Date: prev next · Thread: first prev next last
2012 Archives by date, by thread · List index


webmaster-Kracked_P_P wrote:
On 07/24/2012 09:43 PM, Brian Barker wrote:
At 09:16 24/07/2012 -0400, Tim Lungstrom wrote:
Also the "lag time" for satellite can be up to 15 seconds from ground station through a satellite to the ground station.

Oh dear: the speed of light must have decreased by a factor of 63 since I was at school! Has someone told the scientific community?

(The delay on the double journey to and from a geostationary satellite is about a quarter of a second.)

Brian Barker


The lag time is due to the equipment, not the "travel time".

I have both standard and digital cable boxes in my place. If I have both TVs on the same channel, the digital TV has a 2 second lag for audio and video than the non-digital TV's box. That is do to the time it takes to convert the TV channel to the digital system and then the conversion back to the coax cable going into the digital TV's coax input. Just in that simple case, there is a lag due to the equipment involved.

As for the time lag I gave you, that is the lag time given in my course in telecommunication and communication networking. The problem is the equipment's lag time doing the processing of the signal to be transmitted and then the process of converting the signal back to the original format.



If equipment is imposing such a significant delay, then there's something seriously wrong. As for the difference in TV, I doubt you're seeing much analog to digital conversion. These days, the source is usually digital and has to be converted to analog for analog broadcast. I don't know how that course arrived at such a figure, as I have certainly never heard of it. If it was real, a lot of common services wouldn't work. For example, when trans-Atlantic calls first started going via satellite, the satellite channels were paired with cable channels, so that only one direction would go via satellite, so as to keep the echo delay to manageable levels (< 1/3 sec) . Otherwise, the echo would interfere with speech.



--
For unsubscribe instructions e-mail to: users+help@global.libreoffice.org
Problems? http://www.libreoffice.org/get-help/mailing-lists/how-to-unsubscribe/
Posting guidelines + more: http://wiki.documentfoundation.org/Netiquette
List archive: http://listarchives.libreoffice.org/global/users/
All messages sent to this list will be publicly archived and cannot be deleted

Context


Privacy Policy | Impressum (Legal Info) | Copyright information: Unless otherwise specified, all text and images on this website are licensed under the Creative Commons Attribution-Share Alike 3.0 License. This does not include the source code of LibreOffice, which is licensed under the Mozilla Public License (MPLv2). "LibreOffice" and "The Document Foundation" are registered trademarks of their corresponding registered owners or are in actual use as trademarks in one or more countries. Their respective logos and icons are also subject to international copyright laws. Use thereof is explained in our trademark policy.