Title of Invention	APPARATUS AND METHOD PROVIDING PUSH TO TALK OVER CELLULAR (POC) DYNAMIC SERVICE OPTIONS
Abstract	An apparatus and method for providing dynamic Push To Talk over Cellular, PoC, service options in a wireless communication network. Service options and terminal capabilities for PoC Clients (11, 15) are stored in the network, preferably in a PoC Server (13). A PoC Client (11) uses a SIP PUBLISH message (17) to set the actual status of the answering mode and any barring service, and, if automatic answering mode is set, also stores a list of codecs that the PoC Client (11) supports. When the PcC Client is called, the calling PoC Client (15) informs the Server (13) of supported codecs, and the Server selects a codec supported by both Clients, thus optimizing the connection.

Title of Invention

APPARATUS AND METHOD PROVIDING PUSH TO TALK OVER CELLULAR (POC) DYNAMIC SERVICE OPTIONS

Abstract

An apparatus and method for providing dynamic Push To Talk over Cellular, PoC, service options in a wireless communication network. Service options and terminal capabilities for PoC Clients (11, 15) are stored in the network, preferably in a PoC Server (13). A PoC Client (11) uses a SIP PUBLISH message (17) to set the actual status of the answering mode and any barring service, and, if automatic answering mode is set, also stores a list of codecs that the PoC Client (11) supports. When the PcC Client is called, the calling PoC Client (15) informs the Server (13) of supported codecs, and the Server selects a codec supported by both Clients, thus optimizing the connection.

Full Text	FORM 2 THE PATENTS ACT, 1970 (39 of 1970) & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION (See section 10, rule 13) “APPARATUS AND METHOD PROVIDING PUSH TO TALK OVER CELLULAR (PoC) SERVICE OPTIONS” Telefonaktiebolaget LM Ericsson (publ). of Telefonplan;S- 164 83 Stockholm(SE) The following specification particularly describes the invention and the manner in which it is to be performed. WO 2006/032940 PCT/IB2004/003075 -2- APPARATUS AND METHOD PROVIDING PUSH TO TALK OVER CELLULAR (POC) DYNAMIC SERVICE OPTIONS TECHNICAL FIELD OF THE INVENTION 5 The present invention relates generally to communication networks, and in particular, to an apparatus and method for providing dynamic Push To Talk over Cellular (PoC) service options in wireless communication networks. DESCRIPTION OF RELATED ART 10 Push To Talk over Cellular (PoC) is a fast-connect half-duplex service of the type generally known as Push-to-Talk (PTT) or voice chat services. PTT applications provide wireless users with a virtually instantaneous method of connecting to other users, with just the touch of a button on their handset. The service is half-duplex and can be used for one-to-one private calls as well as 15 one-to-many group calls. Users can take advantage of private, direct, simultaneous radio voice connection over very wide areas, afford ably and conveniently, often replacing other devices such as pagers and two-way radios. Users receiving the call hear the caller's voice automatically without having to answer the call. 20 PoC is the official name used in the open specifications currently being developed by the Open Mobile Alliance (OMA) for this service. The PoC specifications utilize a number of existing specifications from the Internet Engineering Task Force (IETF), the Third Generation Partnership Project (3GPP), and 3GPP2 including the capabilities of the 3GPP IP Multimedia 25 Subsystem (IMS) and the 3GPP2 Multimedia Domain (MMD) to enable IP connectivity between mobile devices. In one solution, PoC uses a server, which is independent of the existing radio and core networks. PoC may be implemented on the IP backbone over radio technologies such as WCDMA, CDMA2000, GPRS, UMTS, and 802.11. 30 The use of IMS and MMD adds the ability to integrate voice and data services over IP-based packet-switched networks. Two fundamental capabilities CONFIRMATION COPY WO 2006/032940 -3- are added on top of the packet-switched domain. First is the via the Session Initiation Protocol (SIP) to initiate a session. S to integrate new services such as PTT. By introducing IM service-delivery capability, a common infrastructure for service 5 and the requirement to build a service delivery infrastructure eliminated. The existing PoC standard defines two barring service answering mode service option requiring configuration in the n ● Incoming Session Barring for PoC Communication 10 ● Incoming Session Barring for PoC Alert; and ● Answering Mode (automatic or manual answering These options are very dynamic, and traditional management The existing PoC standard also defines the following requiring configuration in the network: 15 ● Supported codecs for encoding voice signals; an ● Supported codecs for decoding voice signals. The existing PoC standard specifies some dynamic s* there is no solution for configuring dynamic PoC-related feature in the network. The answering mode, for example, can be s 20 manual mode. If the answering mode is set to manual, call e-* same as a normal SIP call. However, if the answering mode i the network allows the calling PoC user to start speaking at the called user is invited. The SIP protocol requires that the network . codec for use with the call. This creates a problem for the network 25 codec selected for the call may not be supported by the called the network must perform transcoding between the calling called PoC user. The transcoding of audio, compressed wit PoC terminals, will produce poor sound quality. One solution to this problem Is to always use the se 30 default codec). However, this may also be a problem since WO 2006/032940 PCT/IB2004/003075 -4- may be connected via different access technologies with different views on which default codec to use, and with different views on available bandwidth. Accordingly, there is a need for an improved apparatus and method for providing dynamic PoC service options. 5 SUMMARY OF THE INVENTION The present invention provides a solution in which service options and terminal capabilities for PoC Clients are stored in the network. The service options and terminal capabilities may be stored in the PoC Server or in a server 10 close to the PoC server. In a preferred embodiment, a PoC Client uses the SIP PUBLISH method to set the actual status of the answering mode and any barring service, and, if automatic answering mode is set, also stores a list of codecs that the PoC Client supports. By telling the network which codecs the PoC Client supports, the network can then make a more intelligent selection of the codec in 15 the automatic answer case, and can also utilize better codecs when the access technology allows. The service options may be retrieved by the PoC Server or any other service that requires knowledge about the present service option and terminal capabilities settings. Thus in one aspect, the present invention is directed to a method of 20 providing dynamic PoC service options. The method includes the steps of storing service options of a calling PoC client and a called PoC client in a server, retrieving the stored service options during establishment of a data/audio session between the calling PoC client and the called PoC client; and utilizing the retrieved service options to optimize the session. 25 In another aspect, the present invention is directed to a method of . providing dynamic PoC service options that includes the steps of storing in a server, an indication of whether an answering mode of a called PoC client is set to automatic or manual, and an indication of which codecs are supported by the called PoC client for decoding encoded voice signals; and receiving in the 30 server, a request from a calling PoC client to establish a session with the called PoC client. The request includes an indication of which codecs are supported by WO 2006/032940 PCT/IB2004/003075 the calling PoC client for encoding voice signals. If the answering mode of the called PoC client is set to automatic, the server selects a codec that is supported by both the calling PoC client and the called PoC client, and notifies the calling PoC client and the called PoC client of the codec selected for use during the 5 session. In yet another aspect the present invention is directed to an apparatus for providing dynamic PoC service options. The apparatus includes a database for storing an indication of whether an answering mode of a called PoC client is set to automatic or manual, and an indication of which codecs are supported by the 10 called PoC client for decoding encoded voice signals; means for receiving a request message from a calling PoC client to establish a session with the called PoC client and a codec selector for selecting a codec that is supported by both the calling PoC client and the called PoC client. The apparatus also includes means responsive to receiving the request message, for retrieving from the 15 database, the indication of the answering mode of the called PoC client and the indication of which codecs are supported by the called PoC client If the answering mode is automatic, the indication of which codecs are supported by the called PoC client is sent to the codec selector. The apparatus also includes means responsive to an indication that the answering mode of the called PoC 20 client is set to automatic, for extracting from the request message, an indication of which codecs are supported by the calling PoC client for encoding voice signals, wherein the indication of which codecs are supported by the calling PoC client is sent to the codec selector; and means for notifying the calling PoC client and the called PoC client of the codec selected for use during the session. 25 BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a signaling diagram illustrating an embodiment of the method of the present invention; and Figure 2 is a simplified functional block diagram of a PoC Server modified 30 in accordance with the present invention. WO 2006/032940 PCT/IB2004/003075 DETAILED DESCRIPTION OF EMBODIMENTS Figure 1 is a signaling diagram illustrating an exemplary embodiment of the method of the present invention. Illustrated are a called client (PoC Client B) 11, a SIP/IP core network 12, a PoC server 13, an originating network 14, and a 5 calling client (PoC Client A) 15. At step 16, the user of PoC Client 8 changes a service option such as incoming Session Barring for PoC Communication, Incoming Session Barring for PoC Alert, or Answering Mode (automatic or manual). For example, the PoC Client B may change its answering mode to automatic. 10 The PoC Client B 11 then uses the PUBLISH method to set service options and terminal capabilities in the network. The PoC Client B sends a PUBLISH request message 17 to the SIP/IP Core 12 and includes, in this example, an indication that the answering mode is set to automatic, and an indication of the types of codecs supported by the PoC Client B. At step 18, the 15 PUBLISH request message is forwarded to the PoC Server 13. Since the answering mode is set to automatic, the codecs supported by PoC Client B are also uploaded to the PoC Server. The PoC Server then returns a SIP 200 OK message 19 to the SIP/IP Core, which forwards the message at step 21 to the PoC Client B. 20 At that point in the example, PoC Client A 15 invites the PoC Client B 11 to a call. This is done by PoC Client A sending a SIP INVITE message 22 to the originating network 14, which forwards the message at step 23 to the SIP/IP Core 12. The INVITE message includes a list of codecs supported by PoC Client A. The SIP/IP Core, in turn, forwards the INVITE message at step 24 to 25 the PoC Server 13. The PoC Server then selects a codec from the lists of supported codecs received from PoC Client A and PoC Client B. This enables the PoC Server to select a codec and optimize bandwidth efficiency and audio quality with respect to the access technology being utilized by the two clients. The PoC server then includes an indication of the selected codec in a 183 30 Session Progress message 25, which is sent to the SIP/IP Core. At step 26, the SIP/IP Core forwards the 183 Session Progress message to the originating WO 2006/032940 PCT/IB2004/003075 -7- network, which then sends a SIP 200 OK message 27 with an indication of the selected codec to the PoC Client A. Establishment of the session then proceeds. At step 28, the PoC Client A 15 begins to send media coded with the selected codec to the originating 5 network 14. Meanwhile, the PoC Server 13 sends a SIP INVITE request message 29 to the SIP/IP Core 12, and includes an indication of the selected codec. At step 31, the SIP/IP Core forwards the SIP INVITE request message with the indication of the selected codec to the PoC Client B 11. The PoC Client B returns a SIP 200 OK message 32, acknowledging the INVITE and the 10 selected codec to the SIP/IP Core. At step 33, the SIP/IP Core forwards the 200 OK message to the PoC Server. At step 34, the PoC Server returns a SIP 200 OK message with an indication of the selected codec to the SIP/IP Core, which forwards the message to the originating network at step 35. At step 36, the originating network sends the media coded with the selected codec to the PoC 15 Server, which forwards the encoded media to the PoC Client B at step 37. Thus, the invention uses the weft-known SIP protocol to publish dynamic data utilized to optimize bandwidth efficiency and audio quality. The use of SIP makes it possible to route the PUBLISH request to a PoC Server independent of the location in a well-known manner. 20 Figure 2 is a simplified functional block diagram of the PoC Server 13 modified in accordance with the present invention. A dynamic PoC service option controller 41 controls signaling to and from the PoC Server according to service options that are stored in a user database 42. In the exemplary embodiment illustrated, the controller receives the PUBLISH message 18 sent 25 by the PoC Client B11, and stores the answering mode and the indication of the codecs supported by PoC Client B in the database. When the controller receives the INVITE message 24 sent by PoC Client A 15, the controller retrieves the data from the database and determines in an answer mode analyzer 43, whether the answering mode is manual or automatic. If the answer 30 mode analyzer determines that the PoC Client B's answering mode is manual, the controller 41 uses normal SIP procedures 45 to establish the session. WO 2006/032940 PCT/IB2004/003075 However, if the answer mode analyzer determines that the PoC Client B's answering mode is automatic, the controller extracts the indication of the Client A-supported codecs from the INVITE message, and sends the retrieved indication of the Client B-supported codecs and the extracted indication of the 5 Client A-supported codecs to a codec selector 44. The codec selector selects a codec that is supported by both PoC Client A and PoC Client B, and returns an indication of the selected codec to the controller. The controller then includes the indication of the selected codec in the 183 Session Progress message 25 sent toward PoC Client A and the INVITE message 29 sent toward PoC Client B. 10 The session is then established utilizing the selected codec. It should be recognized that the answer mode analyzer 43 and the codec selector 44 may be functionally implemented as part of the dynamic PoC service option controller 41 or as separate functional units. Those skilled in the art will readily appreciate that the present invention 15 may be implemented using either hardware, or software, or both, and further, software implementations may vary using different languages and data structures. The present invention is not limited to a specific language and/or class of languages, nor is it limited to any single data structure implementation. The present invention may of course, be carried out in other specific ways 20 than those herein set forth without departing from the essential characteristics of the invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein. 24-07-2006 IB2004003075 CLAIMS: 1. A method of providing dynamic Push To Talk over Cellular, PoC, service options, said method comprising the steps of: 5 sending service options of a calling PoC client and a called PoC client over a Session Initiation Protocol, SIP, interface to a PoC server; storing the service options of the calling PoC client and the called PoC client in the PoC server; retrieving the stored service options during establishment of a session 10 between the calling PoC client and the called PoC client; and utilizing the retrieved service options to optimize the session. 2. The method of claim 1, wherein the step of storing service options includes storing a service option that indicates whether incoming sessions for PoC 15 communication are barred. 3. The method of claim 1, wherein the step of storing service options includes storing a service option that indicates whether incoming sessions for PoC alert are barred. 20 4. The method of claim 1, wherein the step of storing service options includes storing a service option for the called PoC client that indicates whether an answering mode is set to manual or automatic. 25 5. The method of claim 4, further comprising the steps of: storing terminal capabilities of the calling PoC client and the called PoC client in the PoC server; retrieving the stored terminal capabilities during establishment of a session between the calling PoC client and the called PoC client; and 30 utilizing the retrieved terminal capabilities to optimize the session. AMENDED SHEET 24-07-2006 IB2004003075 -10- 6. The method of claim 5, wherein the step of storing terminal capabilities of the calling PoC client and the called PoC client includes storing an indication of which codecs are supported by the calling PoC client and the called PoC client. 5 7. A method of providing dynamic Push To Talk over Cellular, PoC, service options, said method comprising the steps of: sending over a Session Initiation Protocol, SIP, interface to a PoC server, an indication of whether an answering mode of a called PoC client is set to 10 automatic or manual, and an indication of which codecs are supported by the called PoC client for decoding encoded voice signals; storing in the PoC server, the indication of whether the answering mode of the called PoC client is set to automatic or manual, and the indication of which codecs are supported by the called PoC client; 15 receiving in the PoC server, a request from a calling PoC client to establish a session with the called PoC client, said request including an indication of which codecs are supported by the calling PoC client for encoding voice signals; if the answering mode of the called PoC client is set to automatic, selecting by the PoC server, a codec that is supported by both the calling PoC client and 20 the called PoC client; and notifying the calling PoC client and the called PoC client of the codec selected for use during the session. 8. The method of claim 7, wherein the sending step Includes sending 25 the indications to the PoC server in a SIP PUBLISH message sent by the PoC client and forwarded to the PoC server by a core network. 9. The method of claim B, wherein the SIP PUBLISH message also includes an indication of whether PoC communications or PoC alerts are currently 30 barred in the called PoC client, and the method further comprises the step of determining that PoC communications and PoC alerts are currently allowed in the called PoC client before establishing the session. AMENDED SHEET 24-07-2006 IB2004003075 10. An apparatus for providing dynamic Push To Talk over Cellular (PoC) service options, said apparatus comprising: a Session Initiation Protocol, SIP, interface for sending to a PoC server, an 5 indication of which codecs are supported by a called PoC client for decoding encoded voice signals; a database associated with the PoC server for storing the indication of which codecs are supported by the called PoC client; means for receiving a request message from a calling PoC client to 10 establish a session with the called PoC client, said request message including an indication of which codecs are supported by the calling PoC client for encoding voice signals; a codec selector for selecting a codec that is supported by both the calling PoC client and the called PoC client; 15 means responsive to receiving the request message for retrieving from the database, the indication of which codecs are supported by the called PoC client, and for sending the indication of which codecs are supported by the called PoC client to the codec selector; means for extracting from the request message, the indication of which 20 codecs are supported by the calling PoC client for encoding voice signals, and for sending the indication of which codecs are supported by the calling PoC client to the codec selector; and means for notifying the calling PoC client and the called PoC client of the codec selected for use during the session. 25 AMENDED SHEET

Full Text

FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10, rule 13)
“APPARATUS AND METHOD PROVIDING PUSH TO TALK OVER CELLULAR
(PoC) SERVICE OPTIONS”
Telefonaktiebolaget LM Ericsson (publ). of Telefonplan;S- 164 83 Stockholm(SE)
The following specification particularly describes the invention and the manner in which it is to be performed.

WO 2006/032940

PCT/IB2004/003075

-2-
APPARATUS AND METHOD PROVIDING
PUSH TO TALK OVER CELLULAR (POC) DYNAMIC SERVICE OPTIONS
TECHNICAL FIELD OF THE INVENTION
5 The present invention relates generally to communication networks, and
in particular, to an apparatus and method for providing dynamic Push To Talk over Cellular (PoC) service options in wireless communication networks.
DESCRIPTION OF RELATED ART
10 Push To Talk over Cellular (PoC) is a fast-connect half-duplex service of
the type generally known as Push-to-Talk (PTT) or voice chat services. PTT applications provide wireless users with a virtually instantaneous method of connecting to other users, with just the touch of a button on their handset. The service is half-duplex and can be used for one-to-one private calls as well as
15 one-to-many group calls. Users can take advantage of private, direct, simultaneous radio voice connection over very wide areas, afford ably and conveniently, often replacing other devices such as pagers and two-way radios. Users receiving the call hear the caller's voice automatically without having to answer the call.
20 PoC is the official name used in the open specifications currently being
developed by the Open Mobile Alliance (OMA) for this service. The PoC specifications utilize a number of existing specifications from the Internet Engineering Task Force (IETF), the Third Generation Partnership Project (3GPP), and 3GPP2 including the capabilities of the 3GPP IP Multimedia
25 Subsystem (IMS) and the 3GPP2 Multimedia Domain (MMD) to enable IP connectivity between mobile devices. In one solution, PoC uses a server, which is independent of the existing radio and core networks. PoC may be implemented on the IP backbone over radio technologies such as WCDMA, CDMA2000, GPRS, UMTS, and 802.11.
30 The use of IMS and MMD adds the ability to integrate voice and data
services over IP-based packet-switched networks. Two fundamental capabilities
CONFIRMATION COPY

WO 2006/032940
-3-
are added on top of the packet-switched domain. First is the via the Session Initiation Protocol (SIP) to initiate a session. S to integrate new services such as PTT. By introducing IM service-delivery capability, a common infrastructure for service
5 and the requirement to build a service delivery infrastructure eliminated.
The existing PoC standard defines two barring service
answering mode service option requiring configuration in the n
● Incoming Session Barring for PoC Communication
10 ● Incoming Session Barring for PoC Alert; and
● Answering Mode (automatic or manual answering
These options are very dynamic, and traditional management
The existing PoC standard also defines the following
requiring configuration in the network:
15 ● Supported codecs for encoding voice signals; an
● Supported codecs for decoding voice signals.
The existing PoC standard specifies some dynamic s* there is no solution for configuring dynamic PoC-related feature in the network. The answering mode, for example, can be s
20 manual mode. If the answering mode is set to manual, call e-* same as a normal SIP call. However, if the answering mode i the network allows the calling PoC user to start speaking at the called user is invited. The SIP protocol requires that the network . codec for use with the call. This creates a problem for the network
25 codec selected for the call may not be supported by the called the network must perform transcoding between the calling called PoC user. The transcoding of audio, compressed wit PoC terminals, will produce poor sound quality.
One solution to this problem Is to always use the se
30 default codec). However, this may also be a problem since

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-4-
may be connected via different access technologies with different views on which default codec to use, and with different views on available bandwidth.
Accordingly, there is a need for an improved apparatus and method for providing dynamic PoC service options.
5
SUMMARY OF THE INVENTION
The present invention provides a solution in which service options and terminal capabilities for PoC Clients are stored in the network. The service options and terminal capabilities may be stored in the PoC Server or in a server
10 close to the PoC server. In a preferred embodiment, a PoC Client uses the SIP PUBLISH method to set the actual status of the answering mode and any barring service, and, if automatic answering mode is set, also stores a list of codecs that the PoC Client supports. By telling the network which codecs the PoC Client supports, the network can then make a more intelligent selection of the codec in
15 the automatic answer case, and can also utilize better codecs when the access technology allows. The service options may be retrieved by the PoC Server or any other service that requires knowledge about the present service option and terminal capabilities settings.
Thus in one aspect, the present invention is directed to a method of
20 providing dynamic PoC service options. The method includes the steps of storing service options of a calling PoC client and a called PoC client in a server, retrieving the stored service options during establishment of a data/audio session between the calling PoC client and the called PoC client; and utilizing the retrieved service options to optimize the session.
25 In another aspect, the present invention is directed to a method of
. providing dynamic PoC service options that includes the steps of storing in a
server, an indication of whether an answering mode of a called PoC client is set
to automatic or manual, and an indication of which codecs are supported by the
called PoC client for decoding encoded voice signals; and receiving in the
30 server, a request from a calling PoC client to establish a session with the called PoC client. The request includes an indication of which codecs are supported by

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the calling PoC client for encoding voice signals. If the answering mode of the called PoC client is set to automatic, the server selects a codec that is supported by both the calling PoC client and the called PoC client, and notifies the calling PoC client and the called PoC client of the codec selected for use during the
5 session.
In yet another aspect the present invention is directed to an apparatus for providing dynamic PoC service options. The apparatus includes a database for storing an indication of whether an answering mode of a called PoC client is set to automatic or manual, and an indication of which codecs are supported by the
10 called PoC client for decoding encoded voice signals; means for receiving a request message from a calling PoC client to establish a session with the called PoC client and a codec selector for selecting a codec that is supported by both the calling PoC client and the called PoC client. The apparatus also includes means responsive to receiving the request message, for retrieving from the
15 database, the indication of the answering mode of the called PoC client and the indication of which codecs are supported by the called PoC client If the answering mode is automatic, the indication of which codecs are supported by the called PoC client is sent to the codec selector. The apparatus also includes means responsive to an indication that the answering mode of the called PoC
20 client is set to automatic, for extracting from the request message, an indication of which codecs are supported by the calling PoC client for encoding voice signals, wherein the indication of which codecs are supported by the calling PoC client is sent to the codec selector; and means for notifying the calling PoC client and the called PoC client of the codec selected for use during the session.
25
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a signaling diagram illustrating an embodiment of the method of the present invention; and
Figure 2 is a simplified functional block diagram of a PoC Server modified
30 in accordance with the present invention.

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DETAILED DESCRIPTION OF EMBODIMENTS
Figure 1 is a signaling diagram illustrating an exemplary embodiment of the method of the present invention. Illustrated are a called client (PoC Client B) 11, a SIP/IP core network 12, a PoC server 13, an originating network 14, and a
5 calling client (PoC Client A) 15. At step 16, the user of PoC Client 8 changes a service option such as incoming Session Barring for PoC Communication, Incoming Session Barring for PoC Alert, or Answering Mode (automatic or manual). For example, the PoC Client B may change its answering mode to automatic.
10 The PoC Client B 11 then uses the PUBLISH method to set service
options and terminal capabilities in the network. The PoC Client B sends a PUBLISH request message 17 to the SIP/IP Core 12 and includes, in this example, an indication that the answering mode is set to automatic, and an indication of the types of codecs supported by the PoC Client B. At step 18, the
15 PUBLISH request message is forwarded to the PoC Server 13. Since the answering mode is set to automatic, the codecs supported by PoC Client B are also uploaded to the PoC Server. The PoC Server then returns a SIP 200 OK message 19 to the SIP/IP Core, which forwards the message at step 21 to the PoC Client B.
20 At that point in the example, PoC Client A 15 invites the PoC Client B 11
to a call. This is done by PoC Client A sending a SIP INVITE message 22 to the originating network 14, which forwards the message at step 23 to the SIP/IP Core 12. The INVITE message includes a list of codecs supported by PoC Client A. The SIP/IP Core, in turn, forwards the INVITE message at step 24 to
25 the PoC Server 13. The PoC Server then selects a codec from the lists of supported codecs received from PoC Client A and PoC Client B. This enables the PoC Server to select a codec and optimize bandwidth efficiency and audio quality with respect to the access technology being utilized by the two clients. The PoC server then includes an indication of the selected codec in a 183
30 Session Progress message 25, which is sent to the SIP/IP Core. At step 26, the SIP/IP Core forwards the 183 Session Progress message to the originating

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network, which then sends a SIP 200 OK message 27 with an indication of the selected codec to the PoC Client A.
Establishment of the session then proceeds. At step 28, the PoC Client A 15 begins to send media coded with the selected codec to the originating
5 network 14. Meanwhile, the PoC Server 13 sends a SIP INVITE request message 29 to the SIP/IP Core 12, and includes an indication of the selected codec. At step 31, the SIP/IP Core forwards the SIP INVITE request message with the indication of the selected codec to the PoC Client B 11. The PoC Client B returns a SIP 200 OK message 32, acknowledging the INVITE and the
10 selected codec to the SIP/IP Core. At step 33, the SIP/IP Core forwards the 200 OK message to the PoC Server. At step 34, the PoC Server returns a SIP 200 OK message with an indication of the selected codec to the SIP/IP Core, which forwards the message to the originating network at step 35. At step 36, the originating network sends the media coded with the selected codec to the PoC
15 Server, which forwards the encoded media to the PoC Client B at step 37.
Thus, the invention uses the weft-known SIP protocol to publish dynamic data utilized to optimize bandwidth efficiency and audio quality. The use of SIP makes it possible to route the PUBLISH request to a PoC Server independent of the location in a well-known manner.
20 Figure 2 is a simplified functional block diagram of the PoC Server 13
modified in accordance with the present invention. A dynamic PoC service option controller 41 controls signaling to and from the PoC Server according to service options that are stored in a user database 42. In the exemplary embodiment illustrated, the controller receives the PUBLISH message 18 sent
25 by the PoC Client B11, and stores the answering mode and the indication of the codecs supported by PoC Client B in the database. When the controller receives the INVITE message 24 sent by PoC Client A 15, the controller retrieves the data from the database and determines in an answer mode analyzer 43, whether the answering mode is manual or automatic. If the answer
30 mode analyzer determines that the PoC Client B's answering mode is manual, the controller 41 uses normal SIP procedures 45 to establish the session.

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However, if the answer mode analyzer determines that the PoC Client B's answering mode is automatic, the controller extracts the indication of the Client A-supported codecs from the INVITE message, and sends the retrieved indication of the Client B-supported codecs and the extracted indication of the
5 Client A-supported codecs to a codec selector 44. The codec selector selects a codec that is supported by both PoC Client A and PoC Client B, and returns an indication of the selected codec to the controller. The controller then includes the indication of the selected codec in the 183 Session Progress message 25 sent toward PoC Client A and the INVITE message 29 sent toward PoC Client B.
10 The session is then established utilizing the selected codec. It should be recognized that the answer mode analyzer 43 and the codec selector 44 may be functionally implemented as part of the dynamic PoC service option controller 41 or as separate functional units.
Those skilled in the art will readily appreciate that the present invention
15 may be implemented using either hardware, or software, or both, and further, software implementations may vary using different languages and data structures. The present invention is not limited to a specific language and/or class of languages, nor is it limited to any single data structure implementation.
The present invention may of course, be carried out in other specific ways
20 than those herein set forth without departing from the essential characteristics of the invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

24-07-2006 IB2004003075

CLAIMS:
1. A method of providing dynamic Push To Talk over Cellular, PoC,
service options, said method comprising the steps of:
5 sending service options of a calling PoC client and a called PoC client over
a Session Initiation Protocol, SIP, interface to a PoC server;
storing the service options of the calling PoC client and the called PoC client in the PoC server;
retrieving the stored service options during establishment of a session
10 between the calling PoC client and the called PoC client; and
utilizing the retrieved service options to optimize the session.
2. The method of claim 1, wherein the step of storing service options
includes storing a service option that indicates whether incoming sessions for PoC
15 communication are barred.
3. The method of claim 1, wherein the step of storing service options
includes storing a service option that indicates whether incoming sessions for PoC
alert are barred.
20
4. The method of claim 1, wherein the step of storing service options
includes storing a service option for the called PoC client that indicates whether
an answering mode is set to manual or automatic.
25 5. The method of claim 4, further comprising the steps of:
storing terminal capabilities of the calling PoC client and the called PoC client in the PoC server;
retrieving the stored terminal capabilities during establishment of a session
between the calling PoC client and the called PoC client; and
30 utilizing the retrieved terminal capabilities to optimize the session.
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-10-
6. The method of claim 5, wherein the step of storing terminal
capabilities of the calling PoC client and the called PoC client includes storing an
indication of which codecs are supported by the calling PoC client and the called
PoC client.
5
7. A method of providing dynamic Push To Talk over Cellular, PoC,
service options, said method comprising the steps of:
sending over a Session Initiation Protocol, SIP, interface to a PoC server, an indication of whether an answering mode of a called PoC client is set to
10 automatic or manual, and an indication of which codecs are supported by the called PoC client for decoding encoded voice signals;
storing in the PoC server, the indication of whether the answering mode of
the called PoC client is set to automatic or manual, and the indication of which
codecs are supported by the called PoC client;
15 receiving in the PoC server, a request from a calling PoC client to establish
a session with the called PoC client, said request including an indication of which codecs are supported by the calling PoC client for encoding voice signals;
if the answering mode of the called PoC client is set to automatic, selecting by the PoC server, a codec that is supported by both the calling PoC client and
20 the called PoC client; and
notifying the calling PoC client and the called PoC client of the codec selected for use during the session.
8. The method of claim 7, wherein the sending step Includes sending
25 the indications to the PoC server in a SIP PUBLISH message sent by the PoC
client and forwarded to the PoC server by a core network.
9. The method of claim B, wherein the SIP PUBLISH message also
includes an indication of whether PoC communications or PoC alerts are currently
30 barred in the called PoC client, and the method further comprises the step of determining that PoC communications and PoC alerts are currently allowed in the called PoC client before establishing the session.
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10. An apparatus for providing dynamic Push To Talk over Cellular (PoC) service options, said apparatus comprising:
a Session Initiation Protocol, SIP, interface for sending to a PoC server, an
5 indication of which codecs are supported by a called PoC client for decoding
encoded voice signals;
a database associated with the PoC server for storing the indication of
which codecs are supported by the called PoC client;
means for receiving a request message from a calling PoC client to
10 establish a session with the called PoC client, said request message including an indication of which codecs are supported by the calling PoC client for encoding voice signals;
a codec selector for selecting a codec that is supported by both the calling
PoC client and the called PoC client;
15 means responsive to receiving the request message for retrieving from the
database, the indication of which codecs are supported by the called PoC client, and for sending the indication of which codecs are supported by the called PoC client to the codec selector;
means for extracting from the request message, the indication of which
20 codecs are supported by the calling PoC client for encoding voice signals, and for sending the indication of which codecs are supported by the calling PoC client to the codec selector; and
means for notifying the calling PoC client and the called PoC client of the codec selected for use during the session.
25

AMENDED SHEET

APPARATUS AND METHOD PROVIDING PUSH TO TALK OVER CELLULAR (POC) DYNAMIC SERVICE OPTIONS

Documents:

Inventors:

PCT Conventions: