Handling the Backhaul Link Failure for IEEE 802.16m Femto ABSs

A Fem to Advanced Base Station (ABS) is a low-power base station and used to extend Worldwide Interoperability for Microwave Access (WiMAX) coverage to the indoor areas. The Fem to ABS utilizes broadband connection (e.g., cable or DSL) as its backhaul link to connect to the mobile operator´s network and Internet. However, the broadband connection is less reliable than the dedicate line. In other words, the Fem to ABS has more backhaul failure probability than the Macro ABS which uses the dedicate line. In order to reduce the impact of backhaul link failure, this paper proposes two mechanisms to handle the backhaul link failure based on different interfaces defined in IEEE 802.16m. This paper then compares these mechanisms in terms of the additional interface requirement, the notification method, the authentication/key exchange and the re-registration requirement. This paper also develops an analytic model to study the disruption time and packet loss of the proposed mechanisms.