Analysis of the Decoupled Access for Downlink and Uplink in Wireless Heterogeneous Networks

Wireless cellular networks evolve towards a heterogeneous infrastructure, featuring multiple types of Base Stations (BSs), such as Femto BSs (FBSs) and Macro BSs (MBSs). A wireless device observes multiple points (BSs) through which it can access the infrastructure and it may choose to receive the downlink (DL) traffic from one BS and send uplink (UL) traffic through another BS. Such a situation is referred to as decoupled DL/UL access. Using the framework of stochastic geometry, we derive the association probability for DL/UL. To maximize the average received power, as the relative density of FBSs initially increases, a large fraction of devices chooses decoupled access, i.e., receive from a MBS in DL and transmit through a FBS in UL. We analyze the impact that this type of association has on the average throughput in the system.