I work a small wirless company based out of Maryland. There’s 8 of us right now, and we’re working on getting the company out fo the box. We’ve been having a couple of repeat network issues. In no way am I the network admin, however, seeing as the company is so small, I have direct access to all the equipment, as well as the upper management. Here they go:
->RSSI: Is higher or lower better? I’ve searched the boards, and what I get is conflicting.
->Jitter: Again, I thought lower was better, but I’ve seen conflicting opions.
->Function of gain: It is my understanding that if you raise the gain in the radio, you can go over longer distances. Does this increase the level of interference as well, as it seems with higher gain, you’d pick up more signal?
->Weather Conditions: Wind/Rain have really been messing with our signal. When the wind/rain kick up, is there any way to prevent system outages, or is that just the nature of the beast? How about ice/snow?
->Lastly, we’ve been having issues with customers dropping, especially with 900mhz that would be considered 900mhz, but is going through trees. We’ve been using MaXRad dishes (gain of 8, the network admin said). We’re flipping from a windows assigned DHCP to a cisco router, but up until that point, we’ve had to have customers reset the equipment to get the new DHCP numbers.
Any help is appreciated.
Regards,
-A
RSSI: Higher is better. Under 900 or so is bad but will appear to work down to about 700.
Jitter: Lower is better (unless you have very old radios)
2 to 3 is normal for a good install. 10 will appear to work fine for small clusters but the traffic over the link will be sporatic. Your ping times will wonder all over the place as well.
Gain: More gain means more signal but also means more noise. Antennas aren’t symetrical either so your high gain antenna at one end may raise the noise level at the other end more than the signal.
Wind/Rain: Unless your at the edge of the RF energy you’ve got a different problem. Whats moving? A reflector? Is your tower swaying in the wind? Has the customer end blown a few degrees away? Is there a tree in the way? They tend to blow in the way and when they get wet, they absorb even more RF energy.
on 900 gear rssi’s of less than 1200-1300 are not useable. you need to get above -80db (meaning -79 or better) to have a useable signal
I believe the gain setting on the 900 radios reduces the output so that the aggregate output of the radio and antenna don’t exceed allowable limits.
raising the antenna gain setting on the radio makes it work worse
our experience is that jitter above 6-8 on 900 makes for unreliable throughput. do the pingxxxxxx -t to look at multiple continuous pings and see what the times do over a few minutes. you will be suprised.
also, we have had some favorable results with a 13dbi yagi in place of the maxrad panel antenna. it usually boosts rssi by about 200 units. find at rflinx.com