Catch up on stories from the past week (and beyond) at the Slashdot story archive

 


Forgot your password?
Close
typodupeerror
×
Technology

VoIP Cell Phones Coming 167

Posted by timothy from the when-oh-when dept.
bp33 writes "Wireless Newsfactor is running a story about how the wireless vendors are climbing over themselves to get Voice-Over-IP cell phones. You might ask "why bother? We already have wireless voice now." But with an open platform for wireless (Symbian, JavaPhone etc), your "voice" (er .. audio) just becomes bits that your programs can manipulate before sending."
This discussion has been archived. No new comments can be posted.

VoIP Cell Phones Coming More

VoIP Cell Phones Coming

Comments Filter:

  • Why IP? (Score:4, Interesting)

    by NitsujTPU ( 19263 ) on Sunday September 15, 2002 @09:59PM (#4263326)
    Why do we do everything over IP? I mean, honestly, it's a good protocol and all, but it's not perfect for everything. There are already digital wireless phones, and not all of them use IP.

    Why would one want to use an ATM/IP/IPX/IP network when they could just use whatever works best for that application?

    I think that everyone out there wants to just use IP so they feel like they've made some sort of "internet device" when really they have just another damn device with an IP. You can always tunnel just the portions that you want over IP rather than forcing EVERY square peg into that round hole. /rant

    • IP is good for everything. I remember a chant from a while back:
      IP over Everything
      Everything over IP

      "IP over Everything" is so passe, it refers to using IP over various layer one media, such as CAT5, Fiber, Token Ring, and copper wire. Seems obvious.

      So now that we have IP over everything, why not put all our higher-level devices over IP? Seems like a logical extension, since all the ISO layers below are over IP.

      And no, IP is not a square peg in a round hole. Moore's law isn't working for bandwidth. Like it or not, there is not enough economic demand for bandwidth, or otherwise all the dark fiber would be lit up. And its not being lit up. Personally, I think the obsession with everything over IP is driven by simple economics.

      Do everything over IP, and bandwidth will be demanded, and dark fiber around the world will be used, bandwidth will be sold and resold, and the remarket for IP bandwidth will be virgin once again.

      There was an article in Wired this month about this very subject, for your information.

      • I remember a chant from a while back:

        Actually it wasn't so long ago that ATM was the killer protocol, and people were talking about "IP over ATM". It has a lot going for it, too, like quality of service guarantees, but I guess the idea of shelling out six figures to Cisco for switches just wasn't appealing. IP is a dog of a protocol, but it's cheap to implement, which seems to be thie important thing.

    • For services currently using POTS (Plain Old Telephone System) or related, VoIP can be a heckofa lot cheaper on long distance charges.
      • Think about it though... Why? I mean, the reason that it's cheaper from me in my home, is because I'm already paying for the bandwidth with my cable company, who are paying comparable charges to the same that any phone carrier giving long distance would charge. At the level of phone carriers, the charges are still the same. VoIP is only cheaper for businesses and consumers who aren't already paying routing fees, but rather are paying the phone company's random long distance charges.

    • Re:Why IP? (Score:5, Interesting)

      by Bookwyrm ( 3535 ) on Sunday September 15, 2002 @10:36PM (#4263458)

      Why do we do everything over IP? I mean, honestly, it's a good protocol and all, but it's not perfect for everything. There are already digital wireless phones, and not all of them use IP.

      Why would one want to use an ATM/IP/IPX/IP network when they could just use whatever works best for that application?


      You are confused because you are thinking like an engineer, rather than a philosopher or an idealist. Ideally, we could just have one protocol (to rule them all, in the darkness bind (v9.2) them...), but it is not a very practical solution.

      I rather suspect there is this problem with people getting the network protocols confused with the applications that run over them. The "everything over IP" crowd seems to be mostly the same group that feels that NAT is a bad thing -- i.e. that everything should be one big network with the same addressed space (i.e. the Intranet, really, rather than the Internet, because the latter implies connections between different networks.) From this point of view, the "everything over IP" is the equivalent of saying, for example, "everything over copper wire, and only over copper wire -- it does not matter if fiber optic cable makes more sense for certain specific applications, you would need a converter to convert between copper and fiber, and that would break the end to end connection!"

      If you can pry the application out of the network protocol (i.e. IPv4), such that the application is independent of the underlying protocol (as it ought to be), then you could more easily use the apropriate protocol for the apropriate application when necessary. However, as long as the masses believe there is some magic inherent in end-to-end un-NAT'ed networks, IPv4 will remain God, and IPv6, among other things, will never arrive. (It's not magic, it's bad design which requires end-to-end transport without allowing for the possibility of transport conversion.)

      It is a bizarrely almost Luddite mindset. I mean, honestly, is it just me, or does anyone else feel that the "IP is your Lord god, and you shall have no protocol before IP" mindset is intellectually stifling?

      And now the modding down may commence...
      • Thank God someone agrees with me!
        • After reading some of the comments around here, I think there needs to be a new moderation type of "Missed the point".

      • Re:Why IP? (Score:3, Insightful)

        by alienmole ( 15522 )
        I sympathize with your perspective, but I don't think it's as simple as you suggest. There are a whole host of factors that converge to make IP attractive to a wide audience.

        One important factor is that many people saying "use IP" are really saying "use a standard, packet-switched protocol". There are some good reasons for doing this, too. But it just so happens that in today's world, only one protocol fits that bill. To demonstrate the impact of this issue, from your comment, I can't tell whether you think packet-switching in general is being overused, or just IP. The two have become virtually synonymous.

        Technically, it's not that difficult to support replaceable network and transport layer protocols. Novell did it, a long time ago. That would allow more diversity in the choice of protocol. But the problem is standardization - everyone would have to agree on the infrastructure to support that. To summarize wildly, it was easier just to agree on a single network and transport layer protocol suite, than on a standard for making those protocols pluggable.

        Having agreed on the standard, we're now stuck with a situation in which it tends to make sense to do anything that needs packet-switching, using IP. Even if it doesn't seem to always make technical sense, it often makes economic sense, because you can reuse existing technology, expertise, and infrastructure. Networks effects can be wonderful, but they're also tyrannical.

      • IPv6 is bloody fantastic. It's got little overhead, a rich feature set, lots of addresses (though I might have considered a standard with even more of them, personally) and there is no kind of device being made today which cannot reasonably speak IPv6.

        Now just as people say you cannot prepare for peace while preparing for war (or whatever) you cannot advocate IPv4 without advocating NAT, because IPv4 addresses are too scarce now. However IPv6 doesn't necessarily have this problem. So IPv6 for everything! Why use anything else? Well, except for the fact that everything's IPv4 now. But when we get IPv6 support in everything important and ISPs start pushing out IPv6 I think the world can be a better place.

        Also optimally everything would have a static IP address, whether it's up or not. Can't pull this off with IPv4, obviously. But anyway any device which wants to talk to the internet should have matching forward and reverse DNS and its very own non-shared IP.

      • This is a somewhat 1980s perspective - back when there were multiple layer 3 and 4 network technologies and IP was just one of them, it was common to invent transport-independent APIs. However, this still leaves the issue of transport level gateways to allow the end hosts to communicate. It's much easier to just use IP everywhere so that IF you want your mobile phone to talk to a Sun server there is no technical barrier to doing so.

        The drive for end to end no-NAT networks is exactly why IPv6 should take off - unfortunately NAT is such a popular quick fix that this may take a long time. Ironically enough, transport-independent APIs will enjoy a resurgence as part of the conversion to IPv6.
      • that everything should be one big network with the same addressed space (i.e. the Intranet, really, rather than the Internet, because the latter implies connections between different networks
        The Internet is a public network of networks, not a maze of private IP network gateways. Ever heard of a "Class C Network" or similar? They ARE separate networks, they just use a common protocol and address space to enable communication with each other. NAT is a proxy, not a network.
      • If you can pry the application out of the network protocol (i.e. IPv4), such that the application is independent of the underlying protocol (as it ought to be), then you could more easily use the apropriate protocol for the apropriate application when necessary.

        You can also simplify spinning out the aplication from the network. The trend in Telecom these days is to divorce yourself from the expensive parts of your network that will "never" make money, and focus on the higher margin parts.

        For example, AT&T no longer owns their towers. They lease them from American Tower, because they don't want to be in the tower business. They run and manage their network. Another example is cable television. The money isn't in running the local office, it is in running the channels.

        I think that cellular companies are in the process of doing the same thing. They see themselves as service providers, not infrastructure players. After all, the network is just a big drain on their bottom line, and it will be better to get rid of all that and lease the network you want from someone else.

      • he "everything over IP" crowd seems to be mostly the same group that feels that NAT is a bad thing -- i.e. that everything should be one big network with the same addressed space (i.e. the Intranet, really, rather than the Internet, because the latter implies connections between different networks.)

        Nobody disputes the value of having different networks connected together. But what makes the Internet the dominant network on the planet is that it connected those networks into a single address space. The reason you want this can be summarized as Metcalfe's law. The benefits are eminently practical. For instance, if you have a machine in the Internet address space and you want to make files available to me, you just tell me the IP number of your machine and I can connect and use FTP or WebDAV to get the files. But if you give me an AppleTalk, SMB or Intranet address, I probably cannot connect to you. This isn't utopian idealism, it is pragmatic engineering.

        Now the truth is that I really don't care much whether every two machines in the world choose to talk IP to each other. On a network of Macintoshes, use Appletalk. On a network of cell phones, use whatever protocol they use. But I do want every machine int he world to have a unique IP address so that it can participate directly in Internet protocols like HTTP, SMTP, Jabber and SIP. Supporting IP+X is even better than IP alone, if X adds value to IP.

        • You've confused a single network transport address space with a single application address space.

          The value is in a single *directory* address space. Unfortunately, people use IP addresses to refer to resources, rather than, say, hostnames or something that is not bound directly to the network technology. This is precisely the sort of thing which hinders a transition to IPv6.

          This is a far more practical and pragmatic engineering idea than tying applications to the network addressing. If you want every machine in the world to have a unique IPv4 address, you're walling yourself into IPv4 forever and ever. What you probably want is a unique identifier for each machine that does not bind you to a specific technology or transport.

          Maybe a URL points directly to a machine on the Internet with a static IP address. Maybe it points to a machine behind a firewall with NAT. Maybe it points to an IPX machine on the otherside of a protocol coverter. If you can get the files via that URL, it shouldn't matter, should it? The problem is the current bad engineering practices that make the transport layer addressing entwined with the application layer resource addressing.

          I don't care if the data flows over copper, fiber, or wireless, as long as the proper stream of bits get to the right place. Likewise, I shouldn't have to care if it is IP or anything else transporting the bits in particular.

          • Successful application protocols do not define their own address spaces from scratch. They always build on IP/DNS. This isn't poor engineering. It's separation of concerns.

            You say:

            Maybe a URL points directly to a machine on the Internet with a static IP address. Maybe it points to a machine behind a firewall with NAT. Maybe it points to an IPX machine on the otherside of a protocol coverter. If you can get the files via that URL, it shouldn't matter, should it?

            Now I share the URL with someone on the other side of the planet in another administrative domain. Can I guarantee that they can access the resource? If and only if they speak the same protocol or have access to a gateway (which is from my point of view the same thing as speaking the protocol). What protocol do they have a 95% chance of speaking? IP. What other protocol comes close?

            Sure, my application could support some other protocol, but then I have to convince the application developer on the other side to support that protocol also. For file transfer applications that's essentially impossible.

            Here's a URL [afp] that doesn't use IP. It works great on my machine. I hope it is similarly useful to you!

            Now if IP is totally unsuited for the application then we shouldn't use it for the actual conversation. But IP can certainly be the bootstrap that we used to negotiate a better protocol. If we can't negotiate that better protocol at least we can communicate why so the end-users know what is going on.

            If your application consists primarily of transferring files without stringent latency issues, IP is fine and in fact HTTP is usually fine. Most devices have a need to transfer files, whether they are address books, musical ringers, or other configuration files. Can we agree that IP is the best solution by virtue of its ubiquity and simplicity?

            Once IP is so-deployed, it also makes sense to use it as a boostrap into other protocols -- if you can handle the latency of the negotiation. IP (whether v4 or v6) is the protocol least likely to go away so using it as a boostrap frees your hand to experiment more easily with other kinds of protocols (e.g. streaming sound and video protocols which are always changing).

            Both of these argue that IP really should be deployed everywhere. Anyhow, it is hardly worth arguing about. Before 1990 we lived in the world where there were dozens of competing protocols and applications had to explicitly bridge them. That world went away for a reason and it isn't coming back no matter what we conclude on Slashdot.


      • However, as long as the masses believe there is some magic inherent in end-to-end un-NAT'ed networks, IPv4 will remain God, and IPv6, among other things, will never arrive. (It's not magic, it's bad design which requires end-to-end transport without allowing for the possibility of transport conversion.)

        I don't follow this part. Aren't the alternatives IPv4 using NAT versus IPv6?

    • Presumably, because then you only need to buy a set of really decent IP hardware - which is practically commodity these days compared to something for "insert new protocol here". Lowering the cost (ongoing and initial) makes it closer to achieving profit.

    • The obvious answer: convergence (Score:5, Informative)

      by tlambert ( 566799 ) on Sunday September 15, 2002 @11:07PM (#4263537)
      The obvious answer: convergence.

      If everything is over IP, then you can guarantee at least transport level interoperability with everything. That lets you do things like access mapping services or locale aware restraunt guides, etc., without having to gateway the content.

      It also gets around the price differential for long distance service, and further commoditizes the pipe providers as just that: pipe provider, rather than toll-booths that bill based on destination.

      Back in the DNSEXT (the IETF working group on DNS), there were a lot of cell phone providers who wanted to assign an IP address to every telephone, making it directly addressable from an outside server.

      Among other things, this would let them push content to your phone, based on having a phone/IP identity, so that the phone could be contacted directly.

      The downside of this is that they are not really planning on forcing the use of IPv6, and the IPv4 address space actually has too little remaining space for there to be the possibility of assigning an IPv4 address to every cellular telephone in existance.

      So while convergence is attractive for the cell phone vendors, and the local carriers (neither of which who could care less if the long distance providers continued to make money, other than as flat rate pipe providers), it's unlikely to avoid the issues of having to have a gateway (NAT) device, unless they go IPv6. The current 3G phones in Europe (and the "2.5G" pgones in the U.S. require gateway devices).

      FWIW, both Nokia and Ericson engineers were interested in the IP-per-phone idea when the issue came up on the mailing list, so it's likely they will be the first to be pushing the idea in the future.

      -- Terry
      • All GPRS rollouts today use NAT, because the predicted number of active always-on users was so high - at one point the GSM Association asked for something like 2% of the IPv4 address space and was told to go away...

        UMTS requires that IPv6 is enabled in some areas, and use of IPv6 is mandated by the UMTS Release 5 IP Multimedia System. This is a big driver for IPv6 and is one reason why Cisco, Juniper, Sun and co are shipping production IPv6 code.

      • Re:The obvious answer: convergence (Score:4, Insightful)

        by mesocyclone ( 80188 ) on Monday September 16, 2002 @03:56AM (#4264198) Homepage Journal
        If convergence is the only reason, why not just do it all over TCP/IP or even HTML? (Answer: engineering reasons - same argument one might make against IP itself!).

        Furthermore, IP is a low level protocol. It doesn't guarantee interopterability! To have interoperability, one needs all levels of the protocol stack to be compatable, and the hardest one there is the applications level, not the various transport levels. This means, for example, that if your phone does messaging, that it interoperate with other phones and/or hosts that provide messaging service. IP is the least of your problems in that regard!

        I could see having, IPv6 addressability for all phones, but that is not the same thing as actually using *IP* as the transport mechanism.

    • Re:Why IP? (Score:2, Interesting)

      by silas_moeckel ( 234313 )
      Because IP is working on being ubiquitious no it's not a perfect match for voice applications but everybody wants access to IP networks thats a given so why not run something that works reasonably well and avoid a legacy network. IPv6 is something the telcos are still trying to figure out a way to bill for so it's not happening in the commercial world more than the accountants can avoid. But just think VoIP could be the killer app that gets QOS features standard accross the board finaly. QOS might push us to IPv6 and thus to multicast and finaly getting rid of NAT (this is a good thing) but still dosent solve a better way of figuring out routing better than today. And who knows maybe with VoIP we can just pay for the data as in cell phone in range of home wifi gateway use that connections instead same for office etc.
    • Why IP? Because it's cheaper for the service provider, that's why. And it it's cheaper for the service provider, it's cheaper for the end user. VOIP means they don't have to give you a dedicated line for sending your call. Your call is already multiplexed over the air (What did you think the M in TDMA and CDMA stood for?). So why not multiplex it more over the wired portion of the call? Why do they push digital multiplexing algorithms so much? Because it's cheaper!
    • Good business.

      If you build your network to use IP it can carry anything not just voice, so you increase your market catch.

      Mobile data is one of the few things selling at the moment.

      D.

  • Downloadable Voice Filters (Score:3, Funny)

    by martyb ( 196687 ) on Sunday September 15, 2002 @10:02PM (#4263339)

    ...your "voice" (er .. audio) just becomes bits that your programs can manipulate before sending."

    Great. Just Great. First it was downloadable ring tones. Now it'll be customized voice filters. I can just see the advertisement now:

    For your next heavy-breathing prank call, get our Darth Vader filter NOW! ;^)
  • The clarity is bad enough already. Why throw more noise in the way. Aren't cell phones already kinda internet-enabled? Aren't they just p2p voice-only clients?

  • This could be great (Score:5, Funny)

    by Daimaou ( 97573 ) on Sunday September 15, 2002 @10:15PM (#4263388)
    "your "voice" (er .. audio) just becomes bits that your programs can manipulate before sending."

    I can't wait until someone creates a cell-VoIP-phone virus that scrambles your sentences into vulgarities and profanities whenever you try to call your mom.
    • Hi, Mom! How are you?

      I send you this stream of obscenities in order to have your advice.

      See you later

      Thanks
    • "I can't wait until someone creates a cell-VoIP-phone virus that scrambles your sentences into vulgarities and profanities whenever you try to call your mom."

      This reminds me of a dorm room joke. If you want to spook your dorm-roommate-buddy, then do the following:

      Just before the person is about to enter the room, pick up the phone and pretend to be having a terrible argument. You scream obscenities into the phone and slam the receiver down. Then, you look at your astonished room mate and say, "That was your mom, she said she'd call back."

  • Concerns (Score:4, Interesting)

    by cadillactux ( 577893 ) <jr111@ca d i l lactux.org> on Sunday September 15, 2002 @10:16PM (#4263391) Homepage
    Maybe it's just me, but I am forsee so many problems with this. With VoIP cell phones, your phone would bascially become another 'computer'-like node on a network. Look at the problems facing computers today.

    First, as mentioned a few posts above, it would be simple to add a voice filter to any phone. Download a program into it, and it will manipulate the bits making your voice unrecognizable. While in some cases, this is a plus, with the annonimity of cell phones now, this could be used for all sorts of prank, and malicious phone calls.

    Viruses will run rampent(sp)! A simple cell call from one VoIP phone to another could potentially carry a virus embeded into the bits. Answer a phone call, and your phone's screen starts flashing with Devil horns... or an IE logo... Your phone is now dead.

    In addition to viruses, 'dialer' type programs could potentially be downloaded to your phone, and used to call other phones to spread. Your think pr0n dialers now are bad, imagine your phone bill coming in only to notice that your have 100 out-of-country calls on it.

    These are only a sampling of the problems we could face. DoS phone attacks, worms, everything that attacks a standard computer now could be used against your cell phone, after all, they are all built about bits sent back and forth...
    • How did this ever get modded up? A VoIP virus?

      Yeah.... just like all those viruses my computer got from MP3 files.... I mean, look at them... they've destroyed so many computers. Because I know every phone will try to execute the audio data... Because that's what you do isn't it? You execute audo data as instructions???
    • I'm not specifically picking on the post I replied to, but to all of the posts of this train of thought.

      You guys, I thought we were GEEKS here. I would love a VoIP cell phone, purely because it would be a VoIP cell phone. I am logged into AOL Instant Messenger 24 hours a day on my desktop, my laptop (when not in transit) my work machine AND my cellphone under 4 different names. Why? Just cause it's cool. I spend ridiculous amounts of money to constantly keep my computer hardware top-notch, cause I enjoy it. I run 4 different operating systems (Sun, RedHat, Windows and an AMIGA) on my machines, because I think it's neat. I mess around with proto-type and beta operating systems and software cause it's fun. I built a switch for my gaming consoles so I wouldn't have to unplug and replug their RCA cables, cause it was an enjoyable project. I own a 8-line modem switch so I can dial into my house and tape drives from the 1970's cause they're awesome things to have.

      News for Nerds. Stuff that matters.

      We're geeks, come on. Talk about how cool this is. Don't go attacking everything that comes by that is impracticle! Geeks are all ABOUT impracticle items/obsessions.

      Send me one. I'll start using it now.
    • Your supposition has a fundamental flaw. You are confusing an operating system and an IP stack. Just because has a device has an IP stack does not mean it will start behaving like windows. By that logic, every router, switch, or linux box should do everything a windows box does because of the evil IP stack.
    • Viruses will run rampent(sp)! A simple cell call from one VoIP phone to another could potentially carry a virus embeded into the bits. Answer a phone call, and your phone's screen starts flashing with Devil horns... or an IE logo... Your phone is now dead


      A phone called placed between two VOIP enabled devices using SIP has about as much chance of executing arbitrary code as a browser does displaying a jpg image. Yes, a chance exists (poorly written code with buffer overflows at precisely the wrong time) but on a scale of 1 to 10 it's a -7.

      Everything else you listed can be done using current technology without VOIP cell phones. You can buy a voice muffler device from RadioShack, not to mention a bag with marbles worked well for Charlie Browns teacher (waaah waah wahhh wahh?).

      Put down the joint, lose the paranoia, and see the brigther side of life (tunneling your cell phone calls over WIFI points bypassing Ma'Bell and possibly for free or pennies on the minute).

      -malakai
      • A phone called placed between two VOIP enabled devices using SIP has about as much chance of executing arbitrary code as a browser does displaying a jpg image. Yes, a chance exists (poorly written code with buffer overflows at precisely the wrong time) but on a scale of 1 to 10 it's a -7.


        Have you studied SIP? It's just begging for security problems between the nightmare of parsing and the arbitrary URLs being allowed in various fields. If a SIP message has "Alert-Info: <http://cracked.site.com/booby_trap.wav>", in it, do you think the SIP stack is going to fetch and play the ringtone, or will it hand it off to, say, a browser, or perhaps a media player?

        One still has to wonder about diddling with the Via: headers in a message to redirect the response path to target systems within a network, but, well, that is another topic.

        It's going to take years for SIP to get secured -- it's too new to have had a thorough shake out.
  • so now w/ VoIP they **AA can put DRM in our cell fones and put on content filters to keep us from speaking copyrighted phrases etc, although this could put an end to people calling me and asking me if i can hear them now...
    • the *AA's won't stop you from using it...they'll make you pay per use of each catch phrase...

      Sample phone bill

      "can you hear me now" $1
      "What'chou talkin' bout, willis?" (from a phone call with your friend willis) $1
      "Use the Force" $20 x 456 uses $456 ...and down on the line...
    • Another application could be pgp encryption on phone systems. i don't know if that has anything to do with the network layer......but I think this would be a great deal.

  • and...? (Score:3, Insightful)

    by Scaebor ( 587064 ) on Sunday September 15, 2002 @10:21PM (#4263408)
    You might ask "why bother? We already have wireless voice now." But with an open platform for wireless (Symbian, JavaPhone etc), your "voice" (er .. audio) just becomes bits that your programs can manipulate before sending."
    and... this is the explanation? What am i missing here? This is a serious question. With all the ideas that you people come up with there must surely be some good reason for having a phone that has ip integrated into it.

    • Re:and...? (Score:1, Redundant)

      by SandSpider ( 60727 )
      One example would be encryption - you could, for example, use gpg to encrypt the packets, or whatever the latest hot encryption scheme is. If you want to change it, that's a simple task, since it's just software. You don't have to buy and install new hardware just to change the way the phone works.


      And, of course I know that it would be impractical to do with the current VoIP systems, since a lost packet would cause no end of difficulty. I'm talking in an ideal world.


      It wouldn't be necessary to do VoIP to do this, though. Special 'data-phones' could be made that start a call, check to see if there's a compatible phone on the other end, and start a data connection if so. Though that wouldn't be very high quality over a 56k modem, chances are, though you could get by a lot better with a specialized protocol that doesn't have the overhead of TCP/IP, I suspect. But really, I'm just making all this up, now.


      =Brian

  • I'd rather (Score:3, Insightful)

    by URoRRuRRR ( 57117 ) on Sunday September 15, 2002 @10:22PM (#4263410) Journal
    I'd rather have phones that worked really well first. I'm tried of having half of my calls dropped.

  • Latency & Jitter (Score:5, Insightful)

    by chill ( 34294 ) on Sunday September 15, 2002 @10:24PM (#4263415) Journal
    Voice uses circuits for a reason -- latency and jitter *must* be controlled or the conversation goes to hell.

    There has to be more to wireless VoIP than simply 3G+ data -- it must be able to control the timing of the arrival of packets.

    No, you can't buffer it. Voice conversations are realtime interactive. Fat packet sizes don't help, either. There is a limit to how long you can spend processing the data into and out of a packet before you screw up the timing.

    They have a LONG way to go before this will be realistic.

    • Re:Latency & Jitter (Score:1, Funny)

      by Anonymous Coward
      Hello?

      (wait one and a half seconds)

      (click)

      How weird that a telemarketer shows up on call display as my mother...
    • Voice uses circuits for a reason -- latency and jitter *must* be controlled or the conversation goes to hell.

      True, however if the network is lightly loaded, IP introduces negligable latency and jitter. VOIP is already being used for long-distance telephone calls.

      There is a limit to how long you can spend processing the data into and out of a packet before you screw up the timing.

      True. However we are not talking about big packets. Normal telephone quality is only 64kb/s (56kb/s in the US). The reason they are going with VOIP is compression- you can compress the date down by a factor of perhaps 4 fairly easily; partly because you can compress the sound by that much quite quickly, but also because on most telephone conversations only one person talks at once. That's important in a wireless phone network.

      • Re:Latency & Jitter (Score:3, Insightful)

        by chill ( 34294 )
        True, however if the network is lightly loaded, IP introduces negligable latency and jitter. VOIP is already being used for long-distance telephone calls.

        True, but no phone network is lightly loaded, except at 2:00 a.m. or so. The phone companies have oversubscription down to a fine art.

        The VoIP compression kicks in on the backbone transit, as opposed to the actual endpoint allowing more data to be multiplexed in. Yes, silence supression, comfort noise and single/full-duplex play a big part.

        Actually, many of the phone networks are doing the VoIP modulation at either end, then using ATM switches in between. So, in essence, there is still a circuit. However, MPLS is starting to be a big buzzword and companies are starting to deploy it as opposed to Frame Relay and ATM. Still, ATM is king when it comes to these types of applications. Real QoS, real ToS, can't be beat.

        • True, but no phone network is lightly loaded, except at 2:00 a.m. or so.

          VOIP gives you a 4:1 compression or more anyway, so for any bandwidth you already have, you're better off converting it to VOIP, and bingo- no significant congestion! If you have no congestion on your data network, you have no significant latency. You don't always need fancy protocols. You then have spare bandwidth as well.

          • Traditional voice is compressed as well -- VoIP doesn't add signigicantly to this. There is no real compression benefit here.

            Latency is more than just congestion. It is also affected by the number of 'hops' to go thru, the size of the routing table, any necessary reroutes, etc.

            VoIP is not a magic bullet for networks, it is a buzzword. It also DOES help them consolidate equipment.

            Much of the traditional digital cellular traffic is switched thru an ATM fabric. The ATM units are drastically underutilized by this and adding an OC-12 card and separating out the data would be trivial.
            • Traditional voice is compressed as well

              It can be, but it isn't usually, ISDN voice calls aren't for example, most but not all landlines aren't (except if you are a long way from the office). Even when it is, you still have to leave both directions open I believe.

              VOIP doubles capacity again, because they can usually run it half duplex and rely on statistical multiplexing. That's more difficult with traditional compression techniques.

      • The reason they are going with VOIP is compression- you can compress the date down by a factor of perhaps 4 fairly easily;

        I'm not sure what your point is: Modern mobile phone systems are also digital and doing compression. It actually to find code for GSM compression [tu-berlin.de] on the net! Anyway, compression and digital transport is not a reason for VoIP.

        Lars

        • Ok, I've got this voice network set up, and I can handle 100,000 calls per hour. If I go to VOIP I can handle 300,000 calls per hour. You're arguing that that is not worth doing?

          It's the statistical multiplexing that IP and VOIP provides for that allows the compression to work...

          • And where are you getting these numbers from? I just reread the article and I don't see a claim that VoIP will do better than other digital wireless phone technologies.

            The discussion is about wireless VoIP, and even todays mobile phone systems such as GSM are already doing AD conversion and putting the bits in packets. With compression.

            Lars

            • GSM does use compression, but does not put the voice traffic into packets, they use fixed timeslots, of a fixed size.

              GSM voice traffic doesn't use IP!

              GSM phones use nailed up connections for their voice traffic whilst the call is up. They also have data channels which are used for control information, but the voice goes over the nailed up connections. They therefore can't use the statistical multiplexing that VOIP uses, and they can't run single duplex, because their voice bandwidth is connected at the beginning of the call and disconnected at the end.

    • Re:Latency & Jitter (Score:4, Funny)

      by Arandir ( 19206 ) on Sunday September 15, 2002 @11:18PM (#4263564) Homepage Journal
      You don't understand. VoIP is a buzzword. That means all the cool companies must have it in order to stay cool. It doesn't matter if it works or not. It doesn't matter if you can't understand the guy on the other end of the line. It doesn't matter if it overloads your network to the point of unusability. It's cool so cool companies must have it.
    • You must be confusing "voice over IP" with "crappy free telephone calls over the public internet". Voice over IP in a controlled private network can have strict QoS guarantees on latency, jitter and packet loss. VoIP is actually used by many millions of people, most of them don't even know it.

      Cellular networks use voice compression codecs that must accumulate a complete block of samples before compressing and transmitting it. They also use heavy error correction. Both of these factors introduces a very significant latency. If the voice compression blocks, error correction blocks and VoIP packets are all in sync some of these latencies overlap instead of adding up and it may not add any significant additional latency.

    • QoS for wireless (Score:3, Informative)

      by Cato ( 8296 )
      So VoIP needs QoS - this is a well established technology in IP. There are wireline VoIP providers today who use private IP networks (some using QoS based on queuing) and some who actually use the Internet and get good QoS - the latter have to closely monitor achieved QoS and be ready to switch their traffic to another provider, but they claim good QoS and their costs are very low.

      For dependable service, network switching is not enough and QoS is probably essential. This is particularly true with 3G where you might be able to choose from the following VoIP-related services, all with different bandwidth/latency requirements:

      - simple voice call

      - stereo call (listen in to a live concert perhaps?)

      - conference call (high QoS)

      - multimedia conference (voice, data sharing)

      - videoconference

      These more flexible IP services are where circuit switching falls down.

      IP QoS will have to develop hugely to work for wireless, though. In wireline environments, you can set up a QoS session using RSVP and have it stay up for minutes or hours, so setup latency is not a big issue. In wireless, the caller could be moving between cells in a car or train, and might spend only a matter of seconds in each cell - every time they move to a new cell, their QoS session must be partially recreated (from the core network to the new cell), in a matter of tens of milliseconds.

      For quite some time, it may be more cost-effective to overbuild networks and introduce simplifying constraints, but eventually wireless IP QoS should take off as an invisible support for wireless VoIP and multimedia over IP.

      UMTS, a key 3G standard mostly used outside North America, will be All-IP in Release 5, which is nearing completion and should be rolled out in a few years. This mandates the use of VoIP for all use of the IP Multimedia Subsystem (which enables the advanced services listed above). Current UMTS rollouts are using Release 99 or Release 4 (formerly Release 2000), which are much less IP-based.

    • Re:Latency & Jitter (Score:2, Informative)

      by CiaranMc ( 149798 )
      No, you can't buffer it

      Why not?

      Existing digital cell systems already have a significant delay and you just don't notice it. Next time you're in a cell->cell call try singing along to music that's playing at the other end. To the other person you'll sound hopelessly out of time.

      -Ciaran
  • So i can finally use some software to mutate my voice when i wake up my friend saying 'Hi, this is Detective X from LAPD' or something similar, and as he/she is so sleepy he/she won't check caller information but tries to recognize by voice... so that kind of phone would make it way more easier ;) i wonder how many mornings i have been waken up somebody saying something very odd on the phone and i cannot recognize the voice and just think, wtf, am i suspected about something? being so sleepy that i don't check the phone's screen for who it is... sometimes call was pretty shortly over and at somewhere middle of day i remember and check that caller information... Lol, best one to date have been someone calling me middle of night saying 'is your pillow allright?' and then giving me a long silence before i knew who it was =) Yeah, i know this is way offtopic... and yeah it's middle of night here, 5AM to be exact... perhaps time for a good 'night' sleep... Btw, to be in topic that kind of phone would give probably a lot of some nice features with it...

    Cybernetic Zombie's Network [czn.ath.cx]
  • now all we need is a hack for these to use open wireless networks to make calls to japan for free...without some poor sap to foot the bill for the phone charge, just the bandwith. Does anyone else foresee a new phreaking frontier?
  • It seems today that everyone is trying to take something designed to operate over a private/proprietary network and push it out over the internet. In the article, Waryas says, "there is a potential return for carriers using the IP backbone to transfer calls versus digital signals". If this were to materialize over the next three years, what can we expect of the internet backbone as a whole? Phones already have an addressing system (aka a "phone number"), is it a good idea to provide an IP address to _every_ cell phone? Perhaps IPv6 could help here, but it also begs the question of who will absorb the added bandwith utilization/costs? A call from east coast to west coast could traverse two or three backbone providers. I can just imagine the congestion at the peer points.

    Don't get me wrong, it would be really nice to have a handheld device or laptop + handheld/cell phone to be able to natively handle IP traffic, but I also wonder what the long term affects would be on the traditional internet...
    • If this were to materialize over the next three years,

      The statistic I heard is that already 20% of all long distance calls are on VOIP. (They usually use private networks right now though.)

      what can we expect of the internet backbone as a whole?

      Not a lot actually. We passed the point where most traffic was data traffic a couple of years ago. The data traffic is doubling about every year. The voice traffic is going up by some single digit percentage every year. Therefore very soon, voice traffic will be completely inconsiderable part of the internet.

      • The statistic I heard is that already 20% of all long distance calls are on VOIP.

        I suppose there would be incredible incentive for a company to setup a VoIP infrastructure using standard leased links carrying IP traffic. I'm sure the cost savings would be very substantial. I know of some call centers that trunk calls using VoIP to their satelite centers over leased private networks.

        I also don't doubt that VoIP traffice over the internet is rising in the single digits per year. Fairly insignificant if the true non VoIP traffic is doubling every year. But, would the sheer number of cell phones in use cause this statistic to explode beyond belief? Perhaps to the point where VoIP traffic is on par with the data traffic.

        If the above theory would become a reality, I can imagine wars breaking out amongst the backbone providers over who's going to absorb the costs. Say backbone provider B is a transient between providers A and C. Furthermore, say a healthy percentage of B's traffic is VoIP traffic originating from A to C or C to A. Provider B may get a little discouraged over the idea that the amount of transient traffic (peer traffic) vs. the amount of originated traffic (you know, the bandwitdh they actually charge for) is climbing steadily.

        It would be interesting to see some numbers regarding the number of cell phones in use vs. the number of allocated IP addresses within the U.S. Almost everyone I know of has a cell phone.

        Of course, I also agree that this is futher off than three years. As a previous poster already stated, the latencies your see over the net, most of the time, aren't ideal for voice.
        • I also don't doubt that VoIP traffice over the internet is rising in the single digits per year.

          VOIP as a whole is growing far faster than that. VOIP on the internet- I'm sorry I don't know.

          Perhaps to the point where VoIP traffic is on par with the data traffic.

          The whole point of VOIP is that you send voice as data, so... no. ;-) Besides there's already more data than voice, so it's looking unlikely those two lines are ever going to cross again right now.

  • "Sorry, I got to keep this phone call short! If I talk too long, the VOIP processing chip heats up and burns my cheek!"

  • What's wrong with this picture? (Score:4, Interesting)

    by Animats ( 122034 ) on Sunday September 15, 2002 @10:54PM (#4263509) Homepage
    From the article: "A completely new infrastructure is needed with fatter pipes." Huh? We need a new infrastructure for voice so it will work worse and cost more?

    This looks like yet another dumb justification for 3G cell phone technology. If you just want to ship the voice over long distances as IP, there's no reason to do it in the handset. Do it someplace where you have the connection to a fat pipe in place, like the cellular CO.

    Voice over IP is an artifact of telecom pricing and history, not a technical advance. Circuit switching and packet switching now cost about the same (and they're likely to both be over ATM at the bottom.) But voice is billed by the minute, while the Internet is typically a low flat rate, and many countries use landline voice to subsidize other stuff.

    But cellular has less of that heavily-regulated history. Where's the justification for this?

  • My Programs? (Score:2, Insightful)

    by evilhayama ( 532217 )
    Just consider the possibilites of what I could do to enhance my telephone calls now... Get some mp3s in the background putting my phone call to a soundtrack, maybe adding sound effects here and there to spice up the conversation? ^_^ (not to mention the aforementioned voice morphing)

    More seriously, does this mean i could encrypt my phone conversations with fellow terr... associates?
    • don't let that get out, with the patriot act, you don't want the big guys to even think about the applications we might have until its ubiquitous.

      I love my government, but I fear them more.
  • I mean really, we've been suffering with this lo-fi telephone stuff for a long time. Obviously the technology exists to have higher sample rate/depth audio even on simple computers. I remember recording "CD quality" sound with my 75mhz Pentium and a cheap $5 mic from radio shack. Yet telephones still use incredibly low sample rates.

    We could even use some kind of audio compression on the data to achieve and end up using about the same amount of bandwidth. That normal telephones use now. I mean, a two channel mp3 sounds OK at 112kbps, so a one channel one should sound near CD quality at 56kbps.

    If a cell phone came with VoIP on a G3/G2.5/whatever cell net, I would imagine it would be pretty easy to get it to run with high quality audio. Assuming that anyone would care.

    (It would also probably require modifying the earpieces in cell phones, as they are obviously not designed for high quality audio)
    • I remember recording "CD quality" sound with my 75mhz Pentium and a cheap $5 mic from radio shack

      "CD quality" does not been just having something recorded at 44.1KHz at 16 bits. A $5 rat shack microphone and a sound blaster is not going to get you anywhere near the capabilities of that low (vs. 24/96 or even 24/196) sample rate. Good audio equipment costs some real money. Take a look at this [midiman.net] for a good quality entry level audio card. With good audio equipment (pre/pro [rotel.com], speakers [bwspeakers.com]), your $5 rat shack microphone recording will sound like utter crap compared to something recorded with this card (and a sennheiser or comparable microphone). Simple playback of normal CDs through this setup will also be an eye opening expierience.

  • your "voice" (er .. audio) just becomes bits that your programs can manipulate before sending.

    And just why does this require IP? Did you ever stop to realize that circuits can be digital? Why go to all this trouble to grind the internet to a halt just so you can get packet switching instead of circuitry?
  • Now I won't have to use a clumsy voice changer when I call in my ransom demands, because it will be built into my phone. Boy!
  • what we need is ubiquotous, wireless internet access. forget all these cell standards. just give me airtime, i'll bring the device, what i do with it is my own business. if there were a better mechanism in place for net-to-net phone calls, we could do away with the legacy telephony infrastructure entirely. HOORJ!
  • I've been using http://www.vonage.com for a couple of months now, and despite a few billing issues which have now been resolved, the service is great.

    I can now make thousands of minutes of calls to the USA for $40/mo. I'm in the UK and so effectively get free international instead of free long distance.

    If any of my friends here want to save $40 with a referral then let me know :) graha dot ms at graha dot ms
    • Holy Potato !

      I've spent weeks looking for a US (pref NYC) based VOIP provider and finally on slashdot I find a recommendation. Two questions : How did they respond when you said you were UK based and how did you get the voip router over here ?

      Consider the $40 on the way !! I'll email later.

  • To replace the "whiny little dweeb" module it has now...

  • VOIP?? Do it yourself and do it for free! (Score:4, Informative)

    by Travoltus ( 110240 ) on Monday September 16, 2002 @01:22AM (#4263838) Journal
    I am wondering, don't they have PDAs now that have sound capability? If so, why not get a PDA running Linux and Gnomemeeting, get wireless 802.11b access, and chat with someone else with the same setup, for free?

    Assuming of course that your PDA has sound capability, and you can hook it up to an available wireless high speed net, and the OTHER person has all of this, too. (Or at least, they are sitting by a computer running Gnomemeeting or Netmeeting.)

    The PDA can also do a lot more at the same time, besides acting as an internet "cell phone", so really, it potentially gives more bang for the buck, than a cell phone doing VOIP. (Of course, cell phones are also becoming multifunctional.)

    I have already talked to friends using a laptop on a hardline (ethernet) connection. Setting it up for wireless voice chat - or even wireless VIDEO chat - is now a cinch. The drawback is a laptop, even a "notebook", is unwieldy due to its size, as a makeshift cell phone. But it has vastly higher capacities for running software concurrently, and storing data, than a PDA, much less a cell phone.

    The point is, we 'hackers' should be working to create an infrastructure where we can easily communicate via voice and perhaps even video, over the internet, WITHOUT extra charges (which VOIP inflicts upon you). We can do it - so why don't we?

  • Oh the latency! Oh the latency! (Score:3, Interesting)

    by io333 ( 574963 ) on Monday September 16, 2002 @01:22AM (#4263843)
    My SprintPCS phone already has about a quarter second lag time between transmission at my end and reception at the other end, which, for a fast talker like me, is incredibly annoying. I always end up talking over the person at the other end. If that person doesn't realize what is actually happening, they often think I'm being extremely rude.

    The delay is caused by the lag for A-D conversion in my handset, added to the D-A conversion and then possibly A-D again and then D-A again if I'm talking to a different digital cell phone user on another network.

    Now if something like that were going to be combined with the added, and sometimes horrible latency of VoIP. Oh forget it. Just give me a land line. I'll pay whatever I have to for the luxury of 1880's technology.

  • VOIP rules (Score:1, Informative)

    by Anonymous Coward
    I recently started using a VOIP Blaster between Seattle and Virgina with the open source Fobbit drivers. It works *great*. I love sticking it to the RBOCs.

    With cable modem, the quality and latency are very good with UDP. TCP experiences some jitter, and the quality is only fair.

    Bandwidth is only 1.5 KB/sec. There's no reason it wouldn't work from a wifi laptop.
  • to say VoIP Cell Phones cloning.
    I wonder how long...

  • You might ask "why bother? We already have wireless voice now." But with an open platform for wireless (Symbian, JavaPhone etc), your "voice" (er .. audio) just becomes bits that your programs can manipulate before sending."

    Hey, we've discovered a slash bug.

    See how the article cuts off right there? Where's the rest of the explanation? He must have actually answered the question in the complete article! ;)

  • What everyone seems to be missing is the real usefulness of this, which is indoors.

    Would you as a company rather have your employees wandering around your site running up silly bills on their company mobile phones, or have all calls from within the site routed through your nice cheap switchboard?

    Also I work in a datacentre which seems to have just as much metal as brick in the walls. Wireless VoIP phones are excellent in that you can walk over to a server room and work on a server whilst talking to someone due to the provision of WAPs within the building. With GSM and 'landlines', this would be impossible.
  • I've been saying this was the direction wireless carriers were going to go for several years. Even wrote an article [linuxtelephony.org] on LinuxTelephony [linuxtelephony.org] about it September, 1999.

    Once the carriers are able to deliver real data bandwidth, then using data-centric technologies to transfer voice will make more sense and will ultimately prevail.
  • I've always understood that the big draw behind VOIP (I refuse to lowercase the O!) was that, given a fixed-rate internet connection, you could talk more or less forever without paying anything extra.

    The thing is, my current cellphone plan is $30 a month, and with that I get 250 anytime minutes, 1000 night and weekend minutes, and free nationwide long-distance. And I've never used more than 200 minutes in a month. The service area is pretty good (AT&T Wireless), the service quality itself is pretty good, and my phone (Nokia 6162) is well-designed and easy to use. So what does VOIP offer me?

Slashdot Top Deals

Top Ten Things Overheard At The ANSI C Draft Committee Meetings: (5) All right, who's the wiseguy who stuck this trigraph stuff in here?

Close