WirelessHD presents 60GHz platform, could spark destructive standards war
Published: Monday 6 November, 2006
Six of the world’s biggest consumer electronics companies - Sony, Panasonic, Samsung, Toshiba, NEC and LG Electronics - have turned the short range connectivity world on its head, in forming the WirelessHD (WiHD) special interest group, which will settle on license-free 60GHz spectrum for connecting entertainment devices in the home. This could be seen as a blow to the efforts of the PC/cellphone community to promote UltraWideBand as the fast, low power wireless network of choice for the digital home, but eventually, despite the posturings and vendor politics, an integrated platform combining UWB, 60GHz, Wi-Fi and Bluetooth could be on the cards.
The new standard specification will be with us by spring 2007 and is expected to be based on the work of another WiHD member, specialist SiBeam, which said last week that it would develop the specification for a wireless high definition (HD) digital interface using its existing technology. The new group is calling for other vendors to join.
Until now, the various flavors of UltraWideBand (UWB), including different offerings from Freescale, Pulse~Link and the WiMedia Alliance - whose technology underpins both Wireless USB and future wireless carriers for Bluetooth - had been thought the most likely candidates for general purpose high speed connectivity around the home. UWB was expected to be offer sufficient speed, resilience and low power requirements to be used in portable, battery powered devices. And UWB could still be combined with 60GHz spectrum in future, an approach that has been mooted in the past by Intel.
If the new specification wins out, it is likely to go into cameras, video cameras, HD TV sets, DVRs, DVD players, set tops, PCs, games consoles and mobile phones, taking the chip market for it up into billions of devices per annum and controlled entirely by this powerful CE group. That is one of the key differences from UWB - although Sony, Philips and others assured the WiMedia flavor of UWB a future in consumer electronics by supporting it, and inputting into its current specifications, the technology has its roots in the PC connectivity and cellphone markets, whereas the WiHD platform will be controlled from the outset by its primary would-be customers.
John Marshall, chairman of WiHD, said 60GHz radios would support low cost and higher quality high definition video products because the 4-5Gbps radios will send uncompressed video, skipping compression and decompression steps that require costly chips, degrade video quality and increase latency (Radiospire is taking a similar uncompressed approach in WiMAX). The group is developing a complete spec for 60GHz products that spans physical to application layer details. Initial products based on the spec could draw roughly 5Watts and cost a slight premium over today's wired HDMI links.
The new WiHD system will be backed by all the listed vendors and so drive interoperability between equipment, sending uncompressed high definition TV across a room, and it will also be scalable beyond HD to future high definition AV formats. The system uses smart antenna to overcome line of sight problems that have affected Wi-Fi, and will offer secure communications, working at multi-gigabit speeds and including an error correction system so that the format loses no data in transfer.
The 60GHz frequency band is largely globally available and for the most part has been designated as unlicensed where it has been addressed at all by regulators, and it is often used in point-to-point high speed links across multiple kilometer hops for building out backhaul networks. Statements by the group suggested that there would be versions of WiHD which used HDMI and DVI at the higher levels so that not too much will need to be added to existing wired devices.
“WiHD’s vision to significantly simplify and enhance people’s ability to view and transport multimedia content among a wide range of devices is both exciting and promising; this represents the first application of SiBeam's innovative millimeter wave semiconductor technology,” said John LeMoncheck, CEO of the start-up. SiBeam executives include pioneers who led efforts to promote adoption of HDMI and leaders in multi-gigabit millimeter wave wireless technology from the Berkeley Wireless Research Center. SiBeam was founded in 2004 as a fabless semiconductor company developing intelligent millimeter wave technologies and was the first to build 60GHz chipsets using CMOS technology. But the hopes for convergence of multiple technologies in future, rather than a stand-off between WiHD and other groups, is also highlighted by SiBeam's activities to date. It is part of the IEEE 802.15.3c taskgroup looking at 60GHz standards and is also a member of the EWC (Enhanced Wireless Consortium), the Intel-led group that created the core platform proposed for the forthcoming 802.11n fast Wi-Fi standard.
Its backers are New Enterprise Associates, US Venture Partners, and Foundation Capital.
The impact of SiBeam's heavyweight supporters will not be enough to ensure that WiHD will be a standard, and the body may do better to work with its potential rivals, driving rapid uptake and the possibility of a massive global market unhindered by political feuds. Already, the main UWB-based technology, WiMedia, has attracted several other standards bodies to support a converged path forward, including Bluetooth Special Interest Group, the Wireless USB Alliance and others. And the IEEE has a working group as part of its 802.15 efforts for short range wireless personal networks focused on 60GHz, whose work could also converge with UWB and the new platform.
Until possible cooperation emerges however, the WiMedia Alliance has gone on the offensive. With its own technology hardly off the starting blocks, and UWB still waiting for regulatory approval almost everywhere outside the US, it cannot rest on its laurels because of its early success in the PC and cellphone sectors. Stephen Wood, from WiMedia cheerleader Intel and head of the WiMedia Alliance, pointed out: "The regulations for 60GHz radios are not all in place, and the standards aren't ready yet." He claims the Alliance had studied 60GHz and concluded it would not be market ready for at least two years. The need for multiple sources of chips and interoperability testing would stretch time to market still further, he said.
"UWB is the technology for today," Wood said in an interview. "We haven't talked about 60GHz radios because they are not mature. We could get consumers all revved up about 60GHz, but we would be doing them a disservice."
"From a technical and regulatory point of view, it will be difficult for UWB to get to 4-5Gbps, so I don't see that technology as directly competitive," Mitchell retorted.
However, the stage could be set for another battle royal under the auspices of the IEEE standards body and its 802.15 PAN process. Already, stalemate in its 802.15.3a working group, which looked to create a UWB-based high speed, short range standard led to Intel, Texas Instruments and others leading a breakaway group, which evolved into the WiMedia Alliance and took its technology off to an alternative standards body, ECMA, for ratification. This led to the death of the 802.15.3a effort, raising questions of how far the various 802.15 standards will coexist in future, and leading to the withdrawal of the other major contender for the platform, Freescale, from the UWB market.
Another 802.15 group, 802.15.3c, continues its work however, and is specifically examining a high speed, non-line of sight wireless PAN in 60GHz. It will accept proposals early next year, coinciding with the first WiHD samples. If the WiMedia Alliance, or individual companies that may feel threatened by WiHD, such as Intel, enter a head-to-head for 802.15.3c, yet another IEEE feud could arise, stalling the development of the market - or driving one or all of the contenders towards trying to set de facto standards, or approaching other bodies. All of this would deal another blow to the already discredited IEEE process.
However, the 802.15.3c physical layer for the 60GHz band could also be coupled with the 802.15.3 or other standards' media access control (MAC) layers to create converged standards that are compatible with existing and emerging networks. The application of a MAC such as WiMedia's to multiple physical layers is a powerful way to create standards that are adaptable to changing spectrum allocations round the world, simplifying interoperability between systems in different bands and streamlining the development effort, avoiding the need to create an entire new standard for every frequency band. This will be important as regulators round the world start to respond to the need to open up more spectrum, and to be more flexible over permitted usage.
So in the medium term, 60GHz activities - even if WiHD wins 802.15.3c support - should not operate as a threat or alternative to UWB, but rather a chance to extend the benefits promised by UWB to a wider range of devices and applications. A logical extension of all this activity would be to use the UWB physical layer – whether WiMedia or another – in 60GHz too, leading to even greater harmonization and economies of scale. Two issues make this outcome uncertain – whether key regulators will extend the bands in which UWB is allowed to operate above 10GHz, and whether efficient chipsets could be designed.
Some companies are already working on such projects though, although many are in the military space where UWB is allowed freer rein to span its whole spectrum range. Swiss components maker Huber+Suhner is one company with an R&D project in this area, looking at RF subsystems to combine 60GHz and UWB. Perhaps the most important research has been done by France Telecom R&D under the auspices of the EU IST-Magnet project examining personal area networks. France Telecom and its partners are examining how to implement UWB in 60GHz in order to benefit from the small wavelength and limited interference, hence permitting a higher radiated power level than classical UWB systems. Within the IEEE taskgroup, companies such as Philips - notably absent from the WiHD's founder members - driven by the need to boost data rates for media networks, are prominent. It is vital for the digital home industry that this overriding common interest - to accelerate functionality and time to market for high speed home media networks - takes precedence over political and commercial differences and that another damaging standards war is averted.
The chip challenges:
Although standards will be critical to achieve the cost efficiencies and economies of scale for the consumer electronics market - preferably just one unified standard - equally important will be the creation of chip technology that can be the basis of cost effective devices, the main obstacle that has limited usage of higher frequency spectrum, even when available, to date. As yet, emerging chips for 60GHz are unproven but increasing congestion in 2.4GHz and risk of the same in 5GHz is increasing interest in exploiting other sources of unlicensed spectrum are exploited, especially if these are available on an international basis, as 57-64GHz is in many countries. Such bands are also attractive since they tend to carry more generous power allowances than others – the FCC’s limit in 60GHz is 40dBm, far higher than it permits for UWB in its current US-allocated spectrum range of 3.1GHz to 10GHz, where its power limits are one-10,000th those of a cellphone. However, creating cost effective chips - which usually means CMOS process - is very difficult at these high reaches of spectrum.
There are plenty of technical obstacles associated with implementing access applications in high spectrum. Peak data rates can only be sustained over short distances and with high power, compared to lower bands. This has limited the market in the past and kept equipment costs high, as have the complexities of making 60GHz radios. Traditionally, these have used expensive materials such as gallium arsenide, but now there are research projects examining the potential of the implementations in low cost silicon germanium and, eventually, CMOS, which would drive prices down for a volume market. For instance, IBM’s TJ Watson Research Center in New York state is working on such a project, as are Caltech and some advanced start-ups such SiBeam, along with Intel.
The main interest, from a chipmaker’s point of view, is that high frequencies support very small circuits and antennas. To some extent, these can be designed to compensate for the propagation problems. For instance, tiny antennas – in the more futuristic projects, small enough to be part of a ‘body area network’ – can still achieve high direction gain, or complex antenna arrays can be assembled to boost data rate and range even within the limitations of the frequency, using techniques such as beam forming or MIMO (Multiple In Multiple Out). The higher power limits allowed by the FCC also help make up for the inherent problems of 60GHz radios.
A project at Berkeley University in California is aiming to implement very small circuits in CMOS with a view to creating low cost, mass market miniature devices that will, in their first iteration, perform at 1Gbps over 10 meters – a target the team aims to hit by year end. IBM is looking to build its radio initially in silicon germanium, believing that CMOS will only be appropriate once the market is established and starting to achieve volume. It will have evaluation hardware this year.
Clearly such projects will be of critical interest to Intel, whose ambitious designs on controlling the wireless chip market center on all-CMOS radios supporting one or multiple frequencies. It has several advanced projects in the area of CMOS radios for frequencies above 10GHz, and interestingly, seeks to establish the technology
potential for the full 802.16 standard. While WiMAX has been focused on spectrum below 6GHz, the 802.16 standard can be applied to higher spectrum up to 60GHz. If Intel can create an efficient CMOS radio for 60GHz, delivering advanced performance through MIMO and other techniques, we can be sure interest in applying WiMAX to those devices will be reawakened, both for reduced cost ‘wireless fiber’ backhaul and for multimedia distribution applications.
Another well backed project in this area comes from the recently formed Wireless Gigabit with Advanced Multimedia (Wigwam) initiative, which claims its short range technology can match the performance levels of wireline alternatives and fill in the gaps in Wi-Fi’s functionality, such as low power consumption. The group is working on a 1Gbps wireless link based on an OFDM physical layer that it claims will close, at last, the typical one-generation performance gap between wireless and wireline networks in the same class. Wigwam will run in various frequencies including 5GHz, 17GHz, 24GHz and 60GHz. The main partners in the Germany-based work are Alcatel, carmaker DaimlerChrysler, Infineon, MEDAV, Nokia, Philips, Siemens, Dresden University and Telefunken Racoms System. The project will present its designs next year.
IBM's project:
In February (see Wireless Watch February 13 2006 edition), IBM stood up at the Solid State Circuits Conference in San Francisco to describe a component that would support the proposed 802.15.3c IEEE standard for 60GHz personal area networks, implemented in silicon germanium - cheaper and more flexible than gallium arsenide, though less so than CMOS - and with prototypes performing at 700Mbps.
IBM said its design allowed embedding of antennas directly within the chipset package, further reducing system cost and a prototype chipset module, including the receiver, the transmitter, and two antennas, would occupy the area of a small coin.
IBM is the global leader in chip packaging and a constant focus of its chips designs over recent years has been to reduce inter-chip communication, rather than directly drive up chip processing power. The company said that the technology could be targeted as a 60GHz wireless personal area networks in the 10 meters and below range.
However, even silicon germanium is unlikely to reach the price point that these chips will eventually need given that they will be manufactured in hundreds or millions once they are standardized. This makes efforts by Intel and others to massage CMOS techniques into this speed range all the more important.
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Until next year, adieu.... TM |
