The cost of localization system is related to the price of all equipment’s of the system and the price of the operation and repair include the power consumption. Low costing is one of the many research challenges, however without impacting on the performance of the system.
For example, if high accuracy and precision are required in the first place, the RFID and Bluetooth are most chosen technologies, however …show more content…
It indicates the radio frequency band utilized 2.5GHz for IEEE 802.11b, IEEE 802.11g, or IEEE802.11n, and 5GHz for IEEE 802.11a [20].
Most buildings like a University or an office building have already distributed WiFi hotspots that provide whole building coverage as network access point. Devices which employ Wi-Fi technology include personal computers, video-game consoles, smartphones, digital cameras, tablet computers and digital audio players.
That the infrastructure cost and user device cost for WiFi can be very low. Additionally, Wi-Fi localization based on fingerprinting RSS (Received Signal Strength).
Wi-Fi Fingerprinting builds a radio map of a given area based on the RSS data from different access points and produces a probability distribution of RSS values for a given (x,y) location. On line RSS values are then compared to the fingerprint to find the closest match and generate an estimated (x,y) location [35].
2.5.2.2 …show more content…
It uses 868 MHz band in Europe, 915 MHz band in the USA and Australia, and 2.4 GHz in other regions. ZigBee is used for long distance transmission between devices in wireless mesh network. It has low cost, low data transfer rate, short latency time, comparing to WiFi standards. The technology uses the RSS method to estimate the distance between two or more zigbee sensor devices[36] .
2.5.3 Short Distance Wireless Technology
2.5.3.1 Bluetooth
Bluetooth is intended to enable short range wireless communication between devices. Bluetooth communicates utilized radio waves with frequencies between 2.402 GHz and 2.480 GHz as WiFi does. Bluetooth concerns the power consumption, it uses a very low transmission power. So the coverage of Bluetooth is shorter than WiFi and other WLAN technology. Hence, Bluetooth is not suitable for localization for large area [37].
2.5.3.2 Ultra-Wide Band
The Federal Communication Commission FCC has determined UWB bandwidth more than 500MHz and carrier frequency larger than 2.5 GHz. A Large bandwidth in UWB due to high speed communication, high time resolution, and short wavelength so the WUB is become stronger against multipath interference and fading. IEEE 802.15.4a standard has IR-UWB (impulse radio ultra-wide band) signals to estimate time of arrival and IR-UWB has the capability of accurate ranging