Best practice for CONNEX coexistence with other 5.8GHz systems

Submit a request
Avatar
Shahar Keren

This article explains the best practices for using CONNEX with other 5.8GHz systems. Using more than one 5.8GHz link will cause coexistence interference between the two links, thus this article provides recommendations on how to improve the coexistence of systems. Full link robustness is not guaranteed.

For live demo showing coexistence platform see: Flite Test report

Background

A drone has multiple wireless links:

  • RC uplink for controlling the drone flight

  • Telemetry downlink received from the drone's flight controller and presented in the PC or on the video display using OSD

  • Video downlink

The links above are used with several optional wireless channels: 433MHz, 900MHz, 2.4GHz or 5.8GHz

CONNEX implements an Automatic Frequency Selection (AFS) mechanism. This means that CONNEX selects the best possible channel frequency for performance. Using a close proximity AV radio link of 5.8GHz band may reduce the effectiveness of the AFS mechanism and expose the link to the possible symptoms of:

  1. Black screen - no video or telemetry (highly unlikely)

  2. 'Out of Range' message although you are actually within range (e.g. at 100m or 700m)

Please note that the use of other 5GHz radios may mean the setup time of the CONNEX link could be around 65 seconds. This is due to the fact that all the non-DFS channels are preoccupied (by the other radios). CONNEX scans for a vacant DFS channel.

Recommendations for CONNEX coexistence when using 5GHz AV (Analog Video) links

Ideally, use an AV that does not use the same channel as CONNEX - i.e. NOT a 5.8GHz AV link. However, if you need to utilize a 5.8 GHz AV link, the following recommendations may allow better coexistence with CONNEX:

  1. AV antenna position and orientation

    • The AV antenna should be distanced as far as possible from the CONNEX Air Unit antennas. We recommend to have distance of at least 30 cm.

    • AV antennas should not be installed at the same height as the CONNEX Air Unit antennas (at least 5 cm above or below).

    • Try to find the position which allows the radiation curves of CONNEX antennas and the AV link antenna not to overlap.

  2. Turn the AV transmitter ON first

    • If possible, turn the AV transmitter ON before the CONNEX Air Unit. If that is not possible, we recommend RESETTING the CONNEX Air Unit after the AV transmitter is already ON.

  3. CONNEX Ground Unit position

    • The CONNEX link may cause visual artifacts on the AV video. To reduce these interference, it's recommended to place the CONNEX Ground Unit at least 1 meter from the AV receiver.

Unlikely CONNEX coexistence with DJI's 5.8GHz RC in Europe

CONNEX is unlikely to function if you are using the DJI 5.8GHz RC in Europe, when using the SRD region regulations.

Was this article helpful?
0 out of 0 found this helpful

Comments