Over the water link suggestion

We are currently planning a 2KM long over the water LOS link. Which device will be more reliable in this scenario ?

(PTP 550 with channel bonding)

Hi Dilshan,

Both PTP550 and PTP670 will work over water LOS link for 2 km. Is reliability is your priority then PTP670 is better, however if price point or higher throughput is your priority then PTP550 is better option.




A link over water is often subject to multipath fading. The reflection off the water is greatest when the water is calm. The phase of the reflection changes with the water level, and links over tidal water (an estuary, harbour or sea) often have fading that changes with the tide.

The best approach in these cases is to use spatial diversity at one end of the link. LINKPlanner does a really good job of calculating the optimum antenna spacing to minimise multipath over water.

Remember that in a fade it's likely that only one path will be useful, so the link will be operating on single payload or polarization diversity. During the fade the capacity will be approximately half the normal capacity.


My vote is for the PTP670. This is the go to PTP radio for many off shore oil rigs and ships and military applications. It will handle multipath better then the PTP550.

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I would think that the PTP550 would have the advantage here, because it uses two channels at once (frequency diversity) and (correct me if I'm wrong!) it continues to pass traffic if only one is operative. Multipath fade tends to be short in duration and specific in frequency, since it's cause by a reflection being very precisely out of phase with the desired signal. So if you can  keep the two carriers on different parts of the band, they are likely to fade at different times.

HI What is your location/weather?