| Home |
| About Us |
| Latest News |
| Features |
| R-100 Index |
| Newsdesk |
| Free Email Alerts |
| - - - - - - - |
| Wireless Business Review |
| - - - - - - - |
| 4G wireless: a generation too far? |
|
|
| Saturday, 05 June 2004 | |
|
Although 3G wireless systems are only now beginning to find their commercial feet, the foundations for the follow-on global 4G networks are speedily being constructed…
Fittingly, 3G service pioneer NTT DoCoMo is at the forefront of developments, kicking off research into the next generation of technologies as long ago as 1998, and following up with initiatives such as: the 'MOTO-Media' collaboration with Hewlett Packard in 2000; indoor 4G experiments reportedly achieving 10Mbits/s up-links and 20Mbits/s down-links in 2002; and the unveiling of a 4G field trial in Japan at the end of May 2003. NTT DoCoMo is not alone in committing brain power and cash to 4G. In addition to Japanese government 4G initiatives there are some major government- and vendor-backed Chinese, Indian and South Korean 4G programmes already up and running. This year Nextel Communications in the USA started to trial a 4G wireless broadband service based on Flarion Technologies' 'Flash-OFDM' technology. Also this year, Vodafone KK in Japan announced a technology trial of the Flarion system for 4G mobile broadband services. According to research cited by the Fourth Generation Mobile Forum (4GMF) R&D spending on 'beyond 3G' (B3G) and 4G will exceed US$10bn this year. Depending on who you ask and who you believe, 4G could start to be deployed commercially around mid-2011, or earlier still. Lack of consensus? The difficulty of estimating 4G in-service dates is compounded by the circumstance that, initial foundation activity notwithstanding, there is little wireless industry consensus on what 4G might be, could be, or should be. For some it's a faster version of 3G. For others it's a missing 3G application set. Some experts envisage the commercialisation of new 'bleeding edge' technologies to create 4G, while others perceive 4G almost in new lifestyle terms, regardless of the technologies used to support it. One opinion you can often hear on the 'Wireless Street' is that any advance toward 4G will rely on 3G being a substantial success. There's a persuasive case to be made for this. However, the alternative starting point for the 4G may be the real and/or perceived bandwidth inadequacies of 3G in real-life networks. The 3G deal was supposed to be a speed of 2Mbits/s; so far the deliverable has been in the low hundreds of kbits/s. In the past the notion that 3G would not cut it on its speed, application and availability promises has attracted some very illustrious and vocal support. At one time or another the 3G sceptics camp has included luminaries such as ArrayComm ceo Martin Cooper, Peter Cochrane, former BT chief technologist, Finnish academic Arto Karila, and MIT Media Lab founder and director Nicholas Negroponte. For many wireless experts 4G - or at least an important step in the direction of 4G - might be some version of 3G CDMA, revved up to deliver higher data rates. If so, 4G may turn out to be 3.5G in disguise. 3G-whizz As noted in the recent Baskerville report 'Alternative Mobile Broadband Access', most 3G operators were allocated both FDD and TDD spectrum with their licences but most first-movers chose initially to deploy with FDD since it was found to be very good at delivering high quality voice. Given that it is asymmetric and better suited than FDD for tasks such as Internet access and large file download some improvement on the 3G data speed front may, therefore, be found with TDD. "While recognising the merits of TDD, they [the operators] are being driven towards FDD and do not have the financial or engineering resources to deploy both technologies", notes Ian Channing, author of the report. New 3G hopefuls, several of which are profiled in the Baskerville study, are now turning to TDD-based solutions. Again, operators could be concentrating on things such as CDMA2000 1xEV-DV Releases C and D for a better 3G customer experience. Perry LaForge, executive director of the CDMA Development Group (CDG) believes that CDMA2000 1xEV-DV Release D will enable CDMA2000 1X carriers to significantly improve the efficiency of their networks and offer data applications such as television broadcasts and video telephony. Approved in March, Release D incorporates forward and reverse link technology enhancements to the physical layer design of Release C. New dedicated channels, the forward packet data channel (F-PDCH), and the reverse packet data channel (R-PDCH), were introduced to support high-speed packet transmissions of up to 3.091Mbits/s in the forward and 1.8456Mbits/s in the reverse link. In similar vein, a recent report from mobile analysts ARC Group argues that much wireless industry attention is currently focussing on the potential of high speed downlink packet access (HSDPA), in particular to extend 3G capabilities on the road to an all-IP network and wireless/wireline convergence. In its 'Future Mobile Networks' study, ARC Group maintains that all the major vendors are now shipping HSDPA-enabled W-CDMA infrastructure and, following the lead of NTT DoCoMo which is planning on launching HSDPA services as early as 2005, all the key players are planning trials for the end of this year. ARC Group forecasts that 3.5G (including HSDPA, TDD and proprietary technologies such as 'Flash-OFDM') will reach 9.1mn subscribers by 2008. A somewhat different, but not necessarily mutually exclusive, school of thought has it that 4G will be a multi-network affair, combining existing wireless technologies - including 3G - with wireline and broadcast elements. As well as 2G, 2.5G, 3G and 3.5G, other candidate wireless services and technologies in this scenario could be Bluetooth, Wi-Media, UltraWideBand (UWB), HomeRF, HiperLAN/2 and IEEE 802.11b 'Wi-Fi'. Obviously the really clever bit here would be to successfully interoperate the different technologies and networks to provide seamless service. Probably the most radical reading of 4G is the step-change one - that it will require a new air interface technology, new modulation schemes and new spectrum. In this version of events the suggested access alternatives include multi-carrier CDMA (MC-CDMA), large area synchronised CDMA (LAS-CDMA) and orthogonal frequency division multiplexing (OFDM). Spectrum, depending on the geographic location, could be in the 2 to 8GHz band. Switching would be all packet, traffic would be converged data and voice over IP, and use would be made of more intelligent antennas and software-defined radio terminals. The speeds that have been projected range from 20 to 100Mbits/s. IP talking, talking, IP talk Once upon a time it was not unknown to cast Wi-Fi as both a threat to 3G and as the putative basis of 4G. This view is now less prevalent, with many considering 802.11b to be a serendipitous complement to 3G. It's presently unclear, though, how the relationship between 3G and Wi-Fi might alter if IP voice over Wi-Fi (VoWF) becomes a really major piece in the future wireless jigsaw. Although VoWF has many gainsayers, gaps in both the technology's security and QoS repertoire are being filled in as initiatives such as IEEE 802.11i and IEEE 802.11e begin to firm up. Pushed along by vendors such as Cisco Systems, SpectraLink and Symbol Technologies, VoWF is continuing to beef up its profile in the on-site enterprise arena. This year alone, for example, SpectraLink has inked Wi-Fi telephony OEM deals with Alcatel, Nortel Networks and Siemens AG. Meantime, companies such as Motorola and Nokia are looking at combo cellular/Wi-Fi terminals with varying degrees of interest. US wireless companies are beginning to offer their customers bundled Wi-Fi and VoIP services. One such is FTS Wireless Inc, which in May announced that it would offer its customers bundled Wi-Fi Internet service with VoIP telephony service in combined plans starting at US$39.99 per month. AT&T could be one of the first household name operators to take-up the cellular/Wi-Fi baton. Also in May the company announced that it had taken its first step in re-entering the wireless market by becoming a re-seller for Sprint. Part of this deal was to eventually offer VoWF. An AT&T press statement observed "…as integration of wireless handsets with Wi-Fi networks improves over the next 18 months, AT&T plans to offer handsets that also allow customers to make VoIP calls over broadband connections in homes and businesses." Does VoWF amount to a hill of beans? According to a recently published report from ABI Research, dual-mode cellular/VoWF handsets will represent about 7% of all handsets shipped globally by 2009. "Many enterprises now have established Wi-Fi networks and integrating voice-over-Wi-Fi functionality is a natural progression. As Wi-Fi networks proliferate, it only makes sense to give users the ability to switch from the cellular carrier's network to the enterprise Wi-Fi network", reasons Phil Solis Senior Wi-Fi Analyst at ABI Research. "Initially, of course, carriers may see this as a threat for fear of losing service revenue when these handsets are used on the Wi-Fi network. But long term, as with most new developments, carriers will likely see dual mode cellular/voice-over-Wi-Fi handsets as a means to differentiate their offerings." Market research concern In-Stat MDR has quite an upbeat take on Voice over Wireless LAN (VoWLAN). In its recent report, 'The Marriage of VoWLAN and Cellular: A Wedding Sooner Than You May Think', the company forecasts that VoWLAN integrated with cellular will have a major impact on the world of wireless communication in the years ahead. In-Stat/MDR principal analyst Allen Nogee believes that by 2009 over 220mn cellular handsets worldwide will also posses wireless LAN capabilities, with more than 132mn of these devices also having VoWLAN support. To the MAX? While Wi-Fi is extending its remit into the telephony business, support is building for what might be considered 'the son of Wi-Fi'. IEEE 802.16a is a metropolitan area network (MAN) broadband wireless access (BWA) technology designed to provide a wireless alternative to cable and DSL for last mile broadband access, and to supply back-haul for 802.11 'hot- spots'. According to the WiMAX Forum, 802.16 provides shared data rates of up to 70Mbits/s, will support time-sensitive applications such as voice and video, has a range of up to 50km, operates in the absence of direct line of sight between subscriber terminals and base stations, and will support hundreds if not thousands of subscribers on a single basestation. As of January 2004 the WiMAX Forum had a membership of 67 - many by no means corporate tiddlers. This number was more than double the membership figure for five months earlier. Some wireless industry rune readers contend that WiMAX, its mobile extension 802.16e, and the associated but embryonic IEEE 802.20 standard, could take much of the gloss off of 3G and Wi-Fi. Others see WiMAX as a rival to various broadband wireline offerings, and other folks view it as an opportunity for wireline operators to play a bigger role in wireless. Either way, though, different market research companies have suggested a global WiMAX market worth around US$1.5 or US$1.6bn by the end of 2008. Old familiar story? As is the way of these things, numerous 4G associations and partnerships of academics, vendors, standards bodies and assorted gurus have been, and are being, formed worldwide. Generally, these bodies have the stated aim of shepherding 4G into market existence in a manner most beneficial to all concerned parties. Generally, too, there is public emphasis on inter-agency co-operation to secure the greater good of the future industry. In practice, as in earlier wireless projects, technology, corporate, national and personal agendas seem most unlikely to become fully aligned across the nascent 4G community. Different iterations of 4G look inevitable. John Williamson |
| < Prev | Next > |
|---|
|
|
|
|
|
|
|
|
|
|