Why Sprint says WiMax is 4G
Mobile chips and lower costs wil drive it.
By John Cox, Network World | Network World US | Published: 01:00, 17 October 2006
In a voice hoarse from a day of talking, the man in charge of 4G at US carrier Sprint dissects the physics of mobile WiMax, explains the economics of the Sprint network being built on it, analyses the need for a radically simple user experience and explains what it all means for his grandchildren in England.
Londoner Barry West, formerly of Nextel, is now Sprint's CTO and president of its recently created 4G business unit, charged with spending at least US$2.5 billion to deploy 802.16e mobile WiMax base stations, covering 100,000 points of presence, by the end of 2008. That deployment will start in late 2007, delivering 1Mbit/s to 3Mbit/s service to subscribers.
Sprint will be competing with Clearwire, which reaped $900 million in new funds, including $600 million from Intel Capital, to extend its wireless broadband net and migrate to mobile WiMax.
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Later this year, Sprint will launch some early campus-style 16e deployments for selected enterprise customers, West says. He's meeting with a medical center while here and talked recently with a company that is evaluating mobile WiMax to cover a massive manufacturing plant.
These early deployments will use field programmable chipsets, rather than the more sophisticated chipsets, called ASICs, due next year. As a result, these campus deployments won't be fully mobile - supporting two-way video streams between the network and a car, for example.
Most of these trials will have as many as four or five base stations and users will connect via PCMCIA cards in laptops, West says. "A lot of people are real enthusiastic about having an 'Internet anywhere' experience," he says.
The big pictureWest sounds almost utopian as he explains the big picture of what all this will mean. WiMax-based 4G networks will make possible pervasive, immediate, visual interactions that he believes will make for a better, and more humane, world. "It's hard to stay mad at people when you're in close communications with each other," he says. A mobile WiMax network, with the bandwidth to support voice and video, will make such closeness possible, he says.
He describes a not-too-distant future in which his daughter can set up a small digital camera and a companion, compact flat screen so he can view his granddaughter's recital in real time. "I can literally be there with her," he says.
But there's nothing sentimental in his analysis of the challenges facing Sprint in its plan to create a nationwide mobile WiMax net.
"WiMax creates a 10-fold improvement in the price-per-bit," he says. "That is made possible by the fact it uses a wider channel."
West says that CDMA networks today use a 1.25-MHz channel, which under optimal conditions can deliver 4 bits per hertz, or about 5Mbit/s at the base station. By contrast, WiMax uses a 10-MHz channel, with a total of 40Mbit/s.
And WiMax chips benefit from the economies of price/performance known as Moore's Law, compared to the older Code Division Multiple Access (CDMA) technology. The result: WiMax is one-tenth the cost per bit of CDMA. "It's as simple as that," West says. "It's physics."
Sprint's plan is to have 100,000 points of presence enabled with WiMax service by the end of 2008. The network will be an overlay on the company's existing CDMA EV-DO 1x cellular net. Subscribers will be able to use either network, depending on coverage and services, through network cards and eventually through integrated wireless interfaces, West says.
A related development will be interfaces that combine both 802.11 wireless LAN and 802.16e mobile WiMax chips. "These combined chipsets will be common," he says.
Sprint's subscribers will be using indoor access radios to connect to the WiMax net. The intent is to make this connection extremely simple to use, he says. Initially, a lot of users of the Sprint network will connect via PCMCIA cards with mobile WiMax chipsets. Because West thinks the availability of truly pervasive multi-megabit wireless Internet will be a powerful attraction, part of his time is spent talking to consumer electronics companies, including Sprint's WiMax partners Motorola and Samsung, persuading them to integrate WiMax into their devices.
"This isn't about a data net being used by [relatively] few devices," he says. "We talked to one consumer electronics company about putting WiMax in a TV set, and with another about putting it in printers. Once you do that, you can then deliver other services over that [WiMax] network."