We are in the process of upgrading portions of our network which is quite outdated and causing bottlenecks for our clients. I am just wondering if anyone has comments on what I am hoping to do. I have 2 main questions:
1. The link we are trying to upgrade is a relay point that currently has a single pair of BH10’s. We would like to replace this BH10 pair with TWO BH20 pairs. So we would be running 2 pairs of BH20’s simultaneously giving us 2 separate 20Mb pipes. We do not currently need to actually combine the throughput of the 2 BH’s, because at the relay point we have 2 other BH’s servicing 2 separate sectors of our network and we’d be fine with just using a managed switch to direct one of the pipes to one BH, and the other to the second BH. We are doing this because it is much cheaper to buy 2 pairs of used BH20’s (around $650/pair) rather than something like a PTP-200 (around $3200/pair). Plus we basically get more bandwidth using 2 pairs of BH20’s. And I also like the fact that we would have 2 links, in case one pair goes down, we would not be completely dead. We would just loose half our pipe.
So does anyone have any comments on this approach?
2. We are going to end up having a lot more radios on this relay station. I am trying to decide on what frequencies to use up there. We will be installing a timing device (probably a LMG Cyclone), so I am wondering how much freedom will this give me in terms of mixing and matching frequencies, or else sticking to the same frequency up there. I would imagine that from a stand point of interfering with ourselves, it would be best to have as many different frequencies up there as possible? The downside of that would be that every once in a while we have other people setting up temporary links (for festivals and such), and they usually work with us and try to fit in with our network so that we can all coexist. So if we were to hog all the frequencies, then we would have more possibility of facing conflicts from them.
Again, what if any comments does anyone have?
Thank you.
1.- yes is cheaper to put another ptp100 rather go for a ptp300…but…
there are 2 a reasons for the price gap: avaliability and eficiency.
avaliability:
ptp100 BER=betwin 10E-4 and 10E-5
ptp300 BER=betwin 10E-8 and 10E-11
when you move bigger traffic it maters.
eficiency:
2 x ptp100 uses 40 mhz of spectrum(limited recurse)
1 x ptp300 uses 10 mhz
Its the price of growing…all motorola ptps are great pieces of equipment.
i presently use a lot of BH20s. Reasonable enough for me.
We currently start all our new towers essentially with BH20s (except for our first 3.65Ghz tower which we started right off with a PTP500).
Once our BH20s begin to max our we will swap in for a PTP400 or PTP500 lite. So far it has worked pretty well and there isn’t too much downtime when we’ve had to swap out the BH20s for larger BHs.
Thanks for the replies. but my main question is NOT whether or not we should use BH20’s. That is pretty much all we have budget for. My questions as listed above have to do with any issues running 2 sets of BH in the sane exact link, in the same direction, etc. One simple question is if I am running 2 sets of BHs simultaneously in the same link between 2 locations, i.e they will be attached to the same pole, facing the same way, etc., should I definitely run 2 different frequencies, or will the use of a timing device such as the Cyclone, allow me to use the same frequency, and just use the stepping within that frequency range, i.e 5225 on one pair and say 5325 on the other. Will that be OK, or should I stay as separate as possible and run like a 5.2 pair and a 5.7 pair?
Thanks.
I would try to get as much vertical separation as you can. Also keep in mind that a BH20 is a 20Mhz wide channel so you will want to make sure you have at least that much separation in the frequencies. If you keep that separation you should be fine.
You already have a pair of BH working. You have to “look” at the spectrum both ends to decide if you have enough space to put another in the same band.
pcpolo wrote: I would try to get as much vertical separation as you can. Also keep in mind that a BH20 is a 20Mhz wide channel so you will want to make sure you have at least that much separation in the frequencies. If you keep that separation you should be fine.
Just so I understand correctly, so running one at 5275 and 5300 would be OK? That would be 25Mhz separation, right?
Also, we will be limited in space, so I am not sure how much separation I can get physically (vertically or horizontally). Sounds to me like I am better off using 2 completely separate frequencies if I can. So perhaps going with a 5.2 and a 5.7 would the safest way to go.
Assuming the spectrum is clear, using a 5.2Ghz and 5.7Ghz would most likely work. Keep in mind the distance limitations the 5.2GHz has.
pcpolo wrote: Assuming the spectrum is clear, using a 5.2Ghz and 5.7Ghz would most likely work. Keep in mind the distance limitations the 5.2GHz has.
Link is very short. Under a mile.
Oh ok, you could look at a 5.4Ghz BH20 as well.
pcpolo wrote: Oh ok, you could look at a 5.4Ghz BH20 as well.
I'll probably have 5.4 coming off at the other end of this relay station. Looks like it may take a little bit of trial and error, but sounds like I may have to use as many different frequencies as possible. As mentioned above, I only hesitate to do so, given that these are unlicensed frequencies, and the more frequencies we use, the more we could be susceptible to occasional interference from adhoc networks that are set up in our area from time to time.