Title of Invention

A METHOD FOR ADMINISTERING CONFERENCE RESOURCES IN A COMMUNICATIONS SYSTEM

Abstract

A method for administering conferencing resources in a communications system comprising a plurality of terminals and a conference server, the method comprising: transmitting from a first terminal to the server a first message comprising a request for a resource capable of sustaining a conference call; allocating by means of the server a network address identifying a resource capable of sustaining the conference call; and transmitting from the server to the first terminal a second message comprising the network address. 477/CHENP/2005 ABSTRACT "A METHOD FOR ADMINISTERING CONFERENCING RESOURCES IN A COMMUNICATIONS SYSTEM" A method for administering conferencing resources in a communications system comprising a plurality of terminals and a conference server, the method comprising; transmitting from a first terminal to the server a first message comprising a request for a resource capable of sustaining a conference call; allocating by means of the server a network address identifying a resource capable of sustaining the conference call; and transmitting from the server to the first terminal a second message comprising the network address.

Full Text

CONFERENCING SYSTEM Field of the Invention The present invention relates to a method and appears for setting no conference calls in. communication systems, and in particular but not exclusively to wireless communication systems. Blackstone of the Invention The concept of conference calls in public switched telephone networks (PSTN) is well known. PSTN conferences are typically set up by a first participant calling a specific customer support number and being supplied with a conference bridge number and a PIN code. The first participant can then provide this information to any other potential participants. The participants wishing to join the call would each dial the conference bridge number, and supply the PIN code on demand, and would subsequently be admitted to the conference call. As an alternative, the Internet could conceivably be used to arrange conference calls. A specific web site could be accessed by a first participant, and a bridge number and PIN code could be obtained. The first participant would then be able to provide the details to other participants. Both of these procedures allow for a mobile terminal to be involved in the conference call. However, both procedures have two main disadvantages. Firstly a conference call musts be planned in advance. The various participants must contact each other so . that flay each know when the call is due to tale place and can dial the conference bridge number at that time. Secondly, the participants themselves need to organized for the bridge number and the PIN code to be distributed to all participants. There have been various models proposed for providing conferencing services in third generations Intermit Protocol Multimedia Subsystem (IMS) wireless communication systems, for example in IETF draft "Models for Multi Party Conferencing in SIP", J. Rosenberg and H. Schulzrinne. Each of the models in this draft uses Session Litigation Protocol (SIP) messaging. The SIP protocol is discussed in Internet Standards RFC 3261 and RFC 2543.Some of the models are described briefly below. The first model, norm as "end system mixing", requires that one terminal involved in a conference call performs the mixing (merging) of signals and media streams sent to and from other denials in the call. Figure la is a depiction of a three-way can using this model. In this example, users A and B are involved in a two-way call. At some point during the call, user A decides to bring user C into the cam. To do -flies, user A calls user C using a completely separate SIP call. There is no call set up between B and C. Instead, A receives media streams from both B and C and mixes them. Terminal A sends a stream containing the streams of A and B to terminal C, and a stream containing A's and C's streams to tensional B. la this model, sentinels B and C are unaware from a SIP perspective that the call involves mere than two parties. In the case of a call involving more than three tenninals, more fiat one terminal may perform mining and signaling to sustain the call. For instance, as an extension of the above-described exorable, user C may decide to invite a fourth, user D into the conference call. User C wood then call user D and terminal C would perform the militia of the streams it receives from terminal A with its own stream, and send the combined stream to D, and mix its own stream with that of D and send this to A. This set-up is shown in Figure lb. Serious disadvantages of this model are that when a mixmg terminal leaves the call, the conference must end, and that there is no way for a mixing tenniaal to determine whether a signalling message sent to it was intended for that terminal alone or for all terminals in the conference. A further model, using dial-in conference servers, closely mirrors the PSTN system described above. One participant defines a URI (uniform resource identifier) to identify a conference call, and sends it to other participants. The participants then each call the server, using the conference URI, which maintains point-to-point SEP relationships with each participant that calls in. The server receives media from each participant, mixes them, and sends out the appropriate mixed stream to each participant separately. This model is depicted in Figure 2, which, shows four users A-D talking part in a conference call. Dial-m conference servers are versatile in that they can be used for pre-arranged conferences or for ad hoc conferences. However, this model suffers from the fact that it is possible for the same URI to he used for more than one conference. This would cause conference sessions to be mixed. It is an object of the present invention to provide a solution to one or more of the above-stated problems. Summary of the Invention According to a first aspect of the present invention there is provided a method for administering conferencing resources ia a communications system" comprising a plurality of terminals and a conference server, the method comprising; transmitting from a first terminal to the server a first message comprising a request for a resource capable of sustaining a conference call; allocating by means of the server a network address identifying a resource capable of sustaining the conference call; and transmitting from the server to the first terminal a second message comprising the network address. Advantageously, the method allows for conferences to be set up on an ad hoc basis so that the conferences need not be pre-arranged. In addition, the method prevents the problem of overlapping conference sessions. This problem is overcome by providing for a server to allocate a resource for a conference, and a corresponding address for that resource. In this way, an address can be unique to a particular conference at a given time. A further advantage of the present invention is that it allows for the use of standard SIP messages in the establishment of a conference call Furthennore, no significant user configuration is required in the allocation of conferencing resources. Preferably a user transmits the network address from tiled first terminal to tenninals of other users that will take part in the conference call. Preferably connections are initiated between the terminals and the network address to establish the conference According to a second aspect of the present invention there is provided a conference ■'■ server for administering conferencing resources in a communications system comprising a plurality of terminals, the conference server comprising: a receiver unit for receiving from a first terminal a first message comprising a request for a resource capable of sustaining a conference call; an allocation unit for allocating a network address identifying a resource enable of sustaining the conference call; and a transmission emit for transmitting to the first terminal a second message comprising the network address. Preferably the receiving unit is arranged to receive from a first terminal a first message comprising a request for a resource capable of sustaining a confer ice call. Preferably the allocation unit is arranged to allocate a network address identifying a resource capable of sustaining the conference call. Preferably the transmission unit is arranged to transmit to the first terminal a second message comprising the network address. The server could be provided at a single location, or by functionality that is distributed between two or more locations. According to a third aspect of the present invention there is provided a communicatioiis system comprising: a conference server for administering conferencing resources in a communications system comprising a plurality of terminals, the conference server comprising; a receiver unit for receiving from a first terminal a first message comprising a request for a resource enable of sustaining a conference call; an allocation unit for allocating a network address identifying a resource capable of sustaining the conference call; and a transmission unit for transmitting to the first tensional a second message comprising the network address; and a plurality of terminals including the first terminal. Brief Description of Drawings The present invention, will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 shows a prior art model for a conferencing system; Figure 2 shows patio art dial-in conferencing system; Figure 3 shows a conferencing system according to the invention Detailed Description of the Invention The invention is described hereinbelow with reference to a non-limiting embodiment. In particular, the invention is described in relation to SIP sigjialling in a 3G IMS mobile communications network. However, the invention is not limited to such signalling or such a network. Referring to Figure 3, two user agents 10 and 11 are shown. A first user, using user agent 10, wishes to start a conference call involving user agent 11 and sends a SIP INVITE message 21 to a well-known URI at an operator to initiate the conferencing process. That URI could be stored by the user agent 10. The Festive message 21 indicates that user agent 10 wishes to initiate a confeiesice, and the Request-URI could suitably take the form: sip:conferences®sonera.fi The INVITE message could include details" of the type of conference required, for example a profaned data rate. These details could be contained in the media components listed in the Session Description Protocol (SDP) payload of the INVITE 21. The message 21 is received at a conference server 12 which is preferably a generic user agent server. At this stage, the server 12 could authenticate the conference request by transmitting a SIP message containing an authentication challenge to &e user agent 10 requesting details such as a sesame and a password. In this case, the user wooded then need to provide such details, i.e. valid authentication credentials, in order for the conference request to be authorized. Either in response to receiving message 21, or in response to receiving valid authentication information from user agent 10, the server 12 allocates a dynamic SIP UKI to be used for the requested conference. The dynamic URI identifies a resource 13 that is available to be used for sap porting the requested conference according to the specifications listed by the first user in the INVITE 21. The network is arranged to route to the resource, or the unit that provides the resource, communications directed to that address. To facilitate this the server is preferably arranged to allocate addresses for conferencing according to a pre-set pattern so that they will all refer to a suitable conferencing resource. The server 12 may reserve this resource so that it remains available until the requested conference begins. Alternatively, no resource may be reserved by the server 12 but instead an available resource could be located at the tune when the requested conference is initiated. The resource is capable of establishing point-to-point connections with a terminal of each participant in a conference call. It can merge the traffic signals it receives from each terminal -and transcript the merged signals to the other terminals that are parties to the conference call. Those traffic signals could carry voice data or other data such as video or graphical] (e.g. whitehead-ding) data. The resource could be data handling capacity, bandwidth or any other resource necessary for sustaining a conference call. The resource could be provided by physical equipment such as a part of a server. The dynamic URI is transmitted to user agent 10 by conference server 12 in a SIP message 22. The message 22 is preferably a redirection message with a code in the 3xx range, and the UEI is preferably contained in the contact field of the message. An examples of the form that the contact field could suitably take’s: Contact: On receipt of the redirection message including the allocated URI, the user agent 10 then transmits an INVITE message 23 to the URL The URI identifies the reserved conference resource 13, and responsive to receiving the INVITE message 23, the resource 13 sends an acknowledgement, such as a 200 OK message 24, back to user agent 10. Once user agent 10 receives the 200 OK message, the first user can then refer the allocated URI to a second USKT at user agent 11. A further message, such as a SIP REFER, message 25, including the URI is transmitted film user agent 10 to user agent 11. The REFER could suitably take the form: REFER sip:user__ti®pp.racliolinja.fi SIP/2.0 with the following header: Refer-To: sip ;DKLSKXS7KKJ989SHFKJH(Scociference, sonera. f i ,- Me thod.=INVITE Alternatively, the URI could be sent from the first user to the second user in another way. By the above mechanism, a user can reserve a conference resource on the fly. Without any significant input on the part of the user, other participants can be connected together to form a conference call. In response to receiving the REFER message from user- agent 10, user agar U Ironsmith an acknowledgement, such as a 202 accepted message 26, back to user agent 10. User agent 11 now transmits a request message, such as an INVITE message 27, to the served resource 13, in response to "Which the resource 13 sends an acloiowledgement, such as a 200 OK. message 28, to user agrait 11. The server 12 and resource 13 are able to campmate with each other. In ibis way, The server can acquire authentication information obtained by the resource from a user so that each user can be authenticated before being allowed to join the conference. For example, it may be desirable to check that a user has a subscription enabling him to take part in conferences. Details of subscriptions could be contained in authentication information. Alternatively, or additionally, a user may be required to input a PIN for transmissions to the resource 13 to confirm his identity for security reasons. Following message 28, an acknowledgement, such as a NOTIFY message 29 with response code 200 OK, is sent from user agent 11 to user agent 10, and the conference may begin. It will be apparent that user agent 10 can also send or REFBR the dynamic URI to a number of other users so that they can take part in the conference. A further alternative is that the REFER message 25 could be directed to the conference URI. In other words, instead of referring scar B to the conference, the conference could be referred to user B. The same set of messages could be used as described above, but in this case they are used with dial-out semantics. A summary of the messages required to set up a conference according to a preferred embodiment the invention is given below. 21 INVITE to sip;[email protected] 22 3xx redirection including dynamic URI 23 INVITE to URI 24 200 OK 25 REFER to UA1l 26 202 accepted 27 INVITE to URI 28 200 OK 29 NOTIFY with response code 200 OK The machismo described above can also facilitate dial-in conformers. In the dial-in case, the mechanism. would function in essentially the same manner as described above except that the conference URI would be delivered to prospective participants in a different way, for example via an instant Message or email, rather than using a REFER message to invite them. The applicant draws attention to the fact that the present invitation may include any feature or combination of features disclosed herein either implicitly or explicitly or any generalization thereof, without limitation to the scope of any definitions set out above. In view of the foregoing description it will be evident to a person skilled in the art that various modifications may be made within the scope of the invention. WE CLAIM : 1. A method for administering conferencing resources in a communications system comprising a plurality of terminals and a conference server, the method comprising: transmitting from a first terminal to the server a first message comprising a request for a resource capable of sustaining a conference call; allocating by means of the server a network address identifying a resource capable of sustaining the conference call; and transmitting from the server to the first terminal a second message comprising the network address. 2. The method according to claim 1 comprising the step of transmitting from the first terminal to at least one other terminal a third message comprising the network address. 3. The method according to claim 2 comprising initiating connections from the first terminal and the said other terminal to the network address to establish a conference call between the first terminal and the said other terminal. 4. The method according to claim 3 wherein the step of transmitting the third message comprises transmitting from the first terminal to at least two other terminals the third message comprising the network address; and wherein the initiating step comprises initiating connections from the first terminal and the said other terminals to the network address to establish the conference call between the first terminal and the said other terminals. 5. The method according to any preceding claim wherein the messages are SIP. 6. The method according to claim 5 wherein the first message is an INVITE 7. The method according to claim 5 or 6 wherein the second message is a redirection message. 8. The method according to any of claims 5 to 7 as dependent on claim 2 wherein the third message is a REFER message. 9. The method according to any preceding claim wherein the network address is a uniform resource identifier. 10. The method according to claim 9 wherein the network address is a dynamically generated uniform resource identifier. 11. The method according to any preceding claim wherein on establishment of the conference call the resource merges data transmitted to the network by each of the terminals that are parties to the conference call. 12. A conference server for administering conferencing resources in a communications system comprising a plurality of terminals, the conference server comprising: a receiver unit for receiving from a first terminal a first message comprising a request for a resource capable of sustaining a conference call; an allocation unit for allocating a network address identifying a resource capable of sustaining the conference call; and a transmission unit for transmitting to the first terminal a second message comprising the network address. 13. A communications system comprising a conference server as claimed in claim 12, and a plurality of terminals including the first terminal. 14. The communications system according to claim 13 wherein the first terminal is adapted to transmit to at least one other terminal a third message comprising the network address. 15. The communications system according to claim 14 wherein the first terminal and the said other terminal are adapted to initiate connections to the network address to establish a conference call between the first terminal and the said other terminal. 16. The communications system according to claim 15 wherein the first terminal is adapted to transmit to at least two other terminals the third message comprising the network address; and wherein the first terminal and the said other terminals are adapted to initiate connections to As network address to establish a conference call between the first terminal and the said other terminals. 17. The communications system according to any of claims 13 to 16 wherein the messages are SIP messages. 18. The communications system according to claim 17 wherein the first message is an INVITE message. 19. The communications system according to claim 7 or claim 18 wherein the second message is a redirection message. 20. The communications system according to any of claims 17 to 19 as dependent on claim 14 wherein the third message is a REFER message. 21. The communications system according to any of claims 13 to 20 wherein the network address is a uniform resource identifier. 22. The communications system according to claim 21 wherein the network address is a dynamically generated uniform resource identifier. 23. The communications system according to any of claims 13 to 22 wherein on establishment of the conference call the resource is adapted to merge data transmitted to the network by each of the terminals that are parties to the conference call.

Documents:

0477-chenp-2005 abstract duplicate.pdf

0477-chenp-2005 abstract.pdf

0477-chenp-2005 claims duplicate.pdf

0477-chenp-2005 claims.pdf

0477-chenp-2005 correspondence-others.pdf

0477-chenp-2005 correspondence-po.pdf

0477-chenp-2005 description (complete) duplicate.pdf

0477-chenp-2005 description (complete).pdf

0477-chenp-2005 drawings duplicate.pdf

0477-chenp-2005 drawings.pdf

0477-chenp-2005 form-1.pdf

0477-chenp-2005 form-18.pdf

0477-chenp-2005 form-26.pdf

0477-chenp-2005 form-3.pdf

0477-chenp-2005 form-5.pdf

0477-chenp-2005 pct.pdf

0477-chenp-2005 petition.pdf