River Song's Post TU Telephone Network (PBX)

[River Song]

Following on from my previous thread, I thought I would start a new one. This one now runs ok and so the preliminary discussions in the previous thread are now moot.

So at long last - Part One of the Manual

Download Here

Do enter the discussion.

Part 2 will deal with connecting this to the outside world
and part 3 will look a wide area considerations.

Allons-y

[River Song]

Anyone?

[Devonian]

Well it looks like you've put a lot work and effort into it which is very impressive.

I may be missing something (as I haven't read all of your information), but given the limited range of the system what are benefits of this over say a set of 2 way radios or even cheap walkie talkies which do not rely on the power or phone network still being up?

[Smiffy]

Thats some good work there River Song.

Communication is one area I think gets overlooked by a lot of people because it is "too complicated" which is a shame because good information can be vital.

Not being very technically minded myself, but is it possible to link a number of wireless hubs to extend the range ?

[River Song]

Devonian - thanks for your comments.

Once the system is in place. I'm now working on extending the area.

The scenario is a single village where we try to get everyone covered as possible within the village. Once that is done, we also try connecting one village to another with the same setup.

A set of 2 way radios is fine enough and will probably cover a greater distance. However it remains a one-to-one communications system, needs a licence in pre-TU situations and needs a certain technical skill. I mean have you tried to program a UV-5R?

Imagine if you will trying to build a simple communications infrastructure in the middle of Africa. In a post-TU situation, this is what we may have to contend with. Start all over again.

This system does not rely on the phone network. It BECOMES a new phone network. It does not rely on the Internet (although whilst its there it gives us wide coverage).

Radios require power as well to charge up. The PBX requires 5v at 0.75 amp.

I'm sure someone can tell me how to provide that.

Allons-y

---

Smiffy - Thanks

I am working on range extenders. Connecting commercial hubs would probably not do it as they would be seen as seperate networks. Could be done I guess.

I'm working on two ways to extend.

Repeaters - cheap enough I guess

Meshed Access points. These would provide a WiFi access point but would 'MESH' together with other access points and the PBX.

Watch this space

Allons-y

[Lightspeed]

Very thorough and well written description RS. Thank you.

A couple of thoughts:

Answering Devonian's comments. Yes 2 way radio will out perform this system, but relies on there being enough radios to keep everyone connected. I would guess thatthere are far more wifi routers installed than there are 2 way radios.

Again from Dev's question. The big weakness of this idea in a grid down environment is power. How the Wi-Fi routers will be powered in a grid down environment needs to be addressed.

Range of Wifi is critical to this network's success. Range can be increased simply by getting the WiFi router and its antennas high up in a building, Sitting the router high in the loft with an extension antenna popped out onto the roof through the roof tiles should enhance things no end. One of these will do the job for little money:
http://www.ebay.co.uk/itm/WIFI-2-4GHZ-7-...51bc2b7fd3

Effectiveness of an external antenna mounted high and in the clear will be easy to assess. Simply look at the list of SSID and the number of signal bars on each of them before re-siting and extending the antenna, and than do the same afterwards. The difference should be considerable.

Thanks again RS. Good job

[River Song]

LS - Thanks.

I'm working on range extension - power is a problem
but as I said, the pbx takes 5v at 0.75 amp.

The router takes more of course. In a grid-down situation, I expect the router to be superfluous to requirements. There would be no outsode networks that we could connect to.

That's why I'm working on Wifi access points that can be 'high up'.

On the top of the church tower would be nice !!

Putting an aerial through the roof is an good idea BUT it requires a WifI dongle that has an external aerial connection.

[Lightspeed]

Powering that PBX will be rather easy. 5v 0.75a is USB standard, so any USB port that'll run from your chosen off grid power source will do the job. 12v and 24v USB charger ports are widely available and inexpensive.

USB Hot voltage standard is:

Signal
5 volt DC

Max. voltage
5.00±0.25 V (pre-3.0); 5.00+0.25-0.55 V (USB 3.0)

Max. current
0.5–0.9 A (general);
5 A (charging devices)

[Devonian]

OK, thanks RS/LS makes more sense now, though probably limited benefit for a Billy no Mates like me

So assuming that you can power the PBX and Router, would this system still work if the local BT exchange had no power?

[River Song]

Devonian

Yes it would work. Assuming BT was down, then all of your 'extensions'. i.e. smartphones and desktop based sipphone programs would still be able to talk to each other.

Having said that - with 'no mates' its a bit difficult.

You're never alone with schitzophrenia