SAN JOSE, Calif. AT&T is calling for interoperability standards in VDSL and developing a new class of low loss splitters as two steps forward in home networking. While the telecom giant is betting on phone-line technology, it readily admits there is no silver bullet for home nets.
Those were some of the observations from a presentation by Vernon Reed, principal member of technical staff at AT&T Labs. Reed talked about the thorny problems of home networking and defended AT&T's choice of technology from the Home Phoneline Networking Association (HPNA) in a talk at the IPTV 2007 conference here Tuesday (Feb. 27).
All home network technologies have their pros and cons and none is a silver bullet. In part, that's because all technologies face a difficult set of conditions operating in the digital home, Reed said.
Addressing just one of those problems, AT&T Labs is submitting a request for a patent on a new low-loss splitter. Today's splitters can create signal loss of 20-35 dB, Reed said, but the new AT&T design has a signal loss of just 8 dB. The company expects to license the technology to manufacturers in Asia.
While AT&T is firmly committed to HPNA as its primary home net delivery vehicle, it recognizes the technology has at least one major drawback. Unlike powerline plugs sold at retail today, HPNA services for AT&T's VDSL-based video and telephony service is not something users will be able to install themselves anytime soon.
The industry needs to set interoperability standards for VDSL, then work on a few generations of more simplified systems based on those standards before AT&T could deliver an IPTV set-top users could set up themselves, Reed said.
"It's do-able but it could take three to five years," Reed said. "We're still a long way from VDSL interoperability. The Ikanos, Broadcom and Infineon chip sets don't talk to each other," he added.
Installing an external VDSL termination box outside a user's home for video and voice services today takes as much as five hours, Reed said. With better interoperability, the job could be cut to about two hours, he added.
Reed said the ideal home network could be used over any medium—coax, twisted pair, powerline or wireless. Standards groups such as the Digital Living Network Alliance could do the industry a great service by benchmark various home nets and defining a best physical layer, media access controller and remote management, though that would be a difficult job, he added.