telephone via cable network

This is the place for any magazine-related discussions that don't fit in any of the column discussion boards below.
Post Reply
abu
Posts: 11
Joined: Tue Dec 11, 2001 1:01 am
Location: UK
Contact:

telephone via cable network

Post by abu » Tue Jul 05, 2005 7:44 pm

Hi
Can someone briefly explain how telephone network works using the cable tv network. I am in Uk and we get Tv, internet and telephone all from the same source.<p>Thanks in advance.
Abu :confused:

User avatar
philba
Posts: 2050
Joined: Tue Nov 30, 2004 1:01 am
Location: Seattle
Contact:

Re: telephone via cable network

Post by philba » Tue Jul 05, 2005 9:02 pm

At the simplest level, a computer digitizes your voice and sends it as a sequence of packets to another computer that plays it back to the listener. Very similar to playing back music or a video or radio on the internet but its a two way interchange. The computer can be a PC or dedicated device like a Linksys PAP2, for example. <p>Its all much more complex than that - making the connection, realtime compression of voice packets, maintaining good quality of service, handling packet loss, security, and so on is each an area of great depth.

ezpcb
Posts: 98
Joined: Tue Apr 19, 2005 1:01 am
Contact:

Re: telephone via cable network

Post by ezpcb » Wed Jul 06, 2005 3:03 am

hi Philba<p>I don't think it's that complex. I think this can be done with simple frequency division. the voice is under 3k, the ethernet is 20M while the TV is above 50M, they are easy to devided.<p>accourding to abu's post, I think he did mean analog TV and phone, not digital signal<p>Mike
http://www.EzPCB.com
High Quality PCB for Electronics Hobbists, Pay for Chrokee, Get Land Rover

dyarker
Posts: 1752
Joined: Fri Aug 22, 2003 1:01 am
Location: Izmir, Turkiye; from Rochester, NY
Contact:

Re: telephone via cable network

Post by dyarker » Wed Jul 06, 2005 4:53 am

The telephone is digital too. Probably VoIP. If analog, everyone on the cable segment could hear everyone else's conversations.
Dale Y

User avatar
philba
Posts: 2050
Joined: Tue Nov 30, 2004 1:01 am
Location: Seattle
Contact:

Re: telephone via cable network

Post by philba » Wed Jul 06, 2005 10:05 am

There are few, if any, analog telephone systems left in the world. Even the most third of third world countries have some sort of digital backbone at least. "Analog" switching systems were huge monsters. Mostly built by AT&T and NorTel and so on but the benefits of digital quickly overtook them. But he was asking about a single provider for 3 different services in the UK which I assumed meant a single wire, perhaps I was wrong. <p>Even when you use an analog phone, it gets digitized at the CO and transmitted as some sort of packetized stream. VoIP is the more modern IP based approach but this has been going on for at least 20 years. Digital transmission of media is quite fascinating - I used to work in that area.<p>Phil<p>[ July 06, 2005: Message edited by: philba ]</p>

Post Reply

Who is online

Users browsing this forum: No registered users and 44 guests