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Mike Bushard, Jr
Wisper Wireless Solutions, LLC
-----Original Message-----
Behalf Of Marlon K. Schafer (509) 982-2181
Sent: Monday, June 26, 2006 10:41 AM
To: WISPA General List
Subject: [WISPA] Fw: [isp-wireless] Sector Antenna's I want the Best!

I thought some here my get some use out of this thread.

Hope it helps,
(509) 982-2181                                   Equipment sales
(408) 907-6910 (Vonage)                    Consulting services
42846865 (icq)                                    And I run my own wisp! (net meeting)

----- Original Message ----- 
From: "Marlon K. Schafer" <[EMAIL PROTECTED]>
To: <isp-wireless@isp-wireless.com>
Sent: Sunday, June 25, 2006 7:10 AM
Subject: Re: [isp-wireless] Sector Antenna's I want the Best!

> David, as usual, great thoughts.
> Let me add a bit here on the "but what should *I* do???" side of things.
> I have both omni and sector solutions on the air.  I have both non amped 
> and amped of both.  Let me show you how/where I get to each option.....
> Very rural, few customers likely in the first 18 to 24 months.  The 
> AVERAGE ap out there will service from 75 to 100 subs jut fine as long as 
> you don't have many hogs.  So in a case where I'll likely have less than 
> 50 users I'll go with an amplified omni unless the geography is such that 
> there's just no way to get more than a few miles of service out to people.
> Down town where there are a few companies in the shadows of my main wpops 
> I may put in an omni.  Low gain so that coverage only extends a few blocks

> etc.
> I have some sites on hill sides that overlook many hundreds of houses. 
> Very stiff competition so there number of customers isn't really an issue.

> Spectrum issues are though.  There are at least 4 other wisps on the hill,

> one of whom is both stupid and mean.  You know the type, never met an amp 
> he didn't like.....  He's got a sector that points to NO customers, only 
> to my tower.  The good news is that operators like that eventually run out

> of money and will go away.  But in this location I've got SIX different 
> systems.  4 of them are 2.4 and three of those are on the same channel. 
> Remember you have not only the noise that your ap's see to deal with but 
> also the noise that your cpe sees coming from his ap's.  In my case I have

> sectors as narrow as 30* (panel antennas make nice sectors and are 
> cheap!). I also rotate polarity ass needed to help bleed off as much noise

> as I can.
> There are other spots that I have no customers behind a tower on a hill so

> sectors just make sense anyway.  If long range is needed OR if I do have a

> customer or two out of the main lobe of the sector I may put an amp on the

> sector too.  Usually there's no need though.  It's surprising that a 
> sector with an amp and running at the max legal 4 watts will often not 
> give much more coverage than a sector with no amp running at 1 or 2 watts.

> The main reason for that is the noise that the amp injects into the system

> keeps your SNR about the same as often as not.
> There's also a cost factor.  A good Maxrad adjustable beam sector (the 
> only ones I buy nowadays) is about $400 from EC.  The H-Pol version is 
> $250ish. I tried the cheap sectors from Maxrad and another company and all

> systems running them act just a bit strange.  Drop in a good antenna and 
> it's AMAZING how much better the system runs!  A good omni antenna from 
> Maxrad is about $100.  Others that are worth having are in that ball park 
> (remember, there's ALMOST NEVER a good reason to run an omni over 
> 10dB!!!!!!!!!!  The high gain ones are just more money for the sales 
> geeks).
> Sooo, 360* coverage with an omni and amp.  $400 for a good ap, $250 for a 
> good amp ($800? for a great one), $100 for an antenna, $25 to $150 for 
> cables and we're at around $1000 for an omni based wpop.  (plus backhaul 
> but we'd need that anyhow)  For a sectored solution you've got $400 for an

> ap, $400 for an antenna, $5 to $25 for cable (cat 5 this time).  Times 
> THREE or more puts us into the $1200 to $1500 range.
> Now, there are some that say you should put in the sectors just because 
> it's so close in price and you have better spectrum usage that way.  I 
> don't really buy into that theory.  You'll usually use ALL spectrum when 
> sector vs. one channel when using an omni.  However, with sectors it's 
> easier to avoid noise coming from different directions on different 
> channels/polarities.
> The FIRST thing you should do is figure out if there are enough customers 
> in a given area to at least pay the bills.  Then you need to run a 
> spectrum sweep to make sure that the band you want to use is indeed usable

> (do NOT make the mistake I did and assume that because you are out in BFE 
> you'll not have other wireless users in the area).  NOTE:  Netstubler or 
> anything like it will NOT be of much use for this.  You need a spectrum 
> analyzer.  Rent one for a week or two.  It's well worth the cost as it'll 
> often save you huge amounts of time and money down the road.  Been there, 
> done that, ain't doin' it again!!!!
> Lastly, find a person or two who's advice you trust and don't deviate too 
> much from what you read on these lists.  Hang on to him and let him help 
> design your system.  He'll then also be able to help you fix the things 
> that no one will know about till you've built it.  There's always 
> something that doesn't show up till that 20th customer is online.....
> Hope that helps,
> marlon
> ----- Original Message ----- 
> From: "David Vrablic" <[EMAIL PROTECTED]>
> To: <isp-wireless@isp-wireless.com>
> Sent: Sunday, June 25, 2006 5:56 AM
> Subject: Re: [isp-wireless] Sector Antenna's I want the Best!
>> Good morning Brad,
>> Thanks for a perfect explanation of where I was going with my opinions.
>> A sparsely populated rural market is a "whole nuther ball game" compared 
>> to a heavily populated urban market where Time Warner has lit up every 
>> household with a Linksys AP on Ch 6.    (HEY!  Time Warner, You're a 
>> Jerk!)
>> -----
>> Now lets get back to answering the young mans question:
>> The truth is I have enough population that anywhere I would install a 
>> sector, Sales can get customers.
>> That fact changes the whole design picture.
>>  ----------------------
>> This especially holds true if you are designing a meshed ring / star 
>> network.
>> You have to design it and plan for it, even if you don't build it.
>> You have to design your BH route / topology to cover the whole area you 
>> might wish to cover before you fill it in with sector or node coverage.
>> You are right on the money with your consideration of the opposing beam 
>> width in use.
>> If  polarity of the beam "in either axis" is too wide, you are subject to

>> waste and noise, if too narrow you loose coverage but increase 
>> reliability for where it does cover.
>> I believe careful selection of antennas is where this thread started and 
>> is right where good sector coverage design starts.
>> -----------------
>> The man asked for Best .
>> That can be Reliability, Ease of mounting, Predictable  design plots, 
>> Polarity and overall bang for the buck.
>> What I gleaned from the post was " What is the best first time out 
>> coverage approach to start a new WISP business with.
>> My answer is: It all depends. (On a lot of things that only he can 
>> answer)
>> I had a real eye opener when I started building my first Muni system and 
>> started reading up on the "Cylindrical Model" where you can envision 
>> coverage areas in 3D .
>> The white paper treated the sectors like stacking cans of different sizes

>> to represent the actual service areas in buildings.
>> I realized that this was an omni approach  and wasted  a lot of coverage 
>> and  had a lot of overlap that made for a lot of self generated spectral 
>> noise to overcome.
>>    I thought it over and would rather think of my directional sectors as 
>> wedges of cheese.
>> I can even reuse the same frequency back to back if I am on the opposite 
>> side of a bell or clock tower.
>> I believe you have to engineer everything not just put up an omni, that 
>> with any success, you will be pulling down and replacing with sectors 
>> anyway.
>> ----------------
>> Changing subject here: Adaptive "Smart Antenna Systems" a look at the 
>> future?
>> Just for fun take a look at the Netgear MIMO AP.
>> (Fun to play with and has pretty glimmering lights dancing around in a 
>> circle.
>> Unfortunately it doesn't have very good coverage)
>> It has 7 internal antennas that scan in a circle and stop to transmit / 
>> receive for each transmission.
>>    Now take that concept "out of the box" with external antennas and a 
>> brave new world evolves.
>> It is something that is long overdue.
>> Also I would believe that "Point to point " rules would apply.
>> ---------------
>> Oh well Back to the Cheese errr Drawing board I have a small village 
>> coverage to design this week. ;-)
>>> Simple fact is the BG one channel amp & omni approach will only afford 
>>> you
>>> the capacity of that one radio.  In contrast sectors allow you multiple
>>> radios giving you many times the scalability capacity and frequency 
>>> agility.
>>      David L. Vrablic
>>  Wireless Network Engineer
>>    Logical Net Wireless
>>   Schenectady, NY, 12305
>>    ---------------------------------
>>     Office 518-292-4519
>>       Cell 518-376-2940

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