John Santhoff is baffled. Given that he virtually single handedly invented pulse based ultra wide band, an almost completely original brand of radio frequency engineering, and has over 300 patents to his company’s credit as a result, he shouldn’t be.
In fact there’s not much that he doesn’t understand about radio and Faultline took him through his paces on a whistle-stop tour to London, and found he had better explanations for each of his rival technologies ‘ WiMedia Alliance, MoCa, HPNA, Ethernet ‘ than the people who are paid to evangelize them.
So why is he baffled? ‘It’s the political dimension,’ he says and it confuses us too. For almost 8 years now his company Pulse~link has had the technology wherewithal to send massive amounts of video from one device to another around the home, either wirelessly or over a wire. If the chips were made in serious volume, they could cost as little as a few $ (currently between $10 and $20 depending on order volumes) and create a genuine digital home. But no-one wants that to happen, except Pulse~Link.
Companies like Samsung and Sony and Panasonic, plus all the major pay TV operators like Comcast and DirecTV, as well as companies like Apple, have the need for such a technology, but there have been no major design wins forthcoming, except a few driven out of last year’s CES with Westinghouse Digital and Geffen.
There are two major use cases for such a technology and it’s really a factor of what’s possible elsewhere. High Definition TV signals need to travel around a home in the cheapest way possible, from set top or Blu-ray player to a TV screen or a PC. The other use case is simplified rapid handset sideloading of video files from a home network. One requires high bandwidth due to the bandwidth requirements of the application, the other needs it to allow sideloading to be automatic or last minute, and copying a 1 hour TV program to a handset will need 1 GB in SD, and 250 MB roughly in QVGA, which might need to transfer in the time it takes to put your coat and shoes on in the morning.
The reason these use cases are fairly sacred is because other technologies cannot quite do them and don’t look like achieving them in the near future. Wi-Fi can send video files around a home, and even through a wall, but not every time and not HD files. Ruckus Wireless has improved this to the point where HD files are supposed to be able to be streamed around a home, but that takes the price of each device into the multi $100s, when the price point for putting this in every device needs to be around $2 each.
It may be possible for Wi-Fi to have a more sophisticated Quality of Service software layer, in fact we know some proprietary Wi-Fi that uses the WiMAX QoS schema, and it may be possible eventually to take the MIMO antenna and the packet resend software and drop into a cheap SoC. But it isn’t today and given all the interference that 2.4 GHz suffers from (one of the two wi-fi frequencies which is shared with baby alarms and garage door controllers), there hardly seems any point.
‘MoCA operates in the 800 MHz to 1.5 GHz bandwidth, in a 50 MHz area using QAM 256. Last year it changed the MAC on the chip, but kept the same chip. All it did was drop the Forward Error Correction from 1/2 to 3/4 rate. And then it went around saying that the service worked at 175 Mbps. I’ve tested it in our labs. It will do 175 Mbps over tens of feet, but over 100s of feet it is back to 100 Mbps.
The core complaint that Santhoff comes up with is that many of his rivals use a contention based protocol, in that they support CSMA/CD, which is part of the Ethernet stack and stands for carrier sense multiple access with collision detection. In short this was designed for a data bus that allows anything attached to it to begin sending at random, stop if it collides with other sends and then waits a random period and sends again. Contention based protocols are fine when they are operating at the low end of their capacity, but when up at the high end, performance can become unpredictable, which is why today Ethernet has shifted to 1 Gb Ethernet, so that it has lots of capacity, but Ethernet cable is expensive.
CSMA is used in Wi-Fi and in Ethernet as we said, and even though it can be laid on top of a group of OFDM carriers (thousands of them) and in principle OFDM can allocate those carriers intelligently (as it does in WiMAX), if it lays CSMA on top, the Quality of Service becomes unpredictable.
He has issues with his other rivals too. ‘HPNA and Powerline use 30 MHz of spectrum or less on the cable, and to carry more data they would have to use more power, which would push out more emissions, which would break the rules of the FCC spectral mask.’ The issue here is that the home is a hotbed of signals, and that any radio signal can interfere with any neighboring signal if it is too powerful.
Which is the beauty of using a pulse of radio energy across a very wide spectrum. The FCC defines UWB (ultra wide band) as anything which is spread across 500 MHz or more. By it can be arranged as multiple carrier waves spread in this way, using fast Fourier transforms to disentangle them, just as OFDM does. Which is the direction the WiMedia Alliance took when it defined its version of UWB.
Pulse~link instead puts a single pulse across an entire 1.35 GHz of spectrum sending on all the wavelength at once. The duration of the pulse is around 23 centimeters long, which at the speed of radio (light) is exceptionally short, coded in simple BPSK. The signal can be sent more than once, which improves robustness and distance, but in essence because the data can be picked up from anywhere across the spectrum, if there is any fade or interference, it can be ignored. Sending once gives a native data rate of around 1.35 Gbps, sending twice half that.
The Ultra Wide Band of the WiMedia Alliance suffers from the fact that because it is arranged in a series of separate carriers, to increase capacity requires modulating them at higher frequencies, and that means increasing total power use, and that means breaking the FCC emissions rules. To Santhoff it’s just obvious and incontrovertible. Why anyone thought it might work, is a mystery to him.
On the new wireless effort called WirelessHD, backed by Sony and others for in-room high speed HD communication, and using 60 GHz radio, Santhoff says, ‘It uses 36 different antenna arrays, which means that there are 36 individual receivers and 36 analog to digital converters. That’s going to take a long time to integrate and get right, and it will cost a lot, but it’s the only way that this line of sight technology can get around obstacles.’
‘UPA Powerline from DS2 is about the most honest effort out there and we have tested its performance at around 68 Mbps in real world conditions, which is 10% to 12% better than any of the other technologies. But it uses QAM 1024 as a modulation which means it has to use a very robust FEC scheme.’
To him it is a simple puzzle of how do you go about solving the problem of sending High Definition video around a home, and it was Pulse~link that first came up with using JPEG 2000 (a lossless codec) to send from one part of the home to another and was able to operate in high spectrum above 4 GHz, working beneath the current noise floor of existing transmission techniques.
In effect using a pulse is the difference between sending serially and sending in parallel. You would think sending in parallel would be faster, and in most early adoptions of technology it is. Later, as theoretical limits are reached problems start to occur in coordinating parallel data paths, components get too complex and expensive, and serial comes back into fashion, as it did in optical transports. However in optical you can then begin sending multiple frequencies (think of its as light in multiple colors), as in the Wavelength Division Multiplexing used in Passive Optical Networking, and you have no power penalties, whereas you do in the more saturated and leaky world of radio.
Now let’s get back to what baffles Santhoff. Almost all of his rivals know all this, and because they are not party to the 300 plus patents that Pulse~link crammed into the market before any of them realized that it was happening, they spend all their time denying the fact. To them pulse’s are bad, and parallel carrier waves, the accepted way of doing things, are good. And they say so publicly and loud.
Inventing an entirely new way of transmitting radio hasn’t made Pulse~link popular, but over the course of 8 years the company has convinced a number of eminent people that it is on the right track.
The company recruited the top engineers from Freescale’s effort in UWB, called Xtreme Spectrum once that was closed down and has employed Dr. Henning Harmuth, one of the pioneers of modern UWB and the CDMA Walsh codes, as well as the founders a number of the WiMedia UWB companies and even a WiMedia board member. It seems that once they give up on their own efforts, they are happy to put technical differences aside and join the Pulse~link view of the world.
But while they are outside the Pulse~link camp they continue to smear the pulse approach to doing things.
One reason is because Wi-Fi already has a grip in the home, with over 100 million Wi-Fi enabled notebooks shipping annually, and forecasters saying that around 240 million Wi-Fi-enabled consumer electronics devices will ship in 2011. So Wi-Fi is protecting its base, even though it cannot do the job of sending multiple HD streams around the home in its current iteration (802.11n).
But compared to that, the replacement of communications chips inside 1.25 billion TV sets, and in around 400 million pay TV set tops, and a similar number of DVD players, is a market that Wi-Fi can only dream of. Never mind the 3 billon handsets that would be brought to bear if instantaneous video sideloading could be made possible, and despite widespread use of Bluetooth in handsets and now Wi-Fi, Santhoof insists that Wi-Fi just can’t go any faster.
And all of this has shaped the Pulse~link recent strategy. It no longer expects many people to use its radio technology, but the same CWave chips can now be used with cables, pretty much any kind of cables, but certainly coax and potentially power cables.
‘Our approach now is to be able to deliver HDMI, 1394 (Firewire) and Ethernet over coax on top of our signal, and for that signal to co-exist on the same cable with MoCA or a satellite signal,’ says Santhoff
This works for the same reasons that the radio works ‘ it’s the same wide pulse approach as basic signaling, and then capturing pure HDMI, 1394 or Ethernet bit streams and mapping them across the pulsed network.
‘Back in 2002 we started looking at all home network technology and none of them have a silver bullet, and we decided that what was needed was a hybrid which combines 2 or 3 three media types.
‘Today we have HDMI in and HDMI out, we have 1394 in and 1394 out, and the same with Ethernet. But in our labs we have 1394 in and Ethernet out or any other combination, and that’s useful if you have a TV output in HDMI and you want to send it to a PC which is used to Ethernet ‘ so that’s where we are headed with this.’
It seems to have paid off somewhat within 1394, and given that the FCC has mandated that all US set tops have 1394 Firewire and that it should be an operational port, that will create overnight a 32 million annual chip market on one device in one country. Pulse~link has its PHY and MAC approved for carrying 1394 on coax so far, and hopes that later this year it can prove its legacy compatibility with older (more expensive ) 1394 and show that it can managing the bridging of protocols required in future 1394. Then it has a basis for an all coax network around a home in multiple protocols.
It is already showing this performing at 400 Mbps for 1394, and our understanding is that this 3 to 4 times faster than anything else out there. ‘We can carry 10 HD streams around a home, we have bandwidth to burn,’ says Santhoff.
Rivals continue to issue statements about how their technology can do the same thing, and finally Pulse~link last year realized that it was pointless having 300 plus patents if it was going to let every rival claim similar performance and copy its techniques. Sooner or later it had to sue someone and it chose WiMedia Alliance member Tzero last June. We asked Santhoff how that was going.
‘We hope to have a positive resolution to that legal action in about 30 days, I can’t really say more than that,’ he said. The complaint was really that Pulse~link is not being left alone to plow its own furrow ‘ this hybrid of wireless and multi-protocol coax, after having its technology ignored by the WiMedia Alliance, a collection of companies which now claim to speak for UWB technology which were led by led by Intel and Texas Instruments.
Interestingly we have seen TI leave the camp recently and this week Intel can be seen as an investor in an emerging Personal Area Network supplier using low power Wi-Fi.
Pulse~link accepted that it couldn’t sue Tzero just for coming after the same business applications but instead picked one of its patents (number 6,970,448), based on an idea for two separate slave transceivers operating in different bandwidths with different data rates, and being controlled by a third transceiver by use of timed command slots, up and down a wide piece of spectrum. This is one of the core methods for controlling multiple devices around a home that might suddenly want to broadcast huge amounts of data, like a video stream from a set top to a TV, for instance.
Pulse~link has always offered its patents as a basis for industry standards, but has never been taken up on its offer. It didn’t want an across the board legal battle with Intel and Texas Instruments but once these two stand aside, and they appear to be doing that, then that will leave supporters like Alereon, HP, Kodak, Microsoft, Nokia, NXP, Samsung, Sony and STMicro, all backers of the WiMedia flavor of UWB, with no-where to go.
Most WiMedia UWB members were chasing the markets being created in Bluetooth and USB where both standards committees initially chose the WiMedia technology as a basis for future generations. But this has turned out to be a 50 Mbps market in radio, and has no basis in wires.
Pulse~link at the time said ‘This is only about Tzero. We really are trying to get along positively within our industry. We are engaged with several prominent WiMedia member companies for our specific market applications, and so we value and want to maintain positive community relationships.’
Pulse~link also said at the time, ‘Technically speaking, and from a patent standpoint, often there are a very limited number of technical pathways to overcome a particular problem. If you are the very first to tackle a problem that forms the basis of a new business idea, you are often the first to see all the ways that problem can be tackled. This opens an opportunity to file patents on applicable technical solutions that enable the very foundations of a new business idea.’ In other words you don’t file patents on the business idea itself. So expect to see a very quiet Tzero either licensing the Pulse~link technology or walking away from the overcrowded coax market.
The entire problem with all these technologies which aim to facilitate home networks is that the entire expression of a home network is a misnomer.
There will always be multiple networks in the home. Wifi is great for data networking. But no-one really wants wireless headphones or wireless mouse strokes, working over a wi-fi network. Too many types of traffic, some point to point, others point to multi-point, traveling around the same network. It shouldn’t and it won’t happen. So coax just may end up as the only physical network in the home, and Pulse~link refers to this as its ‘no new wires’ solution for HD video distribution.
Just how will that be embraced? And how can this tiny company (that has soaked up over $80 million in VC funding so far) convince the market politically that its approach is right and that of itself it’s not a threat to established giants.
In our view it only takes one giant, either a Sony, to say that it wants a networking system to join up its PS3, its PSP, its Bravia TV sets (with set tops embedded) and its high speed video cameras and its Vaio PCs, because then it has to think about HDMI, Ehternet, and 1394, at video copying speeds.
Or Apple if it wants to fight Mobile TV, by offering iTunes sideloading onto handsets for files that are Gigabyte class. Apple virtually invented Firewire and could virtually guarantee itself supremacy in copying TV or DVR held content to an iPhone to view on the go, by adopting a wireless or coax connector that can copy the film you recorded last night onto the iPhone in under 10 seconds.
At last year’s CES Pulse~link signed up Geffen to distribute components using CWave over coax, and Westinghouse Digital to use the radio version of CWave to distribute advertising around screens in a retail environment. If Westinghouse likes what’s happened in the intervening year, it could be ready to upgrade its commitment and put the radio version into TV sets, talking HD to set tops across a room.
Our advice to Pulse~link would be that if the technology community finally understands what pulses can do, it should aggressively license its rivals to use its technology, so that consumers can see that coax can suddenly, magically do everything around the home. Once that picks up pace it should then find the biggest home, in terms of a buyer, that it can.