The race is on to be the technology of choice for fourth generation cellular systems. WiMAX is pitching itself against LTE and UMB, each representing an established community in the mobile world. And each technology’s backers claim some sort of superiority for their choice. But does it really matter, asks Priscilla Awde.

Creating a lot of noise and passionate in their arguments, supporters of mobile WiMAX or 802.16e are challenging the GSM juggernaut, suggesting this is the logical next generation technology. Believing they have crucial time-to-market advantage, they say Long Term Evolution (LTE), the WCDMA evolutionary path and Ultra Mobile Broadband (UMB), CDMA’s next generation technology, are so far behind that by the time they are standardised and commercially deployed, mobile WiMAX will have gained market share. They also believe that even with HSPA upgrades, 3G networks fail to meet demand for high-speed data services.

Unsurprisingly such views are stirring heated debate throughout the industry.

All so called 4G mobile technologies are based on O F DM, include smart antennae, MIMO, are flat IP architectures and use spectrum efficiently. LTE is an evolution of the 3GPP standard whilst WiMAX was developed by IEEE. Although many argue they are not comparable, Vikram Saksena, CTO at Sonus Networks says: “Both are different routes to the same goal, are equally viable, deliver the same and are appropriate for different kinds of carriers/scenarios.”

Whatever their characteristics, technology agnostic operators evaluate systems on the business case; compatibility with existing networks and platforms; capacity; available spectrum and subscriber needs. Many GSM telcos participate in the WiMAX F orum to monitor and perhaps influence developments and some are building fixed networks. Ultimately consumer demand dictates operators’ investment plans.

Claiming first to market advantages proponents of 802.16e compare it to LTE which to some undermines their case. Remi Thomas, director, NGMN project for Orange believes it is not technically fair to compare LTE with 802.16e. “The only comparison is between .16e and HSPA which is here now and being rolled out to provide broadband services. I don’t see the advantage of .16e in terms of timing since HSPA is real and deployed and the handover between networks is defined by standards. 802.16e is not suitable to any country where it is possible to have GSM which is true of most places. Mobile data has better economies of scale in UMTS and its evolutions, so what is the use of WiMAX?”

Suggesting technology debates miss the point, Graham Currier, CTO at WiMAX operator Freedom4 considers the benefits of a competitive, innovative, mobile world which meets user needs. “3G has not kept pace with users’ expectations: GSM doesn’t do what people want so we must move forward. We need service innovation.

“WiMAX ticks all the right boxes: it’s a big open environment, not operator dominated, designed for IP, easily delivering applications/services developed by many people. It can be accessed by numerous devices in many form factors.

“WiMAX frightens operators who have spent billions on 3G licences; they don’t want it to succeed because it takes away the captured bundled system. It’s all a question of who controls the market, technology and what services are launched. No one technology will dominate the mobile world any more. Why are operators developing LTE – their own version of WiMAX - if they don’t believe in the way the market is moving?”

Kai Sahala, head, strategic solutions at Nokia Siemens Networks agrees technical comparisons are counterproductive but sees more useful similarities between 802.16e and HSPA than with LTE. “HSPA and .16e are very similar in performance. F rom 2006 HSPA has offered megabit speeds and supports terabits of traffic flowing through networks daily. HSPA networks can be evolved to Internet-HSPA. We are looking at using existing masts and antennae and the same base stations in the evolution to LTE.

“The time frame for commercial LTE networks is 2009/10 and mobile WiMAX will be coming out this year. Both technologies use the same base station platforms. Although mobile WiMAX requires a new network build, the business case is in offering simple broadband access in a flat architecture, data only network which is scalable and offers low latency.”

GSM operators are upgrading networks with HSPA, HSPA+, creating IP systems to support megabit speeds and improve user experience. There are around 200 HSPA networks commercially deployed or planned worldwide. Revenues from new data services are growing exponentially - in some cases, doubling year on year - stimulated by flat rate bundling and easier to use, lower cost smart handsets optimised for voice and data.

“HSPA will in future offer 80-100Mbit/s down with a 23-24Mbit/s return with only software upgrades. Mobile WiMAX is unproven. As a competing technology it spurs development although the first releases can’t compare to LTE in performance: it’s more like 2007’s HSPA,” says Jeanette F ridberg, head product marketing radio access technologies for Ericsson.

Telcos are looking ahead to avoid hitting a capacity wall. F or operators with UMTS networks, LTE is a logical next step: comparatively less expensive to deploy, it is backwards compatible and supports international roaming. New core network equipment must be integrated and base stations upgraded but some elements are re-usable. F or such operators, LTE is an evolution and many of them are already on the path. “Operators are very careful about what to deploy when, and what new technologies to introduce. HSPA and LTE or Systems Architecture Evolution (SAE), are a great deal less risky,” suggests Dan Warren, director of technology at GSMA.

Many believe WiMAX is a niche technology suitable for greenfield sites, developing countries or operators without 3G licences but with 2.5 or 3.5GHz spectrum. Some operators already running fixed WiMAX networks plan to launch mobile services this year. “There will be lots of new entrants,” says Shai Yaniv, senior corporate marketing director for Alvarion. “Giant mobile operators grew fast in a short time: WiMAX gives opportunities for new entrants to develop similarly.”

The question is how a new, untried mobile technology can gain market share in a world where there is an installed base of three billion and growing GSM subscribers supported by a sophisticated supply chain and economies of scale. “The mobile broadband business case is not voice but data,” says Miguel Myhrer, partner, communications, high-tech Group, Accenture. “WiMAX is not going after the wireless handset game yet - voice over WiMAX is not part of the plans for 2-3 years.”

Ovum does not anticipate significant mobile WiMAX take up until 2009/10 but forecasts 31 million fixed and mobile WiMAX users worldwide by end 2011 (over two thirds will be mobile), with 46 per cent in Asia/Pacific, China and India.

In developing countries mobile WiMAX may be an alternative where cost or landscape make it impossible to build fixed xDSL or fibre networks. Yet even there mobile WiMAX must compete with GSM: operators are succeeding with cheap devices and very low margins. In India alone new monthly GSM subscriptions are around six million.

Mobile WiMAX has some giant players from the IT world championing its cause notably Intel which is integrating it into its new platform this summer. “WiMAX is attractive to a number of players and opens up the whole marketplace in ways not seen. We are driving laptops and new ultra mobile internet devices which are low power tablet type PCs,” says Chris Beardsmore, Intel’s WiMAX market development manager.

With the exception of Ericsson, most network and equipment vendors are developing both LTE and WiMAX solutions. Motorola and Nokia are launching devices and Sprint Nextel is rolling out mobile WiMAX networks this spring.

“Mobile WiMAX is a means to address demand not possible with existing technologies,” explains Andre Mechaly, VP marketing/communications for mobile access at Alcatel-Lucent. “Now an IMT 2000 technology, WiMAX offers a means of getting into cellular without buying a GSM licence: 3.5GHz spectrum is available in lots of countries. It is easy to deploy and operate and is designed to handle data traffic. WiMAX will do for data what GSM did for voice.”

Both LTE and WiMAX camps point to the need for higher data throughput; more simultaneous users per cell and cost effective delivery of bandwidth hungry services such as mobile TV. Although 4G upgrades are not yet urgent since there is spare network capacity, operators are considering options.

With significant doubts about next generation mobile generally, Mark Heath, report writer for Analysys, sees no evidence mobile WiMAX will be successful. “The assumptions are incredibly optimistic and the business case marginal. 3G networks can cope with quite a lot of traffic, even with fixed/mobile services so why invest? Operators will have plenty of 3G capacity to provide the right service mix without spending any more than necessary. Operators need spectrum to deliver LTE but where is it coming from?

“Available this year, HSPA+ adds smart MIMO antenna technology to improve data rates, increase range and coverage. In 2010 when broadband penetration will be very high, the only real application for LTE and mobile WiMAX is in developing countries where there is no existing competition.

“ Mobile operators need to invest in fixed broadband, DVB-H, content and femtocells making LTE or WiMAX a step too far. Why do they need them? They need to spend elsewhere and won’t have the necessary investment funds to spend on 4G.”

Perhaps the whole debate about mobile WiMAX, LTE or UMB is a big storm in a small teacup.