LOCAL COOPERATION ARCHITECTURE FOR SELF-HEALING FEMTOCELL NETWORKS

As the demands for mobile phone access to the data services are expanding, advantages in cellular services can be gained by offering enhanced user experience through cost-effective broadband mobile. By reducing the distance between base stations and end users, femtocells provide higher data rates and better indoor coverage. The small size of a femtocell also improves spectrum reuse, which contributes to higher spectrum efficiency. As femtocells are usually unplanned, efficient operation and maintenance are required to maximize the benefits of femtocell access. As one of the fundamental functionalities in network maintenance, a self-healing mechanism aims to autonomously alleviate the impact of coverage or capacity loss induced by cell outage. Existing studies on the self-healing problem have focused on macrocell networks, while none of them has systematically investigated the problem in the context of femtocells networks. In this article we argue that the distinct features of the two-tier macro-femto system require dedicated architectures for self-healing femtocell networks. We present three different architectures, and further investigate their advantages and limitations. Then we call attention to the local cooperative architecture, which, with proper design, satisfies the practical requirements imposed by the salient features of femtocell networks. We further verify the benefits of the local cooperative architecture by proposing a self-healing scheme for femtocell networks.