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May 2003 Issue

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Tech Maverick Picks Transport

Operators are beginning to make difficult infrastructure choices as they seek to find efficient ways of adding new applications.

"The industry right now is recognizing that it can no longer build services over separate infrastructure because it will never get to a point that it will show payback on the investments," says Gary Southwell, Internet Photonics' vice president of marketing. "Now they are looking for very cost-effective and simple ways to integrate multiple services onto one transport network."

There are solutions available from vendors such as Optinel Systems, Internet Photonics, Luminous Networks and Manticom Networks. These vendors aim, in one way or another, to finish the job begun by cable's great rebuild of the past decade by efficiently harnessing the fiber-rich, redundant physical infrastructure that is now largely in place.

Internet Photonics helped itself last month when Cablevision Systems, long a technology maverick, announced that it has deployed its LightStack system.

VOD drives product selection

Cablevision, like many MSOs, is targeting video-on-demand (VOD) as a first service to deploy across the new architectures. The output of a VOD server is Ethernet, as is the other side of the network--the portion from the cable modem termination system (CMTS) to the cable modem. The problem is that Ethernet, which was developed for enterprise local area networks (LANs), is a bit of a hothouse flower. It needs to "ride" on a robust transport protocol from one Ethernet domain to the other.

The Internet Photonics approach is to use one wavelength of a dense wavelength division multiplexing (DWDM) stream and stack the Ethernet frames atop the LightStack VirtualWire. Thus, the VirtualWire acts as a transport protocol--instead of Synchronous Optical Network (SONET) or Resilient Packet Ring (RPR)--to carry the Ethernet frames.

The advantage of VirtualWire, Southwell says, is that it can indiscriminately carry any mix of services without the need for any quality of service (QoS) overhead. The rationale is that a full wavelength--which Internet Photonics runs at 10 Mbps--is automatically delegated when the VirtualWire is deployed. Thus, operators only need to make sure that the aggregate bandwidth necessary to adequately support the services carried does not exceed 10 Gbps.

"It allows us to support any service over an individual interface and multiplex on a single wavelength," says Southwell. "It allows them to be mixed on the same wavelength without any QoS configuration."

Cablevision has deployed more than 200 LightStack multiplexers throughout its New Jersey; Long Island, N.Y., and Connecticut systems, according to Southwell. The company is using Internet Photonic's system initially to carry the VOD element of its iO service.

More Ethernet choices

There are other candidates to partner with the industry. Luminous Networks, for instance, marries RPR with Multiprotocol Label Switching (MPLS) as a means of providing QoS and redundancy without the limitations of SONET. Manticom Networks, according to director of marketing Jan Mul, is an RPR-based system that is aimed at providing full interactivity on a low-cost-per-provisioned-sub basis. Optinel's approach can use Gigabit Ethernet, SONET or QAM to transport signals across the cable operator's infrastructure, says Tim Dodge, director of technical marketing for Optinel.

-- Carl Weinschenk

DPI: Poised for Growth

While not quite the "year" for digital program insertion (DPI), interested operators and vendors are nurturing its development and prepping it for larger-scale deployments.

In terms of technology, people and standards, DPI actually is poised for growth. The current enthusiasm for high-definition television (HDTV), for instance, redounds to DPI's benefit, because the respective technologies for HD management and stream insertion overlap.

Behind the Scenes

Charter's purchase early this year of Terayon's CherryPicker DM 6400 statistical multiplexers illustrates this point. The operator opted for the platform's HD rate-shaping capability, holding off on DPI. But activating that function down the road only requires the addition of software.

Behind the scenes, DPI advocates also have been busy. Perhaps foremost among those is the indefatigable Paul Woidke, whose move last year from CTO of Adlink, a leading digital interconnect, to vice president of technology for advertising sales at Comcast is, by itself, encouraging. Woidke is also chair of the SCTE's DPI working group, the source of the cueing and insertion/splicing standards that became, respectively, ANSI/SCTE 35 and ANSI/SCTE 30. Going forward, the group may consider extensions on the cueing standard that could "help in the area of targeted and addressable advertising," Woidke says.

But what's happened with these standards internationally is a story that highlights the strength of DPI technology.

Standards diplomacy

Forwarded to the International Telecommunications Union, the cueing standard became the normative recommendation, i.e. ITU standard, known as J.181 in March 2001. Only this March did the U.S. State Department group that deals with the ITU submit the splicing standard (along with an appendix to J.181) for balloting.

What happened in the interim was a confusing intervention from Japan. Rich Prodan, vice president and chief scientist at Broadcom Communications and an official U.S. delegate to the ITU, says the Japanese initially complained that J.181 didn't explain how to do seamless splicing.

"I said, 'It tells you where to do the splice. How you do it is up to you,'" Prodan recounts. Responding to Japanese disbelief that this could work, Prodan says the U.S. delegation informed them that equipment in the North American market does this very well. "In particular, anything that was designed to do statistical re-multiplexing."

What the Japanese eventually offered in turn was a combination of J.181 and SMTPE 312M, a standard geared toward constant-bit-rate (CBR) streams which Prodan says works, but only under very limited conditions.

"You have to force the encoder into a certain state on the output stream, switch to a pre-conditioned stream on the input side. And the boundary conditions have to match so that the buffer doesn't overflow or underflow," he says.

Approved last summer, the Japanese recommendation, J.189, became a concern among DPI working group members. Carrying this concern to the March ITU meeting, Prodan says the U.S. delegation established that J.189 is "a way, but not the only way, and certainly not the preferable way."

;The promising bottom line on this tale of international standards is that, in terms of splicing technology, which promises more efficient generation of ad revenues, North America finds itself in "the leading position in the world," Prodan says.

If that's the case, then kudos to the innovators who spun off from General Instruments in San Diego to form the team that Terayon later acquired, and to the folks at BigBand Networks who have taken up stat re-muxing and run with it, as well.

-- Jonathan Tombes

Small Systems Rethink Digital

The bankruptcy of WSNet forced a few dozen smaller systems into second digital launches and raised the question of how far you can go without upgrading.

An extension of what was its core offering to the multiple dwelling unit (MDU) market, WSNet's digital cable package enabled the delivery of all channels in digital, giving vulnerable smaller cable operators a weapon against the incursions of satellite.

But WSNet's approach had its flaws. "We saw the WSNet train wreck long before it took place," says Ward Webb, vice president of engineering for Galaxy Cablevision, whose systems have now migrated to the Headend In the Sky (HITS) hybrid satellite/cable QuickTake service.

"Nothing to do with technology," he explains. "Management issues, and not understanding the business they were trying to enter."

Migration obstacles

While this operator apparently smoothly migrated to QuickTake, others faced at best a headache in their transitions. "The systems that did the digital headend solution lost access to core basic," Frank Hughes, senior vice president of programming at the National Cable Television Cooperative, says. "They had to go back to taking feeds directly from Turner and Comedy (etc.)"

Another issue is that operators issued Motorola set-tops to all subs in their WSNet service areas, whether or not they really wanted one. In the QuickTake model, only those subs opting to pay for the advanced tier of programming get Motorola's DSR 470 integrated receiver/decoder at their homes.

Bandwidth challenge

Because QuickTake uses analog and digital programming, it is more bandwidth intensive than the WSNet service. Hughes says QuickTake works well for 450 MHz plants serving at least 2,500 subs. "We've had probably 150 members deploy HITS," Hughes says. "It's been enormously successful."

In a statement, HITS says that its QuickTake product also has tested well in the 330 MHz range, but the failure of WSNet revives the question of just how little bandwidth an operator needs to survive.

"Ultimately, in the long term, to be able to compete, I think they have to bite the bullet and upgrade the system," Hughes says.

-- Jonathan Tombes

Growing with home Nets

Urgency and momentum appear to be rising simultaneously around the home-networking category.

For momentum, there's Cisco's acquisition of LinkSys, CableLabs certification of three more residential gateway devices (from Ambit, Linksys and Thomson) as CableHome compliant, and ongoing field deployments. On the other hand, there's competition.

"If the cable companies don't get on board, they're going to get passed," says Stephen Brazil, director of technical sales for Home Networking Depot. "A lot of the cable operators still are looking for ways to react to a market they see."

Among those doing more than reacting is Cox Communications, which began offering equipment, installation and 24-hour service last November. As of mid-April, the MSO had launched in 13 systems, a spokesperson said. Linksys and D-Link are partnering with Cox in this relatively new service.

Cox's proactive stance gives it a credible answer to questions such as that posed by Niraj Gupta, a Saloman Smith Barney analyst, during a recent earnings call: "What kinds of applications do you see down the pike that might help sustain the growth?"

The CableHome efforts also give operators such as Cox a way to answer follow-up questions on how cable can serve this market amidst a host of diverse and nonstandard approaches.

Another approach

Adding to that diversity is an offering by equipment vendor SercoNet that aims to underscore the network in home networking by combining wireless access with an Ethernet-based wired backbone.

SercoNet uses a patented, embedded outlet cover (currently with two R11 and one RJ 45 ports), along with an algorithm that takes voice, data and power and multiplexes them over a single telephone line.

"Our system distributes wireless and pushes it closer to the user," Jim Gayton, SercoNet director of marketing, says.

;Without endorsing the company, Brazil praises the idea of a wired backbone "I truly believe in turning the entire home into a real network."

Brazil notes that cable is well positioned to exploit this market. "We've been retrofitting homes with coax for 40 years."

-- Jonathan Tombes

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