Mike, I understand your plight on cable telephone. I have worked extensively on this with Time Warner Communications in Rochester, NY as their program manager. Although it was successful trials, they decided not to roll it out and keep it just to Rochester. The reason you don't hear to much about it is what I call "cable mentality". They want to put it in little by little, without fanfare, over a period of time. Sort of sneaking up on the competition so that they can market it quietly without having the phone company wage a big PR campaign about things like reliability. When they have a big enough penetration, though, they will trumpet their triumph that they are providing x% of service in this market, all over their cable lines and no twisted pair. TW found out that when they made big announcements in Rochester that Rochester Tel pulled out all the stops to discredit the service: inferior quality, inferior customer service, inferior reliability. Whether it was true or not didn't matter. The public perception of this alternative offering was being turned. So now they stay quiet.
To answer your technical question, it HFC telephony is not an IP based network at all (at least the version I worked on). It is a standard circuit switched network that converts the electrical T1 signal from the CO switch into an RF signal. The voice message is digitally modulated using QPSK or QAM or some other scheme and carried over the analog HFC network. It rides in the same spectrum as the video signals in the network. At the home, the voice message is demodulated on the side of the home and split off to the twisted pair of the inside home wiring. The video signal is sent over to the coax cable that feeds your TV. The TV and/or set top cannot demodulate the voice signal in the spectrum, so it just looks like snow if you tune to the channel it's being carried in.
Hey, you asked.
As far as GTE is concerned, phone companies love to put up trial networks to offer services they normally can't like video. Not much surprise there, I think you are right, since this is new to them they want to see who takes the service, what services they buy and when, what people are willing to pay, what maintenance and operations costs they incur, etc. Again, typical. As far as GTE providing phone service on the HFC network they built, it is a very different thing to provide telephone over a cable network than to provide it over the traditional twisted pair network. I think you may have some appreciation for that based on the diatribe above. |
