System Performance Analysis Under IEEE 802.11 DCF Non-saturated State

In recent years,with the rapid spread of network technology and the rapid development of WLAN,the requirements of information processing capabilities is also increased.In order to improve work efficiency,exchange and process information anytime and anywhere,the concept of mobile computing is proposed.As a kind of mobile computing,WLAN is widely used in real estate,medical,military and other fields because of the simple structure,high mobility,high transmission rate,low cost and high quality.At the same time,how to improve the performance of WLAN becomes the focus of current research.The IEEE 802.11 MAC protocol is divided into distributed coordination function(DCF)and point coordination function(PCF).The DCF mechanism adopts the carrier sense multiple access(CSMA/CA)mechanism with collision avoidance and the random backoff access channel.It is widely used due to the characteristics of self-organizing network and random access method,which is the main background of the research of this paper.However,the infinite WLAN under the IEEE 802.11 protocol has certain limitations,and its network performance will be affected by factors such as nodes hidden,system saturation,and channel conditions.In order to improve the efficiency and accuracy of WLAN,this paper will focus on the analysis of hidden node existence and system saturation on network performance in the improvement of WLAN.Firstly,the performance of the system under the basic access mechanism and RTS/CTS access mechanism is analyzed.Then by extending two-dimensional discrete Markov model of the system under saturated state and adding to non-saturated,the non-saturated state discrete is established.the delay and throughput of the network with no hidden nodes and with hidden nodes in the unsaturated state of the MAC layer are studied.Finally,the proposed model is evaluated by numerical simulation.