Network Coded ALOHA for Wireless Multihop Networks
Hyun-Kwan Lee, Seong‐Lyun Kim · 2009
The purpose of this paper is to show the possibility of combining slotted ALOHA with network coding in wireless multihop networks. In particular, we focus on a star topology in which outer nodes exchange data with each other through a center node. The question is how much the throughput increases by adopting network coding at the center node. To answer this question, we analyze the performance of slotted ALOHA for a star topology. In our analysis, there are two versions of slotted ALOHA: conventional ALOHA, and so-called network coded ALOHA, where the center node makes a network coding with the XOR operation to encode bi-directional traffic of the outer nodes. By analyzing the star topology, we can understand how to control the congested node in a wireless multihop network, where a lot of traffic passes through the node. In our analysis, we make cross- layer optimization over physical and MAC layers. Our conclusion is that network coded ALOHA is a good alternative to support the congested node, compared to the other wireless MAC, e.g., CSMA/CA Index.