Study on SPMA Protocol and Algorithm Improvement

Ad-hoc networks have the characteristics of flexible networking, no center, good scalability, and strong survivability. Due to wireless communication, mobile nodes in the ad-hoc network must have high confidentiality and strong anti-interference to achieve secure transmission of data. SPMA protocol uses a frequency hopping and time hopping mechanism at the physical layer, which can improve the safe transmission of signals. However, the collision probability of the SPMA protocol is relatively high, and it is necessary to design a special back-off algorithm for the SPMA protocol to reduce the collision probability and improve the transmission reliability. Aiming at the shortcomings of the existing back-off algorithms, an adaptive back-off algorithm suitable for SPMA protocol is proposed, which can dynamically adjust the back-off time according to the priority, threshold and channel occupancy statistics to achieve better back-off effect. Modeling the SPMA system through the OPNET platform proves that the SPMA protocol can achieve differentiated services with multiple priority levels, and the improved back-off algorithm can effectively improve the throughput performance of the SPMA protocol and further reduce the packet loss rate and average delay of high-priority packets.