Performance Simulation And Research Of The Statistical Priority-based Multiple Access

The basic function of tactical data link is the rapid exchange of various intelligenceinformation between sensors, command and control unit and weapons platform on thebattlefield, monitoring the situation on the battlefield in real time, and improving fightingcapability.U.S. military’s next generation data link system TTNT (Tactical Targeting NetworkTechnology) aims at the defects of the existing data link system and achieves arevolutionary system optimization. TTNT is based on the full IP communication, andrealizes full duplex wireless communication based on the frequency hoppingmultiplexing(FHMA) at the physical layer, realizes SPMA(statistic priority-based multipleaccess) based on the full duplex communication at the link layer. The MAC protocol oftactical data link describes the rules of nodes accessing channel, using the appropriate MACprotocol, can allocate the channel resource more reasonable, enhance the utilization ofchannel resource and achieve high system capacity.This topic compared the characteristics of various MAC protocols and then aiming atthe defects of existing MAC protocols, designed the MAC protocol SPMA and simulatedSPMA on OMNeT++. SPMA sets a threshold to packet of different priority and comparewith the channel occupancy statistics to determine whether the packet can be sent, thusreduce the channel conflict effectively, and ensure the real-time property of datatransmission. The simulation results show that with the increase of the network nodes,SPMA protocol keeps the delay of the highest priority packet at about4ms; With theincrease of the traffic, SPMA protocol can guarantee delivery ratio at the first time of thehighest priority packets not less than90%. SPMA has the advantage of low latency, highthroughput and better QoS guarantee, correspond with the development trend of the tacticaldata link.