Measurements of Signal Strength and Quality

NOTE: The following values are approximations; they are solely CradlePoint's interpretations. Each of these values will vary for different technologies and carriers: contact your carrier for more authoritative information. CradlePoint does not guarantee adequate performance, regardless of the Signal Strength and Signal Quality.

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Signal strength and quality reported units of measurement will vary per modem. The LP4 signal quality is reported by RSRQ and RSRP, not SINR. LPE modems report SINR, RSRQ and RSRP.

The Determining Factors of Signal Values

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

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

Signal Strength and Signal Quality numbers do not incorporate all of the relevant factors. Keep in mind that measurements of Signal Strength and Signal Quality for a specific moment do not reflect on the STABILITY of a connection, as these values will vary as conditions change.

Interpreting Signal Values

Additional Disclaimers:

There is no black and white answer to what constitutes a successful connection. It is possible to disconnect with green values – or connect with red values – for several reasons, including:

1) Modems may vary.

We support hundreds of modems, and not all of them have the same ranges of acceptable values. For example: in our experience the Pantech UML290 and Novatel 551L require minimum RSSI values of −64 for acceptable connections.

2) You must factor in BOTH Signal Strength and Signal Quality.

It is possible to have excellent RSSI but disconnect because of poor quality (and vice versa).

3) Signal Strength and Signal Quality values do not hold constant.

The variance of a signal is a significant factor in the success of a connection. A particular reading represents one moment, but these values may vary dramatically over time. A stable connection requires consistency. This is a sample graph of RSSI values that shows how much the values jump (from https://cradlepointecm.com): Sample RSSI and SINR graph

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4) Environmental Factors can affect all of the above values.

Everything from other network hardware, to heavy machinery, to the weather can have any affect on RSSI, SINR, Ec/Io, RSRP, and RSRQ.

5) Other factors: tower load, signal going through a repeater/booster, etc.

Some factors that don't show up in Signal Strength/Signal Quality values can greatly impact a connection.

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Measurements of Signal Strength and Quality