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Handhelds Hardware

Peer-to-Peer Cell Phones? 216

Posted by michael from the telephone-tag dept.
Mike writes "This Wired article mentions that research firm SRI International has come up with a nifty way to lessen the need for the ugly cell towers that you see popping up everywhere (I love the ones here in Atlanta that are oh-so-cleverly dressed up to look like pine trees). Their PacketHop software would create a sort of peer-to-peer network, utilizing the unused power in phones in the vicinity as miniature relays, with your voice/data hopping from one phone to the next until it reaches a relay tower and its final destination."
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Peer-to-Peer Cell Phones? More

Peer-to-Peer Cell Phones?

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  • And on behalf of everyone... (Score:5, Insightful)

    by brogdon ( 65526 ) on Friday June 14, 2002 @05:28PM (#3704101) Homepage
    Let me just say that these people would have to provide some pretty serious security credentials before I'd let my calls hop along other people's phones. Maybe they could PGP each person's phone. That'd be cool.
    • I agree there. It's already bad enough that people can steal people's phone calls, but then having to worry about the security of everyone's phone? Ick. And then what about if there are not enough phones to keep the link up? Does our call just magically drop into oblivion?

    • Re:And on behalf of everyone... (Score:1, Funny)

      by Anonymous Coward
      Hmmm..... I like all my conversation with my wife and girlfriend(s) to be routed to strangers first.

    • Re:And on behalf of everyone... (Score:5, Insightful)

      by Beryllium Sphere(tm) ( 193358 ) on Friday June 14, 2002 @05:40PM (#3704174) Journal
      Either your call is encrypted or it isn't.

      If it isn't, then any phone within range can pick up your call anyway.

      If there's solid encryption all the way to the wired network, then it doesn't matter if the call hops through the cellphone of the lawyer of your ex-spouse.

      Reminds me of a recent idea (was it from Cringely?) to equip new cars as wireless repeaters.
      • I'd support that idea, and the p2p idea for a small $ recompense. Be it a discount on monthly service fees or a flat discount on the car. But I remove the license plate frame unless the dealer offers 2% off.

  • can't wait (Score:1, Redundant)

    by NMerriam ( 15122 )
    will be great fun once the packet-sniffers are available...

  • Batteries (Score:3, Insightful)

    by Quixotic137 ( 26461 ) <pjennings-slashd ... t ['jen' in gap]> on Friday June 14, 2002 @05:29PM (#3704105) Homepage
    My cell phone battery goes dead soon enough without transmitting data for other people.

    • Re:Batteries (Score:5, Insightful)

      by Beryllium Sphere(tm) ( 193358 ) on Friday June 14, 2002 @05:45PM (#3704208) Journal
      If you only need enough power to reach the nearest peer, instead of enough to reach the tower, your battery might last longer.

      Covering distance in multiple hops is more power-efficient overall than going all the way in one hop. The math is easy to see for inverse-square, and cellphone signals drop off faster than inverse-square due to absorption.

      If you're not mathematically oriented, imagine the battery drain if there were only one tower in your city and your phone had to reach it from everywhere.

      • Re:Batteries (Score:3, Insightful)

        by frovingslosh ( 582462 )
        I certainly agree that overall there would be a savings in battery power with this technique, but issues still exists that would cause individual opposition. The most obvious is that while users would welcome and eventually expect the ability to make lower power calls (assuming they understood this at all), they would still resent others using their batteries. A more reasonable concern is that those who carry the phones only for "emergencies", and who really want the battery to be available if they do need to use the phone, would oppose subsidizing those who seem to live on their cell phone.

        • Re:Batteries (Score:3, Interesting)

          by Arethan ( 223197 )
          So turn it off. If you only use it for emergencies then you shouldn't care whether it is on or off, since you don't make or take calls on it unless there is an emergency.

          There is a very distinct difference between stand-by and off. One still uses battery power, the other does not. Making the network peer to peer doesn't make your phone use power while it's shut off.

          And I don't know what kind of phone you're using if it doesn't still try to check back with the tower every few seconds while in stand-by. Mine sure as hell does. Going underground all day? Then you'd better turn your phone with a "3 day stand-by" off, or else it will be flat dead in under 8 hours. A peer to peer network wouldn't cause this, as each only tries to talk to nearby phones, which in most cases would get your signal back topside within a few hops.

          Realistically, I'd question the scalability. I'd SERIOUSLY question the scalability. Gnutella is peer to peer, and it doesn't scale well at all. Even with UltraPeers (peers that actually act more like routers), the network still uses a HELL of a lot of bandwidth. Even when you throw out the power consumption issue, the processing power and bandwidth issues come up.

          This is a very interesting idea, though I can't say that I haven't already heard of it. Still, if they can put together 1000 units, and make it work for a week inside of a single building, I'll be impressed.
          • So turn it off. If you only use it for emergencies then you shouldn't care whether it is on or off, since you don't make or take calls on it unless there is an emergency.

            If you could conveniently schedule your emergencies that would work fine. But many people (think they) need that phone to receive emergency calls. Imagine being in charge of a real time mission critical system at work, and your office couldn't reach you because you had to turn off your phone so the battery wouldn't die. Or being a doctor on call, or just needing to be able to be reached when your wife goes into labor. Unfortunately, not all "emergencies" are outbound.

            And I too have lots of doubts that it would work, even if customers didn't fight it.

      • or die sooner. you talk on your phone, say, 1/2 hour a day. That's 1/2 hour of transmitting to, say, a transmitter far away.

        Now you serve as a relay, and relay, say 10 hours a day to a cell phone near you. Granted, you use less power, but transmitting is wa-a-ay more expensive in terms of power than being idle.

        I say, use the battery meter to determine whether a particular phone is connected to an external power source, and, if so, make it the more likely candidate to act as a relay than my poor phone with 5 minutes of talk time left for emergencies that I try not to use (say, I'm climbing some glacier, and don't have a power outlet around to recharge).
      • That would be correct if the current consumed was proportional to the RF power emitted, but that's not quite right. Even at low powers, you still have to power up the oscillators, filters, mixers, and the baseband processing. You also lose the benefit of a super-duper receivers in the tower that allow them to be exceptionally sensitive and use less TX power (unless you enjoy carrying around one of these [neiu.edu])

  • Waste of battery power (Score:1)

    by Anonymous Coward
    If your phone happened to be a popular hop, it seems like it'd suck your batteries right down.

    No thanks.

  • What do you do in secluded areas? (Score:5, Insightful)

    by billstr78 ( 535271 ) on Friday June 14, 2002 @05:33PM (#3704125) Homepage
    If the number of cell towers were reduced and relied on proximity to other cell phones for a signal, would'nt that reduce the likleyhood of someone getting a connection in someplace like a national park or the Mojave Desert? People away from people need to talk to other people too!
    • Not if the nearest tower were configured to look like a "peer" -- then your phone would find it and talk to it.
    • Every year the National Park Service spends millions rescuing idiots who do stuff like decide to hike to the bottom of the Grand Canyon with a cell phone but no water bottle.
      Without wireless service in secluded areas, people who deserve to become statistics will do so without a hitch, rather than getting helivac'd out at the last minute because they happen to have their trusty microwave-emitting companion along.
      Anyways, who the heck goes to an isolated area to talk on the phone?
  • What would this kind of technology do to my standby battery life?

  • Gah. (Score:5, Insightful)

    by TheSHAD0W ( 258774 ) on Friday June 14, 2002 @05:33PM (#3704127) Homepage
    Yeah, it's possible. Of course, it'd mean your cell phone's battery would run down within a matter of hours as it relayed other people's conversations around. I'd guess a lot of people would "hack" their phones to not act as relays, so as to conserve battery life. The result would be a breakdown of the network.

    The multiple relay idea isn't such a bad idea, though, if you move the relays out of the phones and onto the power grid. How 'bout if everyone who got a phone also plugged in a base station at their house? That piece of hardware would do the relaying instead. Then battery life wouldn't be a problem. Offer a few people free service if there are dead spots in the neighborhood.

    Add on another feature; plug the relay into your phone line, and when you're at home or near it, your cell phone becomes a cordless phone (like in L. Neil Smith's book Hope [lneilsmith.com].
    • Aw come on,
      My cell with the lith-ion battery has a standby of about 48 hours. It came free with my AT&T cellular service (yeah, a contract.. which is already up), it's just a cute little ericson full-sized. Yeah, the mini ones run out faster (AMAZING!), smaller batteries and all.

      May I also point out, that at no point is your phone truly 'idle' It's sending packets to the nearby cell tower going 'here I am' every once an awhile anyway, and it's always actively scanning the signals it recieves for the messages that are intened for it. So yes.. this will affect the battery life on a phone, yes if you want to get by with an ancient phone (older than 2 years) it'd suck. No, this technology isn't Implemented in those phones, so they could neither benefit nor suffer from this service.

      In cities, where I have trouble getting a signal on the sidewalk (too much concrete, no line of sight), being about to bounce a signal off other phones would be awesome!

      so far as security goes, no more, no less, than a wireless is now. the fact that the broadcast power would be lesser might even help, would get the signal closer to the ultimate in secure transmission, a Beam.

      -GiH

      • Re:Aw come on (Score:4, Informative)

        by TheSHAD0W ( 258774 ) on Friday June 14, 2002 @05:52PM (#3704251) Homepage
        Heh.

        Yes, it sends packets every once in a while.

        Thing is, your battery has a standby time of 48 hours, but a talk time of what? 1 hour? 90 minutes? Most of that power isn't going to sound circuitry, it's going to the radio, and if your phone is busy relaying a call that radio will be pulling just as much power.

        • Re:Aw come on (Score:3, Interesting)

          by GodInHell ( 258915 )
          Thing is, your battery has a standby time of 48 hours, but a talk time of what? 1 hour? 90 minutes? Most of that power isn't going to sound circuitry, it's going to the radio, and if your phone is busy relaying a call that radio will be pulling just as much power.

          Ah, not just a radio, a powerful radio (relatively speaking), with a shared resources system, the signal strength could be lowered, less drain on the battery, the signal range need only be as great as the distance between you, and the next phone over.

          Which is where my whole point of sending a straighter signal comes in, rather than a wide area power wasting brute force attempt (pump enough juice into the transmitter to reach the tower), the range of your signal can be lessened to less than a few dozen feet in an urban enviroment. Pico-cells. Each one supports the other cell callers further from the nearest cell, extending in a chain of small spheres back to the tower, rather than one large sphere that wastes all kind of energy sending random radiation off in all directions as far as it can reach.

          -GiH
          There is no Sig.

          • Completely unworkable (Score:4, Insightful)

            by Subcarrier ( 262294 ) on Friday June 14, 2002 @06:24PM (#3704415)
            Each one supports the other cell callers further from the nearest cell, extending in a chain of small spheres back to the tower, rather than one large sphere that wastes all kind of energy sending random radiation off in all directions as far as it can reach.

            The biggest factor in power expenditure is the ability to put the device into standby mode. The transmission power has relatively little relevance. If the device has be a routing node in a mesh network, it can never go into standby. Even if there is no traffic to forward, it will have to keep exchanging routing information with its neighours, in order to be *able* to forward traffic. This will suck the battery dry in a matter of hours.

            Not to mention the other equally inexplicable down sides:
            1) security - intermediate nodes can tap your calls
            2) security - intermediate nodes can reroute or prevent your calls
            3) quality - packet loss for a number of consequtive wireless links would be stupendous
            4) quality - cumulative delay from a number of consequtive links would be disastrous (more so, if link layer retransmissions were used to improve packet loss)
            5) you've got no neighbours, you've got no calls - where do you get the people who are willing to stand in a chain between you and the tower, while you yabber on with your girlfriend?
            6) would you pay for that service? Would you trust the intermediate nodes to meter your call? Might be a few surprises in store when the bill arrives...
    • Add on another feature; plug the relay into your phone line, and when you're at home or near it, your cell phone becomes a cordless phone

      I had a cell phone that came with a small base station that I plugged into my regular phone line. If someone called me on the cell number and I was within range of the base station, it would still ring the cell phone but connect via the base and I'd have no airtime charges. If I made a call from the cell, same thing.

      The cell service was through the same company I had my regular phone service with. The thing I never thought of at the time is that I was never clear on what happens if I'm already on one of the lines and someone tries to call from/to the other line.
    • How 'bout if everyone who got a phone also plugged in a base station at their house?

      Or, as Bob Cringeley suggested, your car [pbs.org].
      Your cell phone carrier could say: your service will cost $X a month, or it will cost $X-Y a month if you get a relay installed in your car or home.

      "What Ever Happened to Fair Use?! ...HOOOooYAH!!" - Duff Man
      • The biggest problem with using a car phone would be car battery use. I suppose you would have the engine charge a separate battery dedicated to the phone, but you'd still have to maintain it one way or the other.

        It sure would be useful to have cells wherever cars are, since that maps very well to where mobile phone users are.

        Personally, I wish cellphones had never left the car. Car phones can be convenient, but being interruptable anywhere strikes me as a poor idea.

        But that's just me.

        D

        • That's why I turn my phone off.. That way it's always with me.. if I'm hiking up the nearby mountain (no phones around there, but I still get decent analog coverage.. even digital and pcs some places), I can call someone if there's an emergency, as in someone fell off a rock and broke their leg, but I don't have to worry about anyone from work calling to ask me some inane question about their computer.

          Also, I keep a pager with me, so that if anyone does want to get ahold of me with something important, they can page me, and I can decide whether or not I want to call them back. Pagers still have a use, you see. :)

          DISCLAIMER: I work for a paging company, so that was a little bit of a plug. Sort of.
        • "being interruptable anywhere strikes me as a poor idea."

          You make the same assumption as some others who resist cell phones: having a cell phone means you are required to answer each call. What you call interruptable, I call available. You always have a choice as to whether or not you want to be interrupted.

          When I'm meeting up with friends -- especially at a club where it's hard to find people -- it's extremely handy to be able to call them. When I'm in a movie theatre, it's on vibrate and I'll usually ignore it if I don't have some reason to anticipate an urgent call (no wife, no kids). And if I'm intimately engaged, you can count on me ignoring it, thank you very much.

          I'm always surprised when people ask me with surprised shock, "You're not going to answer it?" if I check the caller ID and decide to let the voice mail get it. If I'm having a conversation with someone, the other person can wait their turn. It's the same etiquette that would keep you from interrupting two people in a lively conversation unless you felt welcomed or just wanted them to pass the salt. In this case, the caller doesn't know, so I make the decision.

    • Add on another feature; plug the relay into your phone line, and when you're at home or near it, your cell phone becomes a cordless phone

      You know, I've been waiting for them to come out with a cell phone that was a cordless phone when within range of its base station(s). I'm sure it would be slightly larger than today's current crop of ultratiny cellulars, but not by much.

      I'm sure it would be complicated but might even be worth it to come up with some way for the base station to add the cell line automatically as a conference party when you left base station, simulating a cell-cell handoff.
    • I think you've missed it.

      Designs will vary, but the phone would only act as a relay when it's actually on, this would actually be a win on average; the available bandwidth should go UP and the power DOWN.

      If a phone is close to a wired access point- then it doesn't need as much power its self, because it only needs a fraction of its full power to get to the access point, so it's got power spare, it's underbudget. So it can use the extra for routing others calls. So its batteries will last the normal amount, and those phones further out won't use as much power either, because they only talk to your phone, not all the way to the access point. Everyone wins on average, or doesn't lose. You can certainly arrange it that nobody is worse off than some standard life; and it averages out if the users move around.

    • Re:Gah. (Score:3, Funny)

      by Lumpy ( 12016 )
      Nooo the ultimate hack is to hace 2 phones to contact each other for a call circumventing the cell tower and company resulting in a 100% free phone to phone call.

      800mhz at the 500mw-1 watt the phones are capable of (not that digital crap they are weak) will get you conversation coverage in your local mall. Think of it, you can ring your wife/SO without paying for the call so you can ask her if you can buy more parts from radio-shack while she and your credit cards are having a ball in bed-bath and beyond.

      then you need to hack it so that 100 is a party line. anyone within range dialing 100 will be connected to the party line.

      that would completely rule at raves and other drugfests... imagine... dialing 101 to contact the E dealer, 102 for the hash dealer, and 103 for the pimp as you struck out with every woman in the place.

      oh well.. can someone start hacking these cellphone for fun uses?

  • This means that people can drive like idiots, totally ignoring the road and other cars in front of them further away from those ugly base station towers!

    I feel safer already!

    • Nope. It's the idiot drivers.

      If talking on a com device were the problem, then the police, fire, ambulance, heck, even the truckers on their CBs would be the problem. And there you need to press a key to talk....

      The real problem is the drivers that can barely manage on a clear road with NO distractions that choke when they are on a phone.
  • Very much like the peer-to-peer communication used by nanites in Neal Stephenson's "Diamond Age".

  • Dangers (Score:1, Redundant)

    by gambit3 ( 463693 )
    1. The Obvious: "owning" another cell phone.

    2. Radiation becomes a REAL risk, because the main broadcasting would be done by the phones, not the towers.

    3. Battery life (ok, not so much a danger as a nuisance).

    4. Spam (another nuisance).

    5. Viruses.

    I think I'll stick with my plain cell phone for now.
  • Damn, they beat me to it. But, as several others have pointed out, I'd be surprised if this will go to far. It wouldn't take much to hack a phone and be able to pick up the traffic being routed through it.

    OTOH, what are the odds that the owner of the cell phone your traffic is routed through even cares about your conversation?

    • Three words: public key cryptography. The two sides of the conversation could each be transmitted encrypted on the other side's public key. The private key could be contained in the phone, or on a SIM.
    • OTOH, what are the odds that the owner of the cell phone your traffic is routed through even cares about your conversation?

      Exactly. You can pick up a standard VHF/UHF scanner at Radio Shack right now and listen to all kinds of cordless phone conversations on ~49MHz. The fact is that random peoples' conversations are boring as hell.

    • It wouldn't take much to hack a phone and be able to pick up the traffic being routed through it.

      That is assuming that they are using a static route for the entire length of the phone conversation, which they most certinly will not be doing for the same reasons that they don't do it now. Think about it, if traffic is going through your phone, and you have your phone set up to your nice little hacking station in your basement, and you pick up a guy traveling on the highway with his phone, he will soon be out of range, right? If his entire conversation had to go through your phone, he would be cut off before he was finished talking. Just like if your entire conversation had to go through the same cell tower. Doing that would take the "mobile" out of mobile phone. The fact of the matter is, that each packet is likely to go through a different phone. The end result? You would get bits and pieces of several conversations, that would about to total jibberish. In fact they could even require it to route every few packets to a different phone, and thus eliminate the need for encryption. I hope all of you who are worried about your conversations privacy, suggest this to your telco.

  • but if you used cingular, could your hop conduct through att wireless phones, or even better, would one of the companies program them to use up their competitors' phones first?

  • Signal droppage (Score:2, Interesting)

    by hackshack ( 218460 )
    A system like that's gotta be able to reconfigure itself instantly, at "packet speed;" say I'm carrying some guy's packets and I drive into a tunnel... sorta like Gnutella on crack. Good stuff.
  • Seriously! Couldn't some evil cracker crack the network and use it to create wireless broadband for himself? Or even worse: A spam fest where the guy hacks the phones and they all call numbers.

    The best part is that people could use Internet enabled phones to create DoS attacks. Great idea, a disaster waiting to happen.
  • I don't know if I like the idea of being a cell relay. My arm would get tired holding the phone up I would think.

  • I don't worry about EM radiation eminating from my phone, mainly because I know that most of the time it isn't doing anything while it's in my pocket, fairly close to an important part of my anatomy :)

    But with P2P phones this wouldn't be the case, and given that currently views on the issue are mixed, I'd rather have my phone transmitting as little as possible. That means no P2P for me, thanks.

    There's also the issue of a massively decreased standby time, seeing as my phone is going to be effectively being used all the time.

    I'd rather have ugly cell towers than have yet more EM radiation and decreased battery life.

  • Just like Napster? (Score:3, Funny)

    by Darth RadaR ( 221648 ) on Friday June 14, 2002 @05:38PM (#3704156) Journal
    I guess if you're in a pissy mood and notice that someone is bouncing off of your mobile, you can shut it off in the middle of their conversation pretty much the same way people would shut off their Napster program whist you were downloading an mp3.

    :)

  • Pictures of cell towers disguised as trees (Score:3, Informative)

    by Serk ( 17156 ) on Friday June 14, 2002 @05:38PM (#3704158) Homepage
    And if anyone wants pictures/more info on the new trend of disguising cell towers as trees:

    http://www.signaltower.com/cellular_tower_tree.h tm

  • What "unused power" in phones? (Score:5, Informative)

    by Tim Ward ( 514198 ) on Friday June 14, 2002 @05:38PM (#3704160) Homepage
    Anyone who's done any cellphone programming will know that there aren't an awful lot of spare CPU cycles going begging when the phone is idle, and there are hardly any at all when you're in a call.

    Unless your phone has more CPU power than you need for normal use, and why on earth would the phone manufacturer do that?? - it'll just eat battery and make the phone uncompetitive.

    Sorry, but you can't get this sort of system for free. It will cost, in more expensive handsets and/or reduced battery life. Not to mention a re-run of all the safety research as the things will be transmitting on a higher duty cycle even when you aren't deliberately making a call.

    [Disclaimer: The above is all true for GSM systems as used in 199 countries of the world. I gather things may be a bit different in the USA.]
    • Look, we're basically talking about VOIP. Packet forwarding doesn't exactly need massive computing power.

      The radio power isn't necessarily an issue in fact it will improve the battery life; I'm sure you'd only act as a forwarding device if the phone is actually on- or plugged in.

      And even then, you'd only act as a forwarding device if you were close enough to a mast or another closer user so as to not use any more power than you would 'normally' anyway.

      i.e. if your phone assumes an average distance of 13km, but it might have a range of 20km, and you are 5 km from the mast, then you have quite a bit of power left and you could certainly route someone 8km from you. Don't forget that power is heavily non linear with range- it takes 4 times as much power to go twice as far, so routing someone who is close to you costs you little if you are closer to the mast anyway. Besides, the users don't design the phones- it's the manufacturers. Its in the cable operators interests to minimise transmitted power, because then they can get more users on a single frequency, and transmitted power is closely related to battery life; and they can change the software to hit a power budget.

      Actually this is similar to the way the public roads work. Why would any state pay for traffic that goes to another state?

      There are issues, but it can work. The complexity of the phones is higher- but they sell them by the truckload, and lower call charges, or atleast call costs would make it cost effective.

  • I've already been operating a 12VDC powered cellular jamming system in my truck for over a year. It is simple to make (just a PA driver and some circuitry to generate a null signal). With a 10W amp, it saturates the entire 800 MHz and 1.9 GHz cellular bands with an active carrier, making it impossible for other phones to reach the cell towers. It's about the size of a phone handset. My coworker and I found the range to vary from 80 yards to 110 yards. I am presently dumping the signal out of my own cellular phone antenna, though I have considered using a rotatable omnidirectional antenna to target particular vehicles, but this would be quite conspicuous; a bearded linux hippie would most likely call me in to the Highway patrol, so I have to stick with the smaller iteration. Yes, it's illegal, but how many cops are searching cars for cell phone jammers?
    • What we really need is a way to jam/stop the kids with their 200 watt bass systems. Nothing worse than having your music over-ridden with some RAP from the idiot beside you. The car is falling apart, but boy, does he have a sound system.
      • Maybe, if you can find a way to boost [sharperimage.com]
        this up a little. ;-)

        That, and you can help me in spreading the rumour that exposure to very low frequencies at high amplitude for prolonged periods of time causes impotentcy. If this rumour is properly spread to urban legend proportions, I'm sure the problem will cease. No song will be worth blasting if the fear of erectile disfunction is properly spread.

        If people will believe that green M&Ms can turn people into homosexuals, they will certainly take this as gospel. :-)
        • If people will believe that green M&Ms can turn people into homosexuals, they will certainly take this as gospel.

          Clearly anyone who believes this is an idiot. It's the blue M&Ms that are gay. And the M&M people are still holding the tan M&M in solitary confinement without a lawyer or other advocate. As others have said, the newer blue M&Ms are much weaker and are genetically inferior to the other colors.

  • it would probably work as a serverless p2p á la Gnutella / Flock, otherwise you would still need to connect to the antenna to call.

    How would the latency of all the "packets" coming together from one end of the call to another ?

    Are cellphones capable of more than 1 connection at once ? They have signalling with the antenae together with voice ... but that is really all the same connection
    • Also think about situations where people are moving in and out of areas with the same call. The total time to find a tower through the network would still be huge. Does the call just pause until it finds a new path through the network.

      It's a great thought. I know that I've been cut off a number of times heading to Milwaukee from Chicago. Too many callers and not enough bandwith, but until we find better ways to discover paths through a complex graph data structure, I don't see this sort of technology working for much longer.

      Unless my cell phone is now a P4, with a nice 54Mbps Wi-Fi connection....
  • This type of dynamic wireless network is generally called a "parasitic network".
  • My background and schooling is in market analysis and valuations. With just enough economics and statistics to make me dangerous I have for some time been toying with a concept for an alternative economy based upon the services provided by each individual comprising the economy. Extra storage space, power, bandwidth, relay, intellect, kidney... you get the idea. The accounting would be daunting in any age other than this one but I suspect barter will come into play big time until the Status Quo Ante of our elected governments play catch up with the legislation.
  • Sometimes new technologies make me think why nobody thought of that before. This sort of technology works, as witnessed by the great success of the Internet. Although it's going to put a strain on batteries if all those cellphones have to be constantly sending data...and once they go down, you might suddenly lose your connection. And it sure isn't going to help people in distant areas with low network densities, because mobile devices will also be scarcer there, resulting in a higly unreliable network. Overall, though, I think it's a good idea to spread traffic over more nodes. Heck, P2P for short-distance and using specialized hardware for long-distance is a proven concept.

    ---
    Novinson's Revolutionary Discovery:
    When comes the revolution, things will be different --
    not better, just different.
    • Actually, this concept is a lot more complicated than just the traditional packet-switching we see in the Internet today (although, it's not "new"). The network architecture implied here is referred to as an adhoc, or parasitic network. These networks have to dynamically update the network topology in real time in order to forward traffic appropriately, which is horribly more complicated than the internet we have today which is, in essence, statically routed. The development of these types of networks is currently a hot topic in the networking research community, since there are a number of interesting applications.
  • This seems like a really lame idea. For a start I dont see how it can be so effective - the reason you get a good signal to your cell tower is that its in a nice clearly available place that you can see almost anywhere. How is the phone in my pocket going to make a connection at street level through a dozen streets and building walls to make a connection with someone else's phone - all using a relatively low power signal. As everyone else has said...erm..Battery Life!! Finally...what is the latency going to be like? All these hops equal kakky latency, which cell phones have plenty enough of to begin with.
  • Why the P2P trend lately?.. The technology isn't that great.. After this and the story the other day about P2P TV networks, I'm really wondering why there is so much hype..

    I know when I use Kazaa, i frequently get 0.5 Kb/s transmission speeds, and "Remotely Queued" or "More Sources Needed" messages.. Do people really want this to happen to their phone calls, TV programs, etc etc?.. P2P networks have a lot of overhead spent just to determine how to distribute nodes and route data -- I just don't see it being ready for any kind of realtime application...
  • Individual cellphones don't have very powerful transmitters; 1 watt or so is probably about right. The only reason cellphones work well is because those towers have (1) big antennas and very sensitive receivers to pick up those low-power handset signals, and (2) powerful transmitters of their own. A peer-to-peer cellphone system would likely be very limited in range. In order to complete a call when far away from a cell tower, you'd have to route the call through several, perhaps many, "peer" cellphones, and all that retransmission could cause delays on the line similar to what you get with international satellite calls.

    In addition, there's the problem that many people have already pointed out, which is that, by keeping the transmitter powered up at all times, you'd run down the battery faster. Not to mention that it might be impossible to make a call of your own while your phone was relaying someone else's call...

    In other words, nice thought, but it's not really practical. (Yet?)

    Eric

  • How would this reduce the amount of traffic going through towers? The only traffic that wouldn't go through the tower is traffic that has enough turned-on phones running that software between you and the person you're calling. All other connections would hop through a few phones and go through the tower anyway. At best, local calls wouldn't need to go through towers. This would vary based on the density of cell phone users in your area compared to the density of towers. At worst, one's range or reception from a distant tower could be improved. Of course, there are also the security and power issues mentioned by others to take into consideration. Neat idea, though. Maybe if everyone had a cell-phone with a great battery and an impressive range, towers for local calls, at least, could be eliminated and used just for outgoing calls. So the cell phone network would be one of separate P2P networks connected by towers. That is, until the population is dense enough to send a call from New York to California.

  • What unused power? Where? My cell phone battery is inadequate as it is. Unless they're also developing fuel cells, they'd better rethink the whole concept of 'unused power' in cell phones. As far as I can tell, it doesn't exist.

  • Imagine phones that don't use Telco hardware at
    all. Information hops from phone to phone,
    finding it's target via other people's phones
    exclusivly... What would the big Telcos do then?
    Would they care? They certainly would boast the
    better, more reliable connection. But if such a
    system could be worked out, where individuals
    could CHOOSE to opt in to such a system... would
    it create a (virtually) free method of
    communication that no corporation could charge for
    or userp? Hmmm... Open Source Cellular?

  • This sounds very useful. A bit like the original switch from circuit switching to packet switching for land lines. If done right, this should be cheaper, better, more flexable, and at least as secure. I wonder if we might not be better of with a new cell phone protocal designed from the ground up for packets, though?

    I noticed one person already commented about security issues, but given that some phones broadcast to the cell tower "in the clear", these can't be WORSE. Of course, most phones these days are more secure than that, and already split the signal into tiny "packets", and then transmits each on a different frequency. They do this for reasons of efficiency, but it does make for security. Phones using the tech should be similarly secure, even without some elementary encryption (which I hope does get implemented, of course).

    This isn't going to be magic though. Only in dense cities you can assume there will enough spare capacity to make this interesting, and even then you'll need towers (although fewer). Out in the country, you'll need just as many towers as always though. On the other hand, the real benefits are going to be from reliability, better signal strength, load sharing, etc., not fewer towers.

    Interesting to note some talk [slashdot.org] just the other day about Wi-Fi networks moving towards a more cell-phone like system, complete with towers. Now cell phones may end up looking more like distributed networks!

  • I had a similar idea but using particle entanglement as the transmission medium. I know the technology isn't there(and may never be) but bear with me a moment. Let's say you manufacture phones that have one million halves of entangled particles, preferably entangled molecules [slashdot.org]. If every eight particles is entangled with 8 particles on a different phone you can have 131,000 separate connections. Each of those phones would also have 131,000 unique connections. It doesn't take much to make a peer to peer phone network with such a setup.

    The problem is that if such a communication device becomes feasible, will the manufacturers make them? Surely they would prefer a centralized model where the other half of the entangled particle resides in a network switching device so they can charge for switching.

    OK now take this a bit further and you can make wireless network cards with unlimited range, keyed to a handful of other network cards. Next thing you know there is a growing peer to peer network whose infrastructure is virtually impossible to disrupt. Private networks can be created whose communications are impossible to intercept.

    Cat
  • I think a better example of a P2P network is that direct connect feature that some service providers have. you call someone, you connect to the person via the tower, you hit a button and poof! you're talking on a direct walkie-talkie connection with the other person.

    That way the tower just acts like a coordinator rather than a server.

    I don't know if I'm right here, but isn't this how the nutella(sp) network works?
  • their business model is charging you per second or minute that you use the service. without going through a centralized system like cell towers they lose this ability.

    very nice, but not gonna happen due to existing billion dollar companies not liking it.
  • Comment removed based on user account deletion
  • God, why is everyone trying to apply the P2P paradigm to everything? Somethings just work better in a base-remote configuration. And I would guess that cell phones would be one of them. The only use I could see for this would be as a secondary mode for a phone to switch into to if it is losing the signal to a cell tower. All the phones would be in passive mode all the time, listening, and if a phone began to lose signal it could switch to a promiscuous mode to route calls over near by phones to get to the closest tower.

  • Here's what's under the hood (Score:3, Informative)

    by nbcjones ( 463617 ) on Friday June 14, 2002 @06:09PM (#3704333)
    This technology is based on something called TBRPF [sri.com], which is currently an Internet Draft [sri.com] of a routing protocol for mobile, ad-hoc, wireless networks.

    Cool stuff, really.

  • Isn't this more or less how Ricochet used to work?
  • for most people.

    Let's face it, we can't share. Nobody here was taught how to share their toys, or play with others. The comments suggest that, and I believe that most people just really can't share. We're all too focused on ourselves to care about others...

    This would reduce average power consumption of phones!!!! You would actually have MORE talking time then less. With more antennas, the power required to talk on the network would go down because you wouldn't have to waste all that power trying to talk to a cell tower miles away, as the closest 'tower' (cell phone) would be like 300 feet away.
    Do you realize that power required goes up as the cube of the distance? If you want to transmit twice as far, you need eight times the power, that's what it means. So instead of requiring watts of power when you are talking, your phone would require milliwatts all the time (a hundred times less then today). Shut off backlighting and you don't have to worry about it.
    This will never take off for the same reason that gnutella will die if we are forced to pay for bandwidth.
  • Cybiko - it's not great, but they have done it.

    Here [cybiko.com] is their site if you don't remember this POS. (I've never tried one... sounds cool but no one has one to hook up with)

    The question is: Are we going to be seeing the verizon guy going around standing next to people on cell phones saying "Can you hear me now? Damn! ... Can you... damn dropped call!"
  • We have all seen how P2P networks function: usually it's a select few subsidizing the masses who are unwilling to share their resources. People are greedy. Non-geeks are even greedier. Most of the general public wouldn't understand how the idea of using many phones as a relay in a distributed fashion would provide them with their service as well.

    Not to mention some technical problems -- look how reliable cellular service is now. Even in very well covered areas, call drops from all ranges of carriers and all types of phones are common enough to be annoying for most people. A Peer-to-Peer cell network would be even more unreliable than the current infrastructure, which would force the need to be verbose with things like repeating data to several relays at a time to minimize points of failure. It might work if you had several dozen relays all capable of working for you -- but that's not an efficient use of bandwidth.

    It's helpful to remember that all the phones must share a single pipe which is the air in the frequency they operate in, so there is a finite amount of bandwidth available so it makes sense not to waste any. This is in contrast to p2p on the internet where each host has its own dedicated and usually unshared circuit and more bandwidth can be added by adding more wire.

    What is to prevent people from turning their phones off to save the battery, and if that is impossible, taking the battery out completely? What if there are three phones active and only two relays available?

    What about the situation where there is a low population density and thus even lower phone density? Is this a solution for urban areas only?
    Even in urban areas, demand is going to increase and put more stress per phone on the network.

    Clearly p2p isn't going to work for cell phones for some time. What the wireless companies need to do is get together and establish a grand this-is-it standard that allows any phone to be used on any network. There are enough providers that the cost of infrastructure development could be spread evenly across the market. This idea is flawed both in the social aspect and technically. Plus in a day when people are increasingly carrying phones around for emergencies, would you want the kind of reliability as afforded by Kazaa, an already developed p2p application?

  • Silly business case for a promising technology (Score:3, Insightful)

    by WEFUNK ( 471506 ) on Friday June 14, 2002 @06:23PM (#3704407) Homepage
    According to the article it seems that their only real selling feature is to increase the robustness of a cell network without having to add additional towers. There might be other reasons to have P2P enabled phones but this one is just plain silly.

    First, this would only really work in well-populated areas with high densities of regular cell phone users. But these cities are already very likely to have a strong saturation of cell coverage, and it is probably relatively economical to install new network towers in such high density areas.

    Second, if an emergency occured, a la 911, where the load is exceptionally high, I can't imagine this system of low powered devices holding up anywhere near as well as a decently saturated network of towers (that also have a lot more power). The decentralized network might be theoretically more robust, but not if everybody's trying to make a call at the same time and not when the device range only allows for a very limited number of localized connections to form.

    Wireless P2P and multi-hop [ember.com]) systems are really cool, but it's not going work for everything or solve every problem. One day they may become ubiquitous, but are likely to be first employed for niche applications only. Cell phone applications and benefits will probably be limited to local network communications.

    Maybe such a system could one day be used to help improve coverage deep within buildings, or for very localized load balancing, but I doubt that they will or should be trusted technically as an alternative to building an independently robust network of towers etc. And, if they are only proposing the technology as an adjunct for increased reliability, then I just don't see a very strong business case.

  • Dumb idea (Score:3, Insightful)

    by Animats ( 122034 ) on Friday June 14, 2002 @06:40PM (#3704502) Homepage
    I'm surprised to see this from SRI. They should know better.

    Basic truth: for reliable low-power communication, at least one end of the link needs to be well-sited. That's why cell phone towers are positioned carefully. Even setting up an 802.11b network requires that the base stations be positioned in reasonable locations.

    You can blast your way out of that limitation with power (the military solution), or only expect it to work in areas with very dense node populations (the urban WiFi solution).

    This idea was looked at back when mobile phones were attached to cars. Back then, power levels were higher, battery life wasn't a problem, and antenna locations were better. Even then, it wasn't that attractive.

    Amateur packet radio works something like this, but even there, what makes it all go are VHF repeaters sited on high places.

    GMDSS [gmdss.com.au], the Global Marine Distress and Safety System, really does work this way. Marine radios, since 1999, have had a big red "DISTRESS" button. Pushing this sends out a message that gets forwarded by every other ship that has GMDSS gear. But that's a specialized, low-bandwidth application.

    • ...or only expect it to work in areas with very dense node populations (the urban WiFi solution).

      This might be true if the system relied entirely on peer-to-peer routing.

      Let's say that the system has enough fixed base stations to get full coverage of the operating area. The only problem is capacity - it can't support more than a certain density of terminals per square mile. The standard approach to this problem in cellular networks is to add more base stations to reduce the cell radius leading to a reduction in transmission power and a better frequency reuse factor. With this system whenever there is a high density of terminals it compensates automatically by using a number of short-range low-power hops to get to the nearest base station instead of one high-powered hop that wastes frequency capacity over a large area.

      Basic truth: for reliable low-power communication, at least one end of the link needs to be well-sited.

      This "basic truth" is true only assuming the link has only two ends and therefore just one communication path. If this path is degraded by fading or shadowing you must have adequate power margins to cope with it.

      On an adaptive mesh network you have multiple routes through repeaters to the nearest base station. At least some of those paths should have favorable reception conditions and be capable of running at very low power.

      It may seem unreliable to trust statistics but phone networks have done so for ages. If you are stuck without enough repeaters your terminal can jack up its power all the way up to normal maximum power levels of cellular phones (a few hundred milliwatts) and talk directly to the base station. But wait - this wastes frequency capacity over a larger area, right? Not a problem. If you don't have neighbors to carry your traffic it means that they don't need this capacity at this time!
  • The small-but-noticable delay caused by the encoding/decoding process is already as bad as is usably possible. Adding packet-hopping to cell phones would increase this latency by a noticable degree, making them less usable.

    I know cybikos are not cell-phons, but they do implement a similar packet-hopping technique. see Cybiko.com [cybiko.com]

  • P2P packet radio is an old idea (Score:4, Informative)

    by MountainLogic ( 92466 ) on Friday June 14, 2002 @06:45PM (#3704531) Homepage
    P2P packet radio [bohica.net] is an old [cs.hut.fi] idea. Check out the old Aloha and AX25 [bohica.net] protocols. One of the best sites for amature packet radio is Tucson Amateur Packet Radio [tapr.org] or Packet Primer. [sedan.org]

  • Another potential issue. (Score:3, Insightful)

    by Burning1 ( 204959 ) on Friday June 14, 2002 @07:04PM (#3704627) Homepage
    I've seen several comments pointing out that reduced battery life as a serious issue...

    Here's another one: Signal degradation.

    Anyone with experience in networking knows that while repeaters can be used to extend the maximum length of an Ethernet run, you can only repeat the signal so many times (4, for Ethernet, IIRC) before data error become an issue.

    I paid for a Motorola Startac back in the day... $250 for a cell phone, and even with such a nice cell phone, loss of quality is pretty noticeable when compared to a landline... Wouldn't hoping the signal through 3 or 4 of these make for pretty horrible reception?

    It's possible the loss of quality due to some other aspect of cell technology that I'm not aware of (digital signals and compression, perhaps?) I'd love to hear from someone who knows more about cell technology.
  • I'm doing my masters thesis on bluetooth ad hoc mobile routing, and one thing I can say is it is not easy to setup and maintain a routing structure. If you have a sparse distribution of nodes, you may run into connectivity problems, although the algorithms for routing become fast. If you have a dense dist, the routing becomes increasingly toughter, as you will have more pico-nets, gateways, clusterheads, and routing tables to deal with.

    Scatternet formation has to be done with a distributed algorithm, since, at the start, no node knows where the others are. There are many more problems with a network like this, for information transmission, like latency, reformulation of the network when nodes move, or are turned on or off.

    Now, if cell phone protocols were changed, ie, new cell phones were built to use ad-hoc networks, with cell towers as fixed access points and gateways, the idea will have a good future.

  • Band Split (Score:3, Insightful)

    by FrankDrebin ( 238464 ) on Friday June 14, 2002 @07:31PM (#3704743) Homepage

    The major stumbing block, and why this idea cannot immediately go to cell phones, is the notion of band-split and the fact that the cell-phone network is fundamentally circuit-switched (as alluded in the article).

    Mobile devices are licenced to transmit on certain frequencies and receive on another set. The base station (at the tower) has the opposite band-split. That's how a full-duplex connection is made. One can listen and talk without having to push a button like a walkie-talkie since there are two separate radio connections used together simultaneously. Mobiles typically transmit on the low side of the band and base stations on the high side.

    In order for a mobile to act as a base station (for the purposes of repeating or P2P), it would have to implement the radio hardware to do listen to other phones, like a base station does. Besides the licensing issues, cell phones do not offer this extra-cost (and potentially bulky) RF hardware.

    The P2P cellphone idea demonstrated on 802.11 has a fundamentally different RF architecture, where one band is shared in a multiple-access fashion. It's also inherently a packet-switched technology. In 802.11 band-split is not an issue for P2P.

  • How do they do packet routing?

    Imagine a very dense area of repeaters and a tower. Phone A can't talk with the tower but a lot of phones can and moreover there are a lot of phones that both A and the tower-able phones can route over. Is there some form of "Yes, I will route for you" that cascades up the tree and first-come-only-served? So if A can hit B can hit C can hit the tower, then A sends a request, B gets it, broadcasts it *again*, C gets it, knows it can hit the tower, responds to B, which then responds to A?

    Anybody know how this really works so I don't have to pull ideas out of my ass? ^_~
  • Something like this won't really be pratical until battery life has far exceeded current standards. The difference in battery drain in stand-by mode and in-use mode for most phones is significant, I expect that this would drain batteries in a manner more like the latter rather than the former. As a result, I doubt that it could be implemented in any sort of practical manner at the present. . .
  • Just what I want... a high-frequency transmitter randomly tossing out EM radiation while sitting in my pocket right next to the family jewels....

    Don't fool yourself... SRI is trying to sterlize us.
  • And such a wonderful job P2P does too. You've already heard about the power issues this would create in a phone. Using those "unused" powercycles means you won't be using them later on. A cell battery is a very finite resource. Which would lead to another quite famous P2P problem: Sharing. It's no large stretch of the imagination to see people turning their phones off as not to waste the battery on these extra cycles, only turning them on to make a call. Or here's a good one-- Lag while the phone attempts to sort a path to the nearest main node. You think those MP3 searches take a while sometimes? I'll stick with my Nokia, thanks.

  • Half a dozen (or more) advantages (Score:3, Insightful)

    by DumbSwede ( 521261 ) <slashdotbin@hotmail.com> on Friday June 14, 2002 @09:31PM (#3705486) Homepage Journal
    On whole a good idea.

    My cell phone is often on a charger, either at home or in the car, so no problem with battery drainage. No doubt being used as a relay would be an opt in proposition with many settings like your laptop sleep and idle modes. For instance, only relay while on a charger, only relay while over 50% charge, only relay 50% as many calls (power equivalent) as actual usage. Etc...

    Users to be rewarded by relay discount points in their bills (think frequent flyer miles).

    Encryption no more (or less) needed than regular phone. Why hack your relay phone, when you can just buy a scanner?

    Maybe my phone will work in this near underground apartment, relaying though the phones above, then out.

    More available bandwidth, more calls can get through, by using smaller, but more numerous relay towers, that are closer together, or hop around a tower that is saturated, like often happens Friday nights in this College town.

    Huge events (or disasters) less likely to completely jam network (continue hopping until getting to an unsaturated tower).

    Mini towers possible, by tying phones into land-lines or cable modems. Again, a customer discount or credit option.

    With a diffuse enough network, and mbone like simulcasting, 4G services like mobile HDTV.

    Cellphone network compatible laptops should hardly notice the relay drainage, compared to regular greedy CPU use.

  • Can you hear me now? Good!

    My credit card number is 421766..... wait... wait... wait... I hear breathing on the other end of the phone line. Oh, that's you? I forgot I was calling a phone sex number...

    Can you hear me now? Good!

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