Cooperation for Next Generation Wireless Networks

The vision beyond 4th Generation (4G) wireless technologies targets a technology ecosystem of Heterogeneous Networks (HetNets), where each network is engineered to support a specific service and mobility pattern. Pivotal to this trend are novel wireless networks / air interfaces that can deliver very‐high‐speed and ubiquitous mobility. It is widely accepted that cooperation can play a major role in enhancing communication data rates and coverage by exploiting concepts such as diversity and relaying. In this context, Decode‐and‐Forward (DF) is one traditional cooperative technique that has attracted great interest, especially after the wide spread of mechanisms such as Automatic Repeat reQuest (ARQ) and Network Coding (NC), which are facilitated by the DF operation. Although DF has been extensively studied in the literature, the increasing number of wireless devices in current networks along with the dense urban environment provides the impetus for a Medium Access Control (MAC) layer design based on an inter‐layer engineering without neglecting the physical‐layer impact. In this chapter, we study the performance of an NC‐aided ARQ MAC protocol under correlated shadowing conditions via extensive simulations. Our results highlight the importance of taking into account the shadowing correlation for a realistic assessment of distributed MAC schemes, disclosing interesting trade‐offs between throughput and energy efficiency in the network.