After the various false dawns of UltraWideBand based technologies, it is hard to be positive about the imminent prospects for 60 GHz, but the emergence of yet another wireless industry grouping this week may serve to clear the path for ubiquitous 60GHz devices on the near horizon. Or it may not.
With names like Intel, and the leading Wi-Fi chip makers in Broadcom and Atheros, it’s clear that the new Wireless Gigabit (WiGig) Alliance has its routes in Wi-Fi, coming out of the IEEE 802.11 committee referred to as Very High Throughput (VHT) Wi-Fi study group, established a year or so ago.
But with also the bulk of the handset community, in Nokia, Samsung and LG, as well as dedicated handset chip makers like Marvell and MediaTek, WiGig looks like it also has the mobile angle well covered.
What is fair to say is that this new grouping will certainly be ONE of the 60 GHz consortia that may make it to chip stage and become competitive in the real world arena and if we could keep it down to just one, then given the names behind it, all they would have to do it get the technology to work in order to create a de facto standard.
But what is such a standard FOR exactly. If you read the web site it is for everything, but the likelihood is that this is all about PC-handset interaction, and that the idea that multiple uncompressed HD signals are going to be flying around the home as part of this initiative still leaves us sceptical.
The existence of Microsoft in the WiGig consortia also supports the PC centric world view, as does that of Dell and the few consumer electronics companies are Panasonic which is the leader in plasma TV screens (it’s an also ran in really flat TVs) as well as NEC and Samsung. The last member of the team is Wilocity, a start up which is made up of Intel Centrino ex-employees which have been working in this area for a while. NXP and ST Micro have also come on board as contributors at the last minute, but that can hardly count as commitment.
The original members of the WirelessHD grouping, the first grouping that settled on 60 GHz transmission for the home were Panasonic, Samsung, Toshiba, NEC and LG Electronics and its inventor SiBeam on the US. That teams has now expanded to include many of the WiGig players, including Broadcom, Intel, LG, NEC and Panasonic. The big names missing, and who would need to come on board if WiGig was to hijack and incorporate the work that WirlessHD has done so far, are Philips and Sony.
The way the spokespeople over at WiGig put it, WirelessHD could be incorporated into their new initiative, but give little in the way of technological explanation ‘ beyond saying WiGig will have IP data support and streaming HD video and audio on day one.
If history is anything to go on, all of these big companies will talk, and so will their engineers. The marketers will see a common chip design as a win win, driving chip prices down, the engineers will point out that technical compromises might kill the performance, as they did in the WiMedia Alliance version of UWB. That experience alone should warn us that having all the big names on board does not mean that a technology can be made to work if it isn’t actually fit for purpose.
If Sony and Philips turn up at the next WiGig meeting and drag SiBeam with them, then perhaps we will have some form of consensus at the 60 GHz level, but we are not holding our breaths.
In fact there are key issues with 60 GHz spectrum itself. It quite simply cannot go through walls, so it is a technology for line of sight transmissions across a room. That being the case there are plenty of vital breakthrough applications that it could provide around the home. If it’s not going to be a full feature video capable technology which can support uncompressed HD video streams, then the use case is hyper fast file transfer ‘ for instance file delivery in seconds of large video files from either home servers to handsets or from kiosks to portable devices as a point of sale device. In other words this is a Wi-Fi inspired 60 GHz protocol that will do the job which UWB was supposed to do for Wireless USB. On that basis is could have a future, and a big future, but if it could also have wider applications it could be an overnight success. Again provided it can be made to work.
But Sony already has its own offering in that transfer area, which can be linked closely to its FeLiCa chip, which it supplies throughout Japan as the de facto contactless technology and which it will shortly extend through a relationship with NXP in Europe over the creation of universal NFC chips.
That technology was first demonstrated at January’s Consumer Electronics Show last year and is called TranferJet and it has its own group of companies supporting the development of an open specification in 4.5 GHz spectrum, for very short range connections just 1.25 inches away, supporting data rates up to 560Mbps.
Partners include Canon, Pioneer, Seiko Epson, Hitachi, Nikon, Olympus, Panasonic and Toshiba ‘ and other members include Kodak, Toshiba and Sony Ericsson plus operator KDDI. The use case for this technology is linking video and still cameras to servers for rapid file transfer, and since Sony dominates both types of cameras globally, and all the other companies in that market are on that list, this is a slam dunk for TransferJet. That means that either the new WiGig group can drop video file transport from its list of use cases or it has to somehow get Sony on board, by offering its technology as a new underlying transport for TransferJet. Given that this would cost far more, and also shoot a hole in future Sony royalties, we don’t see it happening, hence our belief that Sony will not come in from the cold on WiGig, as least not in the early days. Sure its Vaio PC designs will incorporate the chips, if they ever emerge, but there’s no guarantee that any of its other devices will.
TransferJet employs a DSSS (direct sequence spread spectrum) modulation scheme. It is also very low power. This means it might be easier than the other approaches to gain regulatory clearance around the world, claims Sony, especially as confining the technology to very short distances reduces fears of interference. Power requirements for 1.25 inches must be miniscule though not published.
If the WiGig specification emerges by late 2009 as promised, and chips merge shortly after and IF they perform at 1.5 Gbps as promised (later they should take this to 6 Gbps WiGig says), then rivals to Sony in the camera world may be tempted and Sony would eventually turn.
But so far the only companies that have reported any success in making chips in samples, working at 60 GHz are Toshiba and IBM, and IBM is not a member of any of these consortia.
IBM was showing off this technology, a combination of Silicon and Germanium, at a Solid State Circuits conference back in 2006. The transition from SiGe to CMOS is notoriously tricky.
Obviously the use case that would definitely make this technology take off, is uncompressed HD video. This is currently pushing up towards 5 Gbps as a requirement and will shortly move onwards towards 20 Gbps (see piece elsewhere in this issue on Valens Semiconductor) as the CE companies look to embrace more and more aggressive video quality standards with higher colour sampling rates and screen refresh speeds and yet even more pixels.
Apart from WirelessHD, Israeli start up Amimon appears can also lay claim to being on the verge of scoring a major win with its WHDI chip design, which it says can send multiple HD signals around a home using MIMO antenna and a 40 MHz wide OFDM carrier, similar to 802.11n wi-fi technology.
The company first showed its face in 2006, and demonstrated its chips at the 2007 Consumer Electronics Show. It finally got Motorola to buy shares in the company in March 2008, and then signed TV maker Sharp to use the chips in it’s TV sets. In July last year it also lined up Sony and Samsung, along with Hitachi, to include the technology in a standard for multi-room audio, video and control connectivity.
The key behind the Amimon approach is that it begins with barely compressed video, using a lossless compression standard that only halves the signal requirement for wireless transmission when compared to uncompressed video, around 1.5 Gbps for a 1080p 30 fps signal. It then decides to divide the data stream into those bits which are more important for quality video rendering, and those which are less important, making the distinction, for instance, between the (important) luminance bits and the less important chrominance bits, in a bit mapped piece of video. It refers to them as most significant bits and least significant bits.
So it gets away from the traditional approach for taking a video source, putting it through a lossy compression system (which has no idea of the state of the network that it will travel across) then coding the communication channel for modulation and then reversing each step in the chain.
Instead WHDI uses a technique called Joint Source-Channel Coding which first prioritizes video components, then applies two separate error correction schemes to the outcome, encoding the most significant bits of the important components using better error correcting code, which means it ends up transmitting that part at a lower rate, then sends the less important video components at a higher rate with a less powerful FEC.
The system then opts to send the less vital information across the noisier frequency and uses space-time coding for better protection of the important components.
The Amimon system requires at least 4 sending antennas which fits in well with the multi-antenna approach of Atheros, which has become a standard for highly reliable Wi-Fi chips. WirelessHD also uses multiple antenna, in fact far more than WHDI.
It sounds improbably complicated, but Amimon received HDCP certification early on in its life, which is usually only feasible when the US Hollywood studios see a technology as a ‘good thing.’
So WiGig will NOT have the video area cleared for its success. Even if it managed to talk one of the WirelessHD or Amimon groups into working with it rather than against it, it cannot talk both of them into it and their specifications are all roughly equivalent. This will be a war fought on execution, not empty promises and speed claims.
We’re not at all surprised to see chip makers and CE companies backing two or three horses here ‘ like we said ‘ there have been too many false dawns in uncompressed HD transmission. They will go with the first one that works.
But even if it just hijacks Wireless USB class use-case of super rapid file transfer, the WiGig specification is likely to be successful and has probably only been announced at this time because the standards work is getting messy. Ideally a PAN which operates at speeds faster than 10 times the speed of wireless LANs should come out of the IEEE, but is that process going well? All of the comments made on the WiGig web site suggest that this new grouping is just a ‘parallel’ development for the IEEE, which might be code for a way to threaten the IEEE into playing ball.
The 802.11 study group was charged with demonstrating that it has technologies and applications which are sufficiently different from the ongoing work of 802.15.3c before it can be approved to proceed in drafting a standard, and other 60 GHz efforts are very keen to point to weaknesses here because this spectrum, now that people realize it CAN be harnessed, potentially with cheap enough chips, is a gold mine, because 60 GHz is currently unlicensed in the US, Japan, Europe and Asia.
To make it in the video world WiGig will have to get its spec out, get chips working and then get the all important HDCP 2.0 certification. The timescale to us looks like that will take until the end of 2010 (if nothing goes wrong) or until 2013 if it goes as badly as the WiMedia Alliance did, which while not too late in 2010, it late-ish and the chip technology difficulties may well trip it up along the way and make is far too late.
‘Our member companies are leaders in the wireless, CE, PC and handheld markets. They have the technical acumen and business experience to make the 60 GHz wireless technology a reality for both the home and enterprise,’ said Dr. Ali Sadri, President and Chairman of the Wireless Gigabit Alliance. ‘To help bring this technology to market, we welcome new member companies to join our group.’
The WiGig specification is expected to be available to member companies in Q4 of 2009 but when, realistically will the chips be out.
We asked one knowledgeable RF engineer who didn’t want to be named who works in this segment, and he gave a few warnings about being too optimistic about any 60 GHz chips arriving soon or potentially ever, including the WirelessHD chips.
One of his main concerns looking over the specification is power consumption, but also cost and signal fragility may also be a problem and the chips would likely run hot and require entirely new clocking designs ‘ all problems that will take time and ingenuity to overcome.
We should perhaps think of WiGig as an interesting science project, rather like the WiMedia Alliance multiband OFDM technology. That project failed, so Intel and its buddies seems to be saying let’s come up with one that’s even faster, but which more or less takes us down the same route.