Group Mobility Indirection

A fundamental requirement of many mobile network architectures, including Mobile IP, MobilityFirst [18], and XIA [9], is to track the network location associated with a mobile user. Group mobility – a group of users whose mobility among networks may be correlated – provides opportunities for efficiently handling the user-location information associated with the users in that group. We introduce the concept of “groupmobility indirection” in which a group identifier references a group of users, updating a location associated with this group identifier, rather than individually updating the locations of each of the users. A central challenge for group-mobility indirection is to determine which (of the perhaps multiple) network locations to associate with the group when users associated with a group identifier may be split among several networks. We present a group-mobility indirection architecture, and propose several algorithms to determine the network associated with the group location. We evaluate the reduction in the location-tracking overhead for these algorithms via a synthetic group-mobility model and via empirical traces of approximately 4000 mobile users. We discuss the performance relation of the algorithms to the periodicity in users’ network-association patterns, and discuss the gain in reducing the location-tracking overhead as the number of groups increases.