Wireless 900MHz connection dropping

What i need to know is what might be powerful enough in that frequency range to knock that unit off line for an hour.
The big delivery van that parks between transmitter and receiver at that time every morning?

Have you tried replacing the customer unit with another, just to make sure that you don't have a defective unit?

It doesn't need to be another RF signal that is knocking it out. It could be a power problem. Is his coffee pot/toaster... on the same circuit?

If this is a stationary mounted antenna: Has anybody inspected the connectors on the coax to make sure they are properly crimped? Is the antenna properly secured against wind gusts?

Just a few thoughts. Maybe some more info is in order. Is this a PCMCIA card in a laptop, or a fixed antenna on the roof? What troubleshooting procedures have you already tried to isolate the problem?

Thanks for the suggestions. The power idea sounds very possible, as this is a truck stop and does shut down in the evening. Im just not sure what time they open. As far as trying a different radio, we have already tried several different radios.

I have had 2 problems with the units I have installed.

One was a power problem. The unit runs on 10-30 VDC and I had it hooked up to a 12 VDC power supply. Sometimes when the AC unit kicked on it would loose it's little mind, and not re-link with the access point. Changed it to a 24 VDC supply hooked to a different leg of incoming power... No more problem. If that is the case you can run it off a battery for a day or 2 for a test.

The other was EMI from a UPS. The radio was just sitting on top of the UPS, and every once in a while (2-3 months) it would lock-up in the same way. I rearranged the cables, and set the radio well away from any other possible source of interference. No problems.

I am off on vacation for 2 weeks, so no more from me. Hope this helps.

sometimes using the cat 5 b standard on all ends can be the fix for this problem if you are using POE injectors to power your units. the number of twists per inch for the second and third pairs are higher than the others. some vendors specify this configuration but it works in all cases. just good practice i have found. hope this might help.

I know the old style analog cordless phones operate on the 900MHz freq. Also microwaves have been known to interfere with wireless routers. Some electronic equipment you have may be cutting on at that time and knocking you off.

also i would try a passive site survey for rf devices that fall in the pager, shortwave radio, or any kind of base station such as a ham radio ect.. maybe someone gets up early at the same time every day and listens to thier ham radio while drinking coffee each morning. those antennae's are easy to spot and can be a good ways down the road somewhere.

Hello garyboyce, There could be an industrial operations close by that uses a RF/microwave heating system of some sort. and if the time is only in the mornings it could be maintainer's or the line starting up. Also is it only during the week or is it random but same time?

An example of the above, a ham club I belonged to, there repeaters would lock in transmit mode for hours on end. One of the members found a box or cabinet company I don't rember but they had a glue machine and they would leave an access door open when the shop got hot to keep it from overheating. When they did that our repeaters would lock. In the end we had to install tones on all the repeaters.

If you said the equipment is located at a truck stop there it could be the satcom systems so many trucks use now or I think some truckers also are wifi hot spots.

It could be some one that has a regular route and they are there at that time. It would not be too hard to find out just ask around for the drivers who frequent there with a regular route or leave a sign on the truckers board.

Hope this helps

Charles

Isn't 902-928 used for traffic control as well?

I think that is a line of sight frequency- so you have about a sixty mile radius to clear.

Personally, My first guess is its some body at the truck stop with one hell of a linear amp on his cb. BUT IF ITS EVERY MORNING RELIGIOUSLY< then that is unlikely and I'd go with the power issue at his site.

I'll spare you the mulder and scully theories, not knowing location of your rural area.

milo

We are going to check it out today and i will post my results tomorrow morning. Thank you for all your great suggestions.

The key thing to check out is: Does anyone else have this issue in the area or just the one customer?

If multiple customers/devices are having the issue, then the problem may be something in your BTS servicing that site -- if there is only one tower in the area. This could be an issue with the BTS equipment itself, or something interfering with the radio signal.

If it is just that one device, then look for the issue around that device. Shielding at that time, power levels, issues, etc. as mentioned in other posts.

are you in the USA? if you are in the USA 902 to 928Mhz is allocated by the FCC for HAM use.

The real question is what are you doing in that frequency? You should be very careful about what you do next. This is a violation of FCC regulations and exposes the owner/installer of the system to enforcement actions on behalf of the FCC. Interference caused my a non licensed operator in that particular range will expose the responsible parties to seizure of their equipment and the possibility of fines levied against your company.

The first thing you should do is to take this unit off the air. Then you should find a solution, something in the unlicensed 5.8Ghz range like a unit on this webpage:

http://www.winncom.com/products.aspx?grcode=WM58

It is not uncommon for Hams to have a 1.5kw pep transmitter system. Normal microwave systems are sub 30w.

If you really want to find out what is going on, you should go camping with a spectrum analyser and a Yagi antenna. You can use the Yagi to do some direction finding and the source of the signal.

You are right about ham radio being in that frequency. However, 902 - 928 is a very populated band and the units we are using are fcc approved. Also, there arent any ham radios in the vacinity.