The minimum value acceptable for network operation is RSSI = -85 dBm. RSSI (Received Signal Strength Indicator) is an indicator of the signal power level received by the modem. A negative or close to zero values LTE connection is impossible to establish, or it will be deficient in speed and quality. NOTE: Important! The higher the CINR value, the better the signal quality.Ī negative CINR value will mean more noise in the received signal than the effective signal. The minimum value acceptable for stable network operation: CINR = 10 dB. The CINR value is measured in dB.Ī positive CINR value means that there is a more effective signal than noise. To measure the signal quality, pay attention to the 'Signal (CINR / RSSI)' values.ĬINR (Carrier to Interference + Noise Ratio), also called SINR (Signal to Interference + Noise Ratio), is the ratio of the signal level to the noise level (or simply the signal to noise ratio). On the 'System dashboard' page in the 'Internet' section, you can see the current status of the LTE connection.Ĭlick 'More details' to display more information. These calculated RSSI values can then be used and as inputs for an indoor location engine for location determination.Keenetic routers with a built-in 4G/3G modem ( Keenetic Hero 4G and Runner 4G models) or a USB port to connect external USB modems allow you to connect to the Internet via a mobile operator's network. Results show that the mean and mode can be used in combination to filter and smooth RSSI values. The Nordic System on Chip (SOC) is used as the low power node together with a series of Raspberry Pi gateways. Therefore, this study proposes the use of a Link Quality Indicator as a reference point for further calculation of the location of an asset or a person. However, due to the changing indoor environment these may become outdated very quickly. Fingerprint databases have been used extensively as a reference to determine location. We then analyse the RSSI from Low Power Nodes, their calculated mean, median and mode values as a basis for further use in an indoor real time location system. This study adopts Bluetooth Low Energy technology and uses the Received Signal strength Indicator (RSSI) from messages as a data source. Technologies such as Radio Frequency Identification (RFID), Bluetooth, and Wi-Fi, together with location algorithms that include optimization, still require further research for large-scale deployments. Technologies that can be used for location outdoors are readily available using Global Positioning Systems (GPS) whilst technologies used for indoor location still prove to be a challenge.
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