Long Rang wide area network?

Question

While I was in Iraq I was in charge of setting up our sat internet. The main problem I had was being able to reach everyone with the signal. I know that they have to have just as stong a signal to go back to them. Does anyone know a semi cheap way to fix this? The farthest person was about 2000 ft. or so away. I just want to know for next time. A lot of guys were pissed off they coudln't get on from their rooms. I used a 2.4 Ghz outdoor router with a 1watt Amp and a 24 Dbi omi directional antenna. Thanks

The antenna I was using was about 4 ft tall. We lived in 7.5 by 20 ft metal trailers. I couldn't even get a signal of any sort from 2000 ft away. It might have been the rock walls in the way too, but I had the antennas over them I tried using a repeater at one end and the router at the other. The only thing about the mesh networking is you lose speed don't you. Internet is VERY expensive there. It cost us $4000 just for Sat and modem, then $1000 a month for just 2048kbs down and 256kbs up. I don't think there's an easy anwser to this, but thanks for all sugestions.

Answer 1

Well lets see, 1 watt (30db) plus 24dbi omni= 54dbi. (Good thing your military! Only they could get away with that much illegal power! - I am envious). Anyway I do understand your frustration.

I run a Wireless ISP and we use about 35db and cover a radius of several miles with it. (have actually used it at 10+)
luckily I am not in Iraq!

Remember line of site! (If the rooms are within a bunker type wall they wont be!) What you may want to do is use some "repeating" client units!

These let you put up remote clients that can the relay the signal into the rooms with much better signal. You can probably drop the power to less than half what you currently are using and just use serveral relays around the main unit thus keeping the adjacent channel noise to a minimum.

Check with http://defactowireless.com or http://echotechwireless.com and you will find some of these little goodies! I use some of the zinwell G192 radios with weatherproof housings for this. You just put a small omni external and set them to universal repeat mode (you can actually set them as routers if you need to and let them dhcp for the smaller local area)
There is a slight penalty in speed for each relay but it is not much. With four of five of these you should be able to cover well enough to eliminate the issues.

You can also go the "high tech" route and go full mesh network! These use ad-hoc mode to communicate with the backhaul and are thus self replicating and self healing!

Hope that helps, contact me if you like I will be more than happy to assist further. AND THANK YOU FOR YOUR SERVICE!

ps. I forgot to question the antenna height? If it is too high all of the singal is going right over the heads of those within its close footprint! You may need to use lower height or downtilted antennas for those within the first 1000 feet or so.

Added---
Actually the mesh would probably be the best way to go. The speed loss with true mesh is fairly small (10% or so) because the all talk to each other and move data about the best quickest path. With only 2meg down you may find web browsing is fine but if someone starts a download (you need to limit those) Mesh lets you control all that. Check out the units that defacto has ( http://defactowireless.com) they will work. My WISP has four mesh type transmitters and from a 3 meg source the slowest we have seen is 1.2meg from a users site so it will handle loading and coverage. You do want that antenna higher than 4 feet - like 15-20-30foot in the air and 4 foot above at 4 foot the angle is flat so nothing gets past the first obstical.

Answer 2

Well, depending on your budget, rather than using a single router, you can use a wired router and attach several wireless access points and attach directional antennas instead. A directional antenna such as a yagi or a parabolic antenna (satellite dishes are parabolic antennas) will give a better antenna footprint for what you want to cover in a particular direction with the same amount of power. Place these in a circle with the directional antenna covering a certain swath of land and you should get much better coverage.

Cellular towers use a similar design. They have panel antennas that cover between 80-120 degrees line-of-sight and put them around the tower mast to basically cover a full 360 degrees around the tower. I have seen antennas triple the usable distance by only covering a small portion of the line-of-sight.

So lets say you have four directional antennas and each antenna can cover 90 degrees and effectively quadruple the distance an omnidirectional antenna would have been able to cover. If this were the case, you can point one northwards, one southwards, one eastwards, and one westwards, to cover all 360 degrees an omni-directional antenna would have been able to cover but now you can reach 4-times father because you used directional antennas.

There is a lot of physics that can go behind all this. Factors such as Fresnel zones, effective antenna patterns (i.e. main lobe and side lobes), channels, power modes, etc. But if distance is a worry, directional antennas used in a circular aggregated pattern (i.e. four sides of a mast) could help reach those users really far out. Some directional antennas can achieve line-of-sight over 5000 feet at lower speeds (1-5 Mbits).

If even with directional antennas you're in need to really provide good reception, mesh networking is an alternative. Mesh equipment is self-healing and the 3-radio (ingress, egress, and local) access points provide better throughput compared to 2-radio models, in theory. I believe Cisco has an access point that provides this capability.

Finally, a point-to-multipoint design could be used to provide a directional wireless backhaul to each bunker/tent and within each, a second access point can provide localized capabilities.

Thank you for your dedication and sacrifice. Be safe!