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The Internet

New Wireless Technologies 89

Codex The Sloth writes "The Economist has an article on 4 emerging wireless technologies: (1) Smart Antennas for improved base-station capacity, (2) Mesh Networks to make each wireless reciever also be a relay, (3) Ad hoc networking to use network devices as routers, (4) Ultra wideband to transmit 100 mbs wirelessly (but only for distances of 10 feet...). Some of these are already in use while others are still in the lab."
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New Wireless Technologies

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  • Doh...and I had such high hopes for UWB.
  • Ultra wideband to transmit 100 mbs wirelessly (but only for distances of 10 feet...).

    Also accomplished by tossing DVD's back and forth....what's the point of that? I mean, only ten feet? Why not just use a cable at that point?
  • ...the article about the wireless technology in the 75ghz range that can span miles and maintain speeds of gigaBYTES a second. I dont like the fact that UWB can only go 10 ft at that speed :-(. Will we see any improvements?
  • by Anonymous Coward on Friday June 21, 2002 @05:21PM (#3746287)
    there are several good articles about uwb at UWBPlanet [ultrawidebandplanet.com]. It appears the Economist is quite wrong about UWB.
  • All I hope for is that they agree on one standard before beginning mass deployment. Not the early-cellphone debacle all over again please...
  • What about (Score:5, Funny)

    by eclectro ( 227083 ) on Friday June 21, 2002 @05:23PM (#3746309)
    the little sticker you put on the back of your cell phone to increase range. Isn't that an emerging wireless technology???

    • Have you seen the way they show the antenna growing in the commercials, so you can see what the antenna "performs" like after you put on the sticker?

      All I can say is they should get the same artists to do the Viagra ads.
  • Me: Hey Joe, got that file?
    Joe: Yeah, it's on a floppy.
    Me: Toss it here.
    Joe: Frisbee's the Floppy across the room (20 ft. [6.1 meters]).
    Me: Catches floppy (Sure it was aimed at my head).
    Me: Thanks.
    Joe: Make sure it gets to Mike tomorrow.
    Me: Ok. (uses sneaker net)


    Look familiar? :)
  • Hm... (Score:1, Funny)

    I can see it now...

    The New Corporate Structure

    June 21, 2002

    New York, Due to the advent of new short-range high speed Mesh Networking systems there has been a huge increase in the need for temp employees. Apparently, when CEOs discovered that their new high-speed UltraNet(R) connections would only work ten feet away from another UltraNet(R) based system they decided to hire UltraNet(R) Extenders(UE) - temporary employees that are specially trained to walk ten feet away from the CEO with an UltraNet(R) rebroadcaster.

    Some UE chains - lines of UltraNet(R) Extenders - have been known to reach twenty or thirty UEs, with the record taking place between the law firm of Samuel, Johonson, & Dickie and the local courthouse three blocks away. When one of the UEs was asked about the experience his response was "I'm just glad I'm not one of them that needed to stand in the road." Of the two injuries incured during the record-breaking event both happened to UEs standing in the streets.
  • Latency (Score:4, Insightful)

    by papasui ( 567265 ) on Friday June 21, 2002 @05:41PM (#3746445) Homepage
    What kind of latency does this add up to? I mean thats really the weakest link when it comes to doing things that require fast response like online games. It's not neccesarily how much data that can get there in a specific time but how quickly you can get the data to a location.
    • Ad hoc networks can support videoconferencing over LANs (in moving cars)... it's really not that big a deal. You just need to be proactive about link breakage prediction, then you can go 4 or even 6 hops with very reasonable latency and jitter.
    • We're [beamreachnetworks.com], using a similar technology called Adaptive Beamforming. Our airframe gives us a latency of 60-80ms. We're still refining things, so the hope is it will be at the lower end of that range. We're non-line of sight, long range (3-5 miles+) and near symmetric T1 speeds. Coming soon to a field trial near you.
  • Lasers (Score:2, Informative)

    by Anonymous Coward
    Scientific American has an article about the last mile by laser.

    http://www.sciam.com/article.cfm?articleID=00080 69 E-808A-1D06-8E49809EC588EEDF&catID=2
  • Wouldn't this run into the same problem that the gnutella network has run into? I mean, as has been reported on /. (too lazy to search for the article), Gnutella doesn't scale very well because you have too much burden in handling the peer-to-peer communication. As more people got connected, wouldn't you run out of bandwidth for actual data?

    • by jbf ( 30261 ) on Friday June 21, 2002 @06:00PM (#3746557)
      Great question. It turns out that ad hoc network capacity is limited; in a randomly moving network, with sane discovery procedures, bandwidth per user goes down at some suprising rate. However, if your communications are local, that isn't a big deal. Also, several research groups have looked into cluster-based routing as a way to make things scale better, so only cluster-heads need to route amongst themselves, and the other nodes just go through the cluster heads.

      I suppose gnutella could also benefit from such an architecture... I seem to recall that some P2P systems have "supernodes." However, the attractiveness of p2p systems is that they're really hard to shut down; 0wning all the supernodes would hurt. (Not shutting them down, just making them stop forwarding requests) Also, if one of these evil companies that advertise using P2P becomes a supernode, there's no end to the evil that company can perpetrate.

      This is all a vast oversimplification, of course...
  • by mir@ge ( 25727 ) on Friday June 21, 2002 @05:56PM (#3746538) Homepage
    IANANE(I am not a network engineer), but it seems to me that widespread mesh and ad hoc networks decentralized nature might prove difficult to "police". Already we see Snort and other tools designed to break into exsisting WiFi networks. The distributed nature of these new networks would lend itself to such attacks. While strong encryption would prevent a properly configured station from being cracked, the real problem with WiFi and perhaps these new networks is foolish people leaving them wide open. Then there is the question of accountablity. What happens when my feed starts providing resticted intellectual property like "Oops!...I did it again"? Just who gets sued. Present laws dictate that ISPs are not liable as long as they take steps to immediately cut the source. Assuming, you would be protected under such a law it seems to me the central feature of the network(relaying others data) is discouraged by legal the standards.
    • First of all, ad hoc networks are currently focused on applications where everyone has a common goal. If you're going to work in an area outside of that, you need security. Jamming, etc can be worked out with spread spectrum or licensing (then it's illegal to jam, not that laws are always so easy to enforce), so mostly you need to worry about the routing and access control. Foolish people leaving them wide open won't happen if people are businesses trying to make a product out of this (otherwise, you're giving away product for free), and those who set up their own "open" manets are like those who leave open 802.11 nets. (Maybe a bit worse, but not much given how easy MAC addr spoofing is).

      Security is a young and pretty exciting area in wireless network routing; some work by Zygmunt Haas, David Johnson, and Adrian Perrig, there are a couple tech reports by Brian Levine, Elizabeth Royer, Robin Kravetz (those you have to dig a bit deeper for...)

      IANAL, but the legal issues come down to two things: (1) whoever was doing things with intent (eg, who put the file on their hard drive and opened it to the network intending for it to be copied, or better yet, who was doing the copying), and (2) did you do anything actually negligent.
    • Then there is the question of accountablity. What happens when my feed starts providing resticted intellectual property like "Oops!...I did it again"? Just who gets sued. Present laws dictate that ISPs are not liable as long as they take steps to immediately cut the source. Assuming, you would be protected under such a law it seems to me the central feature of the network(relaying others data) is discouraged by legal the standards.

      I think it comes down to who owns the antenna. If I own the antenna that's up on my roof and there are many people in my area with their own antenna then who's to stop us from developing our own protocol(s) to share data with each other directly without paying anyone? AOL et al will be trying to get legislation passed that outlaws people from communicating with their neighbor without a license. To get a license you would also have to submit to monitoring by the FBI, CIA, MPAA, RIAA, and maybe the DEA should be thrown in there too.
  • by __aawavt7683 ( 72055 ) on Friday June 21, 2002 @06:00PM (#3746563) Journal
    Couldn't really think of a better/propper name for it. But, I'm referring to that .. "activity" where a piece of mail was given to someone, and they were told a destination. So it'd pass through a shop owner to a company to a branch in a different country and get to the president sort of thing.. basically, just "fling" it and it starts going in the right direction.

    This was thought of with routing. But, it can't work as things are set up now. The reason this works is because they're all grouped. Continents, countries, shop owners, policical candidates and such... computers are just 192.168.0.5. The other IP's can be given out randomly to any place at all.

    Antennas like this, if they were to route in the same way, would need to know where they are, where the message wanted to go, in the physical world. Then the other antennas would need to be able to determine if they were between the source and the destination. And to prevent duplicate messages, tell people "I got it!!" like a football game(...).

    so.. basically I'm saying until the way computers are groupped/assigned IP's is done in some logical manner like countries, the "human" (flinging? just send it out and hope it gets tehre...) form of routing won't work with computers.

    just my comments on a topic that was brought up before..

    -DrkShadow
    • by jbf ( 30261 )
      (so it appears, from previous comment posts). Either that or someone really uneducated about network addressing, CIDR, etc...
  • Errors in the post (Score:5, Informative)

    by sheepab ( 461960 ) on Friday June 21, 2002 @06:08PM (#3746618) Homepage
    From Slashdot: 4) Ultra wideband to transmit 100 mbs wirelessly (but only for distances of 10 feet...).

    From the article: The FCC ruling limits the range of UWB transmissions to about ten metres, although longer ranges may be allowed in future once the question of interference has been sorted out. However, UWB is capable of a data rate of at least 100 megabits per second over such distances.

    The first thing, the Slashdot post makes it sound like 10 ft is the maximum UWB can go, and second, its 10 METERS not 10 FEET
    • Interference from UWB may be a real problem, according to some tests reported in the latest issue of Aviation Week.

      Tests were brief and therefore not completely realistic, but showed actual loss of function of aircraft electronics. At 20 dB over typical single-device levels they were completely shutting down some of a 747's navigational equipment. That's 100 times the normal power level, but consider: what if a hundred passengers are carrying UWB devices? Or what if 20dB isn't enough margin to prevent partial interference from a single device?
  • I haven't seen any technical papers about UWB, and i have some questions.

    How do you make the signal? Is it just a pulse at many frequencies (f, f+k, f+2k, f+nk) where f is the lower limit, and f+nk is the upper?

    Also, looking at an article at UWBPlanet.com, I see
    "It can penetrate solid obstacles with virtually no degradation and has location capabilities that make GPS look like a blindfolded troll with a club. Furthermore, its location-sensing abilities are not limited to outdoor use in any way, as GPS solutions are."
    What kind of solid objects do they mean (metallic, I think not)? Is the lack of degregation because the frequency range is so wide that, if the absorbtion of the object is frequency specific (resonates, etc), there are many frequencies that do not get absorbed?
    It seems that they are being a little over confident...if your in a Faradays cage (building, or cage, heheh), you should still get poor to nill reception unless the wavelength of the signal was smaller than the smallest openening in the room (then of course you would be able to pick up a weak signal).

    "Only a UWB receiver that knows the exact pulse sequence generated by the transmitted signal can in fact make use of the information in the signal"
    This sounds like some kind of frequency hopping scheme more than anything. Unless it used some sort of TDMA scheme.

    Anyone?

    -Nomel
    • See the papers on timedomain.com.
      Their UWB scheme uses .5 nanosec pulses with a
      gaussian waveform that spreads the signal very
      thinly and evenly over a very large spectrum.
      A 100 kbit/s receiver will listen for these pulses at a sequence of 1 ns wide windows.
      The window sequence is pseudorandom, with something over 100k windows distributed over 1 sec. The
      hard part of the technology comes from :
      very wideband antennas
      syncing ghz oscillators at transmitter and rcvr
      precise timing (they have a dedicated chip)
      establishing the sequence with multiple receivers
  • Also accomplished by tossing DVD's back and forth....what's the point of that? I mean, only ten feet? Why not just use a cable at that point?

    Synchronizing your high-capacity portable MP3 player or digital camera without having to buy a USB hub, for two. Bluetooth is one thing, but being able to move that much data in mere seconds has a real appeal. Right.

    It would be a real bummer if the master computer sent an order to kill those pesky humans and the robot got snapped back by the network cable. I mean how embarrassing. Me: Hey Joe, got that file? Joe: Yeah, it's on a floppy. Me: Toss it here.

    Joe: Frisbee's the Floppy across the room (20 ft. [6.1 meters]). Me: Catches floppy (Sure it was aimed at my head). Me: Thanks. Joe: Make sure it gets to Mike tomorrow.

    Me: Ok. (uses sneaker net) (I am not a network engineer), but it seems to me that widespread mesh and ad hoc networks decentralized nature might prove difficult to "police".

    Already we see Snort and other tools designed to break into exsisting WiFi networks. The distributed nature of these new networks is foolish people leaving them wide open.

    Then there is the question of accountablity. What happens when my feed starts providing resticted intellectual property like "Oops!...I did it again"? Just who gets sued. Present laws dictate that ISPs are not liable as long as they take steps to immediately cut the source.

    Assuming, you would be able to determine if they were to route in the same way, would need to know where they are, where the message wanted to go, in the physical world. Then the other antennas would need to know where they are, where the message wanted to go, in the physical world. Then the other!

  • Mesh Networks == bye bye telco monopolies on the last mile
  • I wonder if that has to do with the article posted today [techtv.com] at techt tv from the etherlink company in California.
  • It doesn't seem to me that the business model for deploying mesh networks is rocket science. The article seems to imply that figuring out how to get the neighborhood nodes out there is a problem.

    I'd be willing to bet that for some suffeciently large (but reasonably small) radius, there exists just about everywhere a neighborhood containing at least one person willing to be an early adopter. Give this person a free serious broadband connection, paid training, and perhaps a small stipend, and have him/her keep it running. Everybody else in the neighborhood just buys wireless devices.

    If I had some cash to drop and a telecom network to use, I'd start this myself.

    • As a consume.net node owner I have a particular interest in the idea of using mesh networks to provide an open wireless network based on the idea if it possible to creat bandwidth with every wireless connection, however this bandwidth is relativly limited in its use if it can only reach a fraction of the number of hosts on the Internet.

      As far as I can see todays wireless standards are not capable of supporting enough users in a mesh based network to make the network useful. Beyond a certain number of hosts almost all of the available bandwidth will be used for routing information, especialy if the nodes are not online permanantly or are moving. Even with omni directional antenna 802.11a/b has a very short range, LOS is hard to come by esspecialy since 802.11b does not agree with trees not to mention the chronic shortage of spectra since only 3 802.11b networks can operate at maximum throughput within range of each other...

      Mobile mesh [mitre.org] is one of the leading mesh network protcols but tests by consume.net members have shown that Mobile Mesh strugles to scale past 20 nodes, not to mention the lack of windows support which is a realistic requirement if you expect every user to act as a router, esspecialy considering that 99% of the population (including several of my Comp Sci & Cyberentics course mates) consider the default state of a computer to be off.

      Any mesh routing protocol must be able to cope with re-routing packets when a node is returned to its "default state" by its user, however the problem is acheving sufficient node density to maintain coverage when peoples computers are only on say 4 hours a day. This could be achieved by producing low cost, *nix based APs wether based on COTS or a dedicated AP solution such as the Musenki [musenki.com] or the BAWUG board which was demoed to consume.net members by Matt Peterson of BAWUG as part of his round the world trip with Terry Schmidt of NYCwireless. (cheers guys, it was a very interesting presentation).

      Both the Musenk and the BAWUG APs are very compact and could be pre-configured for mesh networking requiring only to be pluged into the users LAN however they are still relavtivly expensive. (The Musenki M-1 is expected to be $299 and the M-3 $499)

      In short Mesh networkng still has two major obstales to overcome until it can be considered for wide scale deploment..

      1) Windows software is essential to acheive sufficent node density for complete coverage 24/7.

      2) Scaleablity needs to be improved to 1000's of nodes. There is no way to write routing protols that will overcome the speed limitations of existing wireless hardware, even with QoS there will still be physical bottlenecks as there will only be a limited number of users who can connect to the NAP. Intelegent routing can cut down the number of request for routing data, from what I know of Mobile Mesh all the nodes will listen and cache routing information broadcasts which reduces the number of requests the have ot make for this information thus leaving more bandwidth for your data.

  • www.meshnetworks.com


    For some very cool product info on mesh networks.

  • Hi,

    your news reporter from Germany back again ;-)

    Heise had a story about a wireless self organzing net that's up for testing in the city of Ratingen, Germany.

    The main facts: 2,4 GHz like WLAN, max. 1 km distance between the antennas, 44 mbit bandwidth per node - 33 mbit for relaying with the other nodes (normally 3 * 11 mbit) and the rest for the user of the node.

    The links:

    Heise Story in German [heise.de] or google translated [google.com].

    Link to the technology provider DIRC [dirc.net] (click on FAQ to get the main points).

    Bye

    egghat.

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