【正文】 少一年,用于追蹤遷移路徑,避免人為干預。鑒于這種動物大部分在露天的環(huán)境下活動,所以可以通過太陽能來給系統(tǒng)提供電力供應。生物傳感網(wǎng)節(jié)點的硬件系統(tǒng)的體系結構如圖2所示。有兩個可獨立使用的串口。實時時鐘——DS3231[8]——為了能夠使所有的節(jié)點在同一個時間啟動以達到同步。系統(tǒng)中在時間上的任何不匹配(在兩個交互節(jié)點)將會花費大量的電力在網(wǎng)絡的同步上。為了達到較高的精度,它使用十二處理渠道來跟蹤GPS衛(wèi)星信號。自其讀數(shù)開始， GPS每3小時會自動轉換開/關模式。然而和900 MHz相比，傳輸距離相同是，這個頻率導致更高的能源消耗,我們得使用更高的數(shù)據(jù)頻率和更小型而緊湊的天線。幾毫秒的延遲對于系統(tǒng)來說是允許存在的?；赨CBs環(huán)球文件系統(tǒng)[13]的可操作的內部開發(fā)文件系統(tǒng)[12], 的使用,這使得存儲系統(tǒng)簡單和高效。% RH)的組合。這些擁有位置信息的數(shù)據(jù)為更加深入的了解沼鹿的遷移模式及與氣候的變化。整個PCB敷銅用以使噪聲保持在最低水平，同時還消散節(jié)點產(chǎn)生的熱。 （a） （b） 圖3 （a）頂視圖 （b）底視圖2）軟件架構設計主要解決的是問題是能源，wildCENSE軟件工具的有效的調度和事件同步。 GPS每3小時發(fā)送一次數(shù)據(jù)，并安設定好的每十分鐘喚醒相應的傳感器。這的優(yōu)點是在重新啟動的情況下，（如看門狗復位），數(shù)據(jù)段指針可以從EEPROM中重新獲取，一旦發(fā)現(xiàn)了節(jié)點/基站，所以得節(jié)點會在相同的時間開啟和并同時進行數(shù)據(jù)交換。3）系統(tǒng)能源管理WSN的能源需求是設計時要考慮的最最關鍵的要素。能量的具體消費計算在本節(jié)C部分。該系統(tǒng)是由一個可再充電的鋰離子電池供電， V。為了最大限度的利用電池的能量，一個DC / DC轉換器，德州儀器（TI）[17]的一款降壓升壓器TPS63001被使用。這個斷電模式的特點是把所有的一切都關機，并且通常包括時鐘源[7]，“看門狗”。隨著微控制器，其他外圍設備也提出休眠模式，以最大限度地減少能源的使用。表1說明了節(jié)點上的各個組件的電力需求。?只有70％的鋰離子電池的能量已經(jīng)假定可用[20]。為了滿足上述要求，鋰離子電池包8Ah的容量是足夠的。第5列“T”給所采取的傳感器及其它外設單次讀出的典型時間（單位為秒）。除了高效節(jié)能，它還提供詳細的位置信息且擁有非常高的精度。 wildCENSE。s design viz. the strict energy constraints. The recent past has seen a wide variety of WSN applications namely Habitat monitoring, Seismic Detection, Environmental monitoring, Health monitoring systems etc., of which mobile nodes, dynamic network topology, munication failure, limited power supply, harsh environmental conditions are few of the varied challenges. To address the issues in wildlife monitoring and to understand the plex relationship of animals with their surrounding, scientists had to collect the required data manually by visiting the site. In some cases the search was made easier by tagging the animal with radio transmitters to relocate them easily, but yet the seemingly bigger part of the picture remained unaddressed: the efficient data collection. There are numerous reasons why it is difficult and not advisable to visit the site frequently. Firstly, studying the species without avoiding human contact is almost impossible. Frequent human visits or disturbances affect the species in ways unknown [1]. Secondly, keeping track of animal activity in the dark after dusk bee more of an adventure than an experiment or a study. Finally, it is not only time consuming but also money intensive job to keep track of animal migration as well as its feeding habits without using dedicated low cost sensor networking equipments. An automated system would thus be desired, equipping natural spaces with numerous networked sensor nodes to enable longterm data collection at times (even at night), scales and resolution which are very difficult if not impossible, to achieve by manual monitoring. It also allows collecting data without disturbing the ecology and yet represents a substantially more economical method for conducting longterm studies than traditional one. Significant proofs of concepts and previous attempts to monitor wildlife movement and habitat have been made like the ZebraNet [2] and Great Duck Island Experiment [1]. Learning from the experiences of the aforementioned, wildCENSE is an attempt on the same footprint, designed to have lower power consumption, better range, varied environment sensing features and more robust data backup system. wildCENSE is a WSN system which attempts to monitor the behavior and migration patterns of Barasingha (Swamp Deer). System being designed can be suitable for many more species of medium to large size. Equipped with a GPS, Radio transceiver and various other sensors, the hardware is designed to support the needs of wildlife monitoring. The captured data can be provided to the wildlife researchers for their research and study purposes. It will be helpful to them to understand the needs of the endangered species, and the relationship these species share with the surroundings. The paper fundamentally discusses the hardware and software design architecture of the wildCENSE system at the node, base and network levels. In particular, it embodies the issues and constraints, which were met during the design and testing of the system. II. GPS BASED ANIMAL TRACKING SYSTEM The Barasingha is native to India and Nepal. Once it populated throughout the basins of the Indus, Ganges and Brahmaputra rivers, as well as parts of central India reaching out till the river Godavari. But in past few decades its population has declined significantly listing them as endangered species by IUCN from 1984 to 1996 and as vulnerable since 1996 [4]. Wildlife researchers while surveying Jhilmil Tall (Uttaranchal) area came across some 30 heads of the Barasingha on February 3, 2005 [5]. Trails indicate that they might have migrated across the Nepal border. But yet their exact migratory path is unknown。 wildCENSE software implements effective scheduling and synchronizing of events. The node is kept in sleep/inactive mode for most of the time. Desired data is collected from sensors and GPS on the basis of periodic interrupts generated by a real time clock (RTC). The accuracy of the RTC helps the node in synchronization during node to node interactions as also with the base. GPS samples are taken every 3 hours and the wake up of respective sensors is scheduled every ten minute. Since the Radio transceiver, GPS and external flash memory are on separate ports namely USART0, USART1 and SPI, we can afford to use them simultaneously. While the GPS is switched on and tries to get a fix, a radio transmission could be achieved if another node/base is discovered in the vicinity. The pointers to current read/write data se