Radio Access Technology Selection in Heterogeneous Wireless Networks

To cope with the rapid growth of mobile broadband traffic various radio access technologies (e.g. HSPA LTE WiFi and WiMAX) are being integrated and jointly managed. Radio Access Technology (RAT) selection devoted to decide to what RAT mobiles should connect is a key functionality to improve network performance and user experience. When intelligence is pushed to the network edge mobiles make autonomous decisions regarding selection of their most appropriate RAT. They aim to selfishly maximize their utility. However because mobiles have no information on network load conditions their decisions may lead to performance inefficiency. Moreover delegating decisions to the network optimizes overall performance but at the cost of increased network complexity signaling and processing load. In this book instead of favoring either of these decision-making approaches we propose a hybrid decision framework: the network provides information for the mobiles to make robust RAT selections. More precisely mobile users select their RAT depending on their individual needs and preferences as well as on the monetary cost and QoS parameters signaled by the network.