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VoIP Cell Phones Coming
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."
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.
ideas should be free
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
"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 for a good quality entry level audio card. With good audio equipment (pre/pro, speakers), 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.
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?
--- Grow a pair, liberals... stop letting the Republicans bully you!
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.
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.
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