Browse Prior Art Database

In-Building Distribution System

IP.com Disclosure Number: IPCOM000122942D
Original Publication Date: 1998-Jan-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 2 page(s) / 96K

Publishing Venue

IBM

Related People

Barn, B: AUTHOR [+2]

Abstract

In many cases it is desired to send video signals to, or originate video conferencing signals from, a number of rooms within a building. For example, in a school, one may want one class to be able to conference with another site one day, and a different class the next. Without dedicating a special room for this purpose, this either means duplicating equipment in each room (costly if not in constant use), or to move the equipment around (i.e., share it between the various rooms on a reserved or as available basis. One problem that emerges in these cases is the requirement for suitable wiring to each of the rooms that video is to originate from. Installing new cabling is technically the best choice for this.

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In-Building Distribution System

      In many cases it is desired to send video signals to, or
originate video conferencing signals from, a number of rooms within a
building.  For example, in a school, one may want one class to be
able to conference with another site one day, and a different class
the next.  Without dedicating a special room for this purpose, this
either means duplicating equipment in each room (costly if not in
constant use), or to move the equipment around (i.e., share it
between the various rooms on a reserved or as available basis.  One
problem that emerges in these cases is the requirement for suitable
wiring to each of the rooms that video is to originate from.
Installing new cabling is technically the best choice for this.
However, the costs  of installing the cabling may be prohibitive in
some cases and one needs  to look at reusing the wiring that may
already exist in the building.

      In a number of schools, for example, there already exists
coaxial cable infrastructure in place to deliver CATV, in-building
video services or LAN-data to each classroom.  In these cases, it is
possible to use the existing coax to enable sharing of the
conferencing equipment between the classrooms.

      Concept - In the above scenario, there exists a coaxial network
in place.  It connects to an existing video network that provides a
source of programming of some sort (e.g., CATV, captive video
network).  There is an on-site conferencing system located in a
central spot which is able to be shared among a plurality of rooms.
The conferencing system consists of a network terminating device
(e.g., an  ATM switch) and a codec appropriate to the conferencing
network requirements (e.g., H.262 or H.262).  The codec produces
outputs (baseband video, baseband audio and control data), and
accepts inputs (baseband video, baseband audio and control data).

      The in-building system consists of: Mod A.  Mod A accepts
baseband video, audio and downstream control data from the codec and
modulates it up to a standard, unused, RF channel (ch. A).  This
signal is combined on the coax.

      Demod A.  Demod A is tuned to the RF channel assigned to Mod
B.  It  demodulates channel B and demultiplexes the signals into
baseband video, audio and upstream control...