Network Layer Scheduling and Relaying in Cooperative Spectrum Sharing Networks

We consider network layer cooperation in spectrum sharing networks whereby some secondary users relay primary users´ packets, in return for more favorable spectrum access rules. Under this cooperative scheme, we investigate how primary and secondary networks can be stabilized without explicit knowledge of the packet arrival rates. We consider a primary packet generation process wherein a packet is formed by aggregating constant amount of bits that arrive in every time slot from upper-layers of the primary transmitter. For this primary packet generation model we develop a relaying and scheduling algorithm using Lyapunov drift techniques that does not require knowledge of packet arrival rates. We also construct a guaranteed stability region representing packet generation rates for which the algorithm can stabilize the network. The set of secondary packet generation rate vectors for which the network can be stabilized do not decrease under cooperation when the primary packet generation rate is lower than what can be maximally supported without cooperation. For higher primary packet generation rates the algorithm stabilizes the network for a non-empty set of secondary packet generation rate vectors.