Date Added: Feb 2011
The IEEE 802.21 is a recent standard for enabling handover in heterogeneous wireless networks, which defines protocols and messages for mobile-to-node and node-to-node communication in a technology-neutral and flexible manner. The need arises because of the widespread diffusion of different technologies for wireless communications (e.g., WiFi, WiMAX, LTE), which are often coexisting in the same geographical area and supported by the same mobile device, but seldom interoperable. In this paper, the authors propose the architecture of a Media Independent Information Service (MIIS) and the procedures for a network-assisted handover, which are left unspecified by the standard, aimed at reducing the energy consumption of mobile nodes due to scanning. A detailed description of the software modules involved and their interactions is included.