Peplink LTE Signal Troubleshooting

LTE Service

RSSI - Received Signal Strength Indicator (RSSI) is a measurement of the power present in a received radio signal. The RSSI is indicated by a negative dBm value. This value relates to the signal strength of the cellular signal from the tower to the modem. The higher the number, the better the signal.

RSRP - Reference Signal Receive Power is the average power of Resource Elements (RE) that carry cell-specific Reference Signals (RS) over the entire bandwidth, so RSRP is only measured in the symbols carrying RS. RSRP is the average received power of a single RS resource element.

RSRQ - Reference Signal Received Quality, as the ratio of the carrier power to the interference power: essentially this is a signal-noise ratio measured using a standard signal.

SINR - (SINR) (also known as the signal-to-noise-plus-interference ratio (SNIR)) is a quantity used to give theoretical upper bounds on channel capacity (or the rate of information transfer) in wireless communication systems

Notes:

Cloud Based Camera requirements
1. Bandwidth throughout 1024x1024 per camera or 1mx1m we are shooting for upload vs download
2. 3 cameras will require a 3m x 3m minimum throughout to operate.

LTE Troubleshooting Triage

Scenario –

Description: LTE Service is at optimal levels, but throughput is not stable or usable for minimum thresholds for cloud-based cameras.

Step 1. Log into Peplink Modem

Check levels
Do a speed test
1. www.speedtest.net
2. Record levels and throughput

Step 2. Replacing the current LTE Antenna with the following

High Gain Omni Antenna
High Gain Directional Antenna (preferred)

Step 3. Once the Antenna is swapped

Check Levels on the cell modem
1. If an omni antenna is used, if levels increase and throughput is less, we need to attenuate the service.
2. Please look at using an attenuator and or move the antenna inside the MSU power box to reduce RF levels to attenuate the service and recheck levels
3. If that resolves the issue please submit a ticket into support for commissioning.
If service is still impacted
1. Swap to a high gain directional antenna,
  - Point antenna while checking service live.
  - Directional Antennas are typically 70% forward & 30% reverse
    - If service increases, rotate the antenna 180 degrees
If service is still impacted
1. Swap Carriers from sim slot 1 to sim slot 2. Or Verizon to AT&T
If the problem still exists, please go into remote management of the peplink and adjust the signal bands by the carrier. We are looking at the following items to lock service in.

Equipment & Tooling

LMR 240 Cable – 100-150 ft spool per truck
LMR 240 Prep Tool
LMR 240 Crimper
LMR N-Male EZ Ends
Sweep Tester (optional)
Directional Antennas
Omni Antennas
SMA Male to N Female adapter or jumper (depending on wiring)
Heat gun / Shrink Wrap
Zip Ties