The Sextel WiMAX Decision ...
>> Sprint Nextel Comes Over All Wimax
Alexander Harrowell
Telecoms.com
09 August 2006
tinyurl.com
Alexander Harrowell believes WiMAX is coming at last.
US carrier Sprint Nextel has been the great hope of the wireless broadband crowd ever since the merger that created the group, a little more than a year ago. The Federal Communications Commission's terms for agreeing to the merger demanded that the new group start a mobile broadband service pronto or lose its sizeable combined holdings of 2.5GHz spectrum and the company rapidly set about satisfying them.
The merger sparked feverish speculation that a major WiMAX deployment was in the offing. This was mid-2005 and WiMAX hype was cranking up to a high-pitched, chattering whine that could only end in disappointment. Industry watchers soon realised that a WiMAX deployment was far from a foregone conclusion - sister publication MCI reported in the autumn of 2005 that Sprint was buying a range of equipment from different suppliers including the UMTS TDD specialists IPWireless.
Since then, the signals from within Sprint had been fairly thin. Clearly, WiMAX equipment (notably from Motorola) was being subjected to large-scale trials. On the other hand, a trial TDD network was installed in Washington D.C. and is actually serving some commercial customers for the sake of realism. IPWireless was indeed the lucky winner, and has claimed speeds of 2.9Mbps upstream and 5Mbps downstream on the Washington D.C. system.
As the FCC's 2007 deadline marches closer, though, there were increasingly strong signs that a decision may be near, or rather, that a decision is near but difficult. The Wall Street Journal, for example, carried a story on August 8 promising an imminent announcement of a WiMAX roll-out, which it framed as a loss for Qualcomm. This is a little odd, as Sprint has not engaged in trials of the ex-Flarion FLASH-OFDM system that Qualcomm is offering on anything like the scale of its TDD activities. Neither has it done anything like its decision to invest significant funds in IPWireless for the alternative OFDM community.
For their part, the TDD vendors' club - the Global UMTS-TDD Alliance - issued an aggressive statement in their regular email bulletin, alleging that Sprint management is split between WiMAX and TDD factions. The Alliance claims that Sprint engineers are in favour of TDD but the marketing side of the carrier is backing WiMAX. Well, they would say that, wouldn't they? Madelyn Smith, IPWireless's director of communications, is holding a firm line on this. "We are incredibly pleased with the performance of our technology," she said. "We still think we have the highest performing mobile broadband technology."
The WSJ's story, it turned out, was poor on the details but bang on the money when it came to the core of the story. Sprint has weighed the technologies in the balance and picked the WiMAX option, planning to serve 100 million subscribers (the condition demanded by the FCC) with 802.16e Mobile WiMAX, with the bulk of the kit coming from Samsung.
Patrick Lund, managing director of Swedish WiMAX infrastructure vendor QuadMaxSystems, summed up the importance of this contract to the industry: "A big player like Sprint has taken the political decision to go with WiMAX. and now others will follow. The interest in our products is very strong."
Sprint is an interesting case, being a rare mixed-technology carrier. As well as a cdma2000 network (in fact, two networks), considerable fixed-line telephone and ISP assets and a major long distance IP backbone, there is also an iDEN mobile network, with the result that it can be expected to be less CDMA-centric than some. It follows that the various engineering and management teams are likely to form different opinions along the lines drawn by group identity.
More fundamentally, the split is likely to be informed by the nethead/bellhead divide. TDD is a carrier-world technology elaborated by the 3GPP and standardised through ETSI and the ITU, which provides mobile IP service over a centralised infrastructure with SS7 switching and at least the option to have circuit-switched voice and video calls as well as packet-switched data streams. It will use IMS, and incorporates the existing SIM authentication technology and BSS/OSS.
WiMAX is a product of the IT industry, has no centralised switching or circuit-switched domain, and is devoid of telco baggage. Handover and configuration in the 802.16e mobile variant are carried out using a version of the familiar DHCP protocol used to assign IP addresses to computers joining a local network. There is no dedicated voice service, indeed, no applications whatsoever. The WiMAX industry's essential pitch is that only they can offer broadband data rates for mobile radio at reasonable cost, or as Lund puts it, "it's a question of money-they've done their calculations and found that WiMAX is more cost-effective."
Exactly how much more cost-effective is another question. Several recent WiMAX deployments have been heavily vendor-financed, and both Intel and Motorola have invested heavily in start-up operator Clearwire. Smith complains that "it's different for us, a small tech company competing with the biggest IT firms. They were quite clear at their press event that there are significant marketing dollars going into Sprint."
It's not hard to see that much of the divide will be determined by the participants' relative degrees of netheadedness. If the planned service is seen as a telecoms-as-media thing, it's possible this may skew the debate to the more "carrier-like" TDD solution - even though IPWireless, its manufacturer, is keen (the clue is in their name) to portray it as a solution for mobile internet service.
On the other hand, WiMAX is a favourite of IT-world people and a bogeyman for the GSM and CDMA industries. Sprint has been known to toy with radical, e-commerce and internet dominated, business models - Martin Geddes, now better known as the consultant and author of the blog Telepocalypse.net, was hired around the millennium to design a mobile commerce and applications platform that never saw the light of day.
Sprint is pushing ahead with the successive expansion of its cdma2000 1x EV-DO network out of the major metropolitan areas and the faster 1x EV-DO Revision A (equivalent to HSDPA in GSM-speak) within them. This phone-centric network might be a more obvious candidate for a fancy services platform, with bulk data users being covered by the new system, whatever it turns out to be. However, it seems to be something of a rule of thumb that whenever a new mobile data technology is switched on, the demand comes primarily from IP-focused data card or PDA users.
Sprint's 1x EV-DO service (Power Vision, in the mildly embarrassing terminology of Sprint marketers) is no exception, with the bulk of its users on laptop data cards. Another common application has been illicit mobile VoIP, whatever the terms of service may say. One of the commonest reasons given by big carriers for forbidding VoIP on their mobile data networks is that they fear for the network's stability if such bandwidth hogs go unchecked, even though Skype data streams are not actually very bandwidth-intensive. On the mobile WiMAX network, this would be a risible assertion and very hard to defend from charges of monopolistic behaviour.
So now they've got their WiMAX, what are they going to do with it? The terms of the FCC decision are unambiguous. Sprint Nextel must launch a wireless broadband service to at least 100 million subscribers by 2007 or lose its 2.5GHz spectrum. This strongly suggests it is internet service that must be delivered, and the choice of 802.16e means that it's going to be fully mobile internet access.
The entire point of IP is that any form of data can be transmitted over it, so it's also likely that Sprint will want some of the capacity for its own proprietary purposes. With the concurrent roll-out of EV-DO and beyond, there's a clear suggestion that Sprint sees synergy between the systems. Samsung, among other things, is to supply dual-mode CDMA/WiMAX handsets. It sounds very much like Sprint's own media-heavy offering - perhaps mobile TV or video is going to straddle the two systems? with tasters and control functions delivered through the EV-DO network (also usefully permitting the existing billing and identity infrastructure to be reused) and the thick stuff pumped out over the WiMAX system.
Naturally, the EV-DO network will also cover the smaller markets where Sprint lacks 2.5GHz spectrum. Although WiMAX should in terms of radio theory do better than cellular systems in covering underserved and rural areas, Clearwire already has these sewn up. WiMAX is coming.
The other alt.networks are left to rethink. Qualcomm has seen the suspension of the 802.20 standards group amid accusations of unethical practices, and now sees its proprietary FLASH-OFDM miss its chance in North America. At the same time, the TDD community will have to hope their mobile-TV business and the other big deployment (IP-Mobile in Japan) can get their show on the road.
Alexander Harrowell writes for Mobile Communications International, where he specialises in network infrastructure and related issues. He joined MCI in March, 2005, and has been blogging independently since 2003, a passion which saw him short-listed for UK newspaper The Guardian's Political Blog of the Year award in 2004. His specialist subjects include MVNOs, IMS, and UMTS-TDD, as well as telecoms policy and economics. <<
- Eric - |
