The traditional hierarchical structure of cellular networks has led to deployment models which are heavily centralized. Mobility management with centralized mobility anchoring in existing hierarchical mobile networks is quite prone to suboptimal routing and issues related to scalability. Centralized functions present a single point of failure, and inevitably introduce longer delays and higher signaling loads for network operations related to mobility management. To make matters worse, there are numerous variants of Mobile IP in addition to other protocols standardized outside the IETF, making it much more difficult to create economical and interoperable solutions. In this document we examine the problems of centralized mobility management and identify requirements for distributed and dynamic mobility.
