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by Manx Telecom has released what could be the first cellular based technology to rival broadband download speeds. High-Speed Downlink Packet Acces or HSDPA is the new technology that is currently replacing the 3G technology as the faster data network for wireless devices. HSDPA sports a download speed of around 1.3 Megabits per second, although the upload is only 128 Kilobits per second.
Other companies currently pursuing HSDPA networks such as Lucent predict their networks to handle 7.3 Megabit download rights by the first quarter of 2008. There are also companies such as O2 that are developing handsets already to access this type of network. With bandwidth this high, could IP Handsets operating over a wireless type network be possible?
Currently Manx is offering the Wireless Aircard for around £49($85) with service after the first three months costing about £39.95($69) per month for 100Mb of data. Unfortunately it is only available in Europe at the moment, expect it very soon in the USA.
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Wireless VoIP Could Be Done Now by VnutZ :: NR8 :: on 10 November 2005
With bandwidth this high, could IP Handsets operating over a wireless type network be possible?
You never even needed to approach that bandwidth for IP handsets to be possible. Let me borrow from page 9 of Cisco's Voice Over IP Fundamentals book:
The most common method of analog to digital conversion for voice is PCM, pulse code modulation. Your average conversation ranges from 0hz to 4Khz in terms of tonal frequencies. Therefore, according to the Nyquist theorem, an 8 bit sample must be taken 8000 times per second. This 8 bit sample is not a linear sample but rather a logarithmic sample favoring bits at the lower frequencies. 8 bits multiplied by 8000 samples equals 64000 bits per second. Thus, a normal, digital phone conversation consumes 64kbps (which you'll note correlates to old school modem top speeds prior to V.90 style compression).
This all depends on what the service provider is really defining their network to support. Is 1.3Mbps a per handset guarantee? If so, you could run nearly 100 VoIP systems through your single handset (and that's allowing for 50% network overhead). Or they could be touting 1.3Mbps burst speeds which implies a per tower traffic load of 1.3Mbps that could be tapped at any given time provided other users weren't already using it. VoIP is even more efficient than PCM with advanced audio compression, silence detection and less intermediate interfaces to induce delay.
What's really interesting about telecommunications, is that just about everything you're doing is already digitized. Most conversations you have are only analog between your handset and the copper wire local loop to your call office. After that, everything is handled on a digital packet network using ATM, SS7 or other various technologies. In many cases, VoIP already is used on the backbones between call offices. As a cell phone, your entire conversation is digital thanks to technologies like PCS and the like. The next step is converting from proprietary digital signaling formats to using IP. A step that might only be in delay because it frees the consumer from buying into the service providers equipment base.
A lot of the VoIP hype is actually just extending an existing service from the vendor directly to the customer instead of merely passing traffic from vendor to vendor.
Now I'm not advocating that we don't need raw bandwidth on a portable device. That's just cool!