ABSTRACT
In an ad hoc environment with one channel and slotted ALOHA medium access control (MAC) protocol, access probability control is an instinctive solution for the spectrum access adaptation in the underlay paradigm. In particular, each SU virtually tosses a coin
CONTENTS
10.1 Introduction ........................................................................................................................ 185 10.2 Related Works ..................................................................................................................... 186
10.2.1 Path-Predetermined Routing ............................................................................... 187 10.2.2 Opportunistic Routing .......................................................................................... 187 10.2.3 Diverse Routing ..................................................................................................... 187 10.2.4 Epidemic-Like Routing ......................................................................................... 188
10.3 Preliminaries ...................................................................................................................... 189 10.3.1 Susceptible Infected-Recovered Model and Global Timeout Scheme ........... 189 10.3.2 Flooding-Based Epidemic Routing ...................................................................... 189
10.4 System Model ..................................................................................................................... 190 10.4.1 Outage Constraint of PR Sensitivity ................................................................... 191 10.4.2 Avoidance Region .................................................................................................. 192
10.5 Epidemic-Like Routing Model in Multihop Secondary Networks ............................ 193 10.6 Performance Evaluation .................................................................................................... 195 10.7 Simulation Flowchart ........................................................................................................ 197 10.8 Conclusion .......................................................................................................................... 198 References ..................................................................................................................................... 198
independently with its access probability and transmits if it gets heads. By adjusting the access probability, the subset of SUs acting as interferers could be controlled to prevent violating PUs outage constraint, i.e., outage probability relative to a signal-to-interference-noise-ratio (SINR) threshold. However, the random access for opportunistic transmission at the SU introduces an unpreventable medium access delay. In addition, the unreliable links among the SUs introduce a potential retransmission delay due to an unsuccessful reception at the secondary receiver. To concatenate the SUs as a secondary network, quality of service (QoS) provisioning for endto-end packet transmissions is a must. However, the mentioned delays challenge conventional path-determined, single-path routing toward QoS guarantee in the secondary networks [2,3].
