We recently had a chance to hang two new PMP450i 900MHz sectors on a water tower in rural Central Oregon. These two sectors are using an uGPS unit to provide timing and are configured for back to back frequency reuse using a 10MHz channel width. There's also a scada system on the water tower as well that's presenting quite a bit of noise in the upper part of the band. We put this system in place to provide PtMP coverage along with a 'dirty' backup backhaul connection to a non-LOS repeater site about 2.5 miles away. We're able to get about 20mbps download and 4mbps upload for this connection. We're looking forward to adding more clients and more sectors to this deployment! Thanks Cambium!
The two PMP450i 900MHz sectors along with a PTP820 BH on top humming along at 500mbps:
I've seen a few scenarios with WISP operations in 902-928 band. I vacated a couple sites due to co-location and issues which were raised by the municipalities. Scada for water tower monitoring here is dense in the 900 band and brutal in it's RF and hardware deployment.
Another factor which you may experience is the municipal activities to monitor and read electric and water meters in a given city, town or village. Those activities are conducted by several companies which have licensed freqs in the upper 800 band and some in the 900 band.
Sector when you can and be sensitive if you are located on a municipal structure located with RF emissions from these activities.
In my experience, I found a niche market which is to pull the municipal scada thru my network thereby dropping the RF factor and issues which may become an issue. In some cases I pulled them thru my network and in another, I transitioned them to there own 4.9MHz as a Governmental agency network.
I had a meeting of the spectrum analysers and in the weighted end, public services prevailed.
I changed the game and supplied a better network with more functionality on an IP based system which gave them premesis security, video and IP phones, all interconnected to one op center.
Wonder how well this equipment will work in Central Texas with Oil/Gas 900 MHz frequency hoppers. We have Pecan and Oak trees that are all 40-50 feet and full of leaves. UBNT gear is a joke and we have resorted to single polarization Mikrotik gear which will not do the high speeds, but will reliably do 3-5 meg all day.
The area in the photos reminds me of Bend, Or. And while the trees are tall, they are not that thick. Also, i suspect your deployment is a high sierra which means not that much rainfall.
Anybody testing this equipment in Texas or Oklahoma?
The area in the photos reminds me of Bend, Or. And while the trees are tall, they are not that thick. Also, i suspect your deployment is a high sierra which means not that much rainfall.
That water tower shot is located in an area called Crooked River Ranch and is about 30min North of Bend, Oregon. We also have another 450i 900MHz success story posted which takes place in Bend Oregon. A point to point link in the city center with lots of interference and completely non-LOS shot. Check it out!
BTW, 900 MHz should be at least 10 feet above the top of the water tower. I suspect you are getting a lot of refraction being that low. If i were you, put the 900 sectors above the PTP antenna and you will see a nice increase in performance. We have used 900 MHz for about 15 years and have been through all that. First deployment did not work at all until we raised the antenna 12 feet above the bowl. Now, all that being said, Cambium may have some magic that makes it work despite the refraction, and I suspect they do.
Wonder if fog and snow will affect the Cambium equipment like it does other manufacturers.
BTW, 900 MHz should be at least 10 feet above the top of the water tower.
That's a good idea digitexcom and we'll try that! Thanks for the tip! For this test we had limited time and space and we just had to throw them up for the time being. We're also moving the sectors to other sites soon that can better benefit from having a non-LOS option. We don't do very much 900MHz work, so we're new to 900MHz idiosyncrasies. One nice thing about the PMP450i 900MHz gear is it's OFDM and mimo, so reflections and multi-path aren't as much of a problem as the older PMP100/FSK 900MHz radios.
I completely agree on municipal activities. Vendor needs to check the local municipal restrictions if any. if there lets keep the operating frequency a bit away or keep good guard band. It is not that this 900radio gets susceptibility issue ( it is electrically highly rugged system design) but the electric and water meter susceptibility to this radio. Having said that people may mis understand that this radio spectrum is bad. My answer is NO, 900 radio spectrum is very clean and certified for the in-band operation.
digitexcom wrote: BTW, 900 MHz should be at least 10 feet above the top of the water tower. Yes making LOS arrangements will improve the signal quality on the receiving end and chance to get better throughput. He received success stories with SM laying on the Ground, NLOS, behind garage ( brick walls) yet communicating to AP. If the customer is happy with throughput that he intended then lets not increase height. This is because if more AP deployments near by then cell radius must reduce to minimize interference. and if All APs increase its antenna height, as we know free-air loss of 900MHz is low and hence interference will increase.
