Broadband Internet access offers the hope of video-on- demand streaming at near-VHS quality. One way to achieve this is with compression. RealVideo G2 encoded at 320x240 for 300Kbps looks good when enlarged to full-screen in the RealPlayer G2 player. I haven’t done it myself, but I’ve heard that 500Kbps encoding looks even better. How much better may have to do with the limitations of the G2 algorithm, but we expect software compression to continue to advance. Apple’s upcoming QuickTime 4.0, newer versions of Microsoft’s Media Player, MPEG-1, wavelet, and other compression methods may also be able to deliver pleasing full-screen viewing over broadband.

One broadband technology is digital subscriber line (DSL). Phone companies are grappling with (DSL) to provide switched-circuit broadband connections. The phone companies are suffering a DSL learning curve, just like they did with ISDN. Telcos must enable their central offices for DSL, which is not possible in many modern systems where they have duplexed circuits to double-up on POTS capacity.

But the DSL world is a dizzying array of offerings with various upstream and downstream speeds. Some DSL connections promise speeds of 9 Mbps or faster, while others tend to deliver 300-500 Kbps. A new plug-and-play modem standard called “G.Lite” offer less bandwidth. One of the problems with DSL is distance. Subscribers must be fed directly from a central office (CO) without passing through a digital loop carrier (DLC), on less than 1,800 feet of cable. Another problem is that telcos are common carriers, so they have to make their facilities available to others. That means any Internet Service Provider (ISP) can lease DSL lines to sell broadband Internet connections.

Another broadband technology are cable modems. @Home Network (http://www.athome.net) and Road Runner (http://www.rr.com) provide proprietary cable modems and head-end networking equipment to cable subscribers. Unlike DSL, there is no distance limitation to the subscriber, but the cable system must be designed for two-way transmissions, which often requires changing or upgrading every amplifier in the system.

An emerging standard for cable modems called “Data Over Cable Service Interface Specification” (DOCIS) should give rise to cable modems available at retail, that users can install themselves. This would reduce the costly and time- consuming requirement of having the cable operator get inside the user’s PC. DOCIS would also allow each cable operator to construct their own head-end, without deferring to proprietary pre-engineered systems such as @Home. But cable operators are not common carriers, and they can restrict data on their systems as they see fit. Not only can cable operators insist on just one ISP to gateway their subscribers to the Internet, they also can control the gateway, to prohibit streaming video from other sources. Such streaming video may compete with the cable operator’s main offering: cable TV. So while a cable modem connection to the Internet may provide great access to “HTPP” content for web surfing, the gateway could exclude “RTSP” or other streaming protocols from unknown video sources. This means that @Home would be the sole provider (or gatekeeper) of streaming video to @Home subscribers. To exploit this opportunity, @Home has recently made a deal with RealNetworks. RealNetworks will soon release its Commerce Server, which will provide user authentication and billing for streaming media. This will enable pay-per- view either as an impulse purchase for one show, or as a tiered subscription membership.

@Home is also beefing up its backbones in anticipation of sending video from centralized video libraries. The company recently revealed plans buy from AT&T two OC-48 circuits, actually one fiber enabled with two wavelengths, each carrying OC-48. OC-48 carries data at 2.5Gbps. The fiber is crisscrossed at strategic hubs to create 12 rings. But OC-48 is just the beginning. New ways of adding more wavelengths to existing fibers will make it easy for @Home to fatten this pipe when they need to. Dense Wavelength Division Multiplexing (DWDM) is not standardized yet, but some vendors are getting 100-400Gbps on a single fiber strand. And experimental Hyper-Dense Wave Division Multiplexing has clocked at 1.2 Terabits per sec. on one strand.

To reduce the demand on the backbone, @Home will use caching servers from Inktomi (http://www.inktomi.com) in each locality. These caching servers use technology to store a copy of the videos that pass by so if a video is popular, the next subscriber from that same locality that wants that same video can be served from the local cache. A new protocol called Web Proxy Auto Discovery (WPAD) can determine which is the closest caching server that holds a copy of the desired video. We don’t know what the business model will ultimately look like. The Internet is full of freedom-loving techies and is invigorated by enabling software.

(c) Bill Ruhnke, Webstock Media, Inc. via Streaming Media

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