Best Association of Macro User in Two-Tier Cellular Networks

Recently an extensive deployment of small cell Networks (SCNs) called two tier-heterogeneous networks have been proposed, especially for dense urban zone. Therefore, Macro Cell Networks containing a hyper density of SCNs distributed randomly within it will emerge the field. The benefits of two tier Heterogeneous Networks (HetNets) are realized through the traffic flooding via small cells. To enhance the performance of the two-tier cellular networks and offer the best quality service for Macro user, the cell association problem is modeled using the partially observable Markov decision process (POMDP). POMDP works based on a set of beliefs states that the macro-user get considering the impact of the base station's (BS) best channel. The macro-user has to make decisions based on its channel state partially observable and the shared information in order to associate with BS, the association decisions are determined based on the calculated SINR. The numerical results of the proposed solution are given with comments and they show the acceptable system performance.