A distributed network selection mechanism for WCDMA/OFDMA heterogeneous networks

It is well known that network selection plays an important role in heterogeneous wireless networks. This paper investigates this issue in a wideband code division multiple access (WCDMA) and orthogonal frequency division multiple access (OFDMA) overlapped system. Noticing that information exchange between integrated networks may cause excessive signaling overhead and access delay, this article proposes an algorithm friendly distributed network selection mechanism to solve this problem. The key innovative idea of this method is to split the network selection process into two phases: the first phase deals with some pre-computation at the network side before the session arrives; while the second phase takes place after receiving the session request. In addition, a load balancing algorithm is introduced into this mechanism for performance analysis by establishing a queuing model. Simulation results prove that the practical performance is very close to the ideal theoretical performance. Meanwhile, significant signaling load and access delay reduction is realized.