IPTV World Forum is on March 22 to 24 in London, and many of this week’s IPTV announcements are mostly ‘sit and wait ’til next week’ page holders for what is to come, but US VDSL2 chip expert Ikanos says it will be showing its new G.Vector Support chips, offering DSL at 100 Mbps over copper, which are now ready to install in anger. We shall be looking for equipment vendors coming out with designs that rely on them over the coming months.
The company says that many technologies are in evidence in these chips, noise cancellation, bonding, low power, what it describes as wire-speed packet processing and this will show the way for a whole new generation of home gateways. The time gaps between new DSL chip generations are getting larger, and there’s no question that it is having some trouble bridging the gap to Cable Modem DOCSIS 3.0 speeds and the hot topic so far has been Phantom Mode, which has been shown giving speed improvements at Alcatel, Huawei, Nokia Siemens Networks and Ericsson.
Fundamentally there are to two core changes at work in VDSL chips, and these are Dynamic Spectrum Management (DSM) technology and bonding, but it’s not straight forward.
DSL guru Professor John Cioffi, the processor at Stanford University who is attributed with virtually inventing DSL single-handedly, talks about needing to change transmit power dynamically across multiple parallel DSL lines and then dynamically managing physical-layer signal access multiplexers. In other words pick the best line to send stuff over, then turn power up and down to optimize cross talk and multiplex the signals, and use vectoring to cancel out the cross talk.
The Ikanos chip owes more than a little something to Cioffi’s work, as it was one of the first companies to take a patent license, back in September 2009 from his company Assia about a year ahead of the pack.
DSL works by sending electrical signals over a single pair of wires to a subscriber’s premises. DSL speeds can be increased by a process known as ‘bonding,’ where independent signals are sent over multiple pairs of wires to the subscriber’s premises. Phantom Mode goes a step further, sending independent signals not only over each pair of wires, but also between the two which make up the pair. In this way, two pairs of wires can deliver three to four times the data rate of a single pair, rather than the doubling that would occur with bonding of two pairs alone.
The key Assia invention which makes Phantom Mode communication practical, is the DSL modem’s ability to discriminate between the deliberate phantom communication signals and undesirable crosstalk which they can create. Assia removes this using vectoring, making Phantom Mode communication practical.
The basic concept of applying vectoring to Phantom Mode transmission was first reported as far back as 2004, and Assia had to patent the invention and then get it adopted into the standard. Assia said last year that it is now looking to license these patents to DSL chipset vendors, but the Ikanos deal pre-dates that statement, and it could be that it has as much as year’s head start with this technology.
At IPTV World Forum it will introduce its next-generation family of communications processors called the Fusiv Vx185 and Vx183 to enable Telcos to deploy 100 Mbps service over traditional copper lines at what it says is 10% of the cost of laying fiber. We’re not sure over what loop distances, but our guess is that it will be something less than 1000 meters from the exchange, though it might be more.
Ikanos says that using both bonding and vectoring with these chip sets, along with a centralized management system to offer DSM, aggregate data rates can go up to 300Mbps with these chips and that by using dynamic power management any home gateway built using these chips will use way less electrical power than existing devices.
The new chip family offers full ADSL and VDSL2 support on a single chip including support for all VDSL2 profiles and bands used in Asia, Europe, and North America. If the widespread uptake of DOCSIS 3.0 in Europe and the US is any indication, telcos will be panting to get their hands on devices using this type of technology, and will deploy just as fast as they can organize it (which is often a year or two).
Ikanos just came out with its results to end of 2010 with revenues of $191.7 million in revenues, up almost 50% over last year, losing $49.7 million in the process. In August 2009 it bought the DSL segment of Conexant, which doubled its size, but it is still up for grabs whether or not it can scale fast enough with these technologies to reach profitability before the rest of the not so specialized DSL vendors catch up.
Last October ZTE said that it had the world’s first system-level VDSL2 vectoring prototype, the ZXDSL 9836, which automatically analyses interference between line pairs and eliminates it, achieving 100Mbps data downstream speeds on copper.
As far as we can see, ZTE does not have a license to the Assia patents, so presumably it either does this a different way, will get a lawsuit or simply has not declared it has such a license publicly, but has one.
Last week US researcher IHS iSuppli said that it expects sales of VDSL2 chips to triple to 60 million compared 23.3 million in 2010 and said that although Ikanos currently has a 55% share, this will be eroded by Broadcom and Lantiq – with no Chinese companies, such as ZTE mentioned.