Relay-Stations for desaster regions

[Torsten Wagner]

Dear All,

I talked to a group of amateur radio guys as I said in some posts ago.
My idea was if there is a way to establish a bridge like
WLAN/Ethernet ----- ham (packet) radio ----- Ethernet. They conclusion
was that it might be technically possible. However, the speed achieved
over packet radio on longer distances is rather low. Taking into
account that many people on e.g., a shelter side try to access
simultaneously, this could be a real bottleneck and finally people
would run into "server timeouts".
The other problem is that there are very different radio regulation in
different countries, including different radio-frequencies for packet
radio. Some countries require that only people with an amateur radio
licences are allow to operate a packet radio station, others might
require special licences, etc. I wasn't able to figure out the
regulations in Japan. However, taking Japanese habits into account, I
would assume it require some licensing and it might be rather strict.
If we think a bit into the future. What might work now, might not work
elsewhere in the world and vice versa.

The final conclusion was to jump back to wifi. With a good focused
antenna set-up, some dozen of kilometres can be covered. However, it
would require "optical" visibility of both stations. Which means in
principle a straight line between both stations without buildings,
trees, mountains, etc. in between. On the other hand, the focused
antennas help to avoid any conflict with other wifi spots (remember
the number of channels is very limited for wifi).
This would need an high antenna set-up either on top of an building or
on some kind of (extension) mast (which might be problematic with
aftershocks).

I thought about a box mounted on a pushcart (remember they might need
to be installed on a roof and lifts might not work) containing 2-4 car
batteries, a very light extension mast (e.g. a fiberglas fishing rod,
but don't know whether this is stiff enough for a directional wifi
antenna), power converters (would only need DC since the wifiboxes use
DC only) one modified wifi station which would act as an bridge taking
signals from ethernet/wifi to send it over the directional antenna,
additional wifi boxes which could be installed a bit away from the
main station to enable good wifi connection. Cables to provide power
and Ethernet to those satellite wifi-boxes.
The idea with the satellite wifi boxes is due to the fact that the
main station might need to stand on a rather "stupid" place to get a
link with the other base station. Those satellite wifi boxes could
bring the signal down into halls and other designated places. An
additional solar panel might be useful to stretch battery life time.
Another thought is to create only one kind of station which could
easily without much effort act as either wifi-hotspot/bridge, repeater
or bridge/gateway station.
This redundancy might require more electronics, but would make the
system completely interchangeable and provide easily extensible and
much less maintenances at the final end.
Finally the systems should be maintainable from the web to allow
people to check for it without being physically available (not only
the internet part but also battery status, etc.)

Such a system could be easily transported and installed with an
minimum of effort. People in shelters I saw carried around plenty
laptops (people seems to leaving everything behind in their office but
taking
there laptops ;) ), smartphones, etc. They all could start
communication with friends and family as well as get information over
the web with such an system.

I got contact details for a small company specialized in directional
wifi bridging. Guess more ideas will follow from discussion there.

Maybe all this is some stuff for thoughts and if needed I could add
some of the stuff to the wiki

All the best

Totti

[Stuart Woodward]

On 4 April 2011 18:14, Torsten Wagner <torsten...@gmail.com> wrote:

> The other problem is that there are very different radio regulation in
> different countries, including different radio-frequencies for packet
> radio. Some countries require that only people with an amateur radio
> licences are allow to operate a packet radio station, others might
> require special licences, etc. I wasn't able to figure out the
> regulations in Japan. However, taking Japanese habits into account, I
> would assume it require some licensing and it might be rather strict.
> If we think a bit into the future. What might work now, might not work
> elsewhere in the world and vice versa.

These guys have been thinking about how to communicate in an emergency
in Japan since 1972: Tokyo International Amateur Radio Association. It
looks like they have a VoIP repeater network setup.

http://www.qsl.net/7j1yaa/

Stuart

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[Kalin KOZHUHAROV]

On Tue, Apr 5, 2011 at 08:15, Stuart Woodward <stu...@stuartwoodward.com> wrote:
> On 4 April 2011 18:14, Torsten Wagner <torsten...@gmail.com> wrote:
>
>> The other problem is that there are very different radio regulation in
>> different countries, including different radio-frequencies for packet
>> radio. Some countries require that only people with an amateur radio
>> licences are allow to operate a packet radio station, others might
>> require special licences, etc. I wasn't able to figure out the
>> regulations in Japan. However, taking Japanese habits into account, I
>> would assume it require some licensing and it might be rather strict.
>> If we think a bit into the future. What might work now, might not work
>> elsewhere in the world and vice versa.
>
> These guys have been thinking about how to communicate in an emergency
> in Japan since 1972: Tokyo International Amateur Radio Association. It
> looks like they have a VoIP repeater network setup.
>
> http://www.qsl.net/7j1yaa/
>

Well those networks are only _directly_ accessible to licensed hams (slang
for amateur radio geek). There are a couple of international organizations and
a bunch of many local that help in disaster when communication network is down.
They have trainings, field days etc.
The JARL (Japanese Amateur Radio League) is co-ordinating the efforts in the
region and they seem to have made quite a progress (page in Japanese, see maps):
http://cacplan.jp/ja3lxj/tizueq-jititai.html
They have quite a few repeaters in the area as well as portable stations
and some mobile (car/bike mounted) that travel and relay weaker signals.
JARL has coordinated with makers the distribution of 300 free handy transceivers
to licensed hams in the area.

So, if there are other licensed hams in THS we can probably help a bit, but for
one reason or other amateur radio requires licensing.

73 DE LZ2SAF/JA AND KF6UTZ/JA QTH Minato-ku OP Kalin.

[sonicviz]

Today: Telecoms networks back / 90% of cell phone base stations, land
lines restored in disaster-hit areas
http://www.yomiuri.co.jp/dy/business/T110404003785.htm

Not bad, in just over 3 weeks...