hello
i am going to set up a 23 kilometer point to point link, connecting a building which is located in the city to an area outside the city. fresnel zone might not be completely clear.
i have had no previous experience with MT products on this kind of long distance link. i would appreciate your opinion on the following configuation:
on each site:
RB/5LD3 (Routerboard 532 Outdoor PoE) complemented with two R52 radio cards (for dual-nstreme)
5G/PAR (30db Solid Parabolic Antenna)
AC/LAR58 (Lightning Arrester)
we need to acheive at least 20Mbps throughput, the link will be used for transferring VoIP traffic. i’m planning on using dual nstreme on 5GHz,
any thoughts?
by the way, i have noticed in the forum that the SR5 radio card is not very popular. i couldn’t find out why. for example, in the above scenario, does anybody recommend using SR5 cards instead of R52?
You’re in for trouble. RF propogation in cities is not nice, and if you don’t have a completely clear fresnel zone you won’t have a good experience.
Your free space loss will be at least 150 db in an urban environment over 23km if you have a perfect fresnel zone. If you don’t change something (higher gain antennas, clear fresnel zone, or higher power radios) you will have small outages pretty frequently, adding up to maybe 20 hours per year.
The other problem you have is that the antenna you have chosen is only single polarized - so unless you use two antennas at each end you won’t be using nstream dual.
We have until now used custom amps from Hyperlinktech in to overcome such situations. I ordered four SR5 cards from Mikrotik yesterday for testing, so in a few weeks I’ll be able to advise.
In theory, even if the cards operate at 23dbm (200mW) instead of 26dbm (400mW) you will be ok. But in order to tell for sure you’d need to state the degree of fresnel zone obstructed.
We have a 20 Mile link with 29dB gain 2’ dishes, and 400mW SR5 cards on both ends. We’re also using RB532’s. Signal = -71/-72dB @ 5320MHz.
UDP data rates of 16mbps using NSTREME. I could probably get that a little higher if i did some more tweaking to the NSTREME protocols framing policies, but haven’t had the time to play with it.
We use the SR5/2’s for all of our point to point and point to multi-point links. Except the older POP’s that still have a CM9 or a 200mW Prism cards.
Hi, We are running a 24 km PtP link with 26 dbi grid H-pol over a city and water. we get on R52 cards a signal -70/-72 db and we get today with R532 15-18 Mbits TCP. and we dont have clear fresnel zone.