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How to aim long distance WiFi antennas - the low-cost way

Very often I'm being asked how can we aim such long distance WiFi links.

A relatively simple way of doing this would be to use a high-power analog signal transmitter fed into the antenna on one side, with a spectrum analyzer identifying that signal on the other side.

In our global village world - we can find the above for less then $300 (total for both sides), which conventionally would cost way over $10,000:

Buy a high-power 2.4Ghz video transmitter from:www.chinawholesaleonline.org
At first - I was a bit worried to give my credit-card on an unknown Chinese web-site. For once, I'm happy that I was brave enough. The owner of that site - Adam, had dispatched the transmitter immediately, and I got it days later via DHL. However, the unit was faulty, it would often not turn-on, the frequency would not be stable and would shift with temperature and the power was less then 300mW.
For a moment I thought to myself that I deserved it for buying from such an unknown source. However, I have emailed Adam, and he had quickly <"read more", to continu>

 

Chinese video transmitter - 2w

Here is the small transmitter being measured with a spectrum analyzer to establish the power. Look at the nice and stable analog signal which is so easy to spot on the far side.

Yahel's talk at UC-Berkeley - October 11th, 2007

My talk at UC-Berkeley, could serve as decent and current source of information about AirJaldi.
While surely not my best talk from a personal point of view (my excuse is that I was sick and under-slept),
I did got to address many issues tanks to the questions from the audience.

It's an hour long and no commercials ... Enjoy:

Watch the video -
* Yahel's talk at UC-Berkeley (new window) *

UCB-Talk

Czech router in the Himalalyas...

   
I'm happy to announce that all 4 wireless routers which where installed on AirJaldi's main tower in Upper-TCV school, where replaced by a single router from the Czech republic!
Thanks to the generous donation of Mr. Lukas Hudecek from IteQ s.r.o of his newly designed quad-radio router.
The robust cast-Aluminum weather-proof enclosure with a massive heat-sink, hosts a MikroTik Router-Board 523A board.
The 4 high-quality Reverse SMA RF connectors at the bottom are an excellent choice for the most demanding outdoors installations of both 5.8 and 2.4 bands, while maintaining a port-density better then what bulky N-type connectors offer.
We feed the router with 48v (it's more like a 56v with batteries fully charged) over a very long PoE drop, through the IP67-rated Ethernet connector.
A proprietary optional connector is added for special applications, such as daisy-chaining additional routers, connecting a video camera etc.
The router is loaded with an AirJaldi Mesh firmware, based on Kamikaze release of OpenWRT.
More details can be found on Itec's web sites:
http://www.outdoor-wireless.com/
Hopefully - we where able to provide Lukas with valuable feedback, which will contribute to an even better version of this router in the future.
Many thanks Lukas !
We look forward for future collaboration...

Installation of Czech router on TCV tower

Dinesh & Rana install the IteQ router on the TCV Tower.

Iteq Outdoor router

Free telephony project

 

This post is long due, but like they say - better late then never.

Following the AirJaldi conference (end of October 2006) David Rowe came to visit us in Dharamsala, all the way from far Australia.

 

David is leading a unique and exceptionally important project of revolutionary potential: Free Telephony Project

While many of us are still getting used to, and learning the concept of Free / Open Source Software (F/OSS), David's project introduces additional confusion, yet equally innovative concept: Open-Source-Hardware

Open Source Hardware - VoIP PBX

More...

The new AirJaldi server - is alive !

Finaly, the new server for AirJaldi is installed and is ready for service.
In fact, if you see this page - it means that it's still working ;-)

Well, this is what it looks like ------------------->>>

The server is hosted in Hurrican Electric farm in Fremont, Califronia.

AirJaldi server
Jim - installing the server

The new server will host all sites, content and services related to AirJaldi. In addition, pending bandwidth and time constrains, we welcome all Tibetan non-profits and other non-profits affiliated with us to host their sites with us. The machine is managed by a group of volunteer system administrators from around the world.

 

Thanks everyone for the hard work in making this operational.

 

<< Jim - installing the server at HE.net.

Photo: Yahel.

 

AirJaldi @ Sun MicroSystems

Very soon after the installation on Intel's roof in Berkeley, we'd setup the other end of the link - on the roof of Sun-Micro-Systems in Menlo Park .

It was a very clear day - we could actually see the Intel building all the way far at the Berkeley side - easy aiming...
Excellent link..

Yahel installing a grid on the roof of Sun MicroSystems

Yahel installing a 2.4 grid on the roof of Sun MicroSystems - in Menlo-Park, CA.
Photo: Jim Forster.

 

AirJaldi @ Intel Research, Berkeley.

The year (2007) started with Mikey's visit to California.

The plan (which did happen) was to go over the year's workplan and genrally do lots of talking...
As per the AirJaldi tradition, talks must be accompanied with actions - so Mikey was draged to the roof to get some work done...

 
Mikey on Intel's roof  

Mikey on the roof of Intel Research - Berkeley - mounting an antenna which is used for TIER's long-distance WiFi experiments.
The far end of the link is in the sount-bay, on the roof of Sun-Microsystems.
In the background: San-Francisco, The bay-bridge and the golden-gate bridge.
(C) Photo: Yahel Ben-David.