Wireless Network MAC Layer Performance Evaluation with Full-Duplex Capable Nodes

This paper demonstrates the potential performance gains that the introduction of full-duplex nodes can provide to a wireless network. The paper focuses on two common issues in current communications networks; bottlenecks and hidden nodes. The technical approach used simulates a simplified MAC protocol and scans over the parameter space for which full MAC simulations would not be computationally tractable. In contrast to most literature which focusses on saturated traffic, this study identifies the capacity region, i.e., vectors of demand that can be met by the system. The study shows that introducing full-duplex access points alone mitigates against the problem of bottlenecks, reduces the impact of hidden nodes and can increase the capacity of a network. When full-duplex access points are able to work with full-duplex clients, the capacity gain is much more significant, however it is shown that much of this capacity gain occurs at uneven demand combinations. When the demand to all nodes is equally high, the introduction of full-duplex capability to clients is shown to increase the number of transmission attempts resulting in a significantly increased number of collisions and reduced network performance. Further we observe that at low traffic levels, a full-duplex access point may improve throughput by simply transmitting a busy tone to silence other transmissions whilst it receives, mitigating against the hidden node problem