The Analysis, Based On The Probability Of Detection Csma / Ca Wireless Sensor Network Protocol And Control Circuit

Wireless sensor network (WSN) is a new type of sensor network, which is the cross of multi-disciplinary field and use IEEE 802.11 protocol standard. It has perception capacity computing power and communication ability, the tiny sensor terminal node structure, through wireless communication form a multiple hops and the configuration of the network system, its purpose lies in gathering information, and through the network coverage of the area in the sensor terminal node, wireless communication way will send the collected information to processing center.It is widely used in many fields,such as the military, health care, explosion-proof, industrial, relief. The main research direction is reducing data sending conflict rate and improving throughput, shortening the time delay, reducing the energy consumption of wireless sensor network protocol to solve the sensor terminal node carry energy limited, replacement batteries or supplement energy work difficult problem.The main object of this paper analysis is wireless sensor network MAC protocols and sensor terminal node.I study and learn about the wireless sensor MAC protocols literature and terminal node, introduces CSMA/CA technology and multi-channel random multi-access technologies to study the sensor network protocol and get energy saving for main goal.This paper carefully analyzed based on the probability function testing CSMA/CA wireless sensor network MAC agreement, through the information transmission cycle TP group (1+2a+Ï„A) is divided into information packet, send time "1", an ACKÏ„A and circuit information time delays time A. In "1" and (2a+Ï„A) two slots, the information packets are accessed channels by detecting way probability p. In the information sent time "1",arrived information in probabilistic function value group, protected reliably against detective channel continued p and probability (1-p) give up, take different protected reliably against detective channel through the probability of dynamic control dormancy p value nodes. According to the working principle, establish agreement system model. Put the channel in three kinds of random events may occur idle, group sent:channel success and information packet sent a collision and of three kinds of random events division, establish systems and mathematical model, through the strict mathematical formulas are calculated respectively, leisure, group sent successfully channel information packet collisions occur, the average length of three random events, the average period analysis method system throughput, respectively, get the life cycle time delay, terminal node such performance index theory and half-theory. Using simulation programming language, get the corresponding simulation results, the theoretical analysis and the simulation results data value maintained good consistent, verify the correctness of the theoretical derivation, reached improve throughput, shorten the time delay, extend node in the life cycle of goals.In the fourth chapter, analyses the working principle of sensor terminal node, and the hardware circuit for a detailed analysis and use the software design the circuit principle diagram, and soldering PCB. Introduction to the wireless sensor network GAINZ experiment platform of two kinds of node respectively, the paper briefly introduces the development platform, combining with laboratory of the existing equipment for wireless sensor network related experiments.