Latency and cost requirements of systems for teaching MAC protocols

Over the past decade, the physical (PHY) layer of communication systems has evolved with the addition of techniques such as orthogonal frequency division multiplexing (OFDM) and multi-carrier aggregation. This has resulted in significant performance improvements, but it has come at the cost of increased power consumption and system complexity. To overcome this problem, a wide range of new Medium Access Control (MAC) protocols have been proposed for wireless networks. However, the speed of innovation in MAC protocols has not been able to keep up with the fast pace of PHY layer research; the latter being fueled by the availability of a variety of Software Defined Radio (SDR) platforms. These systems have eventually made their way into the classrooms and labs, thus giving communication engineers an experiential learning opportunity. They have provided students cost effective options to acquire real-world signals and analyze them using digital signal processing techniques. In essence, this has done for communications engineering students, what the sound card did for students learning audio signal processing. On the other hand, computer science students have been left with the option of learning about MAC protocols only through text books or by using software simulations. This is because most SDR systems do not meet the stringent latency and performance requirements required for creating real-world communication links; and the few that do are priced out of reach for classroom sizes typically found in Indian engineering colleges. In this paper, we analyze this situation at hand and discuss the emergence of a new design space for MAC layer prototyping systems. This paper discusses the key requirements, namely latency, processing speed, and cost, of systems in this design space. Finally, this paper describes how availability of commercial technology and careful trade-off with other requirements, such as throughput and frequency agility, is making it feasible to design a system that meets these key requirements.