Wireless Community Summit Tackles Digital Divide

jens writes "More than 150 participants (including Matt Westervelt, Seattle Wireless) from 30 countries will discuss on how to overcome the digital divide building wireless community networks. The freifunk.net summer convention 2004 takes place from 3rd to 10th September in Djursland, Denmark. The convention's location is well chosen -- DjurslandS.net (in Danish) itself is probably the most ambitious wireless community network of the world. About 200 volunteers installed more than 100 masts on the remote area's 32 000 sq mi. Using the wireless standards 802.11a/b/g about 1'500 households enjoy a symmetric 1-2 MBit internet connection via WI-FI (the WI-FI network has 8 direct uplinks to the danish backbone and several DSL fallbacks). The wireless4development track organized by wire.less.dk will show other projects how to follow the DjurslandS.net example. The convention starts off with a 3 day program including VoIP, development for the meshcube and antenna building and finishes off with a 5 day hands-on workshop."

Comments

Switch Theory

[Anonymous Coward]

Anyone know enough about Cellular Switching theory and wants to start an open architecture for switches using 802.11?

One day the 2.4ghz spectrum is going to be saturated that the technology used in TDMA (time division) and CMDA (code division) will be used to separate the communication. Switching technology is actually quite simple (once theory is applied to practice) and 802.11 equipment could be used to hop frequency just like cellular does. Now if you can get some inspiring engineer to handle pass-off of equipment then you have yourself an open architecture to replace Cellular with VOIP wireless.

Re:Switch Theory

[rokzy]

The new Motorola CN620 automagically switches to WiFi in hotspots.

Re:Switch Theory

[GuardianAngus]

With enough knowledge of wireless technologies to be dangerous, I am willing to state that the technical implementation of such a system would be relatively easy. The legal environment and treatment of RF emissions in just one country, however, would be enough to prevent such a solution from being implemented wide scale.

By the way, the digital divide is a social problem - it is unlikely to be solved simply by applying technology.

Re:Switch Theory

[TommydCat]

TMI filters on!

For CDMA at least, I doubt many AP owners will want to purchase a stratum-3 clock source or better to keep the strict timing requirements, let alone tackle the technical aspects.

Most CDMA cell systems use [C]BSCs ([centralized] base site controllers) that derive timing from the MSC (mobile switching center) which in turn keep the BTSs (cell sites) in sync using timing derived from the DS1s that connect the two. The sites themselves need to know the precise GPS coordinates (a couple hundred feet off can really affect the timing in this system). The BTSs (cell sites) use a "PN offset", basically a time slot, for each sector (cell sites usually have 1-3 or 6 sides that act independantly) to keep from colliding on the same channel. RF Engineers wake up screaming in the night because a little overlap of two sectors in the system that overlap time slots will clobber usability. At 1.9GHz, weather plays a significant role (water reflects like a mirror, leaves eat up the RF which someplaces disappear in the fall), ensuring the need that the system has to be tuned constantly.

The cell phones listen to the "sync channel", then sync to and descrypt the "long code" to catch up and keep in sync with the system.

Summarizing this rather sloppy overview of CDMA, such an AP network would require 1) precise timing 2) precise coordinates (to keep BTSs/sites from colliding on same channel), 3) a strict sector/site management plan, and 4) active management of coverage. Note that this precludes anything like WDS - each point needs a backhaul or you could potentially bring the available bandwidth down by 2^(number of sectors adjacent to repeater).

Needless to say, I think the average layman is out of his league trying to link up a homebrew network in his neighborhood using CDMA.

TDMA could work with sloppy timing, but isn't that basically what 802.11b/g is now?

Re:Switch Theory

[geomon]

By the way, the digital divide is a social problem - it is unlikely to be solved simply by applying technology.

Agreed. There are places in Arizona and New Mexico that still do not have land-line telephone coverage. Granted, some of that is due to the lack of substantial penetration of technology into traditional communities (i.e., they LIKE being disconnected from modernity).

Summit, Eh?

[darth_MALL]

Sounds like a good, high location to set up an ambush with the BlueSniper

Re:Summit, Eh?

[ackthpt]

Sounds like a good, high location to set up an ambush with the BlueSniper

Don't look for high places in Denmark, the highest elevation is on a bridge.

The highest point (according to CIA) is at Yding Skovhoej 173 m.

Ejer Bavnehøj which is 0.06 meters higher than Yding Skovhøj.

Storebelt East Bridge, Storebæltsbroerne pylon height 254 m

Wow

[johnnyb]

"The convention's location is well chosen -- DjurslandS.net (in Danish) itself is probably the most ambitious wireless community network of the world. About 200 volunteers installed more than 100 masts on the remote area's 32 000 sq mi. Using the wireless standards 802.11a/b/g about 1'500 households enjoy a symmetric 1-2 MBit internet connection via WI-FI (the WI-FI network has 8 direct uplinks to the danish backbone and several DSL fallbacks)."

Sounds like you could microwave a hot dog just by holding it up in the air. This conference was probably envisioned by a seminar given the previous year on "new and effective revenue generation techniques for oncologists".

Pringles - Available in Denmark?

[justanyone]

Are Pringles even available in Demmark?

On that note, it seems like the antenna would not be the most expensive thing to buy as an extra, being usually aluminum in a nice shape. So, do people have links to cheap antenna sales locations and/or directions for build-your-own?

On a personal level, I'd be okay with running a CAN (community area network - is this the right terminology) if I could make sure I interoperate well and share bandwidth across 2 or 3 (or more) uplinks (comcast or DSL included). But, I don't know if this is possible, illegal, immoral, mischievieous, evil, okay, cool, encouraged, verboten, slimey, offbeat, and/or reprehensible in anyone's eyes but my own.

Any ideas? Links?

Re:Pringles - Available in Denmark?

[wjames]

http://www.speakeasy.net/ They provide DSL service that allows sharing the connection with your neighbors (And they'll even help you bill your neighbors!). On another note, Check out the WRT54G made by Linksys and get the sveasoft firmware for it with some aftermarket antennas, Works great!

Left out in the Cold

[ackthpt]

Yeah, lovely, tackling the divide... Like it does me any good. It's a real pain in the back to lug a desktop system around town looking for Wi-Fi hotspots...

Digital Divide != Squalor

[sockonafish]

"Digital divide" describes a situation in which one class has access to computers, and another does not. Really, its not that bad.

I'm not slamming the efforts of the guys in the story, but I am angry that I've seen the President talk more about the digital divide than say, the situation in the Sudan. There's another divide there - those who are victims of genocide, and those whore are not.

There are too many people who have an infatuation with computers and want them to be ubiquitous. This kind of thing is an example, as is computerized voting.

Re:Digital Divide != Squalor

[rm007]

Even without comparing the digital divide with bigger issues, it seems to me that there are problems with the whole concept itself. The idea of a digital divided appears to have an underlying assumption that poor people - regardless of where they live - are poor because they do not have access to information in general and the Internet in particular. While this is unquestionably a symptom of poverty - I am not sure that this is the biggest structural hurdle that has to be overcome in order to provide equal opportunity for all. It sounds great but what will it actually do for most people?

Speakeasy allows WiFi Sharing

[sunilonline]

SpeakEasy DSL has a program called Wifi Netshare which allows you to share/resell your internet access.

I am not affiliated with nor am I a customer of Speakeasy...

The biggest divide

[Brandybuck]

The biggest divide in the wireless community is support for non-Windows operating systems. A coworker and I have been trying to get wireless working on our laptops for several weeks now. We've been trying Linux 2.4, Linux 2.6 and FreeBSD 5.2. It's been extremely difficult because the cards supported by native Open Source drivers are considered horribly obsolete in the marketplace.

Will the future be Windows and Ndis wrappers only? How free will our software be when all of our hardware is held hostage by Windows-binary-only drivers?