Multichannel Dual - Clock Two - Dimensional Probabilistic Protocol Analysis For Random Multiple Access Systems

The theory of random multi-access communication system is one of the key theory of supporting theoretical research of communication protocols, which can provide rich theory results for the analysis of wireless LAN, Ethernet, Internet and mobile communication network. With the rapid development of the communication technology, the increase of the users, more and more multi-task requirements will be presented by users who want to take advantage of the wireless access. It proposed new requirements and challenges for multi-users to share limited spectrum resources and ensure the Quality of Service of wireless communication network. And thus designing the effective and reasonable of wireless shared channel’s allocation strategies for normal operation of the network is particularly important, and the random multi-access system theory is an important control theory of the network resource allocation and MAC control protocols. The goal of analyzing random multi-access system is to establish the mathematical model and its functional relation which can deduct the random multi-access control mechanism, gain exactly the expression of throughput, the mean transmission delay, the packet loss rate and other parameters of the system. Among them, the throughput is the most important performance measure for analyzing the underlying system.We introduce the related work of multi-access in Chapter 1. We propose the protocol of random multi-access with Double Clocks to solve the low throughput of basic ALOHA systems, which combines continuous and slotted control modes. Based on the successful application of double clocks control to ALOHA, we try to apply this theory to the CSMA protocols. Meanwhile, we set the probability of sending packet P1 and the probability of sensing channel p2 to improve system performance. Based on the above two considerations, we propose the protocol of Multi-channel Random Multi-access with p-Persist and p-Sense of Double Clocks (MRMPSDC) in Chapter 3. In a wireless communication network, it is a distributed behavior of each terminal station to send packet or sense the channel. The results of taking appropriate behavior for each station not only depends on its own behavior, but also on other stations’actions. Based on this interaction, it is suitable to model the behavior of the stations’ to a game, we introduce the game theory to analyze the MRMPSDC protocol. As an application of the above theories, the fifth chapter performs the classic pure-ALOHA protocol and the MRMPSDC protocol in the wireless sensor networks.The main contributions and novelties of this thesis are summarized as follows:1. We propose the protocol of random multi-access with Double Clocks based on the pure-ALOHA and slotted-ALOHA protocols to improve the system throughput performance. And the control clocks of protocol are double clocks. That is, the continuous clock combines slotted clock. We derived the system throughput performance by average cycle method which has greatly improved compared to the basic ALOHA protocol. The simulation results is consistent with theoretical analysis.2. We propose the protocol of Multi-channel Random Multi-access p-Persist and p-Sense of Double Clocks (MRMPSDC). From the perspective of improving the Service of Quality (QoS) and channel-utilizing rate of wireless communication network, we present the MRMPSDC protocol. Take advantage of the double clocks control mechanism, we choose the probability of sending packet and the probability of sensing channel at the same time, divide different priorities for multi-service and apply of the multi-channel to meet the QoS requirements of different services. The system throughput and the every priorities’throughput are two important performance parameters. We can gain them by average cycle method. The simulation results show that the theoretical analysis and simulation experiments have better consistency, and system of the MRMPSDC protocol can achieve higher system throughput performance.3. We study the modeling of the MRMPSDC protocol based on game theory. In a random multi-access scheme, in order to achieve optimal throughput performance or QoS, the terminal stations access channel through competitive way. We use random muiti-access game to describe this distributed random multi-access problem. We can analyze the behavior of every terminal station and obtain steady-state behavior of each one under the following way:discretize continuous pure strategies space of terminal stations’sending and sensing behaviors to discrete mixed stratages by the discrete degree. Utilize the genetic algorithm for computing the approximate Nash equilibrium. Experimental results and theoretical analysis has better consistency, and the algorithm has high computational efficiency and accuracy, which indicate that using the game theory to analyze the random multi-access protocol is an effective and feasible method.4. We study the energy efficiency issues of applying random multi-access protocols for wireless sensor networks. As an application of the above theories, we apply the classical pure-ALOHA protocol and MRMPSDC protocol for wireless sensor networks’ (WSN) MAC layer modeling. Aim at the concept of the wireless sensor networks’ energy efficiency, we analyze the average power consumption of the system by the average cycle method. The comparison of simulation results and theoretical calculation has shown a lower average system power consumption of WSN with the MRMPSDC protocol. It is very important to prolong the network life cycle, which shows that application of the MRMPSDC protocol to analyze the WSN is valid in terms of energy consumption savings.