Page 3 of 4 12 3 4
Reply
Thread Tools
Wikiwide is offline Wikiwide
2010-11-26 , 00:37
Posts: 2,006 | Thanked: 3,351 times | Joined on Jun 2010 @ N900: Battery low. N950: torx 4 re-used once and fine; SIM port torn apart
#21
Originally Posted by justice4all3000 View Post
That is the best idea I have seen in ages however im very sure that cellular transmission software in all mobiles is closed source
In MeeGo and OpenMoko it should be open-source.

I'm not the first to offer it, Wikipedia says:
http://en.wikipedia.org/wiki/TerraNet_AB
http://news.bbc.co.uk/2/hi/technology/6987784.stm

Year 2007.
What is with it now?

There are only TerraNet test networks in operation today. There is at least one commercial implementation planned during 2008, and we will publish more information here on TNMC at a later date.

There are no productified handsets available ‘on the shelf’ or in production at this time. The technology itself is developed, demonstrated in a laboratory environment and in test networks, and is already included in implementation projects that are scheduled for completion in 2008.

Congestion, or traffic overload, can happen in any mobile phone network where the use of the network is excessive, or where the network is not scaled to fit the amount of users. There is of course a limitation as regards the data flow in each TerraNet handset. The TerraNet technology strives to distribute the traffic over the full network to minimizing the risk of congestion, by e.g. using TerraNet HelperNodes to offload the handsets’ load of forwarding.

The latest news:
2009-09-01

But, the site it alive, therefore they continue to pay for it, therefore they continue to work.

Mobile phone manufacturer Ericsson had invested around £3m in TerraNet around 2007.
Panda Electronics
http://www.panda.cn/SJTCMS/html/pand...4967040601.asp
 
qwazix's Avatar
qwazix is offline qwazix
2010-11-26 , 01:10
Moderator | Posts: 2,622 | Thanked: 5,447 times | Joined on Jan 2010
#22
Originally Posted by Wikiwide View Post
Quick question...
Why cannot cellular frequency be used without cellular towers, in peer-to-peer style?
Like: you send SMS, it's regularly broadcasted to all phones within reach, they re-broadcast it regularly, it's received by the end recipient, it replies instantaneously with "Message X received, stop shouting", they broadcast messages "Message X received by the end recipient, stop shouting" to everybody, when sender receives this message, he knows that message is received and stops sending it.
It has large potential for an avalanche, but utilizes no costly cellular towers. If you send/receive messages rarely and place calls once in a month, the P2P network will be underused.
It works better when the density of phones is high enough to be reliable and low enough to prevent an avalanche.
I'm positive I saw some news about an android app created in a university that did that but I can't find it now. It wasn't a market app of course, and I'm not sure it was even released.
________
COLORADO DISPENSARIES
Last edited by qwazix; 2011-08-21 at 10:44.
 

The Following User Says Thank You to qwazix For This Useful Post:
Wikiwide is offline Wikiwide
2010-11-26 , 03:20
Posts: 2,006 | Thanked: 3,351 times | Joined on Jun 2010 @ N900: Battery low. N950: torx 4 re-used once and fine; SIM port torn apart
#23
Originally Posted by Wikiwide View Post
Quick question...
Why cannot cellular frequency be used without cellular towers, in peer-to-peer style?
Like: you send SMS, it's regularly broadcasted to all phones within reach, they re-broadcast it regularly, it's received by the end recipient, it replies instantaneously with "Message X received, stop shouting", they broadcast messages "Message X received by the end recipient, stop shouting" to everybody, when sender receives this message, he knows that message is received and stops sending it.
It has large potential for an avalanche, but utilizes no costly cellular towers. If you send/receive messages rarely and place calls once in a month, the P2P network will be underused.
It works better when the density of phones is high enough to be reliable and low enough to prevent an avalanche.
And, you could attach to the message a location tail where you expect the recipient to be so that intermediate nodes broadcast more frequently when closer to this location (using cellular triangulation/GPS to find it out).
 
theonelaw is offline theonelaw
2010-11-26 , 03:33
Posts: 671 | Thanked: 1,630 times | Joined on Aug 2010
#24
Originally Posted by Wikiwide View Post
Quick question...
Why cannot cellular frequency be used without cellular towers, in peer-to-peer style?
Like: you send SMS, it's regularly broadcasted to all phones within reach, they re-broadcast it regularly, it's received by the end recipient, it replies instantaneously with "Message X received, stop shouting", they broadcast messages "Message X received by the end recipient, stop shouting" to everybody, when sender receives this message, he knows that message is received and stops sending it.
It has large potential for an avalanche, but utilizes no costly cellular towers. If you send/receive messages rarely and place calls once in a month, the P2P network will be underused.
It works better when the density of phones is high enough to be reliable and low enough to prevent an avalanche.
Really cool thought, but you need a population of phones with the
same code in them.

However, Your Truly Magnificent Idea leads to another thought,
just being able to send an SMS by itself would be brilliant,
because the problem with WiFi or Bluetooth is distance,
whereas the lower frequency GSM bands (800-900mhz)
have much more penetration than the higher ones (1800-1900mhz) and the FM transmitter is quite weak.

Sending an SMS across a couple of km without needing
a carrier to handle would be a killer app.
It would be a showstopper for network carriers.
You would see the n900 banned, outlawed, and people who
had it would need "carry permits".

Reason I am bumping this though is I have big problems maintaining
a massive wifi network through a very serious rainforest,
and the bottom line on NLOS data transfer is that wifi
can only do so much in the trees before the signal dies off.
We have places where we can get distant GSM signals with
handphones where our supercharged wifi systems working at
2400mhz with heaps of watts and focused beams cannot go.
I can park at a long distance in clear line of sight of one of our
towers and connect wirelessly over considerable distances,
but the helicopter time is too expensive.
It would be an amazing feat to get phones that could
transmit simple text messages over some distance,
through trees and other NLOS obstacles,
even if it were only point-to-point.

With a 6m limit on FM and 30m limit on Bluetooth,
the GSM radio would be the best way to go for peer-peer
handset communication.

Originally Posted by justice4all3000 View Post
That is the best idea I have seen in ages however im very sure that cellular transmission software in all mobiles is closed source
However, if you could run a dual sim card and
somehow create a second sim card as a carrier-less account
and make it work on the low-frequency range,
then it becomes conceivable perhaps.

A sim card is merely an obstacle,
there are ways to triggger an sms once you have a channel set up,
I read it somewhere, it is in C if I remember correctly...
__________________
Three n900s: One for stable working platform,
One for development testing Chopping Onions
One for saltwater immersion power testing resurrected ! parts scavenging

My Mods for Wonko's Advanced Clock Plugin:
ISO8601 clock mod and Momental_IST clock mod

Printing your Email with the N900
 

The Following User Says Thank You to theonelaw For This Useful Post:
Wikiwide is offline Wikiwide
2010-11-26 , 04:23
Posts: 2,006 | Thanked: 3,351 times | Joined on Jun 2010 @ N900: Battery low. N950: torx 4 re-used once and fine; SIM port torn apart
#25
Originally Posted by theonelaw View Post
Really cool thought, but you need a population of phones with the
same code in them.

However, Your Truly Magnificent Idea leads to another thought,
just being able to send an SMS by itself would be brilliant,
because the problem with WiFi or Bluetooth is distance,
whereas the lower frequency GSM bands (800-900mhz)
have much more penetration than the higher ones (1800-1900mhz) and the FM transmitter is quite weak.

Sending an SMS across a couple of km without needing
a carrier to handle would be a killer app.
It would be a showstopper for network carriers.
You would see the n900 banned, outlawed, and people who
had it would need "carry permits".

Reason I am bumping this though is I have big problems maintaining
a massive wifi network through a very serious rainforest,
and the bottom line on NLOS data transfer is that wifi
can only do so much in the trees before the signal dies off.
We have places where we can get distant GSM signals with
handphones where our supercharged wifi systems working at
2400mhz with heaps of watts and focused beams cannot go.
I can park at a long distance in clear line of sight of one of our
towers and connect wirelessly over considerable distances,
but the helicopter time is too expensive.
It would be an amazing feat to get phones that could
transmit simple text messages over some distance,
through trees and other NLOS obstacles,
even if it were only point-to-point.

With a 6m limit on FM and 30m limit on Bluetooth,
the GSM radio would be the best way to go for peer-peer
handset communication.



However, if you could run a dual sim card and
somehow create a second sim card as a carrier-less account
and make it work on the low-frequency range,
then it becomes conceivable perhaps.

A sim card is merely an obstacle,
there are ways to triggger an sms once you have a channel set up,
I read it somewhere, it is in C if I remember correctly...
For jungles, try OpenBTS.
http://en.wikipedia.org/wiki/OpenBTS
It will give you mobile phone service without a conventional GSM basestation system.

SIM card without a carrier sounds interesting.
 

The Following User Says Thank You to Wikiwide For This Useful Post:
Wikiwide is offline Wikiwide
2010-11-27 , 00:41
Posts: 2,006 | Thanked: 3,351 times | Joined on Jun 2010 @ N900: Battery low. N950: torx 4 re-used once and fine; SIM port torn apart
#26
Quick reply...
Is it a possibility to send SMS through your own SMS centre bypassing normal service providers?
Conversations->Settings->SMS centre number
Maybe, you could set up laptop at home to receive SMS as SMS centre, and to send them through your PC Internet connection for free (you know, websites which allow you to send SMS for free). Then set SMS centre number in your N900 to laptop's number, and send SMS through Internet for free.
Or, if you are good at compiling, compile SMS centre at your N900 and set its number as SMS centre. Then N900 would use its own SMS centre and try to send SMS directly to any nearby (several kilometers) phone.
I just don't know. It's the strangest setting I have ever seen.
 

The Following User Says Thank You to Wikiwide For This Useful Post:
theonelaw is offline theonelaw
2010-11-27 , 02:10
Posts: 671 | Thanked: 1,630 times | Joined on Aug 2010
#27
Originally Posted by Wikiwide View Post
Quick reply...
Is it a possibility to send SMS through your own SMS centre bypassing normal service providers?
Conversations->Settings->SMS centre number
Maybe, you could set up laptop at home to receive SMS as SMS centre, and to send them through your PC Internet connection for free (you know, websites which allow you to send SMS for free). Then set SMS centre number in your N900 to laptop's number, and send SMS through Internet for free.
Or, if you are good at compiling, compile SMS centre at your N900 and set its number as SMS centre. Then N900 would use its own SMS centre and try to send SMS directly to any nearby (several kilometers) phone.
I just don't know. It's the strangest setting I have ever seen.
I have been following your link to OpenBTS
and as I read it the phone radio firmware is probably locked
into needing a BTS to camp on.

The open BTS way sounds completely workable though.

As the radio firmware is probably one of Nokia's darkest secrets
it may be impossible to find a way to actually drive the radio
to to call/sms another radio without going through a BTS.
Just guessing - never really studied GSM before this.

I guess probably the easiest thing to do, if it can be done at all,
would be something like the following:

Pure guesswork here - invitation open for a GSM guru
to step in and correct all this:

1. Monitor the radio for beacons from handphones that can be reached
- build a list of handphones known to be in-range + known handphones (friends).
(how do we do this? I don't see any way to pull that off unless
the radio traffic can be monitored somehow - I suspect not,
but then you never know till you dig into the code.
The unit does scan-monitor for BTS units when signal is lost,
so if it could be tricked into listening for handset beacons, then...)
This is complicated because as I read it the phones are
split off into different frequencies and allotted time slots?
Your list then would be:
cell_number frequency timeslot A-Key?

2. There is probably a transmission header that needs to be
spoofed or perhaps simply copied and pasted
if the intent is to send SMS or transcieve with a unit that
thinks it is logged into a particular BTS or tied to a specific carrier.

3.
There is an encryption handshake that goes on between the
BTS and the handset to establish linkage - not sure yet
whether it is same for voice and SMS
This your handset would need to perform with the other handset.

4. I give up here for the moment.
__________________
Three n900s: One for stable working platform,
One for development testing Chopping Onions
One for saltwater immersion power testing resurrected ! parts scavenging

My Mods for Wonko's Advanced Clock Plugin:
ISO8601 clock mod and Momental_IST clock mod

Printing your Email with the N900
 

The Following User Says Thank You to theonelaw For This Useful Post:
TiagoTiago is offline TiagoTiago
2010-11-27 , 03:09
Posts: 1,522 | Thanked: 392 times | Joined on Jul 2010 @ São Paulo, Brazil
#28
A while ago, i think it was on the IRC channel, there was someone talking about how they had used a SIP server (i think it was running on a N900, though there might have been a laptop and/or a WiFi router involved) to call other SIP+WiFi enabled devices, i think this was done while camping, creating their own little SIP network while they were there.
__________________
NOKIA N900: IT'S OVER NINE THOUSAND


How to use HotspotShield in the N900
Google Voice from outside the US + Free international calls: LEARN HOW HERE!!!
 

The Following 2 Users Say Thank You to TiagoTiago For This Useful Post:
Wikiwide is offline Wikiwide
2010-11-27 , 04:28
Posts: 2,006 | Thanked: 3,351 times | Joined on Jun 2010 @ N900: Battery low. N950: torx 4 re-used once and fine; SIM port torn apart
#29
Originally Posted by TiagoTiago View Post
A while ago, i think it was on the IRC channel, there was someone talking about how they had used a SIP server (i think it was running on a N900, though there might have been a laptop and/or a WiFi router involved) to call other SIP+WiFi enabled devices, i think this was done while camping, creating their own little SIP network while they were there.
There is Asterisk PBX workable on N900 or a laptop. What does it do? It seems that it allows attached telephones to call to each other.

When a phone connects to Asterisk server, using login and password, Asterisk finds corresponding number in conf file, and then any phone attached to Asterisk can dial this phone using this number.

As N900 supports SIP calling out-of-the-box, the main question would be how difficult it is to get SIP client and Asterisk server talking with each other on the same machine. Though Wi-Fi should be able to be used by several programs at the same time in all directions.

https://wiki.asterisk.org/wiki/displ...p+Applications

Asterisk can also connect to cellular network. But it seems that it isn't working like BTS, though I'm not sure.

Originally Posted by theonelaw View Post
I have been following your link to OpenBTS
and as I read it the phone radio firmware is probably locked
into needing a BTS to camp on.

The open BTS way sounds completely workable though.

As the radio firmware is probably one of Nokia's darkest secrets
it may be impossible to find a way to actually drive the radio
to to call/sms another radio without going through a BTS.
Just guessing - never really studied GSM before this.
Very well, can an open BTS be compiled on N900?
It should be possible, because MeeGo should be completely open, and MeeGo works on N900.
When BTS works on N900, can N900 use it for transmitting its own SMS aka through SMS center? It's most likely impossible because one antenna would have to transmit and receive at the same time. Or it might be possible by telling BTS to use external headphones antenna.
Is SMS centre also used for phone calls? It would simplify switching N900 to an alternative BTS.
Besides, if certain frequency supported by N900 isn't used by telephony in your region, but isn't used by any other service either, then BTS would have much less interference with existing towers.

Just throwing in some ideas...

Hoping some GSM guru will come and tell whether it's implementable and possibly code a basic program.
Last edited by Wikiwide; 2010-11-27 at 05:59.
 

The Following User Says Thank You to Wikiwide For This Useful Post:
theonelaw is offline theonelaw
2010-11-27 , 06:19
Posts: 671 | Thanked: 1,630 times | Joined on Aug 2010
#30
Originally Posted by TiagoTiago View Post
A while ago, i think it was on the IRC channel, there was someone talking about how they had used a SIP server (i think it was running on a N900, though there might have been a laptop and/or a WiFi router involved) to call other SIP+WiFi enabled devices, i think this was done while camping, creating their own little SIP network while they were there.
Good point - we have tried SIP on the n900 over our lan here
using LinPhone on other machines and it works ok.
It is true peer-to-peer and needs no server on the linphone side.
The n900 needs a server though as the Nokia implementation
assumes SIP requires an account, a rather Neanderthal obstacle.

(We can even use it over GSM but for that we need a carrier account.)

However - the connection was through Wifi.

What we want is through the GSM radio in the 900mhz area.
__________________
Three n900s: One for stable working platform,
One for development testing Chopping Onions
One for saltwater immersion power testing resurrected ! parts scavenging

My Mods for Wonko's Advanced Clock Plugin:
ISO8601 clock mod and Momental_IST clock mod

Printing your Email with the N900
 

The Following User Says Thank You to theonelaw For This Useful Post:
Reply
Page 3 of 4 12 3 4

« Previous Thread | Next Thread »
Thread Tools

 
Forum Jump


All times are GMT. The time now is 09:29.

Contact Us - Home - Archive - Top