Wireless communication was traditionally based on the idea of enabling voice communication to and from a mobile terminal residing in the coverage of a mobile communication network. The communication channel was established over circuit-switched technology. However, a packet-switched technology was later introduced for improving the efficiency in utilization of the capacity of a mobile communication network. As the data is delivered in packets between the parties there is no need to reserve the whole communication channel for a specific connection. Additionally, some other benefits may be achieved with packet-switched technology, such as those relating to error correction.
The packet-switched technology also enabled a whole range of new services. One reason is that wide range of enterprise and commercial applications are based on IP (Internet Protocol) and thus they can be almost directly imported into the mobile terminals residing in the packet-switched mobile communication network. Examples of such services are so called IP (Internet Protocol) messaging and other communication related to services such as SIP (Session Initiation Protocol), IMS (IP Multimedia Subsystem) and RCS (Rich Communication Suite).
On the other hand, since the services as described above have been adopted by the users of mobile terminals it has brought out another challenge. Namely, the use of the services causes a lot of traffic in a mobile communication network. For example, a presence service by means of which a user can deliver e.g. his/her status information to other parties is very popular. The provision of the presence service is carried out with so called presence server or presence proxy which may be configured to maintain status information of the users or a group of users or relay the information between user terminals. The status information of a user maintained in the presence server is visible for at least limited group of other users. In the case of a presence proxy the information is not stored in the proxy but instead it controls the presence traffic flowing between the terminals and controls it. The visibility may be controlled by the user through an application installed in the mobile terminal of the user. As can be directly seen the updates with respect to users' status may cause challenges for the network as well as the presence server or presence proxy due to the amount of traffic, especially when taking into account the traffic caused by other services.
There has been developed some methods to control the traffic caused by presence services. For example, document U.S. Pat. No. 8,078,191 B2 discloses a proposal for reducing network traffic in the context of presence services. One idea is to postpone the delivery of status updates by a network node until a client especially requests for updates. Alternatively, the network node may accumulate the changes and deliver the presence updates when the final state for each presence attribute is received. This relates to a solution in which there are multiple attributes with respect to the presence information.
However, the known solutions are not widely in use. Typically the known solutions provide only a partial solution i.e. the solution is only for the mobile terminal or the network side. Additionally, the solutions are not implemented by mobile terminal vendors or deployed by telecom operators for one reason or another. Generally speaking none of the known solutions take into account the changes in the network environment. More specifically, the status of the client terminal or the congestion of the network is not anyhow taken into account in the known solutions.