Apabila menjelaskan rangkaian sensor wayarles, lokalisasi ialah isu penting untuk dibahaskan. Lokalisasi nod sensor kos rendah tanpa perkakasan tambahan adalah sukar kerana memerlukan maklumat jarak ke titik rujukan. Kaedah paling sesuai memenuhi permintaan ini adalah menggunakan nilai RSSI untuk menentukan jarak antara nod sensor. Beberapa faktor mempengaruhi nilai RSSI perlu dipertimbangkan ketika mengaplikasikan kaedah ini untuk mendapatkan keputusan MLAT berkualiti. Dalam pengajian lokalisasi, satu teknik untuk mendapatkan kedudukan yang serupa seperti MLAT adalah TRILAT, TRILAT berbeza kerana hanya terhad mempunyai tiga nod sensor. Tapi, jarak anggaran sentiasa mengandungi ralat yang mengakibatkan ralat lokasi. Seterusnya, teknik TRILAT memiliki keterbatasan bahawa tiga titik rujukan diperlukan untuk menentukan lokasi objek. Dengan ini, pengukuran teknik TRILAT adalah kurang tepat dibandingkan dengan MLAT berkenaan beberapa faktor seperti orientasi nod dan kualiti pengukuran. Teknik MLAT dicadangkan untuk meringankan keterbatasan TRILAT dan meningkatkan prestasi lokalisasi. Hasil dari membandingkan kedua-dua teknik menunjukkan bahawa MLAT meningkatkan keterbatasan TRILAT dalam julat tertentu. Dengan mengambil purata hasil simulasi, pendekatan yang paling berkesan dalam melakukan lokalisasi adalah dengan menggunakan 10 nod rujukan.
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When describing about wireless sensor network, localization is an important issue to be discussed. Localization in low-cost sensor nodes without additional hardware is difficult since positioning sensor nodes requires distance information to reference points. The most suitable method to meet this demand is by using the RSSI values to determine the distance between sensor nodes. There are several factors to put into consideration while implementing RSSI method which affect the RSSI value to get high quality MLAT results. In the area of localization, one technique to obtain better positioning that has similar approach to MLAT is TRILAT. But TRILAT technique has its limitation in that at least three beacons are needed to determine an object’s location. Furthermore, distance estimation always contains error that will lead to location errors. By this limitation, the TRILAT technique will be inaccurate in comparison to MLAT with respect to some factors such as node orientation and measurement quality. MLAT technique is proposed to relieve this limitation of TRILAT technique and significantly improve localization performances. The results from comparing both techniques show that MLAT does improve the limitation of TRILAT by some margin. By taking the averages of the simulation results, the most effective approach in conducting localization is by using 10 reference nodes.
RSSI values to determine the distance between sensor nodes.; implementing RSSI method which affect the RSSI value to get high quality MLAT results; MLAT technique is proposed to relieve this limitation of TRILAT technique and significantly improve localization performances. The results from comparing both techniques show that MLAT does improve the limitation of TRILAT by some margin
Study of multilateration technique_Ammar Rasydan Bin Rodzali_E3_2010_875003577_00003084267_NI