Mesh Networks: Possible to make one for perosnal use?

I watched this video last night and
found it fascinating

The idea was to make each car in the US
a combo wifi repeater..... so that each
car sends and receives data but also
relays other's data as well.

This would create one huge shore to
shore free wifi network such that the
economic implications would be enormous.

How feasible is all this?

And can one easily create a mesh network
in their home or even neighborhood?

see the video

http://www.ted.com/index.php/talks/r..._big_idea.html

(E-Mail Removed) wrote:
> This would create one huge shore to
> shore free wifi network such that the
> economic implications would be enormous.

Shore to shore, huh? So that means about 3,000
car per square mile even distributed across the U.S.

> How feasible is all this?

Totally not feasible. But that is to be expected from people
that have no idea how wireless works.

Let me guess...you're thinking that a wireless signal can go several
miles from car to car. You're thinking a signal can be repeated
hundreds of hops from car to car to car to car.

> And can one easily create a mesh network
> in their home or even neighborhood?

Municipal mesh networks have been a dismal failure. So no...one
can not easily create a neighborhood mesh network.

On Aug 13, 6:09*pm, DTC <DTC@no_spam_nothing_here.foob> wrote:
> m...@privacy.net wrote:
> > This would create one huge shore to
> > shore free wifi network such that the
> > economic implications would be enormous.
>
> Shore to shore, huh? *So that means about 3,000
> car per square mile even distributed across the U.S.
>
> > How feasible is all this?
>
> Totally not feasible. But that is to be expected from people
> that have no idea how wireless works.

Hmm...I think you have to qualify that statement a bit, since,
technically it is feasible. The end-to-end delay would be far from
optimal, however.

> Let me guess...you're thinking that a wireless signal can go several
> miles from car to car. You're thinking a signal can be repeated
> hundreds of hops from car to car to car to car.

It can, if Layer-3 routing is used. However, I will concede that some
cheating would be required (topological cheating that is).

> > And can one easily create a mesh network
> > in their home or even neighborhood?
>
> Municipal mesh networks have been a dismal failure. So no...one
> can not easily create a neighborhood mesh network.

Now this is very doable, using existing hardware, and new software.

Not sure how hard it is to do with TCP/IP and related topology-
discovery algorithms, but if one rearchitects a new protocol in
parallel TCP/IP, I think it would be frighteningly simple, relatively
speaking.

-Le Chaud Lapin-

Jeff Liebermann <(E-Mail Removed)>
wrote:

>Place your bets on this one:
><http://www.open-mesh.com/store/>
>On a small scale (apartment building) it might work. On a city wide
>scale, forget it.

I might give that one a try!

On Aug 14, 6:45*am, Jeff Liebermann <je...@cruzio.com> wrote:
> Repeat a dozen times until it sinks in:
> * "802.11 wireless is Layer 2 networking"
> What that means is that anything you do on Layer 3 and above, has no
> effect on packet delivery, error rate, collisions, thruput, etc. *It
> does make some things easier, but doesn't fix the underlying problems.

The problems you mentioned, in a stochastic sense, would be mitigated
by Layer 3 and above, which is why I qualified the quality. That does
not mean that it is not feasible.
>
> Even OLPC (one laptop per child) is going MESH:
> <http://wiki.laptop.org/go/Mesh_Network_Details>
>
> >> > And can one easily create a mesh network
> >> > in their home or even neighborhood?
>
> >> Municipal mesh networks have been a dismal failure. So no...one
> >> can not easily create a neighborhood mesh network.
>
> >Now this is very doable, using existing hardware, and new software.
>
> It's always "new" software that's going to fix things. *Show me a
> municipal network that's actually more cost effective than giving all
> its existing users home DSL line or cellular wireless card? *In the
> few cases I've looked at, the cost per user or per megabloat delivered
> absolutely sucks.

Probably. But that is existing technology, not technology that no one
has seen yet.

> >Not sure how hard it is to do with TCP/IP and related topology-
> >discovery algorithms, but if one rearchitects a new protocol in
> >parallel TCP/IP, I think it would be frighteningly simple, relatively
> >speaking.
>
> Please read:
> <http://pdos.csail.mit.edu/roofnet/doku.php?id=interesting>
> It's some numbers from the MIT Roofnet mesh network project. *Note the
> low thruput and lousy delivery probability. *This is for a rather
> small mesh network.

Interesting. I have had personal disucssions with one of the
priniciples of that project, back in 1995, when he was a young man.

Let's just say that there are alternative methods to achieve what they
are trying to do which have not yet been seen.

> Light reading:
> <http://www.smallworks.com/archives/00000072.htm>
> <http://www.moskaluk.com/papers.htm>
> <http://wifinetnews.com/archives/003972.html>
>
> Place your bets on this one:
> <http://www.open-mesh.com/store/>
> On a small scale (apartment building) it might work. *On a city wide
> scale, forget it.

Aside from the latency issue, a city-wide network is quite doable.
There are a wide-variety of applications that would benefit from such
a network, but of course, there are some that would not.

But the key point here is that one must not expect to be able to do it
using software that is commonly available, on the Internet, as of:

2008-08-14

That does not mean that, as of 2008-08-14, it is not feasible.

-Le Chaud Lapin-

Jeff Liebermann <(E-Mail Removed)>
wrote:

>>How feasible is all this?
>
>Nope. Not in the slightest. Metricom tried that about 10 years ago.
>Cost of infrastructure, greedy site owners, and municipal bureaucracy
>killed it (among other problems).

OK point taken

>There are lots of problems, but the killer is store and forward
>performance. Let's pretend your system can do 10Mbits/sec point to
>point. Add one mesh repeater into the system, and the maximum speed
>goes down to 5Mbits/sec. Add another and it does down to
>2.5Mbits/sec. Keep going and you rapidly approach zero. The number
>of packets that will be flying through the air doubles with each
>repeater, resulting in nothing but collisions and retransmissions.

Hmmm.... I see..... too bad. I thought
maybe this had some SERIOUS potential.

>>And can one easily create a mesh network
>>in their home or even neighborhood?
>
>Home, yes. It's called a "range expander", "repeater", or other form
>of marketing speak for something that barely works. Compatibility
>with existing access points and wireless routers are the big problem.
>Repeater were not clearly specified in IEEE 802.11 specs, resulting in
>some rather creative and incompatible implimentations.

OK so for home use entirely possible to
use small mesh system then.

What is currently the best low cost
hardware for this? Someone a DUMMY like
me could use and setup? Say to create a
small mesh network over a few acres or
large apartment building?

On Aug 14, 12:53*pm, m...@privacy.net wrote:
> Jeff Liebermann <je...@cruzio.com>
> wrote:
>
> >>How feasible is all this?
>
> >Nope. *Not in the slightest. *Metricom tried that about 10 years ago..
> >Cost of infrastructure, greedy site owners, and municipal bureaucracy
> >killed it (among other problems). *
>
> OK point taken
>
> >There are lots of problems, but the killer is store and forward
> >performance. *Let's pretend your system can do 10Mbits/sec point to
> >point. *Add one mesh repeater into the system, and the maximum speed
> >goes down to 5Mbits/sec. *Add another and it does down to
> >2.5Mbits/sec. *Keep going and you rapidly approach zero. *The number
> >of packets that will be flying through the air doubles with each
> >repeater, resulting in nothing but collisions and retransmissions.
>
> Hmmm.... I see..... too bad. *I thought
> maybe this had some SERIOUS potential.

I would not be so quick to discard your idea.

Jeff it talking about Layer-2 impediments.

There are many, many things that can do to get around the repeater
"issue". I put "issue" in quotes because they are not really issues,
any more than eating sweets are "issues" for diabetics. You know what
you are going to get when you do it. The key is to ask what you want,
then find a way to do that given what you have. Putting up repeaters
is obviously not the way to do it. You have to rely on Layer 3
software and above. And there are some tricks you can do with
routers to guarantee scalability. Unfortunately I cannot yet say what
they are.

In other words, you do not have to be an electrical engineer to solve
this problem, but you do have to know how to write software, and it
would not hurt to have solid understand of graph-theoretic algorithms.

If you can code, DD-WRT is not a bad place to start, but again, you
will have to solve some theoretical problems (in software) to make it
work.

http://www.dd-wrt.com/dd-wrtv3/index.php

-Le Chaud Lapin-

Le Chaud Lapin wrote:
> Aside from the latency issue, a city-wide network is quite doable.
> There are a wide-variety of applications that would benefit from such
> a network, but of course, there are some that would not.

"City-wide" as in greater than a single neighborhood or a few square
city blocks has never been successfully deployed. All the companies
have dropped out, some even being sued by the city.

By the time you see silicon with noise levels at least two magnitudes
better than today, there will be better solutions than wireless.

Considering how line of sight the signal is, is it any wonder why
they have to place an access point on every third utility pole?

Sure...its doable, but who will pay for the millions of dollars to
provide a free service? BTW, the "pay for no advertisement" or "pay
high speeds" model floundered.

(E-Mail Removed) wrote:
> What is currently the best low cost
> hardware for this? Someone a DUMMY like
> me could use and setup? Say to create a
> small mesh network over a few acres or
> large apartment building?

Generation 3 mesh

On Aug 14, 1:26*pm, DTC <DTC@no_spam_nothing_here.foob> wrote:
> Le Chaud Lapin wrote:
> "City-wide" as in greater than a single neighborhood or a few square
> city blocks has never been successfully deployed. All the companies
> have dropped out, some even being sued by the city.

That is a cost issue, not a technical issue. But even if infinite
amount of funds available, there would be technical issues, because
the manner in which it is being done is not the way it should be done
if it is to scale to the size of a city.

> By the time you see silicon with noise levels at least two magnitudes
> better than today, there will be better solutions than wireless.

One should not rely too heavily on the wireless aspect. In particular,
use should be made of the network itself.

> Considering how line of sight the signal is, is it any wonder why
> they have to place an access point on every third utility pole?
>
> Sure...its doable, but who will pay for the millions of dollars to
> provide a free service? BTW, the "pay for no advertisement" or "pay
> high speeds" model floundered.

I posed this question one day at my friend's home, who lives in upper-
middle-class neighborhood. Many people would pay for their part, if
their part were limited to < $50 one-time fee.

But I need to emphasize... there are technical problems that have
nothing to do with radios that need to be solved first.

But that does _not_ mean it is not feasible. It only means that those
who have tried have not yet figured out how to do it.

There is a big difference in these two assertions.

-Le Chaud Lapin-