----- Original Message ----- From: "Blair Davis" <[EMAIL PROTECTED]>
To: "WISPA General List" <wireless@wispa.org>
Sent: Wednesday, February 08, 2006 9:03 AM
Subject: Re: [WISPA]Farmers Wanting full Farm Coverage


Why not use the same essid on all your towers?  That works for me.

It'll cause trouble when there's more than one ap per tower. The cpe will tend to "hunt" from ap to ap casing flaky performand and outages.

Then there's the small problem of using a tower to feed another small tower. If you use the same essid the two local systems will hook up to each other rather than the previous tower in line.


Or use MikroTik AP's with a secondary essid that is the same on every tower just for roaming users.

I've got 6000 square miles of coverage. Changing out all devices isn't an option.

Most of the "tower sites" are very, uh, crude. Hostile may be a better word. I use my system to test gear so I can tell you guys what'll hold up and what won't, even when you do things you shouldn't.

And you've missed the whole point in the first place..... My solution to this problem allows the use of EXISTING infrastructure from MULTIPLE providers. Think cell phone system evolution here guys.....


Marlon K. Schafer (509) 982-2181 wrote:

As an FYI, we've had wifi in cop cars since 2002. They get 15 MILES and can roam from tower to tower as well.

http://www.odessaoffice.com/wireless/mobile.htm

We used to just use the essid of ANY and they'd tie into any of my towers that they could see. That no longer works due to all of the local wlans out there. As soon as someone FINALLY builds me a smart cpe that can be told to associate with a list of 3 dozen or so ap's this mobile wifi stuff is really gonna take off for applications like this!

Laters,
Marlon
(509) 982-2181                                   Equipment sales
(408) 907-6910 (Vonage)                    Consulting services
42846865 (icq)                                    And I run my own wisp!
64.146.146.12 (net meeting)
www.odessaoffice.com/wireless
www.odessaoffice.com/marlon/cam



----- Original Message ----- From: "James McKinion" <[EMAIL PROTECTED]>
To: <wireless@wispa.org>
Sent: Tuesday, February 07, 2006 2:58 PM
Subject: Re:[WISPA]Farmers Wanting full Farm Coverage


We have had two commercial cotton farms in Mississippi under complete wireless local area network coverage for about 3 years in a current demonstration project for precision agriculture applications. The farm in eastern Mississippi has about 1600 acres of contiguous farmland with gently rolling land. We used Alvarion BreezeAccess II equipment with an omni antenna at thebase station to communicate to three repeater station located at the edges of the farm. Directional panel antennas connected to BreezeAccess II 2.4 GHz radios which then went to Breezecomm radios connected to 120 degree sector antennas which broadcast into the farm to the equipment in the fields. THe farm equipment was equipped with Breezecom radios attached to omni antennas. All of these radios are frequency hopping spread spectrum radios. These have a range of about 2.5 miles talking from sector antennas to omnis. Wifi will onlu have a range of 1500 feet talking to omnis. An omni antenna is the only cost effective practical device to put on a tractor, combine or truck. The other reason we chose Alvarion is that their radios automatically handle mobility. That is, they can automatically hand over communcation from sector to sector as boudaries are crossed with loosing connection or packets of data. This system has a user data rate of 2 Mbps. The base station has a Starband satellite link to the Internet. We have also used DirecWay satellite links.

The other farm is located in the Mississippi Dellta and is set up similarly with the exception being that the communication from the base station to the 9 repeater stations is handled using the Waverider 900 MHz radios. This farm consists of over 12000 acrs of cotton farmland separated by various tree lines and is roughly oval shaped with the major axis being 12 miles from side to side with the farm headquarters situated in the middle. We needed the 900 MHz radios to penetrate the trre lines to reach the Breezecom repeaters with 120 degree sector antennas to provide field coverage. THe siganl from the base station reaches almost 10 miles so the entire farm is covered by the base station. However, you must use yagi antenna precisely aimed to get reception. Thus, the use of the repeater station using Alvarion Breezecom as before.

I can sen you a copy of the research paper we published if this is of further interest to you.

James

Dr. James M. McKinion
USDA-ARS
Genetics and Precision Agriculture Res. Unit
P. O. Box 5367
Mississippi State, MS  39762
Ph: 662-320-7449
FAX: 662-320-7528
Email: [EMAIL PROTECTED]


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