Advanced Wireless Networks, 3rd Edition

3Mobility Management

3.1 Cellular Networks

As already indicated in Chapter 1 the generic model of 5G/6G wireless networks will integrate services of different segments, such as cellular networks, WLAN, WPAN, and even LEO satellites. Several alternative backbone networks will be used like the public land mobile networks (PLMNs), mobile Internet protocol (Mobile IP) networks, wireless asynchronous transfer mode (WATM) networks, and low Earth orbit (LEO) satellite networks. The backbone network will be most probably organized on the software defined network (SDN) principle. Regardless of the network, one of the most important and challenging problems for wireless communication and computing is mobility management [1–62]. Mobility management enables communication networks to locate roaming terminals for call delivery and to maintain connections as the terminal is moving into a new service area, process known as handoff. The handoff may be executed between different segments (cells) of the same or different systems. The handoff event is caused by the radio link degradation or initiated by the system that rearranges radio channels in order to avoid congestion. Our focus in this section is on the first kind of handoff, where the cause of handoff is poor radio quality due to a change in the environment or the movement of the wireless terminal. For example, the mobile user might cross cell boundaries and move to an adjacent cell while the call is in process. In this case, the call must ...