A communication system can be seen as a facility that enables communication between two or more entities such as user equipment and/or other nodes associated with the system. The communication may comprise, for example, communication of voice, data, multimedia and so on.
A communication system typically operates in accordance with a given standard or specification that sets out what the various elements of the system are permitted to do and how that should be achieved. For example, the standard or specification may define if the user, or more precisely, user equipment or terminal is provided with a circuit switched service and/or a packet switched service. Communication protocols and/or parameters to be used for the connection may also be defined. In other words, a specific set of “rules” on which the communication can be based needs to be defined to enable communication via the system.
Communication systems providing wireless communication for user terminals or other nodes are known. An example of the wireless systems is a cellular network. In cellular systems, a base transceiver station (BTS) or similar access entity serves mobile stations (MS) or similar user equipment (UE) via a wireless interface between these entities. The operation of the apparatus required for the communication can be controlled by one or several control entities. The various control entities may be interconnected. One or more gateway nodes may also be provided for connecting the cellular network to other networks, such as to another cellular system or to a public switched telephone network (PSTN) and/or other communication networks such as an IP (Internet Protocol) and/or other packet switched networks. The communication between the user equipment and the elements of the communication network can be based on an appropriate communication protocol such as the session initiation protocol (SIP).
For example, in the current third generation (3G) multimedia network architectures it is assumed that various servers are used for handling different functions. The SIP is implemented by means of an SIP proxy server. A UE wanting to establish a session with another UE communicates with the SIP proxy server by way of the air interface, and the SIP server then establishes and maintains the required channel.
One difficulty with this arrangement is that if a user wants to use SIP as a basis for sending messages for a group of recipients (such as text messages or data), the message must be sent multiple times from the user to the proxy server, and thence to each intended recipient individually. This consumes bandwidth between the user and the proxy server. The problem is exacerbated in a mobile telecommunications environment, where this link can be the air interface, where bandwidth is at a premium.
Another difficulty is that instant messaging under, for example SIP, does not presently provide an option for users to find out the status of messages they have sent.