Hi,
I’m tasked with building a wireless network (on a tight budget) and need some help with planing.
It’s going to be a star, all clients connect to a central node.
It would be nice if I could get max throughput between the clients.
The central node has 100/100Mbit net uplink.
Currently there are 2 clients, client A 700m, client B 3km.
Clients are on completely different sides, almost 180 deg, but both have clear LOS to the central node mast.
I am under the impression that on with these distances I could get over 100Mbit with the SXT dual polarity antennas (I’ve seen people quote 200-300Mbit).
setup 1. One idea was to use SEXTANT G-5HnD, 2 for each client, connect the CPEs at the node through a switch as to get maximum throughput client-to-client.
That came out a bit pricy as SEXTANT G-5HnD is around 110eur, so 220eur for each client + a gbit switch.
setup 2. If I go with a cheaper CPEs, SXT 5HPnD(78eur), I lose on gbit ethernet so client-to-client would be limited to 100Mbit. The other problem is that client-to-client communication would also slow down internet access.
setup 3. I could get an even cheaper CPEs, SXT-5NDR2 (54eur) or SXT Lite 5 (57eur). Maybe SXT 5HPnD for client B?
So my questions are:
could I really expect ~200mbit throughput with setup 1?
would the CPEs in setup 3 have enough output power for managing decent throughput with those distances?
regarding the budget, is there a better way to set this up?
would SXTs hold up well in the continental climate, snow rain and all that? Sextant seem to be less mentioned with regards to environmental induces failure
would the different CPUs in these CPEs be a limiting factor in reaching high throughput?
could I really expect ~200mbit throughput with setup 1?
*Yes, you could, but keep in mind that it is simplex.
would the CPEs in setup 3 have enough output power for managing decent throughput with those distances?
*Yes, all of them will handle those distances without any trouble assuming that other considerations such the noise floor are not a problem.
regarding the budget, is there a better way to set this up?
*You didn’t say what you were using for the center node…probably and OmniTik? This is about as cheap are you are going to be able to do it. Use the gigabit versions like the Sextant “G” or the RBSXTG-5HPnD-SAr2, you’ll much happier with them in the long run.
would SXTs hold up well in the continental climate, snow rain and all that? Sextant seem to be less mentioned with regards to environmental induces failure
*They will hold up ok. In comparison to other inexpensive radios, they will work outdoors just as well. I have some that I put up when they first came out and they are still running just fine. Make sure you ground it well as possible and use good POEs.
would the different CPUs in these CPEs be a limiting factor in reaching high throughput?
*The connections rate at which the radios establish the link will be the biggest factor. Next will be the link speed of the Ethernet port (you can deliver more than weakest link). If you have a Gigabit Ethernet port, and were assuming a perfect connection, then yes, the CPU will determine how much B/W can actually be passed across the link.
I did say, maybe not clear enough. I didn’t plan to use a central node, but 2x SEXTANT G-5HnD or 2x SXT Lite 5. I’d connect them through a switch for now.
If need arises I’ll throw in a RouterBOARD RB750 or similar instead of a switch.
I discarded the Omnitik, as I don’t think I can get decent speeds or link quality on these distances. Omnitik seems fine for a few km but throughput is 10-20Mbit not 100-200mbit
So I’m considering 2 configurations, either maximum bandwidth between the clients (so 2x SEXTANT G-5HnD per client + gbit switch/router to connect them), or 100Mbit as cheap as possible (2x SXT Lite 5 + 100mbit switch/router).
Gotcha, I wasn’t sure what you doing in the middle, but two separate PTP links will handle that sort of traffic without any problems. Hope the project goes well for you!
Thanks.
Been looking some more into what can I expect.
Using the radiolabs calc I got this:
3km link
-73.93dBm RX for both SXT llite5 and SEXTANT G-5HnD
-69.93dBm RX for SXT 5HpnD
What connection rate coul I expect with those values?
From what I could find on the forum, it won’t get me 200mbit.
Is there a way to aproximately calculate bandwidth from signal strength?
I haven’t had any trouble out of the SXT series with distances that short. As far as what connection rate can you expect at those values, once you have done a link budget, you take your received signal strength and compare it the signal/ rate chart for the product. The problem in this case, is that these products do not have detailed charts the way that 802.11a/b/g wireless cards did. As far as being able to calculate the connection rate from signal strength is concerned, that is really not practical. There many factors which determine which MCS rate you will connect at such as signal strength, noise floor, CCQ, the quality of the 2nd chain, ect. If you are concerned that it won’t work, the only safe thing to do is to over engineer the link. Many of the distributors have MikroTik based systems already assembled. You may want to browse through those and find something with a higher gain.
