Analysis of relay network duplexing, multiplexing, & multiple access: Application to aeronautical networks

Relay networks have seen use in many systems, including satellites, sensors, aeronautical systems, etc. Advantages of relays include range extension, capacity increase, reduced transmission power, and possibly diversity. Disadvantages include increased latency and implementation complexity. In aeronautical applications, link distances can be orders of magnitude larger than in terrestrial cases, and propagation conditions are also substantially different. Thus, solutions for terrestrial settings are not necessarily applicable to aeronautical cases. Although relay networks have seen increased attention, optimal resource allocation methods have not been determined. The question of which multiple access, duplexing, and multiplexing (MA/Dup/Mux) techniques are preferable for relay networks is still under study. In this paper, we analyze several MA/Dup/Mux techniques in non-redundant uni-directional and bi-directional relay networks. These techniques allocate resources to network nodes in the time, frequency, and time-frequency domains. We provide comparisons among the various schemes for uni- and bidirectional relay networks, in terms of resource allocation, duty cycles, required data rate per transmission, required transmit power per link, and relative range. Although commonly employed techniques that only use time division appear adequate in some cases - such as short range networks - our results show that appropriate time-frequency schemes can be superior in terms of data rate and/or quality of service, especially for long range aeronautical networks. Pure frequency division schemes also attain the largest range for a given data rate and performance.