Managing availability in wireless inter domain access

This paper deals with how the availability of wireless/cellular access networks depend on the cooperation between the operators as well as with transmission network operators and professional land lords. The forthcoming 4G network will consist of diverse sets of wireless/cellular networks integrated into IP-based networks. Mobility, QoS and seamless handover between the networks are key features. In the work of Gustafsson and Jonsson (2003), the concept of always best connected is defined as means that the user is connected through the best available device and access technology at all times. Availability of the access is fundamental for QoS and critical services (e.g. emergency services, health services) are more and more dependent of wireless/mobile access. Availability can be increased by utilization of several accesses through seamless handover and/or multihoming. Usually, the availability has been calculated assuming independencies between the access network operators, but in this paper we show that the actual cooperation between the market actors has significant impact on the availability. We propose a solution by usage of the IMH 802.21 framework to build and distribute network topology information with availability estimates allowing to predict the overall availability for the access networks accessible as one of the criteria for a handover decision.