Abstract:
A technique for sharing multimedia sessions between users that share a directory number allows incoming calls to be routed to both phones. Once one party picks up, the other party is alerted to this fact. Both parties may then exchange multimedia information to help in the handling and disposition of the call.

Description:
FIELD OF THE INVENTION 
     The present invention relates to using multimedia features to supplement call coverage for two or more entities that share an extension. 
     BACKGROUND OF THE INVENTION 
     Traditional telephony services provided by digital switches, such as digital multiplexing switches, have reached their functional limits with existing user interfaces, which essentially are telephone sets having limited displays and simple keypads. Further, the telephone sets have limited bandwidth. Over newer packet networks, multimedia services are flourishing and are capable of exploiting the capabilities of advanced user terminals, desktop computers, and network appliances. 
     Currently, the vast majority of voice telephony is provided, at least in part, by traditional circuit-switched networks. Given the extensive infrastructure, reliability, and quality of service, the traditional telephony systems are likely to remain a significant part of communications for the foreseeable future. Unfortunately, there has been difficulty integrating voice sessions over the traditional telephony network with multimedia sessions over packet networks. Users prefer the traditional telephony network for voice, yet the voice network is unacceptable for facilitating advanced multimedia services, such as screen sharing, video conferencing, and the like. 
     In addition to the difficulties of integrating the voice and multimedia sessions, integrating services that heretofore were available on voice systems is proving problematic. For example, several years ago, a voice service was introduced which allowed two extensions to share a number such that if a call came in, the phone at both locations would ring, calls could be put on hold at one phone and picked up at the other, or other similar sorts of activities. This was particularly useful for boss-secretary arrangements. 
     While the problem of porting this functionality over to a packet based network has been solved, there remains a need to exploit the full force and power of multimedia services in combination with this call coverage functionality. 
     SUMMARY OF THE INVENTION 
     The present invention uses a combined user agent to allow parties associated with a shared directory number to communicate with each other in the multimedia domain before, during, and after a call. This allows the parties to share information about the nature of the call, determine how a call should be handled, and assure that incoming calls have been answered. 
     In a particular embodiment of the present invention, a call is made to an intended recipient. The intended recipient has a second individual associated therewith providing joint call coverage. The call is routed to a combined user agent, which receives information about the caller so that call screening and routing may be performed based on a pre-established user profile. Call information is forwarded to computers associated with both the intended recipient and the second individual. 
     When one party answers the call, the phone at the other location stops ringing. The answering party may initiate a multimedia session with the other party so that an informed decision may be made as to who is best to handle the call. Alternatively, the individual answering the call may annotate call logs using multimedia features and share the annotations with the other individual. Incoming or outgoing call logs may also be shared between the parties for outgoing calls. 
     Those skilled in the art will appreciate the scope of the present invention and realize additional aspects thereof after reading the following detailed description of the preferred embodiments in association with the accompanying drawing figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the invention, and together with the description serve to explain the principles of the invention. 
         FIG. 1  is a schematic of a communication environment adapted to support the present invention; 
         FIG. 2  is a second embodiment of a communication environment adapted to support the present invention; 
         FIG. 3  is an alternate embodiment of the communication environment of  FIG. 2 ; 
         FIG. 4  is a block diagram of a combined user agent according to the present invention; 
         FIG. 5  is an exemplary embodiment of the present invention integrated into a communication environment; 
         FIG. 6  is a second embodiment of the present invention; 
         FIG. 7  is a flow chart of the methodology of the present invention for an incoming call; 
         FIG. 8  is a flow chart of the methodology of the present invention for an outgoing call; and 
         FIG. 9  is a third embodiment of the present invention integrated into a wireless environment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The embodiments set forth below represent the necessary information to enable those skilled in the art to practice the invention and illustrate the best mode of practicing the invention. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the invention and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure and the accompanying claims. 
     The present invention is designed to allow individuals that share an extension number or directory number to communicate with one another in the multimedia domain such that the call is handled appropriately. Instant messaging, whiteboarding, video sessions, and other multimedia functions may be exchanged between the two individuals to help the individuals arrive at a mutual decision on how the call should be handled or to pass information relating to the call back and forth so that both parties are fully apprised of events surrounding incoming and outgoing calls. 
     Underlying this invention is commonly owned technology embodied in U.S. patent application Ser. No. 10/028,510, filed Dec. 20, 2001, which is hereby incorporated by reference in its entirety, which discusses facilitating efficient unification of parallel voice and multimedia sessions, wherein the voice session takes place in part over a traditional circuit-switched telephony network. A call signaling agent is created to control packet-based multimedia sessions, as well as to control call signaling at a traditional telephony switch, for a telephone and an associated multimedia device, such as a computer. The multi-functional call processing agent, typically referred to as a combined user agent (CUA), can effectively establish multimedia sessions with the multimedia device and voice calls with the telephone. 
     With reference to  FIG. 1 , a communication environment  10  according to the teachings of the &#39;510 application is illustrated. The communication environment  10  may include a packet network  12  having a CUA  14  and a supporting proxy  16 . The CUA  14  acts a virtual agent for a computing device, such as a computer  18 , which is capable of supporting multimedia sessions. The computer  18  may connect to the packet network  12  via a network access  20 , which may include a local area network (LAN), frame relay, digital subscriber line, cable, or other such methods. 
     The CUA  14  also acts as an agent for a traditional telephony device, such as a telephone  22 , which is supported by a telephony switch  24  such as a DMS-100 central office switch, sold by Nortel Networks Limited of 2351 Boulevard Alfred-Nobel, St. Laurent, Quebec, Canada H4S 2A9, public branch exchange (PBX), or the like, that is capable of providing circuit-switched communications between the telephone  22  and other telephony devices. To allow the CUA  14  to interact with and control the telephony switch  24 , legacy access  26  is provided between the packet network  12  and the telephony switch  24 . The legacy access  26  may be provided by existing intelligent networks (IN), including the advanced intelligent network (AIN), session initiation protocol for telephones (SIP-T) capable networks, TAPI networks, and the like, that provide access to telephony switches  24  to facilitate call signaling. The CUA  14  is configured to establish multimedia sessions over network access  20  with the computer  18 , as well as provide call signaling for the telephone  22  through the telephony switch  24  via the legacy access  26 . 
     Although the concepts of the present invention are applicable to various communication environments and related protocols, the present invention is preferably implemented using the session initiation protocol, commonly referred to as SIP. The specification for SIP is provided in the Internet Engineering Task Force&#39;s Request for Comments (RFC) 3261: Session Initiation Protocol Internet Draft, which is hereby incorporated by reference in its entirety. In general, SIP is used to establish media sessions between any number of endpoints. Typically, these endpoints may support any number or combination of data, audio, and voice media sessions, depending on the configuration of the device. A SIP endpoint is capable of running an application, typically referred to as a user agent (UA), which is capable of facilitating media sessions using SIP. In certain embodiments, user agents may register their ability to establish sessions with a SIP proxy by sending “REGISTER” messages to the SIP proxy. The REGISTER message informs the SIP proxy of the SIP universal resource locator (URL) that identifies the user agent to the SIP network. The REGISTER message also contains information about how to reach specific user agents over the SIP network, typically by providing the Internet Protocol (IP) address and port that the user agent will use for SIP sessions. When a user agent wants to establish a session with another user agent, the user agent initiating the session may send an INVITE message to the SIP proxy and specify the target user agent in the TO header of the INVITE message. Identification of the user agent takes the form of a SIP URL. The SIP proxy will use the SIP URL in the TO header of the message to determine if the targeted user agent is registered with the SIP proxy. Generally, the user name is unique within the name space of the specified domain. 
     If the targeted user agent has registered with the SIP proxy, the SIP proxy will forward the INVITE message directly to the targeted user agent. The targeted user agent will respond with a 200 OK message, and a session between the respective user agents will be established as per the message exchange required in the SIP specification. Media capabilities may be exchanged in other messages, such as the SIP “INFO” message. Media capabilities are typically described using the session description protocol (SDP). Once respective endpoints are in an active session with each other and have determined each other&#39;s capabilities, the specified media content may be exchanged during an appropriate media session. 
     According to the Internet Engineering Task Force&#39;s RFC 3261, a user agent is an application that contains both a user agent client and a user agent server. A user agent client generally refers to a client application that initiates SIP requests, wherein a user agent server is an application that contacts the user when a SIP request is received, and returns a response on behalf of the user. Typically, the response accepts, rejects, or redirects the received request. 
       FIG. 1  illustrates the CUA  14 , which is an application, program, or function that acts on behalf of a multimedia client, provided by the computer  18  or like device, and a telephone  22 . The computer  18  may have a SIP user agent, which is represented by the CUA  14 . In essence, the CUA  14  will function to control call signaling to effect voice sessions between the telephone  22  and other devices via the telephony switch  24 , and other multimedia sessions via the computer  18 . Notably, the CUA  14  can effectively facilitate the integration of and association of voice and other multimedia sessions provided by both devices. To devices needing to establish sessions with either the computer  18  or the telephone  22  in a SIP environment, the CUA  14  presents both devices as a single device having voice and other multimedia capabilities. The other devices need not know that the telephone  22  resides on a circuit-switched network. 
     In one embodiment, the CUA  14  will cooperate with the proxy  16 , which is configured as a SIP proxy, in traditional fashion to establish multimedia sessions involving the computer  18 . The sessions will be supported across the network access  20  in the packet network  12 . With respect to voice communications via the telephone  22 , the voice path may take various routes, remaining entirely within the public switched telephone network (PSTN), or venturing into the packet network  12  to communicate with a packet-switched telephony device or simply to bridge to another circuit-switched network. 
     The communication environment  10  illustrated in  FIG. 1  illustrates voice communications between the telephone  22  and a voice-capable packet-switched device  30 , such as an IP telephone  30 A or a computer  30 B. The packet-switched devices  30  are connected to the packet network  12  via a local area network (LAN)  32  to support packet-switched communications. Since the telephone  22  and telephony switch  24  facilitate circuit-switched communications, a gateway (GW)  28  is integrated with the telephony switch  24  or provided as a separate device (as shown) to convert circuit-switched communications to packet-switched communications capable of being transported over the packet network  12  to the desired packet-switched device  30 . The connection between the telephony switch  24  and the gateway  28  may be any traditional telephony line or trunk. The gateway  28  appears to the telephony switch  24  as another switching device supporting a variety of telephone numbers, which are associated with the packet-switched devices  30 . Typically, the time-division multiplexed (TDM) circuit-switched communications are converted into packets to facilitate voice communications over the Internet Protocol (VoIP). Importantly, although the voice session spans the circuit-switched and packet-switched networks, the CUA  14  represents the telephone  22  to the devices with which it communicates. In essence, the telephone  22  and the computer  18  form a combined legacy client  34 , which is represented by the CUA  14 . 
     With reference to  FIG. 2 , another CUA  14 A is provided to support a computer  18 A via network access  20 A and a circuit-switched telephone  22 A, which is supported by telephony switch  24 A. The CUA  14 A provides call signaling to the telephony switch  24 A via legacy access  26 A in a similar manner to that described above. Further, the telephony switch  24 A is associated with a gateway  28 A to convert circuit-switched communications into packet-switched communications for transport over the packet network  12 . The communication environment  10  in  FIG. 2  illustrates the communication path between telephone  22  and telephone  22 A during a voice session being routed over the packet network  12  between the gateways  28  and  28 A. Multimedia sessions other than voice between computers  18  and  18 A may be established in traditional fashion over the packet network  12 . Again, the CUA  14  represents the combined legacy client  34  containing the computer  18  and the telephone  22 , whereas the CUA  14 A supports the combined legacy client  34 A, which is made up of the computer  18 A and the telephone  22 A. In this embodiment, the CUA  14 A is supported by the proxy  16 . 
     With reference to  FIG. 3 , the CUA  14 A may be supported by a separate proxy  16 A. Further, the communications between the telephone  22  and the telephone  22 A during a voice session may be supported entirely within the PSTN  36 . The CUAs  14 ,  14 A may provide call signaling not only to the respective telephony switches  24 ,  24 A, but also to other network elements within the PSTN  36  such that they have enough information to establish an end-to-end connection across the PSTN  36 . In short, the CUAs  14 ,  14 A are configured to provide the necessary call signaling to establish voice sessions that are supported at least partially over the circuit-switched network of the PSTN  36 , as well as multimedia sessions with the computer  18  over the packet network  12 . 
     As illustrated in  FIG. 4 , the combined user agent  14  is preferably implemented in a control system  38  associated with a packet network interface  40  for communicating over the packet network  12 . The control system  38  will support software applications providing a legacy adapter  42 , a multimedia client adapter  44 , and the basic CUA logic  46 . The legacy adapter  42  will provide the necessary protocol adaptation and call signaling control necessary to control the telephony switch  24  in light of SIP or related protocols for establishing media sessions. The multimedia client adapter  44  is used to support sessions with the associated computer  18  or like multimedia device. The multimedia client adapter  44  may provide protocol adaptation as necessary to establish the media sessions of a SIP implementation, wherein when the computer  18  emulates a SIP client, the CUA logic  46  will simply represent the multimedia capabilities of the computer  18  for the non-voice media sessions. The CUA logic  46  will also cooperate with the legacy adapter  42  to provide the necessary call signaling for the telephony switch  24  to control voice communications with the telephone  22 . Accordingly, the CUA logic  46  cooperates with the legacy adapter  42  and the multimedia client adapter  44  to provide an interface to the computer  18  as well as an interface to the telephony switch  24 , and an interface for communications with other devices, such as the proxy  16 . In an exemplary embodiment, the CUA  14  may be incorporated into the Interactive Multimedia Server sold by Nortel Networks Limited of 2351 Boulevard Alfred-Nobel, St. Laurent, Quebec, Canada, H4S 2A9. 
     Against this backdrop, the present invention is readily implemented as seen in  FIG. 5 . A second client  34 B exists with a computer  18 B and a telephone  22 B. The telephones  22 ,  22 B may be communicatively coupled to the switch  24 B while the computers  18 ,  18 B may each have independent network accesses  20 ,  20 B (shown) to the packet network  12 . Alternatively, the computer  18 B may share the network access  20  (not shown) of the client  34 . The switch  24 B may be an internal public branch exchange (PBX) for an enterprise or similar device and is programmed to allow telephones  22 ,  22 B to share a common directory number or extension number. Depending on the nature of the switch  24 B, a legacy access  26  may be positioned between the switch  24 B and the packet network  12 . The CUA  14  serves both clients  34 ,  34 B as previously described. 
     An alternate embodiment is illustrated in  FIG. 6 , where a plurality of clients  34 ,  34 B– 34 N may exist. While clients B–N are contemplated, other numbers of clients may be present. In this instance, N represents an arbitrary number of clients. Again, the clients  34 ,  34 B– 34 N may have separate network accesses  20 ,  20 B– 20 N or share a single network access  20 . All of the telephones  22 ,  22 B– 22 N are communicatively connected to the switch  24 B. Again, the switch  24 B may be an internal PBX for an enterprise. The telephones  22 ,  22 B– 22 N and computers  18 ,  18 B– 18 N are served by one or more CUA  14 , although a single CUA  14  is preferred. The telephones  22 ,  22 B– 22 N may share a directory or extension number as described above. 
     The methodology of the present invention is illustrated in  FIGS. 7 and 8 . An incoming call is initially illustrated in  FIG. 7  assuming a two client environment such as that illustrated in  FIG. 5 . User  1 , associated with the client  34 , has an incoming call from the PSTN  36  through the switch  24 B (block  100 ). The call is duplicated by the switch  24 B such that the call also is directed to user  2  (block  102 ). Both telephones  22 ,  22 B ring (block  104 ). The CUA  14  gets information about the calling party from the switch  24 B (block  106 ). The CUA  14  may interact with the SIP proxy  16  to get specific features or information to perform call screening and routing based on a pre-established user profile if needed or desired (block  108 ). As an example, user  1  may want all calls except the ones from a pre-defined list to be forwarded to user  2 . 
     The incoming call information and any information from the proxy  16  may appear on computers  18 ,  18 B in parallel (block  110 ). This may appear in a pop up window, in a call management window that has already been opened, or otherwise as needed or desired. For the sake of simplicity, the present disclosure assumes that user  2  answers (block  112 ); however, it is readily apparent to those of ordinary skill in the art that the process is essentially the same, albeit reversed, if user  1  answers. 
     The telephone  22  stops ringing in response to user  2  answering the call (block  114 ). The switch  24 B may inform the CUA  14  that the call has been answered (block  116 ) including informing the CUA  14  that user  2  answered the call. Alternatively, the client  34 B may inform the CUA  14  that the call has been answered as part of the SIP communications therebetween. Both clients  34 ,  34 B may be informed of the answered call so that user  1  knows that the call has been answered (block  118 ). 
     At this point, many things may happen depending on the needs of the parties. However, for the sake of example, user  2  may initiate a multimedia session with user  1  through the CUA  14  (block  120 ). This multimedia session may be an instant messaging (IM) activity (block  122 ), a video conference, document sharing, or other multimedia activities. Shortcuts to achieve the more common activities may have been created on the desktop of the computer  18 B if desired. As yet another option, user  2  may record a voice message on computer  18 B and forward this voice message to computer  18 . 
     User  2  may also access the call logs for user  1  for the purpose of annotating the call logs (block  124 ). When user  2  terminates the call, user  1  is alerted to this fact through the CUA  14  (block  126 ). Specifically, the switch  24  may alert the CUA  14  that the call has been terminated, and the CUA  14  alerts user  1 . Alerts may be done through an audio tone from the computer  18 , the telephone  22 , a visual indication on either device, or other appropriate alert. Note that the call logs may be stored in memory associated with the CUA  14  or may be stored at the computers  18 ,  18 B. The call logs may be passed back and forth as needed, or accessed, stored, and/or updated at the memory as needed. 
     User  1  may subsequently review the call logs (block  128 ) and see the annotations provided by user  2 . The annotations may be voice or text messages, thereby replacing physical paper message notes. When user  1  reviews the call logs, user  1  may make a more informed decision about how to return the call with the assistance of the annotations. Alternatively, user  1  may review the call log while the call is still in progress (i.e., before the call is terminated). Note that in general, the present invention need not occur in the linear fashion as indicated by the flow chart of  FIG. 7 , but rather, commands may be made as needed, connections formed in response to commands, and the call passed back and forth between user  1  and user  2  as needed. The methodology of  FIG. 7  is provided by way of guidance, and other variations in the order are readily apparent to those of ordinary skill in the art. 
     As an example, user  2  may be an administrative assistant for user  1 . When a call comes in from an unknown source, user  2  may answer the call and determine that the call is from a prospective client. User  2  instant messages user  1  to see if user  1  is available to take the call. User  1  assents, and user  2  transfers the call to user  1  using features on the switch  24 B or through the CUA  14 . 
     Note that there are many permutations in how the present invention may be implemented. Many of the elements of the communication environment  10  may be equipped with microprocessors that act upon instructions embedded in software or in sequential logic. The software may be resident upon a computer readable medium or in memory associated with the microprocessor. Further, while the particular embodiment shows certain functionalities associated with certain elements, it is possible that the functionalities may be rearranged or redistributed without departing from the scope of the present invention. 
     Outgoing calls are illustrated in  FIG. 8 . While there are numerous variations on the theme of this process, an exemplary embodiment is presented below. Specifically, this embodiment assumes that user  1  shares information fully with user  2 . It is possible that some or all sharing may be restricted. In this embodiment, user  1  makes a call (block  150 ). This call is routed to the switch  24 B, and the switch  24 B alerts the CUA  14 . The switch  24 B or the CUA  14  may route the call to the PSTN  36  so that the call may be completed as previously described. During the making of this call, a call log may be generated (block  152 ). This call log may be stored at the switch  24 B, the CUA  14 , on the computer  18 , on the telephone  22 , or other device as needed or desired. Regardless of routing, the switch  24 B informs the CUA  14  that the call is occurring (block  154 ). The CUA  14  may then share the call log with user  2  (block  156 ). This sharing may be done concurrently so that user  2  is kept apprised of calls in which user  1  is involved as they occur (block  158 ) or subsequently as needed or desired. Further, any multimedia sessions in which user  1  is involved may be shared with user  2  (not shown). In this manner, the user  1  may share call information with user  2  and bring in user  2  as needed or desired. 
     For example, user  1  may place a call, alerting user  2  as to that fact. User  1  may need a document to share with the called party. User  1  instant messages user  2  to retrieve the document. While user  1  continues to converse with the called party, user  2  retrieves the document electronically and makes the document appear on user  1 &#39;s computer  18 . User  1  then sends the document to the called party. Of course, other uses of this technology could also be possible. 
     Expanding the concept of the methodology of  FIGS. 7 and 8  to multiple clients  34 ,  34 B– 34 N, such as the embodiment of  FIG. 6 , is a simple extension. The CUA  14  shares the information amongst all the clients  34 ,  34 B– 34 N according to the sharing restrictions in a user&#39;s profile or other regime as needed or desired. 
     Likewise, the present invention is also well suited for use in a mobile environment as illustrated in  FIG. 9 . In this embodiment, the switch  24 B may interface the public land mobile network (PLMN)  48  through an appropriate network access  20  as is well understood. The PLMN  48  may include one or more mobile services switching centers (MSC)  50  (only one shown) that use an antenna  52  (or multiple antennas, not shown) to communicate with mobile terminals  54  (only one shown). The MSC  50  may communicate with the packet network  12  via a network access  20  as is well understood. The communication between the MSC  50  and the mobile terminals  54  may be by any conventional standard such as WCDMA, D-AMPs, GSM, and the like. The CUA  14  sets up parallel voice and data sessions through the MSC  50  to the mobile terminals  54 . The mobile terminals  54  may share directory numbers, just like the desktop telephones  22 . In this embodiment, the mobile terminal  54  acts as both the telephone  22  and the computer  18 , although they could be separate devices if needed. It is particularly contemplated that display  56  may work with keyboard  58  to mimic some of the functions of the computer  18 B. 
     In short, the present invention is well suited for use by people sharing a directory number or an extension. Such individuals may swap multimedia content via instant messaging, whiteboarding, video conferencing, and other programs as well as share comments about incoming or outgoing calls so that a consistent approach is taken by both parties without the need for transferring paper messages. Other uses will be readily apparent to those of ordinary skill in the art without departing from the scope of the present invention, 
     Those skilled in the art will recognize improvements and modifications to the preferred embodiments of the present invention. All such improvements and modifications are considered within the scope of the concepts disclosed herein and the claims that follow.