Pada dekad yang lalu, peningkatan jumlah jenayah di kawasan perumahan telah menggalakkan pertumbuhan teknologi sistem keselamatan. Bagi sistem keselamatan yang sedia ada, mangsa tidak boleh mendapatkan bantuan daripada pasukan peronda serta-merta jikalau jenayah berlaku. Oleh itu, sistem pemantauan keselamatan komuniti berdasarkan rangkaian sensor tanpa wayar dicadangkan dalam kajian ini untuk menangani kelemahan sistem keselamatan yang sedia ada. Sistem yang dicadangkan dibina daripada Xbee modul dalam bentuk yang berbeza, iaitu Penyelaras, Router, dan Peranti akhir. Apabila butang di peranti akhir ditekan, Peranti akhir mampu menghantar isyarat kecemasan kepada komputer Individu yang disambunkan Penyelaras. Di samping itu, rangkaian ZigBee yang diliputi oleh Router dapat mengesan isyarat daripada Peranti akhir dan isyarat akan diproses melalui aplikasi di komputer individu, kemudian maklumat yang dipaparkan di laman web. Apabila isyarat kecemasan dikesankan, SMS akan dihantar kepada pasukan peronda. Prototaip bagi sistem yang dicadangkan dibangunkan dalam kajian ini. Selain itu, ujian julat dan liputan antara Penyelaras-Router, Router-Router, Router – Peranti akhir, tiga peranti router dijalankan dalam dua persekitaran, iaitu Garis penglihatan (LOS) dan luar garis penglihatan (NLOS). Dalam sesi ujian, nilai-nilai RSSI, jumlah kesilapan penghantaran dan jumlah paket hilang direkodkan. Daripada keputusan yang diperolehi, julat optimum yang dicadangkan dalam persekitaran LOS bagi empat kes adalah 80 meter. Walau bagaimanapun, bagi kes Koordinator-Router julat optimum adalah sehingga 20 meter, julat optimum bagi kes Router-Router sehingga 20 meter, julat optimum bagi kes peranti Router Akhir sehingga 10 meter dan bagi kes tiga Router sehingga 30 meter di dalam persekitaran NLOS. Kesimpulannya, kajian ini menunjukkan satu perkembangan sistem pemantauan keselamatan masyarakat berasaskan rangkaian sensor wayarles.
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The growing number of crimes in residential has encouraged the growth of security system technology in the past decade. In existing security system, the victims are unable to seek help from residential patrol team once crime happened. Thus, a Wireless Sensor Network (WSN) based community security monitoring system is proposed in this study to tackle the drawbacks of existing security system. The proposed system consists of the deployment of XBee module into a residential area in different forms, i.e. coordinator, router, and end device. The end device hold by the users is capable to send a distress signal to a PC connected coordinator once the button at the end device is pressed. In addition, the ZigBee mesh network covered by the routers is able to locate the signal from the end device and the signal can be processed via a window application in PC then information is displayed in a webpage. When a distress signal is detected, a SMS will be sent to the patrol team. A prototype for the proposed system is developed in this study. Besides that, the range and coverage tests between the coordinator-router, router-router, router-end, three routers devices are conducted in two environments, i.e. Line-of Sight (LOS) and Non-Light-of Sight (NLOS). RSSI values, number of transmission errors and number of packet lost are recorded during the test session. From the obtained results, optimum range suggested in LOS environment for four cases is 80 meters. However, it is up to 20 meters for Coordinator-Router case, up to 20 meters for Router-Router case, up to 10 meters for Router-End device case and up to 30 meters for three routers case in NLOS environment. In conclusion, the study demonstrates a community security monitoring system development based on WSN technology.