Valid Cellular Data Connections are dependent on a cellular modem’s:
A. Signal Strength, and
B. Signal Quality
A. Signal Strength
- Influences connection to the cellular tower.
- Represented by RSSI, measured in dBm.
- RSSI is a negative dBm value. Values closer to 0 are stronger signals.
- The ‘lower number’ represents better signal strength.
- Influences data throughput speeds on mobile broadband networks.
- Represented by signal noise ratios, measured in dBm.
- Noise ratio representation varies by mobile broadband technology:
- LTE: SINR
- SINR is a positive dBm value.
- Higher SINR numbers = better quality connection.
- WiMAX: CINR
- CINR is a positive dBm value.
- Higher CINR numbers = better quality connection.
- CDMA EVDO: EC/IO
- EC/IO is a negative dBm value. Values closer to 0 are stronger signals
- Lower EC/IO ‘numbers’ = better quality connection.
- Exceptions apply to the following modems in LTE mode only: Pantech UML290 and Novatel 551L.
- LG VL600 does not report db values, only bars. LG VL600 requires a minimum of 2 bars.
- 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.