Abstract:
According to one aspect of the present invention, there is provided a method, in a telecommunication system, of establishing a connection between a calling terminal and a called terminal, the called terminal having an associated presence status, the connection establishment being initiated by a connection establishment request sent by the calling terminal, comprising: obtaining, in response to the connection establishment request, the presence status associated with the called terminal; and supplying the obtained presence status to the calling terminal.

Description:
The present application claims priority under 35 U.S.C. §371 to PCT Application PCT/EP2005/053145, filed on Jul. 1, 2005, and entitled “Presentation to Caller of Presence Information About Called Party” which is hereby incorporated by reference in their entirety. 
     FIELD OF THE DISCLOSURE 
     The present invention relates to the field of telecommunications, and particularly to the accessing of presence-type information using telephone communications. 
     SUMMARY 
     In recent years the use of presence information has become increasingly widespread in the field of telecommunications. Presence information is now widely used, for example, by instant messaging applications, use of which is being increasingly made by many private and enterprise computer users. Instant messaging applications enable a user to publish presence information, such as a presence status, to view the presence information of other users, and enable instant messages to be sent to other users. The term ‘publishing’ is commonly used in the field of presence in relation to the making available of presence information to other users to enable them to view or access that status. Some presence systems use a central storage repository, often referred to as a presence server, to which presence information may be published to or retrieved from. Other systems store presence information locally and, through a local presence server, make this information available directly to other users, for example using a point-to-point connection. For the purpose of the following description the term presence server is used generally as relating to an element containing presence information and for making that presence information available to one or more other users. 
     Instant messaging applications are also finding their way onto advanced mobile telephones and personal digital assistants, bringing the advantages of instant messaging to mobile users. 
     Advanced telecommunication system, such as session initiation protocol (SIP) networks inherently provide support for presence. Indeed, many instant messaging applications use the presence framework provided by SIP. SIP enables users of SIP phones to access advanced telephony functionality based on presence information. Such functionality includes, for example, advanced rules-based call routing and forwarding based on the published presence status of a user. For example, a SIP phone user having their presence status published as ‘at work’ may cause all telephone calls made to the user&#39;s SIP phone to be automatically forwarded to the user&#39;s work phone. 
     Presence is also widely used in advanced telecommunications systems such as push-to-talk, a type of Voice over IP (VOIP) system available on some mobile telephones. Push-to-talk systems use presence to enable a user to see which members of their contact or ‘buddy’ list are presently contactable, and enables quasi-instantaneous voice messages to be sent to available contacts. 
     However, in order for a user communication terminal, such as a telephone, to be able to make use of presence systems, the user communication terminal has to be presence capable. Since presence systems are controlled and managed by a user-side presence application on the user communication terminal, the user communication terminal has to have sufficient processing power and capabilities for executing such an application. Thus, presence systems are only available on modern microprocessor-based user communication terminals such as so-called smart-phones, advanced mobile telephones, personal digital assistants, personal computers, and the like. 
     Currently, however, there are vast numbers of legacy user communication terminals, such as conventional so-called ‘black phones’ and older mobile telephones which do not have any, or at least not sufficient, processing capabilities, and thus are unable to access presence information. Thus, if a user of a conventional telephone wishes to check the presence status of a user they wish to call prior to calling them, they currently have to use a separate terminal, such as a personal computer running a suitable presence application to determine whether that user is available, and then to place a call using the conventional telephone. This situation is somewhat inconvenient for the user of a conventional telephone who may not always have access to a separate presence capable terminal. 
     Accordingly, one aim of the present invention is to overcome, or at least alleviate, at least some of the above-mentioned problems. 
     According to a first aspect of the present invention, there is provided a method, in a telecommunication system, of establishing a connection between a calling terminal and a called terminal, the called terminal having an associated presence status, the connection establishment being initiated by a connection establishment request sent by the calling terminal. The method comprises obtaining, in response to the connection establishment request, the presence status associated with the called terminal, and supplying the obtained presence status to the calling terminal. 
     Advantageously such a system enables users of non-presence capable communication terminals to access presence information previously only available to presence capable communication terminals. 
     Suitably the telecommunications system includes at least one network switching element for use in establishing the connection and wherein the presence status associated with the called terminal is obtainable from a presence server, the method further comprising one of the at least one network switching elements obtaining the presence status from the presence server. 
     Suitably the obtained presence status is converted to an audio format and is supplied to the calling terminal by way of a ringing back tone. 
     Alternatively, the obtained presence status may be encoding supplied with a ringing back tone to enable display of the encoded status on a suitable display unit of the calling terminal. 
     Suitably, the network switching element pages the called terminal only once the obtained status has been supplied to the calling terminal. 
     According to a second aspect of the present invention, there is provided apparatus for establishing a connection between a calling terminal and a called terminal having an associated presence status, the connection establishment being initiated by a connection establishment request sent by the calling terminal. The apparatus comprises processing logic for obtaining, in response to the connection establishment request, the presence status associated with the called terminal, and an output element for supplying the obtained presence status to the calling terminal. 
     Suitably, the apparatus further comprises a presence server in which the presence status of the called terminal is held. 
     Suitably, the processing logic is adapted for obtaining the presence status from the presence server. 
     Suitably, the apparatus further comprises a converter for converting the obtained presence status into a format suitable for output on the calling terminal. 
     The converter may be adapted for converting the obtained presence status to an audio format and for supplying the converted presence status to the calling terminal by way of a ringing back tone. 
     Alternatively, the converter may be adapted for converting the obtained presence status into a textual format and for supplying the encoded presence status along with a ringing back tone to enable display of the encoded status on a suitable display unit of the calling terminal. 
     The apparatus may be further adapted for supplying the obtained presence status to the calling terminal prior to paging the called terminal. 
     According to a third aspect of the present invention, there is provided a telecommunications network comprising apparatus as mentioned above. 
     According to a fourth aspect of the present invention, there is provided a method of operating a network switching element of a telecommunication network as described above. 
     According to fifth aspect of the present invention, there is provided a network switching element adapted for operating in accordance with any of the above-described method steps. 
     An embodiment of the invention will now be described, by way of example only, in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram showing a telecommunications system  100  according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to  FIG. 1 , there is shown a telecommunications system  100  comprising a telecommunications network  106  comprising various network elements  108 ,  110 ,  112 ,  114 ,  116  and  118 . A calling terminal or device  102  places a call or communication establishment request to the called terminal or device  104  via the telecommunications network  106  with a view to establishing a communication, such as a call, between the two terminals in the normal manner. Typically, a call establishment request is made by the user of the calling terminal  102  dialing the telephone subscriber number of the called party  104 . Those skilled in the art will appreciate that the placing of a call generally involves the sending of one or more messages or control signals, at least one of which is, or has as its effect, a call establishment request, between the calling party, and the network and/or the called party  104 , with the exact mechanism dependent largely on the type of network. 
     In the present embodiment the calling terminal  102  is a mobile telephone and the network  106  is a mobile telephony network. It will be appreciated, though, that other configurations could be used. For example, the calling terminal  102  could be a conventional ‘black phone’ for use on the plain old telephone system (POTS) and a POTS type network (not shown) could be used to connect the calling terminal  102  to the mobile network  106 . The calling terminal  102  is non-presence capable terminal—in other words it does not posses any presence capable applications or functionality. If the calling terminal  102  were to be a presence capable terminal, it is assumed, for the purposes of this example, that such functionality is disabled. 
     The called terminal  104 , on the other hand, is a presence capable terminal, such as a so-called smart phone, personal digital assistant, or other suitable communication terminal. By presence-capable is meant that the terminal  104  runs a suitable presence application capable of publishing presence information associated with the terminal  104  to a presence server, such as the presence server  116 . As previously mentioned, the presence information published by the terminal  104  may relate to the presence status of a user of the terminal, or may result to the presence status of the terminal itself. 
     The calling terminal  104  determines a presence status of either the terminal itself or of a user of the terminal through use of a suitable presence software application running on the terminal. The presence status may be determined in a number of ways. For example, the presence status may be periodically entered or changed by the user of the terminal, or the terminal itself may automatically modify the presence status based on, for example, usage made of the terminal. 
     Presence statuses may be predefined by the terminal or may be user configurable. Example presence statuses may be “uavailable”, “busy”, “not connected”, “in a meeting”, “driving until 16h00”, and the like. The determined presence status is published to a presence server  116  so that the presence status of the terminal  104  is available to other user presence-capable terminals. The presence status may be published to the presence server  116  in the normal manner. For instance, if the called terminal  104  is a SIP phone the presence status may be published by sending a SIP REGISTER message to the presence server  116 . If the called terminal  104  is a so-called smart phone having an Internet Protocol (IP) connection, the current presence status of the called terminal  104  may be sent to the presence server  116  by way of a suitable presence application, such as an instant messaging application. Such an instant messaging application may use SIP or any other suitable protocol. 
     The call establishment request made by the calling terminal  102  is received by the originating mobile switching centre (MSC)  108  to which the calling terminal  102  is currently connected. The MSC  108  queries the home location register (HLR)  112  to determine the location of the called terminal  104  and routes the call establishment request, based on information obtained from the HLR, to the MSC to which the called terminal  104  is currently connected, in this case the terminating MSC  110 . Upon receiving the call establishment request the terminating MSC  110  queries the HLR  112  to determine whether the called terminal  104  has subscribed to any value added data service requiring use of the SCP  114 . This information may be provided by way of a flag associated with the called terminal&#39;s subscriber number stored in the HLR  112 . 
     If, based on the flag, the MSC  110  determines that use of the SCP  114  is required the MSC  110  queries the SCP  114  to determine whether the called terminal  104  is subscribed to a service hereinafter referred to as the presence announcement (PA) service. 
     If the called terminal  104  has subscribed to the PA service the service control platform (SCP)  114  obtains the current presence status of the called terminal  104 . In the present embodiment this is obtained from the presence server  116 . The presence information of the called terminal  104  may be obtained by requesting the current presence status of the subscriber number of the called terminal  104  from the presence server  116 . The request may be made through a suitable presence application or processing logic. 
     The MSC  110 , under the control of the SCP  114 , connects to a presence information player  118  which takes the retrieved presence information, supplied by the SCP  114  through the MSC  110 , and provides a suitable audio output representing the presence information. For example, the presence information player  118  may use a text-to-speech (TTS) engine (not shown) to convert a textually retrieved presence status into a spoken message. The audio output of the presence information player  118  is output to the calling terminal  102  by way of a ringing back tone. In other words, the MSC  110  replaces the usual ringing tone heard by the user of the calling terminal  102  with the audio output from the presence info player. The audio output may suitably be mixed over the top of the conventional ringing tone. 
     At this point, the MSC  110  has not yet paged the called terminal  104  and hence the called terminal  104  has not started ringing. Preferably, the MSC  110  only pages the called terminal  104  once the output audio message has been played at least once, preferably in its entirety, the reasons for which are explained below. 
     Since the called terminal  104  is running a suitable presence application (not shown), it is possible that the presence application may also affect the way in which the called terminal  104  responds to calls. For example, the presence application running on the called terminal  104  may cause all calls made to the terminal whilst the presence status is ‘busy’ to be automatically forwarded to a voice-mail service. If the MSC  110  thus pages the called terminal  104  upon receiving the call establishment request the call would be automatically established with the voice mail service, without the calling party being able to hear the audio output provided by the presence information player  118 . By delaying the paging of the called terminal  104  until after the message has been played enables the user of the calling terminal  102  to hear the message and to decide whether or not continue the call establishment or to hang up. Alternatively, the presence application on the called terminal could alternatively prevent the called terminal  104  from ringing, for example by entering a silent profile, depending on the presence status of the terminal. 
     It is important to note that the present embodiment enables the user of the calling terminal  102  to obtain the presence information of the called terminal  104  without incurring a call charge. This is because the presence information is provided to the user of the calling terminal  102  prior to the called terminal  104  being paged. Even once the called terminal  104  is paged there is still no call established unless the called terminal  104  accepts the call or forwards the call to a voice mail service. 
     If, for example, the user of the calling terminal  102  hears the presence information of the called terminal  104  as being ‘in a meeting’ the user of the calling terminal  102  has the choice of hanging-up calling terminal  104 , or waiting until the end of the audio message, at which time the called terminal  104  will be paged. As previously mentioned, whether the actual paging of the called terminal  104  will cause the called terminal  104  to ring will depend on the configuration of the presence application controlling the presence thereon. 
     In an alternative embodiment, the presence status of the called terminal  104  is stored locally thereon, and is not published to the presence server  116 . The called terminal  104 , through use of a local presence server, makes the presence status of the called terminal  104  available directly to other users having appropriate authorization. In local presence systems, authorization is achieved by a ‘request and active accept’ mechanism. This may be achieved by having a suitable network-based presence application running on or accessible from, for example, the SCP  114 . The network-based presence application (not shown) may request that the called terminal  104  makes its presence information available to the network-based presence application. The called terminal  104  actively accepts the request, and thereafter the network-based presence application may obtain, for example via a point-to-point connection with the called terminal  104 , the presence status of the called terminal  104  on demand. If, for example, the called terminal  104  has an IP address, the network-based presence application may obtain the presence information of the called terminal by way of a point-to-point connection using TCP/IP. The SCP may be used to store, for example, the IP or other address of the called terminal  104  through which the presence status may be obtained. 
     The MSC  110 , upon receiving the connection establishment request may request the presence status of the called terminal  104  directly from the local presence server of the called terminal  104 . Alternatively, the MSC or other network element may periodically request the presence information of the called terminal  104  and may store the obtained information in a local store for later use. 
     In a further embodiment, the called terminal  104  may not itself be presence-capable. For example, the called terminal  104  may be a conventional ‘black phone’ and the presence status of the terminal  104  may be published to the presence server  116  on behalf of the called terminal  104  through a separate presence-capable terminal such as a personal computer or personal digital assistant. This allows the terminal  104  to define a presence status for use by other terminals without requiring the terminal itself to be presence-capable. 
     In yet further embodiments, instead of the MSC  110  connecting to the presence information player  118  to create an audio output of the presence status, the presence information obtained from the presence server  116  is converted to a suitable textual format and is presented to the calling terminal  102  by way of a visual display on the calling terminal. Many conventional telephones have a small display which enables the caller line identity of a caller to be displayed thereon. In the same way that the caller line ID is encoded between ringing tones, the presence status of the caller party  104  is encoded in the same way and is sent with the ringing tone by the MSC  110 . 
     In a yet further embodiment, instead of the MSC  110  connecting to the presence information player  118  a connection is made with an interactive voice application (not shown). Using an interactive voice application enables increased functionality to be easily added to accommodate, for example, rules based functionality associated with the presence status of the called party  104 . The voice application can obtain the presence status of the called terminal  104  as described above and may additionally provide a series of voice menus enabling a calling party to select numerous options such as requesting callback or SMS notification when a called party&#39;s presence becomes ‘available’, having an SMS message sent to the called party to indicate that a call establishment request was made, and so on. 
     Although reference has only been made to a single presence server  116  it is possible that different called terminals may make their presence status available to different remotely accessible presence servers. In this case, the SCP preferably contains a record for each called terminal detailing the address at which the presence status for each called terminal may be obtained. Such presence servers may be provided within the telecommunications network  106  or via an externally accessible network or network of networks (not shown) such as the Internet. 
     Since the presence information of the called party  104  is provided free of charge to the calling party  102 , it may be preferable for the called party  104  to pay a subscription to the provider of the network  106  so that the presence information of the called party  104  is available to callers. If such a subscription is taken by the called party  104  the network provider stores a flag in the HLR  112  indicating this, and may store additional data in the SCP  114  providing further details of the service subscribed to. 
     It should be noted that the presence status associated with a terminal is independent from and potentially different from the network-based availability of that terminal. For example, the presence status of a terminal may be ‘available’ indicating that the user of the terminal is generally available even though the terminal itself may be already connected in a call and therefore appears as ‘busy’ from the network point of view. 
     Although the above embodiments have been described with reference primarily to mobile communication terminals and mobile telecommunications networks, it will be appreciated that the inventive concepts described herein are in no way limited thereto. For example, the above embodiments may be suitably modified to enable the presence information of a fixed line called party to provide their presence status to a calling party. In this case the mobile switching centers  108  and  110  may be replaced, for example, by intelligent switches of a non-mobile network. 
     Those skilled in the art will appreciate that the term ‘call’ used herein, whilst generally referring to telephony-type calls may also refer to other communication establishment requests and/or communication establishments.