Dynamic Hierarchical VAP-Based Location Management for Mega Satellite Networks

Mega satellite networks consisting of hybrid orbit satellites play an important role in the sixth generation (6G) wireless networks. Location management (LM) can ensure service continuity for mobile users (MUs) and is one of the key technologies in mega-satellite networks. Moving satellites [e.g., low Earth orbit (LEO) and medium Earth orbit (MEO)] and users require repeated location updates, which creates the challenge problem of significant LM overhead. In this article, we propose a novel dynamic hierarchical LM scheme based on the virtual attachment point (VAP). The approach utilizes MEO satellites to provide LM, and divides the direct association between the user and the satellite into two independent steps, including the association between the user and the VAP, and the association between the satellite and the VAP. With this mechanism, the user’s location no longer needs to be updated due to satellite movement. Besides, a dynamic adaptive location area (LA) scheme is proposed to update the user’s location. The scheme can reduce the update frequency of high-speed MUs, keep the number of paging satellites controllable, and not increase drastically with the constellation scale, thus reducing the paging overhead. The simulation results demonstrate that the proposed LM technology solution can reduce the total LM overhead by at least 40.6%.