[MLB-WIRELESS] [TECH] Dipole antennas, and melbwireless structure

Ben Anderson a_neb at optushome.com.au
Tue Mar 19 00:49:48 EST 2002


I disagree with this as a "structure" as it's backbone based, and won't
scale to more than a few of handfuls of nodes.
For it to have any chance of scaling larger (both technically and socially)
each node has to be capable of routing for another node... thereby building
a large mesh, where one only has to be able to see one other node to
communicate, though the better connected, the more 'useful' that node is for
the rest of the network.  And to encourage this 'better connectedness' I've
been proposing (and hoping for comments) a "mojonation" like setup, where
the more traffic that gets transferred through your system, the more "mojo"
you have to spend on routing traffic through other systems...  This isn't
pay for bandwidth as such, just 'premium access' -- any spare would go to
whoevers demanding it in a 'fair' fashion.  And this encourages people to
network better so _they personally_ get better access -- most people seem
very willing to spend a thousand dollars on better equipment if they get
'better access'.
Some people have brought up the fact that people on 'edges' will get
discriminated against by getting poorer access because they're not
transferring others data....   One potential thing could be other services,
hosting, data, etc, but since the network is primarily about transferring
data, I suspect that it's going to have to be a consequence to get it to
scale.  Unless someone else has an idea to bypass this limitation?  (I
purposfully built in this 'leaf node discrimination' to prevent leaf nodes
logging on and doing nothing but sucking down high bandwidth apps off the
network (mp3, warez, movies, etc).

Also, to prevent lots of bandwidth being wasted doing network discovery as
in OSPF, or mobilemesh, I'm proposing a networking scheme that relates to
physical location....  This has privacy concerns, but so far I've not come
up with any reasonable alternatives that don't have a central administrative
overhead that limits the scalability of the network.  So for example, to get
a packet to a device, you need to know it's gps co-ordinates.  I'm proposing
a network layer implimentation of this so tcp/udp apps can still be run over
the top of it.  Intelligent caching, even perhaps a 'dns' style node
location system may be useful in producing a "nasty hack" version of what
i'm talking about using current networking stacks...

Encryption in this network would be a very high priority, to prevent nodes
from intercepting traffic, and modifying it unknown.  For example, a
commercial entity could setup a load of nodes, and use it to insert spam
randomly into all our traffic....  With encryption, that dissappears.  And
it also removes some of (but not all) the privacy concerns.  Encryption
isn't really a "hard" problem based on the ready-made libraries that
exist...  The routing protocol, and actually getting it working (and then
getting it working on win* platforms...  (I don't even want to _think_ about
a network layer win32 app, let alone build one))

Ideally, I'd like to have a pll, a mixer, a big, high-bandwidth DAC/ADC and
a dsp/fpga combo to impliment a lot of different modulation techniques (ie
the closer you are, the more wideband, spread spectrum high bandwidth
protocol you use.  And the further you get, the more narrow band, slower,
reflection and fade resistant modulation you use.  So you can still get
_any_ connectivity when you're 'just' out of range...  But this is definatly
a long term 'fun' project (money, time...)  (though if someone wants to hire
me...  ;)
Beauty of this, you could implement 802.11, 802.11a, bluetooth, IR, GPRS,
ham radio protocols all in the one device, allowing widespread
interoperability between devices...  I'm not proposing doing all the
applicaiton layer stuff to make this work, just the hardware and low level
software to provide an interface to do cool stuff...  Provide cool stuff,
the coders will come :)

Yes, I know I've written about this before, but last time I mixed it up with
the 'committee' stuff, and it seems the tech detail got confused...  So here
it is again for your perusal :)

Have fun,
Ben.

> From what I'm reading, the basic proposed structure for nodes is you
> have one (or two) directional antennas, to connect you to the rest of
> the network, and one omni so people can connect to you.
>
> Now, my understanding of a dipole antenna design is the AP finds the
> strongest signal on an antenna, then uses that ONE antenna to pick up
> the signal. .. so you can only receive one signal on one antenna at
> one time.
>
> Therefore, if someone with a 100mw laptop is sitting in your front
> yard, your AP is going to use the omni, not the directional antenna,
> thus cutting out your link to the rest of the world.
>
> Am I reading wrong, or do I have my technical info wrong?
>
> Will.
>
> ---
> "They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety." -- Benjamin Franklin, 1759
>
>
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