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- Newsgroups: comp.protocols.time.ntp
- Path: sparky!uunet!mcsun!sun4nl!relay.philips.nl!prle!ebrandsm
- From: ebrandsm@prl.philips.nl (Ewout Brandsma)
- Subject: Re: Wireless time services -- standards?
- Message-ID: <1993Jan7.084153.14129@prl.philips.nl>
- Originator: ebrandsm@prl.philips.nl
- Sender: news@prl.philips.nl (USENET News System)
- Organization: Philips Research Laboratories, Eindhoven, The Netherlands
- Date: Thu, 7 Jan 1993 08:41:53 GMT
- Lines: 26
-
- In article <JIM.93Jan5183518@hunter.cs.strath.ac.uk>
- jim@cs.strath.ac.uk (Jim Reid) writes:
-
- >TV teletext services already do this (at least in the UK). However, it
- >is up to the broadcaster to determine the accuracy of the teletext
- >time information. Some may be less bothered about this than others - I
- >have seen cable-supplied teletext with times minutes away from GMT. [UK
- >broadcasters sync their teletext clocks to the UK MSF signal.] This
- >would add extra complexity in the user interface to household gadgets
- >that are already over-complicated. [eg - how do you tell the VCR what
- >timezone it's in or which channel's teletext to believe?]
-
- Actually this is exactly what my VCR (Philips VR 813) does. This deck
- is equipped with a teletext decoder to enable programming via teletext
- (VPT) and program start/end detection (PDC). Given the fact that it
- already contains a teletext decoder, using it to synchronize the clock
- shouldn't cost much extra.
-
- It always uses the teletext signal present on the first preset channel
- to synchronize clocks. So you should program your channels in such a
- way that the first one contains a reliable teletext clock of your own
- timezone. This may take away some freedom in channel allocation (though
- not much in my opinion), but it doesn't complicate the user interface
- at all.
-
- Ewout Brandsma (ebrandsm@prl.philips.nl)
-