Mobile Signal Strength Recommendations

Signal Measurement

Signal strength values are defined by a few different measurements which vary even more for different service modes. These measurements are as follows:

2014/08/12 - [Mobile/LTE and 5G] - [LTE] RSSI, RSRP, RSRQ, RSCP, SINR, EC/IO

[LTE] RSSI, RSRP, RSRQ

More on these measurements in separate service mode sections.

Determining Factors of Signal Values

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There are many different factors that influence signal strength and quality, including but not limited to:

• Tower load
• Proximity to the cellular tower
• Signal going through a cellular repeater
• Competing signals
• Physical barriers (mountains, buildings, trains, etc.)
• Weather

Therefore, measurements like Signal Strength (RSSI) and Signal Quality (EC/IO) do not incorporate all of the relevant factors to describe the quality of the connection. For example, you may have an excellent RSSI value of -51 dBm, but the Tower Load (the number of mobile users) in your area is very high. In this case, even though you have a great Signal Strength value, you may not achieve maximum mobile data speeds.

Disclaimers

• Both Signal Strength and Signal Quality must be considered for successful cellular data connection
• Measured or reported values vary by modem, carrier, and network environment
• There is no black/white answer to what constitutes a successful connection
• Although signal strength may appear to be adequate, throughput speeds may vary due to dependencies on cellular tower loads

2G (GSM)

2G (GSM) Signal strength is defined by only one value: RSSI – Received Signal Strength Indicator; RSSI is a negative value, and the closer to 0, the stronger the signal.

RSSI

Excellent (>= -70 dBm)	Strong signal with maximum data speeds
Good (-70 dBm to -85 dBm)	Strong signal with good data speeds
Fair (-86 dBm to -100 dBm)	Fair but useful, fast and reliable data speeds may be attained, but marginal data with drop-outs is possible
Poor (< -100 dBm)	Performance will drop drastically
No signal (-110 dBm)	Disconnection

 

3G (WCDMA, TDSCDMA, CDMA, EVDO, CDMA-EVDO)

For 3G service mode, there are three relevant measurements:

• RSSI - Received Signal Strength Indicator. RSSI is a negative value, and the closer to 0, the stronger the signal
• EC/IO - indicates the downlink carrier-to-interference ratio (signal quality).EC/IO is a negative dBm value. Values closer to 0 are stronger signals
• RSCP - indicates the Received Signal Code Power

The RSSI standard values for 3G are basically the same as 2G

RSSI

Excellent (>= -70 dBm)	Strong signal with maximum data speeds
Good (-70 dBm to -85 dBm)	Strong signal with goodta speeds
Fair (-86 dBm to -100 dBm)	Fair but useful, fast and reliable data speeds may be attained, but marginal data with drop-outs is possible
Poor (< -100 dBm)	Performance will drop drastically
No signal (-110 dBm)	Disconnection

EC/IO

Excellent (0 to -6)	Strong signal with maximum data speeds
Good (-7 to -10)	Strong signal with good data speeds
Fair to poor (-11 to -20)	Reliable data speeds may be attained, but marginal data with drop-outs is possible. When this value gets close to -20, performance will drop drastically

RSCP

Excellent (-60 to 0)	Strong signal with maximum data speeds
Good (-75 to -60)	Strong signal with good data speeds
Fair (-85 to -75)	Fair but useful, fast and reliable data speeds may be attained
Poor (-95 to -85)	Marginal data with drop-outs is possible
Very poor (-124 to -95)	Performance will drop drastically, closer to -124 disconnects are likely

 

4G (LTE)

For 4G service mode, there are four relevant measurements:

• RSSI - Received Signal Strength Indicator. RSSI is a negative value, and the closer to 0, the stronger the signal
• RSRP - the Reference Signal Received Power is the power of the LTE Reference Signals spread over the full bandwidth and narrowband
• RSRQ - Reference Signal Received Quality is a C/I type of measurement and it indicates the quality of the received reference signal (similar to EC/IO)
• SINR - Signal to Interference plus Noise Ratio (A minimum of -20 dB SINR is needed to detect RSRP/RSRQ). Indicates the throughput capacity of the channel. As the name implies, SINR is the strength of the signal divided by

the strength of any interference

RSRP

Excellent (>= -80 dBm)	Strong signal with maximum data speeds
Good (-80 dBm to -90 dBm)	Strong signal with good data speeds
Fair to poor (-90 dBm to -100 dBm)	Reliable data speeds may be attained, but marginal data with drop-outs is possible. When this value gets close to -100, performance will drop drastically
No signal (<= -100 dBm)	Disnonnection

RSRQ

Excellent (>= -10 dB)	Strong signal with maximum data speeds
Good (-10 dB to -15 dB)	Strong signal with good data speeds
Fair to poor (15 dB to -20 dB)	Reliable data speeds may be attained, but marginal data with drop-outs is possible. When this value gets close to -20, performance will drop drastically
No signal (<= -20 dB)	Disconnection

SINR

Excellent (>= 20 dB)	Strong signal with maximum data speeds
Good (13 dB to 20 dB)	Strong signal with good data speeds
Fair to poor (0 dB to 13 dB)	Reliable data speeds may be attained, but marginal data with drop-outs is possible. When this value gets close to 0, performance will drop drastically
No signal (<= 0 dB)	Disconnection

RSSI for LTE is a calculated from several other signal related measurements: RSSI = wideband power = noise + serving cell power + interference power. For example, a 4G LTE modem might report an RSSI of -68 dBm, but:

RSRP = -102 dBm

RSRQ = -16 dB

SINR = -1.8 dB

In this case, the signal quality is actually very poor. This could be due to the device being some distance away from the LTE transmitter. It’s also possible that something is interfering with the signal, such as a building or other obstructions between the device and the tower.

RSSI

Excellent (> -65 dBm)	Strong signal with maximum data speeds
Good (-65 dBm to -75 dBm)	Strong signal with good data speeds
Fair (-75 dBm to -85 dBm)	Fair but useful, fast and reliable data speeds may be attained, but marginal data with drop-outs is possible
Poor (-85 dBm to -95 dBm)	Performance will drop drastically
No signal (<= -95 dBm)	Disconnection

 

Original : 

https://wiki.teltonika.lt/view/Mobile_Signal_Strength_Recommendations

Mobile Signal Strength Recommendations - Wiki Knowledge Base | Teltonika