【正文】 etting for each road at an intersection. While this might prove effective for light traffic, heavy traffic requires an adaptive system that will work based on the density of traffic on each road. The first system proposed for adaptive signaling was based on digital image processing techniques. This system works based on the captured visual input from the roads and processing them to find which road has dense traffic. This system fails during environmental interaction like rain or fog. Also this system in testing does not prove efficient. The advanced system in testing at Pittsburgh [2] involves signals municating with each other and also with the vehicles. The proposed system does not require a work between signals and vehicles and is a standalone system at each intersection. III. THE PROPOSED SYSTEM This paper presents the concept of intelligent traffic routing using wireless sensor works. The primary elements of this system are the sensor nodes or motes consisting of sensors and a transmitter. The sensors interact with the physical environment while the transmitter pages the sensor’ s data to the central controller. This system involves the 4 x 2 array of sensor nodes in each road. This signifies 4 levels of traffic and 2 lanes in each road. The sensors are ultrasonic or IR based optical sensors which transmits status based on presence of vehicle near it. The sensor nodes transmit at specified time intervals via ZigBee protocol to the central controller placed at every intersection. The controller receives the signal and putes which road and which lane has to be given green signal based on the density of traffic. The controller makes use of the discussed algorithm to perform the intelligent traffic routing. IV. COMPONENTS INVOLVED IN THE SYSTEM The proposed system involves wireless sensor works which are prised of three basic ponents: the sensor nodes or motes, power source and a central controller. The motes in turn are prised of Sensors and transceiver module. The sensors sense the vehicles at intersections and transceiver transmit the sensor’ s data to the central controller through a wireless medium. The Power source provides the power needed for the sensor nodes and is mostly regenerative. The central controller performs all the putations for the sensor works. The controller receives the input from all sensors and processes simultaneously to make the required decisions. Sensors are hardware devices that produce a measurable response to a change in a physical condition like temperature or pressure. Sensors measure physical data of the parameter to be monitored. The continual analog signal produced by the sensors is digitized by an analogtodigital converter and sent to controllers for further processing. A sensor node should be small in size, consume extremely low energy, operate in high volumetric densities, be autonomous and operate unattended, and be adaptive to the environment. As wireless sensor nodes are typically very small electronic devices, they can only be equipped with a limited power source of less than amperehour and volts. Sensors are classified into three categories: passive Omnidirectional sensors。現(xiàn)有的實(shí)驗(yàn)系統(tǒng)包括了基于密度識別的圖像處理，而在像霧、雨或沙塵的情況下規(guī)劃路徑是低效的。這個系統(tǒng)的主要元件是傳感器節(jié)點(diǎn)組成的傳 感器和發(fā)射器。傳感器可以感應(yīng)在節(jié)點(diǎn)上的車輛，而無線電收發(fā)機(jī)通過無線媒介發(fā)送傳感器器數(shù)據(jù) 到中央處理器。 一個節(jié) 點(diǎn)，在無線傳感器網(wǎng)絡(luò)中，也被稱為傳感器節(jié)點(diǎn)，能夠執(zhí)行一些工序和收集的傳感器信息，并與其他連接的節(jié)點(diǎn)在網(wǎng)絡(luò)中通信。無線傳輸介質(zhì)的可能的選擇是射頻（ RF），光通信和紅外線。一個 DVS 方案變化取決于非確定性的工作量傳感器節(jié)點(diǎn)內(nèi)的功率電平。這使得對ZigBee 網(wǎng)絡(luò)形成特設(shè)的，沒有集中控制或大功率發(fā)射機(jī) /接收機(jī)能夠達(dá)到所有的設(shè)備。在大多數(shù)大的網(wǎng)絡(luò)情況下，網(wǎng)絡(luò)將集群的集群。 圖 4 考慮交叉口 1）對所有道路均可以自由左轉(zhuǎn)（自由右轉(zhuǎn)適合右側(cè)行車系統(tǒng)）。 2 ）控制器接收該信號，并計(jì)算如下 3）對每條道路的具有最高優(yōu)先級傳感器 AX 進(jìn)行比較。使用的傳感器節(jié)點(diǎn)的各種系統(tǒng)可以根據(jù)要求改變，并且可以根據(jù)場所的可行性，可以使用任何類 型的傳感器。轉(zhuǎn)左車道是自由的，所以不需要傳感器。該系統(tǒng)可以很容易地修改為右側(cè)行車系統(tǒng)（美國，加拿大，阿聯(lián)酋，俄羅斯等）。它不能中繼來自其它設(shè)備的數(shù)據(jù)。 H. Tmote 主要特點(diǎn) ? 250KBPS 的 IEEE Chipcon 公司的無線收發(fā)器 ? 互操作性與其它 設(shè)備。電池，無 論是充電電池和非充電，對傳感器節(jié)點(diǎn)供電的主要來源。 ? 由于節(jié)點(diǎn)尺寸的縮小和功耗，可以想象利用太陽能發(fā)電，甚至許多外國的東西如振蕩電源，讓他們運(yùn)行。該傳感器是靈敏的障礙探測器，探測在其附近的車輛。中央控制器執(zhí)行所有的計(jì)算為傳感器網(wǎng)絡(luò)。同時該系統(tǒng)在測試中并不能證明有效。這個系統(tǒng)不需要交通工具搭載任何系統(tǒng)，可以在交通系統(tǒng)中很容易地實(shí)現(xiàn)。 and GHz. The functionality of bothtransmitter and receiver are bined into a single deviceknown as a transceiver [3]. To bring about uniqueness in transmitting and receiving toany particular device various protocols/algorithms are devised. The Motes are often are often provided with powerful transmitters and receivers collectively known as transceivers for better long range operation and also toachieve better quality of transmission/reception in any environmental conditions. F. Power Source The sensor node consumes power for sensing, municating and data processing. More energy is required for data munication than any other process. Power is stored either in batteries or capacitors. Batteries, both rechargeable and nonrechargeable, are the main source of power supply for sensor nodes. Current sensors are able to renew their energy from solar sources, temperature differences, or vibration. Two power saving policies used are Dynamic Power Management (DPM) and Dynamic Voltage Scaling (DVS). DPM conserves power by shutting down parts of the sensor node which are not currently used or active. A DVS scheme varies the power levels within the sensor node depending on the nondeterministic workload. By varying the voltage along with the frequency, it is possible to obtain quadratic reduction in power consumption. G. Tmote Sky Tmote Sky is an ultra low power wireless module for use in sensor works, monitoring applications, and rapid application prototyping. Tmote Sky leverages industry standards like USB and to interoperate seamless