[MLB-WIRELESS] [Fwd: [>Htech] meshnetworks]

[dwayne]

has this been through here already?

oh, by the way, Transhumantech is EASILY the best list I am on.
No discussion, just a central clearing-house for ultra-cool shit


Dwayne

-------- Original Message --------
Subject: [>Htech] meshnetworks
Date: Wed, 6 Feb 2002 14:12:28 +0100 (MET)
From: Eugene Leitl <eugene.leitl at lrz.uni-muenchen.de>
Reply-To: transhumantech at yahoogroups.com
To: <transhumantech at yahoogroups.com>
CC: <consume-thenet at lists.consume.net>, forkit! <fork at xent.com>


http://www.80211-planet.com/columns/article/0,4000,1781_961951,00.html

Mesh Networks: Disruptive Technology?
By Gerry Blackwell


MeshNetworks Inc. (www.meshnetworks.com) aims to turn the wireless world
on its ear.

In its vision of WLANs and wireless access networks of the very near
future, MeshNetworks sees every client device also becoming a relay point
or router for network traffic.

One immediate benefit is that such networks can in effect see around
corners. Even line-of-sight network technologies like 802.11 can become
non-line-of-sight - almost overnight if MeshNetworks can deliver what it's
promising.

And the next-generation networks the company is building will also power
mobile broadband services.

The Maitland FL-based network equipment maker is so sure it's going to
turn things topsy-turvy that it actually has a director of disruptive
technologies, Rick Rotondo.

Rotondo's title, he explains, is derived from Clayton M. Christensen's
1997 business book The Innovator's Dilemma, which tried to show
established companies how to withstand the impact of revolutionary
technology from upstarts like, well, MeshNetworks.

The definition of a disruptive technology?

"In real-world terms," Rotondo says, "it has to meet at least two of three
criteria: be ten times cheaper than any alternative, have ten times higher
performance, and ten times higher functionality. All three is best."

There are two parts to MeshNetworks' supposedly disruptive technology.

One is QDMA (quad-division multiple access), a proprietary radio
technology developed for and currently used by the military.

MeshNetworks has enhanced the technology and is now commercializing it
under an exclusive license from its original developer, White Plains
NY-based ITT Industries (www.itt.com). ITT is also an investor.

QDMA's most notable characteristics are that it's IP from end to end and
supports high-speed mobile broadband access and infrastructure-free "ad
hoc peer-to-peer networking."

The company claims it can deliver up to 6 Mbps to each user in a QDMA
wireless network.

The technology also has built-in GPS (Global Positioning System)
capabilities and, in MeshNetworks' implementation, QoS (quality of
service) for IP voice and video.

The ad hoc peer-to-peer part means that nearby clients in a QDMA network
can talk directly to each other over the air rather than going through
network access points and routers. (This is a capability also possible
with both Bluetooth and 802.11.)

QDMA could work in any sub-10GHz frequency band. MeshNetworks has
implemented it first in 2.4GHz and has already built prototype routers,
relays and PDA-size client devices. Next it's developing equipment for
licensed MMDS (2.5GHz) operators.

The company is using the prototype 2.4GHz gear in a five-square-mile
QDMA-based test network around its headquarters in Maitland, a suburb of
Orlando.

It now has an FCC experimental license to build a much bigger nationwide
4,000-node test network. This time it will use the next generation of QDMA
client devices which come in a PCMCIA form factor. The company hopes to
start building the new network in cooperation with service provider
partners later this year.

The second part of MeshNetworks' disruptive technology, and the core
intellectual property the company brings to the party, is the set of
tricks and techniques for mesh networking.

This is the part about turning every client in a network into a relay
point or router. It's the part MeshNetowrks can and is extracting and
applying to other non-QDMA network technologies, including, first up,
802.11.

The company claims that by the end of this year it will start shipping a
software-only overlay solution that lets 802.11b clients in existing
networks work in mesh-mode. Each client device would run the MeshNetworks
software.

It hasn't worked out pricing for this offering but it will likely be no
more than the volume pricing for the chipset version it is also
developing, which is less than $30.

So. Is this truly disruptive technology?

"We definitely meet the ten-times cost and ten-times performance
advantages," Rotondo contends.

On the third criteria, it's a question of whether you interpret it to mean
ten times the value or ten times the number of features. Rotondo argues
that the extras in the company's QDMA-based technology - built in QoS and
GPS and support for infrastructure- free peer-to-peer networking - are ten
times more valuable than any alternative.

"I wouldn't bet my pay check on the last one," he concedes, "but I would
the first two."

Whether its technology is "disruptive" according to a definition laid out
in some book most of us haven't even read is ultimately beside the point,
of course. The real question is, what can MeshNetworks do for 802.11 and
802.11 users?

The software solution for 802.11 networks will do a couple of things, says
MeshNetworks CTO Peter Stanforth.

While it will not add any mobile broadband capabilities beyond what
802.11b can already support, it will extend the range and link robustness
of existing Wi-Fi networks by allowing mesh-style multi-hopping.

Instead of a network client communicating with the nearest access point or
base station, it finds a nearby client and hops through it - or possibly
multiple clients - to get to the nearest POP.

One major benefit is that mesh networks provide non-line-of-sight linking
which dramatically increases network coverage. The initiating client may
not have line of sight to a POP, but the next one it hops to will, or the
one after that.

"There are fixed wireless providers we've spoken to who tell us that
without a non-line-of-sight technology they will miss anywhere from 40 to
60 per cent of their market," Stanforth says.

Mesh networks also reduce the distance of each link. This is important
because in any wireless network there is always a trade-off between packet
throughput and link range.

All other things being equal, as data throughput requirements increase -
as in 54-Mbps 802.11a networks - range is reduced.

Mesh networks can facilitate higher throughput without sacrificing
effective range - or greater range without loss of throughput.

Furthermore, because link distances are shorter in a mesh network, there
is also less inteference between clients. And that makes for much more
efficient re-use of frequency.

Stanforth says the primary advantage MeshNetworks has over other
technologies, especially others targeting operators using MMDS and PCS
spectrum, is that because of its non-hierarchical topology, it offers far
superior frequency re-use.

It comes down to how many bits per hertz per square mile you can squeeze
out of the network. "We will get orders of magnitude better bits per hertz
per square mile than hierarchical network systems like cellular," Rotondo
says.

This also equates to the number of simultaneous users at a given
throughput rate for a cell sector or POP. MeshNetworks claims it will
outperform hierarchical systems on this measure by a factor of ten to 30
times.

Sounds impressive.

We did think of a few possible downsides to such a network architecture,
but Rotondo and Stanforth had answers.

No, they say, individual clients in a retrofitted 802.11b network will not
take a performance hit because of overhead associated with establishing
and maintaining the mesh topology.

There is certainly some overhead, but the intelligence in MeshNetworks'
technology more than compensates for it, says Rotondo. "When you take it
on balance and say, 'What's my real packet throughput?' in general we're
as good as or better than [a native 802.11b network]."

Nor, they claim, is security a problem - at least from a technological
point of view - even though packets destined for one client pass through
another to get there.

Security features in the company's QDMA-based systems include a hardware
firewall on a chip that makes it impossible for a client to access
somebody else's packets.

That feature will not be available in retrofitted 802.11 networks using
the software overlay technology, but there are plenty of other security
tricks MeshNetworks uses, including route diversity.

In a well-populated mesh network it will be possible to send packets by
different routes so that any one client-relay point will see only every
second or third packet in a transmission hopping through it.

And the hardware firewall will be a feature of the mesh-enabled 802.11
gear the company hopes to get existing manufacturers to make under
license.

"Security is clearly a big issue," says Stanforth. "We've spent a lot of
time working through it - to the point that we do not believe it will be a
significant issue [in selling the technology], beyond the fact that it's
not easy to give a two-second answer as to why it shouldn't be."

Longer explanations and white papers will convince network operators, he
believes. But in the case of wireless ISPs, we wonder how easy it will be
for them to convince subscribers that using their devices as relay points
is such a great idea.

This is a quibble, though. We think any 802.11 network operator - whether
access service provider or enterprise - that doesn't watch very closely
what MeshNetworks does in the next few months really ought to read that
book Rotondo and Stanforth are so big on.

January 25, 2002


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