Brad Ideas - Mesh network of cell phones when the towers go down - Comments

emergency cell phone operation

Mike Stull — Tue, 24 Oct 2006 09:18:27 -0700

Brad my partner and I developed a portable power source for charging personal electronic devices when the power fails or is unavailable for a friend that was in Miss. during Katrina I wanted to know if it was possible for the first responders, fire&rescue,fema and gov to commicate by cellphone using direct connect in a emergency situation It seems like a simple fix for interoperabilitly between different departments like police or fire or rescue personel to connected to each other without bandwidth problems or stepping on each others signal

How hard would it be to

Anonymous — Fri, 10 Feb 2006 18:03:38 -0800

How hard would it be to create a network of cellphones where each one was capable of routing calls as well as recieving calls. Could we not then do away with most cell sights and simply bounce calls from cellphone to cell phone? This would make each cell phone a cell sight and a switching center (call multiplexing, etc).

The easy answer to the

Nigel — Fri, 06 Jan 2006 14:47:31 -0800

The easy answer to the "islanding" problem would be for a message to only be sent onwards if the ID of the receiver was unique. If the message was passed back, then both phones would be told that the message hadn't got throguh yet, and would then continue trying to send the message to others that were new. This would further increase the odds of one of the phones getting through. Of course, it increases bandwidth a little and processing and storage overheads by an amount.

Might be tricky getting the ringback to say the message has been delivered, but normally it wouldn't be a problem, only in certain circumstances.

Peer to Peer SMS Article on O'Reilly

Brian McConnell — Sat, 05 Nov 2005 09:40:13 -0800

You might be interested in an article I wrote for O'Reilly in 2001. In this piece I proposed modifying phones to allow SMS relay. Mesh networking for voice is problematic for a number of reasons. However for SMS, you can implement a simple store-and-forward mechanism with best effort routing. It might take messages a while to escape an area that has been "islanded" but eventually they'll be delivered.

SMS Relay - An Idea For Fault Tolerant Communications

I like it

herr_theoretiker — Thu, 29 Sep 2005 20:42:26 -0700

Sort of a "cellular BitTorrent." It fits along with the decentralization of digital services that's been going on for a while now.

Photo

Hisham Elkadi — Thu, 29 Sep 2005 02:06:46 -0700

Dear Brad.. couldn't locate your e-mail address. Anyway, I wonder if I can use a low resolution photo of Shanghai for an academic publication. I need a very low resolution one. Would you give me permission? I don't get paid for this academic publication and I can put your name on it if you like...
Hisham

Professor H. Elkadi
Professor of Architecture
University of Ulster

Mesh network of cell phones when the towers go down

brad — Tue, 27 Sep 2005 21:42:53 -0700

Klein Gilhousen, one of the founders of Qualcomm, proposed this evening at Gilder’s Telecosm that cell phones be modified, if an emergency shuts down the towers, to do some basic mesh networking, not so much for voice, but for text messaging and perhaps pust-to-talk voice packets, as well as location information from their internal GPS if present.

Thus, in New Orleans, everybody would have been able to text in and out, at a battery cost to those who relay the messages to the working cell towers. Texting doesn’t require continuous connectivity. In time, of course, towers would be repaired or they could be flow in on blimps or choppers.

I suggested that in fact this could be a commercially viable service, allowing people to text who are beyond the range of cell towers, possibly quite a bit beyond the range. Operators could still charge for this. (Others, more cynical, felt operators would never want stuff in phones that made them usable without the carrier.)

He also suggested some simple improvements. During Katrina, people who did get their cell phones out of town could not make calls because the databases that let them roam were “under water.” The databases need to be backed up, or more simply during an emergency, switch so that unknown phones are allowed to make calls if their home system does not response, rather than blocking them.

This requires hardware mods, unfortunately (phones today can’t transmit and receive on the same bands) but otherwise is easy and could keep comms up in an emergency. A number of other cheap devices can keep power to phones.

Another person suggested phones have an ELT-like mode, where a person can enter a text message of the SOS form. Messages might indicate if the person is just advertising their location, or needs urgent help. Helicopters flying overhead could identify the phones, triangulate on them and locate all mobile owners who need rescue.