Delay characteristics of TDMA medium access control protocol for cognitive radio networks

In this work, we have evaluated the delay characteristics of Time Division Multiple Access (TDMA) protocol. In our simulation scenarios, primary users and secondary users exploit TDMA as a medium access control protocol. We have designed a network environment in Riverbed (OPNET) simulation software that consists of primary users, secondary users, and base stations. In our network model, secondary users sense the spectrum and inform the base station about empty channels. Then, the base station decides accordingly which secondary user may exploit the empty channel. Energy detection technique is employed as a spectrum sensing technique because it is the best when information about signal of primary user is obtained. Besides, different number of users is selected in simulation scenarios in order to achieve accurate delay results. Comparing analytical model with simulation results, we have shown that delay analysis of our system model is reliable and correct.