Motorola’s SURFboard line of modems, enabled to deliver
voice over IP (VOIP) traffic, is one of Comcast’s
choices for next year’s cable telephony rollout, officials announced Friday.
The other two, ARRIS and Terayon, complete Comcast’s vision for embedded
multimedia terminal adapters (eMTAs), a modem that puts VOIP technology and
cable modems in one device. VOIP opens the door to set-top telephony,
where customers can access a telephone directory, screen calls using caller
ID and other services on a TV set.
Comcast plans to roll out circuit-switched telephony to parts of
Philadelphia in mid-2003. The cable operator has been testing Motorola’s
equipment since April in Detroit. Using older technology, 40,000 users in
Michigan in Virginia are using VOIP on Comcast’s network.
Details remain secret for now. Tim Fitzpatrick, a Comcast spokesperson,
said the costs for VOIP service hasn’t been completely worked out yet, as
well as the exact locations in Philadelphia the service are going to be
available.
Cable technology, available for years now, has been plagued with latency
and voice quality issues from the beginning and has been used in test
trials by all the major cable networks in the U.S. DOCSIS 1.0, the
standard used by cable modem manufacturers, however, was never designed for
voice traffic on a data network.
DOCSIS 1.1 has come out in recent times, however, and modem makers have
been scrambling to get new modems under the standard certified by
CableLabs, the organization that signs off on the equipment’s adherence to
standards.
Cable operators are eager to roll out VOIP to its customer base because it
provides a competing service to the more traditional copper-based telephone
service provided by the telephone carriers and brings in more revenues to
pay for the digital upgrade they paid millions to accomplish.
There’s been a host of problems, though. The cable network’s broadband
architecture is a shared network resource, meaning the more people on the
Internet, the more they are sharing bandwidth, driving speeds down in
populated areas. Though VOIP’s data packet compression technology reduces
a packet to around 8 KB, the potential for dropped packets (i.e., hangups)
and an “echo” on the line is huge.
The cable companies would love to tell its customers they can replace its
VOIP offering with telephone company-based voice, but they would run into
many problems. The biggest factor is emergency availability; if the power
goes out, you can’t use the phone on a PC or TV.
Fitzpatrick said it was “too soon to say” how it would market the service
to it customers, but said the company would have a strategy before the
launch next year.
