I have a 450I AP where i labeled AP on the bottom center of the photo. Each well site has a Subscriber module pointing back to the AP. Due to the Terrain, Well 19, 20, and 8 have connection issues. To try to solve one of these connectivity issues, I installed a PTP 450 link. One PTP at Well 19 and an addittional PTP at Well 18 (well 18 has both a PTP and PMP Subscriber), as well as a switch to bridge the Subscriber module and PTP link to get a connection to both 18 and 19 back to the AP. With this being said, the subscriber module will lose connection to the AP randomly for a random amount of time and then come back up on its own cuasing me to lose comms to both 18 and 19. The subscriber module at 18 will try to register to the AP over and over again until it is successful. They are on different color codes, different channels, as well as different frequencies. I have even adjusted the power level on the PTP link so only 1dB of power is being transmitted. The only thing I have not segregated is the mounting point for the Subscriber and PTP radio at well 19.
Does anyone have any idea how to fix this problem? I have plans to do the same thing to gain connectivity to Well 8 and 20 but I want to solve this issue first.
I asked a few of the engineering folks to look at this... It would help us if you indicated the frequencies at which the radios are set (i.e. the AP, and the PTP link).
I suspect that even though they are on different frequencies, you're still interfering and may need to adjust timing/ duty cycle.
In addition, physical isolation will help. Anything you can do to spread apart or block the SM and PTP locations at Well 18 would be beneficial.
Not sure what the issue is exactly, but do you have your AP and PTP GPS synchronized? I recommend putting the Backhual Slave (BHS) on the same side as the SM so both are receiving at the same time. Then using Frame Calculator input in the range for the BHS and setting the Downlink Data percentage to match the AP's transmit end times in it's Frame Calculator. Then the SM won't be transmitting while the backhaul at the same site is receiving.
Mike - I understand you have a support ticket opened for this. We understand the urgency behind this request, but suggest you follow through with support. They will work with you to resolution. We can post the findings here on the forum in order to help folks that might encounter similar situations in the future.
Mike, hehe thanks for the offer. But I'm not sure I'm am helpful as customer support would be. (I'm stuck in a cube writing software most of the time) :)
Maybe I can put a plug into for Cambium Prime support? :)
I've seen a suggestion to use airlink security on the SMs and AP, would that help segregate the radio signals at all? i don't want to implement such a big change and take all the radios down on a running system if it won't do me much good.
I’m not sure what “airlink security” is and have never heard of this term. As suggested above you need to rethink your channel plan along with implementing proper GPS sync across both your AP’s and PtP’s. This is critical as there is such little 900mhz spectrum available. This should have been done from the very beginning.
I didn't think it would. that was the idea that Tech support came up with. I think I was having some issues with a language barrier as tech support was out of country...
I apologize in advance I am a noob when it comes to cambium, but when you say a "proper gps sync", what do you mean exactly ?Â
Who are you buying this equipment from? Do you know who your Cambium Regional Sales manager or technical manger is? The reason I ask is that these people should be able to help get you the equipment and support you need to implement GPS sync properly. In a nutshell GPS sync allows for multiple radios to share a common timing source which in turn allows them to synchronize their transmissions, thus reducing self interference. The less spectrum that is available and the closer competing radio’s channels are to one another, self interference becomes a major issue. This is a common and severe problem when using 900mhz systems.
