Tools and Techniques for Backhaul Link Quality Verification

  1. It is recommended that LinkPlanner ( is used to simulate the link. LinkPlanner can predict link performance in terms of signal levels, achievable modulations and throughput based on selected equipment, radio configuration and environmental conditions (antenna/device positioning, obstructions, interference level, etc).
  2. Using the LinkPlanner simulation, verify the radio link parameters have been configured similar to the Configuration -> Radio page of the devices.
  3. Link alignment can be verified using the Tools -> eAlign page. An aligned link will have very close signal levels between the two antenna polarities (Ch0 and Ch1).

  1. Link performance can be greatly affected by the presence of interference in the operating channel. Because ePMP operates in unlicensed bands which are open to any user, it is important to perform an initial band scan to identify the best (low interference) channels available. Ideally, the band scan should be performed at both endpoints of the link. The ePMP software provides a spectral analysis tool which identifies channels with lower interference for best performance.


  1. eDetect (Tools -> eDetect) is another available tool to help identify in-channel interference. eDetect is capable of identifying WiFi-based interferers transmitting in the same channel as the link. eDetect is not a replacement for the band scan using the spectral analysis tool since eDetect cannot detect interference other than WiFi-based signals or channel-overlapping interferers that are not transmitting on the same channel.


  1. Wireless Link Test (Tools -> Wireless Link Test) tests the link capacity and performance. The test utilizes the air interface and uses UDP-like packets generated within the devices under test (it does not send traffic over the Ethernet interfaces). The test is performed in each direction (downlink and uplink) individually, not simultaneously.


  1. The Monitor -> Performance page allows monitoring of key performance parameters for the link.
  • Ethernet stats – Packet errors/drops


  • Wireless stats – Packet error/drops


  • System errors – Reboots/link (session) drops


  • MCS distribution