dc.description.abstract | With frequency channel expansion, device renovation of global positioning system (GPS) and global navigation satellite system (GLONASS), and the deployment of new satellite navigation such as global navigation satellite system (CNSS), quasi-zenith satellite system (QZSS) and European geostationary navigation overlay service (EGNOS), the outdoor positioning technology has become the well-known navigation system in the world. In recent years, GPS has become the most important navigation system in the world. Moreover, it stimulates the need of cell phone with build-in GPS module. Because the GPS technique is designed for personal navigation device (PND), cell phone and electronic products, and it can provide various kinds of location-based service (LBS) for users.
However, the accuracy of satellite-based positioning significantly degrades when the receiver is located in the urban area, i.e., the non-line-of-sight (NLoS) environment, or inside the building. In order to solve this problem, the widely deployed wireless network becomes a potential solution. There are many wireless technologies (e.g., Wi-Fi, Bluetooth, RFID and Ultra-wide-band) could support indoor positioning. This paper chooses IEEE 802.11 wireless local area network (WLAN) technology as the position estimating solution. Unfortunately, the WLAN-based positioning technology usually cannot provide accurate positioning results due to sophisticated environment. Hence the users are frequently misguided and unable to reach the place they want to get. In order to resolve this issue, we propose an indoor-positioning solution to obtain precisely estimated position, which is particularly used for non-real-time applications such as invaluable equipment property monitoring, fixed wireless measuring sensors and so on.
This paper proposes the methodology using long-term wireless measurement to prevent the issue of time variance of signal strengths. Therefore, the precise locations of monitored devices could be acquired.
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