP internally to the infrastructure 14 and OTA
protocol between the telephones 12,
13 and their respective BTS 16, the advantages of using IP internal to the infrastructure
14 are realized, whereas the
advantages of OTA protocol in wireless communication to the telephones 12, 13 are
preserved to maximize the over-the-air
capacity of the system 10. Accordingly, the infrastructure components (BTS) 16 can be
thought of as virtual IP endpoints, with
the actual communication endpoints being the telephones 12, 13.

[0019] As contemplated herein, the transmitting wireless telephone 12 can communicate,
using the infrastructure 14, with a
communication manager 20. In one non-limiting embodiment, communication between the
infrastructure 14 and communication
manager 20 is over a link 22 such as but not limited to the Internet. The communication
manager 20 is an appropriate device
that manages one-to-many communications in accordance with principles known in the art. To
this end, the communication
manager 20 accesses a group database 24 that contains identities and memberships of
self-defined groups of telephones 12,
13. In one non-limiting embodiment, the communication manager 20 can be a QChat
communication manager.

[0020] With the above overview of the present architecture in mind, it is to be understood
that the present logic is executed on
the architecture shown in FIG. 1 in accordance with the flow charts discussed below. The
flow charts herein illustrate the
structure of the logic of the present invention as embodied in computer program software.
Those skilled in the art will
appreciate that the flow charts illustrate the structures of logic elements, such as
computer program code elements or electronic
logic circuits, that function according to this invention. Manifestly, the invention is
practiced in its essential embodiment by a
machine component that renders the logic elements in a form that instructs a digital
processing apparatus (that is, a computer,
controller, processor, etc.) to perform a sequence of function steps corresponding to
those shown.

[0021] In other words, the logic may be embodied by a computer program that is executed by
a processor within, e.g., the
infrastructure component 16 and/or communication manager 20 as a series of computer- or
control element-executable
instructions. These instructions may reside, for example, in RAM or on a hard drive or
optical drive, or the instructions may be
stored on magnetic tape, electronic read-only memory, or other appropriate data storage
device that can be dynamically
changed or updated.

[0022] Now referring to FIG. 2, the logic of the present invention can be seen. Commencing
at block 26, a user of the
telephone 12 can press a hardware- or software-implemented "transmit" button 28 on the
phone 12. The button 28 can be any
suitable telephone button used for one-to-many communications, such as, by way of
non-limiting example, a "send" button. It is
to be understood that when the one-to-many service enables the telephone 12 to belong to
multiple groups, the user can first
select the desired group in accordance with one-to-many communication principles known in
the art.

[0023] In any case, when the transmitting button is pressed, a "transmit" signal is sent
to the component 16 at block 30. In the
case wherein the telephone 12 supports IP for data services, depressing the transmit
button can stimulate the telephone 12 to
issue a signal to the infrastructure that the ensuing voice communications are undertaken
as set forth below using OTA
protocols that are not encapsulated in IP.

[0024] The transmit signal can be any appropriate signal used for signalling a one-to-many
session is sought to be entered. For
example, the transmit signal can be a CDMA signalling message indicating a request for
one-to-many communication, and
identifying the transmitting telephone 12 and the one-to-many group sought to be included,
as indicated by the user by
appropriately manipulating the control keys of the telephone 12.

[0025] At block 31, the transmit signal is received by the first component 16 (e.g., BTS),
where in one non-limiting
embodiment it is converted to IP and sent through the infrastructure 14. In one exemplary,
non-limiting embodiment, the
process at block 31 can include receiving a CDMA protocol one-to-many origination message
from the telephone 12 in, for
example, IS-95 protocol, and then in response essentially transforming the one-to-many
origination message to IP by sending
an IP-based Session Initiation Protocol (SIP) messages from the first component 16 to
other appropriate components such as
the communication manager 20 in accordance with principles known in the art.

[0026] Next, at block 32, the communication manager 20 receives the one-to-many request
and establishes the priority of the
transmitting telephone 12 to speak. Also, the communication manager 20 accesses the
database 24 to identify the individual
recipient telephones 13 in the group, as indicated by information in the signalling
message. Communication channels to the
group members are then established within the infrastructure 14 using the above-mentioned
SIP messages, which establish
communications with the intended recipient telephones 13 through their respective IP
endpoints, e.g., through the first
component 16 (e.g., BTS) in the simplified embodiment shown in FIG. 1 or through another
BTS.

[0027] The user then speaks into the phone 12, at which time OTA voice packets such as
CDMA voice packets are generated
at block 34 and sent without encapsulating them in IP. At block 36, the OTA voice packets
are received at the first component
16, i.e., at the IP endpoint, and translated to IP. To make this transformation, the
contents of the OTA voice packets are
rearranged as appropriate to conform to IP packet requirements. Typically, since OTA voice
packets are smaller than IP
packets and frequently are smaller than the headers of IP packets, several OTA packets
might be combined into a single IP
packet, although this might not necessarily be the case particularly for latency intensive
applications. One of the benefits of
encapsulation in IP at the infrastructure is the bandwidth use is seldom a concern, and
individual voice frames may each be
encapsulated in IP. Additionally, well-known IP header compression techniques can be
employed to reduce the size of the
headers.

[0028] The information in IP is sent through the infrastructure 14 to the communication
manager 20 at block 38. Moving to
block 40, the communication manager 20 copies the packets as necessary, one copy for each
recipient telephone 13 in the
group, and sends the duplicate IP packets to the IP address for each respective recipient
telephone 13 in the group. The IP
packets are then routed through the infrastructure 14 to the appropriate IP endpoints
(e.g., BTS) that are in communication
with the recipient telephones 13.

[0029] At the IP endpoints (e.g., BTS) for the respective recipient telephones 13, the IP
packets representing the voice
information from the transmitting telephone 12 are converted to OTA packets at block 42.
In the simplified embodiment shown
in FIG. 1, the first component 16 functions as the IP endpoint for both the transmitting
telephone 12 and the recipient
telephones 13. The OTA packets are sent to the recipient telephones 13 at block 44. The
transformation from IP to OTA
protocol is the reverse of the process for converting OTA packets to IP packets, i.e.,
each IP packet might be separated into a
set of smaller OTA packets as appropriate to conform to the OTA protocol used by the
recipient telephones 13.

[0030] The communication manager 20 also arbitrates between the telephones 12, 13 for
establishing a half duplex session,
i.e., a communication session wherein only a single telephone 12, 13 at a time is
permitted to transmit voice packets. This
arbitration can be undertaken by means known in the art. For example, when the user of the
transmitting telephone 12 holds
down the transmit button 28, no other telephone 13 in the group will be permitted to
transmit OTA packets, until the user
releases the button. Then, a user of one of the recipient telephones 13 can depress and
hold their transmit button to talk in
accordance with the principles set forth above.

[0031] While the particular EFFICIENT CDMA ONE-TO-MANY SERVICE as herein shown and
described in detail is fully
capable of attaining the above-described objects of the invention, it is to be understood
that it is the presently preferred
embodiment of the present invention and is thus representative of the subject matter which
is broadly contemplated by the
present invention, that the scope of the present invention fully encompasses other
embodiments which may become obvious to
those skilled in the art, and that the scope of the present invention is accordingly to be
limited by nothing other than the
appended claims, in which reference to an element in the singular is not intended to mean
"one and only one" unless explicitly so
stated, but rather "one or more". All structural and functional equivalents to the
elements of the above-described preferred
embodiment that are known or later come to be known to those of ordinary skill in the art
are expressly incorporated herein by
reference and are intended to be encompassed by the present claims. Moreover, it is not
necessary for a device or method to
address each and every problem sought to be solved by the present invention, for it to be
encompassed by the present claims.
Furthermore, no element, component, or method step in the present disclosure is intended
to be dedicated to the public
regardless of whether the element, component, or method step is explicitly recited in the
claims. No claim element herein is to
be construed under the provisions of 35 U.S.C. .sctn.112, sixth paragraph, unless the
element is expressly recited using the
phrase "means for" or, in the case of a method claim, the element is recited as a "step"
instead of an "act".

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