Cooperative Load Balancing for OFDMA Cellular Networks

Traffic shifting based load balancing (LB) schemes reduce the load of the hot-spot base station (BS), by shifting its traffic to its less-loaded neighbouring cells, called partners. Under the condition of multiple hot-spot BSs shifting traffic to one partner, this partner becomes a public partner. In conventional LB schemes, each hot-spot BS makes its traffic shifting decision independently. This could result in the public partner becoming heavily loaded, which is defined as the “aggravating load” problem in this paper. The aggravating load problem increases the call blocking probability of the public partner and might lead to LB handover failure. This paper proposes a cooperative LB scheme, which is composed of a relative load response model for solving the aggravating load problem, and a relative load based traffic shifting mechanism. Simulation results show the proposed cooperative LB scheme can mitigate the aggravating load problem and keep LB handover failure rate at low level. Keywords-Load balancing; traffic shifting; call blocking probability