Has To Ack The Control Joint Probability Random Multiple Access Mac Protocol

Based on the analyses of the existing random multiple access technology, multi-channel technology, and the MAC protocols of random-competition-based wireless sensor networks, we propose a novel wireless sensor network MAC protocol. The protocol, which is called ask-answering MAC protocol, is proposed based on the multi-probability-joint-control and random-multiple-access mechanisms. Adding the ACK ask-answering mechanism to it, the protocol can reduce the number of lost packages.The proposed protocol can be applied in the localized wireless networks with high load and high sudden data streams. The work mechanism of this protocol is that the message is divided into two parts when the channel is busy. The first part is the transmission period "1". The second part, denoted by "3a", is the sum of group transmission delay "a", ACK message transmission period, and the ACK message delay "a". Between these two parts, we use the way of P-detection-control, which is based on the way of two-section-probability control. The message groups, which arrive at the transmission period"1", continuous monitor the channel with the probability of P2. The message groups, which arrive at one of the three cases, which are transmission delay period "a", ACK message transmission delay period, and delay period "3a", continuous monitor the channel with the probability of P3, and send the message groups when the channel is empty. As for the message groups those arrive when the channel is empty, send the message with the probability P1 through the way of P-holding. The ACK message is back when the data is sent successfully or not. We can improve the system's performance by choosing different groups of these three probabilities. And the control flexibility is improved as well. On the other hand, the proportion of lost packages is down by adding the ACK ask-answering mechanism, that is, the reliability of wireless sensor networks can be improved.Adding multiple access technology to the protocol, we can apply the principle of higher priority groups can use a more channel. The principle can guarantee the QoS of high priority tasks and can guarantee the fairness and effectiveness of the systems.We use the way of average cycle analysis to modeling and analysis the protocol. We obtain the mathematical expression of joint probability distribution, throughput, throughput of each priority group, the average transmission delay, and other network performance parameters. We also test the performance of the protocol through computer simulation experiments. The results of the simulation experiments show that the system has a higher quality of service (QoS) under the control of the protocol proposed in this thesis.