Advice required on the NLOS video link over a range of 3Kms

The_Imperium said:

Hello everyone. I am new to the forum.

I am taking care of the communication part in TEAM RUDRA. TEAM RUDRA is a team competing in the URC Mars Rover Challenge. I need your help.


I need to transmit good quality videos from 4 cameras on the rover to the ground station. The rover will trace a path of maximum 3kms. The path the rover will trace is NLOS and will have few obstacles as high as 5m. The obstacles are mostly pound of sand. The rover will moving at a speed no more than 5Km/hr.
We need to create a wireless link to achieve this. The link should be strong enough for the videos to be streamed without any lag as all mission critical operations on the rover depend on the video stream.
Please advice on the setup.
Give details on the frequency range, antennas and equipments. We will be operating our rover in Hanksville, Utah, United States.
PS: We will not be able to use directional antennas.

What have we tried:

On the rover side we connected 2 of our IP camera to the Asus RT-AC66U router with a omni TP-Link antenna with a gain of 15dBi. On the receiving station we conntected the Asus RT-AC66U which was configured as client of the router in rover. The receiving station also had a omni TP-Link 15dBi antenna. The results were not good. The range we got was very less and the video lagged very much. The setup was operated on 2.4gHz frequency.

We tried replacing the routers with TP-Link outdoor router but the results were same.

Now we are thinking to switch the frequency to 900Mhz, but before spending money we would like to know will it be beneficial.


Please feel free to pitch in your ideas.

Thanks
Survesh

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jiripolivka said:

Most professional video links like yours use 2.4 GHz. End antennas MUST see each other, so NLOS is excluded. You simply MUST set up the conditions to achieve LOS communication.

Cameras for cyclist and motorist racing are carried on helicopters or drones above any terrain obstacles. Receiving antennas on the ground MUST be directional and operators MUST point the after the transmitting copters or drones.

Changing frequency is not important, it only slightly affects propagation loss but strongly antenna size for the same gain. The problem is that video spectrum is wideband and only LOS can carry it without distortion.

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If you cannot meet the above conditions, record your videos on rovers and play it back later.

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The_Imperium said:

Thanks for the reply. The rover's drive control is based on the feed from camera. So it cannot be recorded and played back later. Also the competition is not completely LOS. Please do post if you find any equipment that meets my needs. Also the path is not fully NLOS. I will be getting LOS mostly. But in some places it is NLOS, since it is a competition I don't want to lose points due to communication failure. So I posted the thread like that. Please do advice on the setup now.

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