Introduction to Videoconferencing
 


This page basically provides you with a bit of information about videoconferencing, what it is and how it is beneficial. It also goes on to describe the different types of the videoconferencing there are available today.

It can save travel costs but time savings are the big business benefit.

  • Time savings that can reduce time to market and enhance competitive advantage.
  • Meetings and update sessions that would take days to organise can be done that day.
  • It does enable new ways to do business - Information Kiosks, Tele-Medicine, Remote Learning.
  • It is not just see me and hear me, it is collaborative working, sharing ideas, information and tasks.

The benefits of Videoconferencing are many and the choices are getting larger. It is not a simple question of can we justify a room based system? The questions people like yourselves are asking us are:

  • How can we use this technology to gain competitive edge?
  • What are the benefits and costs in putting videoconferencing on the desktop?
  • Is collaborative working just transferring documents and spreadsheets?
  • Should I put ISDN to the desk or can I risk using the LAN for connection?
  • Not just conferencing but can I store video and broadcast it later?


The options can look daunting but they are simple:

  • You can interwork between differing equipment, desktop and room systems, different manufacturers.
  • You can use existing networks, both LAN and WAN but there are considerations.
  • ISDN is the widely used telephone network for videoconferencing.
  • Gateways provide a link between LAN based systems and ISDN videoconferencing units.
  • Mulipoint conferences can be made using an MCU (Multipoint Control Unit) or an MCU Service and you can see multiple people at the same time.

 

 
 

The keys to success are :

  • Don't look at the very low end PC addons for Internet and telephone casual use, it will put you off.
  • Don't just think of seeing and speaking but collaborative working, reviewing promotional images, editing documents, arguing sales figures, sharing ideas, that's collaborative working.
  • Think about the business possibilities and applications, the benefits that they can bring, not savings in travel costs, but savings in time, efficiency and differentiating the way your customers perceive you.
  • Pick an application not a pilot, define what benefits videoconferencing can provide, then install it and measure it. You will be surprised, it will exceed your expectations.

The Standards
There are many 'Standards' in Videoconferencing. Here we are just explaining a bit about the three main catorgories, H320, H323 and H324. These standards determine how to transport youre videoconferencing calls, there are three ways to do this as explained below.

H.320 (Videoconferencing over ISDN)

Videoconferencing over digital networks such as the ISDN telephone network are covered by the H.320 set of standards. The H.320 elements are shown below, some are mandatory and some optional, this means that whilst a video call can be made between different types of systems (room to desktop) from different manufacturers, the functionality may be dictated by the lowest common standards.


T.120 was one standard that had differing implementations. It covers data sharing and collaborative working and their was some mismatch of function between some systems. This has mainly been resolved and with many vendors now opting to support Microsoft's NetMeeting for this role the problems are now minimal.

H.323 Videoconferencing over IP

Local Area Networks or LANs have become very common within companies today, they interconnect computers (PCs, mini computers and mainframes) allowing information to be easily transferred around the company or stored on centralised servers. These LANs can also carry videoconferencing calls and as typically they already connect not only people within your own building but also other buildings, perhaps other countries and often to business partners and customers they offer a connection service that reaches many of the right people and already exists. Exploiting this existing network may have many benefits. As IP bandwidth becomes more widely available at both home and in the business market, videoconferencing over IP is becoming the more popular transport for videoconferecing. With technologies such as xDSL and Cable Modems, video over IP/Internet is becoming the favoured videoconferencing transport.

 
 

H.324 Videoconferencing over POTS (Plain Old Telephone System)

The normal telephone system has been around for many years with very little change in its basic workings i.e. a microphone turns sound waves hitting it into a variable "analogue" electrical current. That signal is carried to the far end of a call and the sound is reconstituted by the "analogue" signal going through a loud speaker. Also for years we have used "modems" (MODulator/DEModulator) to turn computer signals, "digital" "1"s and "0"s, into electrical signals that look like sounds, thus allowing computers to "talk" over the telephone network ("its good to talk" even for computers). Originally these modems run at relatively slow speeds 2400 to 9600 bps (or 240 to 960 characters per second) and because of this slow speed and large amount of information needed for video the normal telephone network was just not fast enough for videoconferencing. ISDN was developed as an alternative to the analogue telephone system, as it is a digital service offering 128,000 bps (2 channels each of 64 Kbps) it has become the standard for videoconferencing over a telephone network.

Advances in technology has now started to challenge that.

  • Modem technology is now at 33.6 and new technologies at 56 Kbps.
  • Compressiopn techniques and faster processors enabling higher compression.

H.324 is a set of developing standards to enable videoconferencing over the normal "analogue" phone system. Many in the US view Christmas 1997 as the year of the "Home PC Videoconferencing Unit" Christmas present. We will see but we should all be clear on what it is aimed to be, that is a low cost, low quality video system for occasional personal use.

Word of caution: If companies are going to gain real business benefit from video and videoconferencing then they must look past the cheap Internet and POTS based video phone systems available and concentrate on business level solutions (the price difference is small the usability difference immense)

The up side: Many of the advances in "tighter" compression algorithms etc. will be adopted and integrated into the business level systems.