Power Saving in a Device Compatible with Cellular and WLAN Networks

A computer-readable medium having computer-executable instructions which when executed by a computer in a mobile communication device result in:

• transmitting presence signaling to a mobility manager via a cellular network;
• in response to recognizing that a user of said device is initiating a communication session to another communication device, activating a wireless local area network interface of said mobile communication device and searching for and attempting to establish a connection to a wireless local area network;
• and
• if a connection to a particular wireless local area network is established, transmitting updated presence signaling to said mobility manager via said particular wireless local area network.

A mobile communication device comprising:

• a processor;
• a cellular communication interface coupled to said processor;
• a wireless local area network interface coupled to said processor;
• and
• a memory to store code which, when executed by said processor, causes said mobile communication device to transmit presence signaling to a mobility manager via a cellular network using said cellular communication interface and in response to recognizing that a user of said device is initiating a communication session to another communication device, to activate said wireless local area network interface and to search for and attempt to establish a connection to a wireless local area network, and if a connection to a particular wireless local area network is established via said wireless local area network interface, to transmit updated presence signaling to said mobility manager via said particular wireless local area network.