Signal transmission for WISP Network


#1

I am finalizing my first wireless network for deployment. Here is my layout: (I was not able to paste a drawing here)

Link 1 (A) to Link 2 (B) using C5c with 30 dbl antenna, 18.7 mile link with clear LOS.
Link 2(B) to Link3 © using C5c with 30 dbl antenna, 8 mile link, clear LOS.
Link 2(B) to Link 4 (D) using C5c with 30 dbl antenna, 6 mile link, clear LOS
Link 2(B) to Link 5 (E) using C5c with 30 dbl antenna, 4 mile link, clear LOS

Here are my concerns:

  1. How would I connect Link B to transmit received signal from A to links C, D, and E?
  2. Would you recommend using an A5c at link B? Again, how to connect to make signal pass through to rest of network?
  3. With the shorter distance, would a sector antenna work? (or multiple sectors for Link B to C,D, and E)

I am trying to set the initial network to minimize changes to the hardware within the first year. My team and I have been going in circles about Link 2 (B) bottlenecking the network without proper planning for signal transmission. This will be our first Wireless network for a small community of 880. We want to make a good impression out the gate since larger telecommunication companies do not want to provide needed service to this area. Thanks in advance for everyone’s input.


#2

Well,

How much bandwidth are you trying to push through your A-B link? I am hesitant to say that you won’t have issues there unless you expect the spectrum to be really clean. At that distance we only use Licensed links especially since it looks like you are conglomerating connections. Have you looked at a B11?
I have not worked with C5cs on a 30 db antenna, but we have worked with them on 25s and pointing at an A5c. we max out around 8-9 miles (and by maxing out I mean the customer is tenuously connected at ~-70db, not good)

How come you are not using a B5c (or B5) anywhere? The C5c can be used as a PTP, but I think you are pushing the C5cs farther then anyone else I have seen on the forums. If you are looking to impress and save money you are going to make your life really hard.

to answer your questions.

  1. You will need a network switch or router (if router, have different subnets going to C, D and E. If switch usea Netonix to power everything and use VLANs) or if you are trying to save money a plain old switch will “work”, but not well and is not good practice.

  2. Depends on how much bandwidth you are pushing, if C, D and E are customers and all you need to do is push ~30 Mbs to each, then ya, go with an A5c. That said, if you are trying to do back-hauls to separate towers, then you ‘can’ still use an A5c, but the connections will have to be within your antenna angle for them to work. You can get more then 30Mbs through an A5c to C5c, we have done it, but at those distances you are going to work hard getting your antennas lined up well and finding good spectrum.

  3. Depends on what you are doing at C, D and E and how far apart they are from each other. If they are only like 30 degrees distant from each other from location B then sure use a sector. If they are more then 50 degrees you are looking at higher costs with A5cs and their sector antennas. So it depends on how much you are willing to spend and time you want to spend on setup.

As an aside, do not go over legal EIRP on 5GHz gear, it is possible to do that if you miss-configure the C5c gear. You will only make your life harder and other Wisps in your area will not like it either.

What do you mean by “bottle-necking the network without proper planning for signal transmission.”


#3

Hi William,

Thank you for your input. It gave me and my team some insight on things we overlooked.

We have considered the B11 for the first link of the network. But at $2K each, we wanted to look at a less costly alternative. The C5c with the proper high gain antenna will work fine for the longest link of our network with little issues. We strongly considered the B5 as our edge radio for links C, D, E. Again, we were looking at cost but I really like the B5 and rethinking the network design. (I am footing the bill on my own for this project.)

I did overlook the switch component of the equation and that should solve my concern. We will be using Netonix. The bottle-necking I referred too is the point where congestion may occur on the network slowing everything down. It can be avoided if you plan your switches/cabling configuration correct for bandwidth need the first time. (My years of working with LAN networks have made me put this at the top of my list.) We have a fast-Ethernet connection where we can increase bandwidth as the network demand. (fraction T3 connection to start. Easy for us as most customers will start with 30 Mbps and up.)

Link C, D, E are radios at the edge of the network to cover the community footprint. I want the signal levels to be strong across the network and concerned the sector antenna may not provide enough power level to keep the signal high and strong from point to point.

Thanks again for your insight.


#4

Franklin,

Glad to be of help, this industry has so many things that are black magic without some insight.

I kinda figured you were going for the cost savings. Sounds like you have thought it through pretty well.

One last thing, make sure you setup your system so your antennas can access the Mimosa Cloud. (or have an SNMP server setup) Wireless systems change so much through the day/night that getting the insight without having to be up all night is really helpful.

Good luck, if you run into issues the Mimosa Support guys are super helpful and their white papers are some of the best I have had the pleasure of reading.