Slashdot Mirror
Wireless ISP Using 802.11?
netheadglenn asks: "I'm trying to set up a small ISP using wireless delivery in a developing country. I'm considering 802.11 as the protocol. Our available spectrum is from 3.7 to 4.2 Mhz. My understanding is that this works fairly well without perfect line-of-sight. We aren't limited by enforced regulation of power output - and in any case regulations here are as flexible as currency. Over here, 64kbps shared between 10 users is considered broadband. The isps simply don't offer anything better than that over dial up connections. Believe it or not, we plan to have 6 users per 64kbps. At $1000/month for 64 kilobits per second, you can see why sharing such limited bandwidth is common. We will start with serving an area within 10 miles of our server. Later we'd like to service two cities that are each about 20 miles away. What is the the absolutely least expensive solution for this?" While the idea of a wireless ISP is a good one, is 802.11 the best protocol for this kind of service?
At high power, 400+ watts, you can set up over the horizon 190 mile shots at those frequencies. Finding inexpencive commercial radios to support 802.11 at those frequencies will be extremely difficult though. Probly why those frequencies were made available to you. Wait, 3.4 MHZ? plenty of commercial radios in that frequency. You can only pull about 9600 kb/s for every .5 mhz of bandwidth though. So you own about 28.8 TOTAL kb/s from any given central location
If voting were effective, it would be illegal by now.
This is a fascinating story. I wonder what country the writer is from.
Secondly, I have researched this idea at some length for use here with my company. Some pretty decent range can be squeezed out of long range antennas (20 miles, $2000 for the antenna) and there are cheap antennas ($200) that will provide around 10 miles of connection in a spherical shape to other high gain antennas. The catch with all these is that the antenna on the other side has to be high gain as well, so you double your costs, but it will work. 802.11b is the current and cheapest standard, and also quite fast at 11Mbps. 802.11g will replace it with higher speeds (50Mbps, and there's some talk of 2X mode at 100Mbps) but backwards compatability. I am not familiar with any other protocols that have such wide industry acceptance, so 802.11b would be my suggestion.
Thanks,
Travis
forkspoon@hotmail.com
802.11 is for 2.4Ghz range, not the MEGAhertz range.
You'd have to rely on something like a TNC, but even those [I think] rely on 27Mhz...
With only a few Mhz to play with you wont get very far at all.
Try to put 64 kb/s in that mhz range and you will have only a couple of customers and your bandwidth full.
OTOH in think your planned use for 802.11 is out of scope, why not simply put line of sight radio or laser links?
NEOCA - Custom LED Flashlights
I own a WISP on a developing country :-).
We use standard 802.11 equipment on the 2.4 Ghz band. Here is some information I can share with you:
We have operational clients up to 5 km from us ( a little less than 3.5 miles ). More than that, we start to get important signal loss. But we use one omnidirectional antenna on our HQ, so I guess you could increase range by using directional ones. You would need one per client though.
In order to minimize cost, we offer our service mostly to appartment buildings. We install one server with NAT and offer access to all tenants through wired ethernet connection. We even give the network card for free ( if needed ).
We have a 1Mb link serving about 250 clients, 50 of each are commercial. in order to save bandwidth, we run a transparent proxy SQUID server for all our clients. Our average load on the link is about 67%, but it is almost 100% during daytime hours. However, I would say our service is good during all times, with sufficient bandwidth to play streaming audio and video.
So far we have been quite successfull. We are instaling one new building per month with an average of 20 to 25 new clients. We just don't do more because of lack of financing.
Good luck to you.
For your information, IEEE 802.11(b) products are in the 2.4 GHz range and future 802.11(g) products will be in the 5 GHz range.
So it won't work except if you develop a new version of 802.11 in the MHz (and products).
Good luck !
(frequency hopping will be very hard to do in a 0.5 MHz bandwith)
#include "coucou.h"
OK, the problem as I see it as follows, you claim to be giving better than local broadband conditions. This is good. But you will have to charge at least $167/month, just for the bandwidth. In most places with an unstable currency this would be considered expensive. Then add in the fat that you have to make some profit, and you are looking at least $200/month. I would not buy real broadband for that money!
So unless you have a high local concentration of rich people, all within line of sight of your offices, then this would appear to be a business plan to fail.
If you have done the homework and believe that I am wrong, then I wish you all the best in your venture.
I've personally been bouncing ideas off him for setting up a community network in the city where I live and he's been great to talk with.
DO THE MATH!!!!!!
802.11 uses the 2.4GHz spectrum. I don't think you'll find anything inexpensive that would run it at the 3.7 to 4.2GHz range you mentioned. And the you also have to factor in the cost of that equipment for both the central location and all outlying locations.
-> Capt Cosmic <-
First and formost, check out the ISP Wireless mailing list and archives here:
http://ISP-Lists.ISP-Planet.com/isp-wireless/
Plan on spending a couple of long weekends looking over the archives because just about every question has been asked and answered multiple times on this list. If you subscribe, be aware that it is a very high volume list.
Also, give up on the idea of using NLOS connections. Yes it's possible under certain conditions to shoot through certain kinds of materials but if you plan your business around making that happen every time you're begging for trouble.