RF and DTN networking

JDH services jaydeeaich at gmail.com
Thu May 6 07:51:48 EDT 2010

Hello every one!

I'm working on developing a low-power Delay Tolerant Network.

For those that don't know what Delay Tolerant Network is:

My idea is to have small device that people carry on them. As the user
goes about their day, they will move among different groups of people
and these movements with be fairly regular. (Going to work everyday,
visiting your grandmother of the weekend, etc.) keeping track of which
nodes it sees and when it should be possible to identify these
patterns. It should be a small-world network and this network should
be similar to the socio-network. So it should be easier to find routes
between people that are better associated with and assumingly people
will be more likely to communicate with people people they are better
associated with.

The other part of the network would energy harvesting(solar,wind)
Relay Stations that would be connect to other(through WiFi, Ethernet,
direction antennas) and/or have a large amount of storage so it can
take custody of several messages at once.

The devices would form P2P mesh networks that world allow
conversational connections. These would be used to  allow streaming
voice communication and transfurs between gateways.

 My first thought was to layer it on top of Zigbee, but Zigbee lacks a
P2P architecture and it is proprietary.
I then looked at making my own stack on top of IEEE 802.15.4.
Wolfgang told me that they are evaluating HopeRF's RFM12B. it only
goes up to 115.2 kbps in digital mode thou with an external RC filter
highest data rate is 256 kbps data rate, but the FIFo can not be used
in this mode and clock is not provided for the demodulated data.

HopeRF's new modules like the RFM22B look nice with 256 kbps data
rate.  I just started looking into the lower layers of RF
communication and am not sure about compatibility of the radios with
radios from other companies  Being out of WiFi's frequency range seems

Jennic's JN5148 looks interesting it has a interface for a audio CODEC
so I might be able to make a small communicator without adding another
processor and it has a ranging engine which might be good for
predicting contacts and mapping the network. They use GCC toolchain
which is nice But they operate at in the 2.4GHz band.

I'm still checking on some potential cultural issues on the project
name. But if all goes well it will be

Panthera Tigris Altaica

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