Realization of Mobile Femtocells: Operational and Protocol Requirements

Femtocells are commissioned in wide range of commercial systems, such as CDMA, GSM, LTE, Wi-Fi, and WiMAX, and offer economically viable solutions to improve network scalability and indoor coverage. The ability to offer multitude of context-aware and value added services, and per-user customization have caught world-wide research interest on femtocells. In this article, we have investigated the feasibility to use femtocells as short-range mobile base stations, and discussed the demanding architectural requirements and challenges. The protocol stack on legacy femtocells must be modified to realize mobility. Mobility introduces new challenges in security and user privacy. Firstly, we analyze several candidate mobility protocols that are deployable on Mobile Femtocells (MFs). Among them, Host Identity Protocol (HIP) was chosen due to enhanced support in flexible mobility, security and end-user privacy. Secondly, we propose the indispensable modifications that enable device mobility, and the suitable transport architecture options based on direct IP links and relay chains. Finally, with the simulation results, the proposal is verified, and the architectural options are evaluated. That, in turn, proves the proposed mobility protocol has low latency in location locking with respect to another competing protocol and low resource utilization as it is depicted from mean round trip time.