Outdoor wireless

[tmuneer]

I want to give a complete Wireless blanket coverage within a radial distance of 50 Kms. The total Area is about 7800 SQ Kms. I have an option of point to point wireless links for back hauling and point to multipoint for access coverage.

Plan can be form core to distribution & Access, Point to point links & for Access a multipoint solution.

Any Ideas...

[engineerjeremy]

I'd start out by conducting a sight survey of the area with a spectrum analyzer.

[BER_vs_SNR]

Question to the member who previously answered on this:

An area of 7800 square kilometers?????? This is an area roughly 55 miles by 55 miles. Site survey with a spectrum analyzer?????
How on earth would you propose to do that? Not to mention, why?

Question to the thread originator:
What type of wireless network is it that you are looking to? Master-systemt to basestations coverage for cellular? wireless Internet? Broadband services (video, etc.)

[engineerjeremy]

Basically if the area is trashed with junk in the 2.4 field, why even bother with anything else. This is called RF engineering, and is pretty much done before any professional wireless installation.

[spiderbite]

Jeremy's Spoken!
Did you read that on a shirt at the mall? That space is bigger than Manhattan and probably a few fourth world countries! Try shlepping around a Sitemaster to map interference across 55 miles square. I get winded in a hospital. By the time you finished, the analysis would be invalid.

By the way, you might want to find out who knows what they're talking about before you go pissin' people off!


Now tell me, are you a real engineer or do you just run a train?

[mvario]

Originally posted by spiderbite
Jeremy's Spoken!
Did you read that on a shirt at the mall? That space is bigger than Manhattan and probably a few fourth world countries! Try shlepping around a Sitemaster to map interference across 55 miles square. I get winded in a hospital. By the time you finished, the analysis would be invalid.


:p :D I am sooo laughing my butt off right now.

[HITMONEY]

Originally posted by spiderbite

Now tell me, are you a real engineer or do you just run a train?

ROFL



Hey mvario, funny meeting you here.
;)

[engineerjeremy]

You really have do not have a clue do you. You have never professionally deployed an outdoor wireless installation. Think of the companies that deploy celluar gear, they do site surveys, and CDMA cells tend to be large. I would rent or buy a truck with a retractable mast and preform the site survey with a yagi randomly through the area. Your stupidity was prevelant with comparing this job with a site survey for hospital deployment with a psuedo Anritsu spectrum analyzer that doesnt even pick up 1/2 of the license free spectrum commonly used in broadband deployments. If you only knew that there is a program called RUS. Oh what do they do? They grant money to people installing wireless broadband in areas not able to get bandwidth. I took the question seriously. Next time forget about your pathetic indoor wireless experience and realize that outdoors it a totally different beast all together. Someday people will not try to install equipment before they know that it can even work. *hops of the train*

[BER_vs_SNR]

I have long outdoors RF engineering experience and I admit I had not understood what engineerjeremy was originally saying as what he now explained at the end. Thanks for clarifying your thought but you must admit you worded it in a frugal way that was open to misinterpretation especially by people with predominantly indoors experience.

There is no reason to drop the civility level of the discussion.

I am going back to my original question. If a central point needs to broadcast to multiple points and if the work does not have to happen on a cellular model say due to frequency reuse, due to base station costs, due to channel allocations, due to the nature of the application ....due to God knows what... etc. the solution will have to be architected completely differently than if a more traditional cellular structure must be deployed.

What is the application? Is part of the transmission possible in optical frequencies using broadband laser-based communication point to point? Or everything must be done in microwave? In the former case, RF surveys and RF engineering will not help you a bit.

I'd like to hear back from the thread originator.

[engineerjeremy]

Sorry for the uncivil remarks, you threw me into defense mode with the whole train comment, most people engauge a defense mode when verbally being poked at . Actually I am a security engineer, with a heavy test equipment background, now I am providing consulting services for WISP's as well as speaking at conferences here and there. Sorry for the misunderstanding, the question was vauge so I gave a vauge answer.

[engineerjeremy]

If you providing coverage for a large area FSO probably wouldnt cut it. FSO is also extremely expensive and subject to rain fade due to the high frequencies. FSO can be nice a for small 100Mbit hops, but even then its still expensive.

[oshea85]

Originally posted by engineerjeremy
If you providing coverage for a large area FSO probably wouldnt cut it. FSO is also extremely expensive and subject to rain fade due to the high frequencies. FSO can be nice a for small 100Mbit hops, but even then its still expensive.


I'd have to disagree with a blanket statement like that. First, free space optic is subject to attenuation from fog particles, not rain droplets so much, although a monsoon will knock out many wireless technologies regardless.

I have found FSO to to be cheaper to install and maintain on a $/Mbps basis. Unmanaged 100Mb shots can be installed for $12-15K, even in the NYC market. No interference issues, either.

As for the site survey, I agree with engineerjeremy, although a finding of clear airspace doesn't guarantee you much, due to the lag time between the survey and the install. A negative finding would tell you what you definitely can't do, though. Should be done regardless. Depending on the app, you could probbably just wardrive around and see what you see, might not need a drive-test truck.

[BER_vs_SNR]

The originator of the thread seems to be based in Dubai, UAE. Assuming the application is in the area, rain does not seem to be a major factor (as it would be in NY for instance, that was just mentioned as an example), although there may be at times heavy humidity in the air from the Gulf.

Frequent sandstorms on the other hand will definitely be a classical problem for FSO.

[oshea85]

Well, actually, probably not.

I'm can't pretend to understand the physics, but it has to do with particle size. Snow, rain, and (I'd guess) sand, have particle sizes larger than the wavelength of the FSO.

Fog, on the other hand, has a particle size that's just the right size to disrupt the beam.

I'm going to ask someone who'd know for sure and get back.

[engineerjeremy]

You are correct. The wave length of a radio frequency most be longer than the object it passes through to not attenuate to a high degree. WISP's have problems with trees mainly because a 2.4Ghz wavelength is roughly the size of a normal leaf. Also 2.4Ghz is premo for water absorbtion. Which is way most microwaves run at 2.4Ghz.

[BER_vs_SNR]

We are not in major disagreement. I want to point out however that one is only right to a certain extent by widely using the term "particle" here.

Sand particles, independent of their size are opaque to visible light. Fog/water drops on the other side are more or less transparent to light (depending on wavelength, for instance CO2 IR lasers used by the military as target designators do have issues in specific types of weather by the water absorption characteristics of some IR bands), albeit facilitating a cascade of diffractions, scattering, and ultimate losses. Lossy transmission is not the same thing as no transmission. That is why the term "particle" is not good for the non opaque case of water droplets.

Also in the case of sandstorms, besides the light being reflected or scattered by individual sand grains, the average distance (mean free path) in space that scattered light travels from sand grain to sand grain (in the analogy of thermodynamic analysis of Brownian motion in gases) and further scattering away from the intended coherent transmission direction, depends on the intensity of the storm and the density of sand grains (expressed as number of grains per unit volume).

Again macroscopically speaking, there can be either a lossy transmission or no transmission at all depending on many things like transmission power, distance from transmitter where measurements are made, etc.

Odds are that in a sandstorm you will experience a worse optical communications link than in a wet foggy rainy day.

There is massive information on the subject. Take a look for instance at:

"Propagation Data and Prediction Methods Required for the Design of Terrestrial Line-of-Sight Systems", CCIR Rec.530-4, RPN Series, CCIR, Geneva, 1992

or

Naval Shore Electronics Criteria, "Line-of-Sight Microwave and Tropospheric Scatter Communication Systems", Navelex 0101,112, US Departement of the Navy, Washington, DC, May 1972.

[Mobile Dunny]

tmuneer

Q
I want to give a complete Wireless blanket coverage within a radial distance of 50 Kms. The total Area is about 7800 SQ Kms. I have an option of point to point wireless links for back hauling and point to multipoint for access coverage.

Plan can be form core to distribution & Access, Point to point links & for Access a multipoint solution.

Any Ideas...


A

Your request to obtain blanket coverage of 7855 sqkm will require a very large financial investment and not possible without a large number of access points.

The average access point working in ideal conditions has a typical working radius of no more that 150m (500') and area of 0.0707 sqkm - Vendor product specification may say something different, however in practice that's what you get.

To cover the area you require, would require 111,103 access points.

At an average price of $800 per Access Point, this = $88,882,400

Each Access Point requires a backhaul circuit (prices shown below is for basic ADSL services). At an average price of $150 install with 100/month service charge = $16,665,450 install with annual service charges of $133,323,600

So to recap

Your initial install fee for your requirement is Hardware + Backhaul Network Install charge = 88,882,400 + 16,665,450 =

INITIAL FEE = $105,547,850
ANNUAL ONGOING SERVICE FEE = $133,323,600

The figures above do not take into consideration the following:
1- cost to locate each Access Point (Mast/Roof top etc) - anything from $1,000 - $3000 per site.
2 - the power requirements for each access point (payment usually included with site charge (see above))
3 - Central Site facilities costs to locate racks for backhaul network modems (ADSL Modems) - although the Telco would multiplex the circuits into multiple high speed links (several gigabit links).
4 - The power requirements for the Central site! etc etc

And a final note, the above pricing does not show any discounts that could be negotiated - given the size of the network

What's your budget for your requirement?

:) :)

[engineerjeremy]

The typical INDOOR access point only has a distance of 150ft. Outdoor equipment can often span upto 12 miles depending on terrain. I know people thate service up to 12 miles with a 12dBi Omni. Obviously that is a bit on the extreme side. But you can think about indoor solutions when it comes to outdoor wireless. So you price quotes are so far off that they shouldnt even exsist

[Mobile Dunny]

engineerjeremy (junior)

Before you get up yourself once again and have a tantrum,

Ist Rule - understand what the Customer requires. - come on this is customer service 101.

In this instance BLANKET coverage was required. I assume you understand what that means! Read the requirements once again and then comment - constructively.

The point I wanted to make was that that if you want blanket coverage with good signal coverage, with minimum error - you have to spend buckets of money to do this.

One day you will see beyond the suppliers specification sheets.
Why not spend some money and buy a system and try it out on second thoughts I suggest you stick with security systems and leave the really communications to the professionals

[engineerjeremy]

There is a difference between using specifications of indoor equipment in reference to quality of service. Thinking than an outdoor accesspoint will only cover 150 ft is not right. So instead of the omni direction example maybe I should have had said sectorized antennas. 4 90* sectors running from 4 accesspoints. I am just trying to tell you, outdoors IS NOT the same as outdoor wireless. Its a whole different ball game. I do know more than what is printed on the specifications. In an outdoor situation you wouldnt use 2dBi dipole antenna that are used on normal indoor equipment. You can have an EIRP of 1Watt on PtMP deployments. So stick to the indoor market and I'll stick to the outdoor market. Have a great day.

[engineerjeremy]

indoors is not the same as outdoors

[oshea85]

Nice cat fight you chicks have going on there...

Engineerjeremy, would you really use (4) 90's? That's excessive...
What channels would you put the APs on?



Anyway, lets assume the client devices are mobile.

In Dubai, I'd guess it's pretty flat, if it's a Gulf nation. IEEE 802.11b can go a mile or more before you start running into MAC layer timeouts, unless you can use any one of the proprietary enhancements to extend the range. Some claim success doing much better than 1 mile...too many variables, and this is a budget estimate, so let's stay conservative and see where we end up...we can fudge later...

So, Pi x 1 square mile = something around 3-3.5 square miles from each AP. This is a very rough estimate we're doing...let's say we get 5 square miles.

tmuneer's only post states 50 km radius. That's something like 30 miles, so we have around 2900 square miles.

Whew, that's like 600 basestations (not 111,000)

OK, 600 basestations. Let's say we sink an 85' telephone pole into the ground for each one. Maybe we get a deal on APs and misc because we're buying in volume; lets say it costs $3K to put APs on polls with antennae and cabling. A solar power battery system can easily be had for $1K each in volume, that brings us up to $4K a basestation.

Without clustering 3-4 basestations together in a root/child repeater setup, the backhaul gets pretty hairy...I'd rather take a performance hit, and only backhaul every third or fourth basestation with 5GHz 11a link, but it's not my network, and maybe tmuneer's got bucks to burn.

So, $2.5 million puts the polls up with power, and the remaining piece is the backhaul. We could probably do that for another $2.5 million, maybe more. Certainly under $10 million. Certainly less than half a billion dollars.

Of course, this assumes that you put it all in yourself...:)

[BER_vs_SNR]

These numbers start coming closer to reality, especially if the customer does a side-by-side analysis of the costs assuming a different technology approach.

One should also look at UMTS as well as at GSM/GPRS/EDGE and at least one of the wideband flavors of CDMA, (albeit they suffer from admittedlylower bit rates) to fully compare costs and benefits.

The infrastructure may be easier to bear with a cellular approach, because you will need less base stations than access points, and especially if towers already exist and the owner (assuming it is different) can be lured into a teaming relationship that can further control the overall cost. Of course the nature of the application will dictate what technology is needed, which was my original question, in the first place.

Another approach would be for tmuneer to see if ordinary payphones cannot be hooked up e.g. through existing fiber as a desirable backhaul approach, like Verizon is doing in NY City tying up "hot spots" they deploy at humble payphones. Then deploy access points at those locations. It may require teaming up with the fiber owner (if there is one) but it can save much money.

In any event, hundreds of millions of dollars for this project is a real stretch of imagination.

[Firmware Guy]

Originally posted by oshea85
Nice cat fight you chicks have going on there...
LMFAO!!! :D

I like Oshea's numbers much better than Dunny's or Jeremy's. Dunny got blinded by the numbers, Jeremy doesn't comprehend just how big an area that is.

The real question is what is the site like? I've seen assumptions made about it being flat and evidently unobstructed, but is it? You can't just model Dubai as a flat plane of sand surrounded by water and populated with Arabs and oil wells! You need to know the terrain and presence of obstructions like buildings, hills, etc. I would want "blanket coverage" defined too! :) I've never seen anything that covered 100% of everything.

Unfortunately while this is a great argument (or cat fight) one thing is clear: The dude who started the argument hasn't been back since his thread starter post, so site details probably won't be forthcoming.

[oshea85]

Posted by BER_vs_SNR
Another approach would be for tmuneer to see if ordinary payphones cannot be hooked up e.g. through existing fiber...

Hmmm....Verizon used existing copper plant, and a DSL modem/POTS splitter to provided connectivity for the APs in NYC. There's no fiber to the vast majority of those phones, believe me. I doubt Dubai is going to have existing fiber laid out near the basestation locations.

[tmuneer]

Dear All, Thanx 4 ur comments. I actually started the project and is going on well. I have made a core site consisting of 6 Point to multipoint radios which cover a radial distance of 11 KMS. From Core I have done backhauling by connecting 4 point to point radios with the distribution using 45 MBPS radios and then from distribution I have repeated point to multipoint solution. It is working on one area now. I still need to cover 270 Degrees. I diid in Angular distance of 60 Degrees.

Guys It works, there are 1500 ISP's in america itself providing this solution. It is WISP solution. I have tested VOIP as Well on this and works cool.

[oshea85]

What product solution did you go with? We were all a tad unclear about what the application was....

[BER_vs_SNR]

Allow me to correct a small detail: Verizon is not done with the project I talked about because it only very recently started. Maybe we are not talking about the same thing.

I happen to work closely with the top management of the Verizon division that is now starting to deploy FIBER to connect all of these hot spots and yes you are right that today there is only copper, but guess what, it is only a matter of time until there will not be copper but fiber connecting these hot spots and that was the very reason why so many organizations felt the immediate and competitive threat of the Verizon move and the upcoming elimination of the average "hot spot" as a viable business model in some NYC venues.

On the Dubai case, we don't know what is the nature of the required coverage area is. Dubai itself is a sparkling western-like looking megalopolis with all the bells and whistles we are accustomed in seeing and having, but around it there is only flat desert and the sea. In Dubai itself I would not be surprised if fiber is deployed although I don't know if for sure. Most likely you are right there is no fiber.

[mvario]

Originally posted by HITMONEY
ROFL



Hey mvario, funny meeting you here.
;)

I get around ;-) Small world, eh?