Abstract:

Opportunistic spectrum access (OSA) is considered as a promising approach to mitigate spectrum scarcity by allowing unlicensed users to exploit spectrum opportunities in licensed frequency bands. Derived from the existing channel-hopping multiple access (CHMA) protocol, we introduce a hopping control channel medium access control (MAC) protocol in the context of OSA networks. In our proposed protocol, all nodes in the network follow a common channel-hopping sequence; every frequency channel can be used as control channel and data channel. Considering primary users’ occupancy of the channel, we use a primary user (PU) detection model to calculate the channel availability for unlicensed users’ access. Then, a discrete Markov chain analytical model is applied to describe the channel states and deduce the system throughput. Through simulation, we present numerical results to demonstrate the throughput performance of our protocol and thus validate our work.

Key words:

channel hopping, MAC protocol, OSA, Markov chain