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Paul ended his part of the presentation by streaming live video back from Cisco's facilities in Israel direct to his laptop, as well as showing two real incidents which were resolved using CCTV footage processed in a different country to where they took place. Hopefully, the audience was left in no doubt that the benefits of Ethernet CCTV are most certainly already here.

When we consider the whole concept of integrating Ethernet networks with our own CCTV systems, it's important to bear in mind that there are a number of ways this can be achieved, each with subtle differences between them.

To some, the natural assumption is that CCTV images will simply migrate on to networks and be available for viewing, control and recording all via the network. While all the above is possible, it certainly will not happen overnight – for a variety of reasons which we'll explore later.

In addition to this truism, as the digital video recorder market has grown so quickly, we've found that many users have been spearheading the CCTV-over-Ethernet revolution without even realising it.

The birth of networking
The first networked systems were in fact conventional CCTV systems connected to 'network-enabling' devices. The earliest of these was known as a Slow Scan Television System and accepted ordinary CCTV inputs – making these available to a remote party using the telecommunications network.

This technology was actually developed mainly by radio amateurs in the 1970s, but believe it or not the Slow Scan Television Systems used in our industry were direct descendants of this early kit. In those days it took around 20 seconds to carry a 256 x 512 picture across a PSTN line (which was all you could really get hold of). In black and white, too, as the only colour SSTV equipment commercially produced was never approved for use in the UK due to lack of demand! Then, following the advent of ISDN lines the rules and regulations regarding image transmission over public networks were relaxed in an effort to promote usage. The much higher bandwidth ISDN lines offered far faster transmission rates and a plethora of image transmission devices sprang up which could be integrated with existing CCTV systems to enable a third party to connect using the ISDN network.

Right from the earliest days, the main advantages of these systems were cost savings (no need for on-site personnel), flexibility (they could be interrogated for a remote patrol) and improved response by visually verifying alarm signals. There were of course some limitations and disadvantages to all of this, with achievable image quality, picture update rates (in terms of images per second) and cost being the main ones.

Perhaps it's a coincidence that the limitations of all the communication mediums applied over the years have manifested themselves in similar ways – but it has also proved that the benefits really do exist. If the latest generation of networks can be harnessed to dramatically lessen these impacts then it doesn't take a genius to recognise that the potential here is truly enormous.

TCP/IP as a standard
The emergence of TCP/IP as a true standard has been the main enabling factor in moving away from 'stand-alone'-type systems (perhaps offering remote access via PSTN or ISDN). A whole new generation of IP-addressable CCTV products can now be specified.

Probably the most commonly used IP-addressable CCTV device would have to be a digital video recorder (DVR), many of which have been 'networkable' since their inception. As digital recorders were the first CCTV system components to make any real use of TCP/IP networks, their operation has become highly evolved and integrated. Many now offer live viewing and camera control functions alongside their primary task of allowing remote access to the recordings.

Although not initially promoted as 'network CCTV devices', DVRs have been proven to offer one of the most effective CCTV/IP convergences, mainly due to the fact that they're extremely network friendly in most modes of operation.

IP video servers, IP cameras and many other network CCTV products must somehow integrate with existing CCTV systems to be of any use. By exploiting the limited bandwidth available in the short term, CCTV-over-IP can be deployed as a cost-effective additio

We've not yet mentioned the thorny problem of bandwidth, but at this stage it's probably worth pointing out that DVRs are as far down the networked CCTV path as many organisations have seen fit to go. This is mainly due to a lack of bandwidth to do anything else, and the lack of any real need to go further at the present time.

DVRs already integrate with standard CCTV equipment, so they are in themselves Ethernet CCTV enablers. Crucially, most put out no network traffic until being interrogated by an authorised user. When they do, only recordings – which are already compressed – are output to the network.

True 'network CCTV' products
There are now hundreds of products which fall under the banner of 'network CCTV' products. These are truly hybrid CCTV/IT crossover products, and fall into two main categories.

On the face of it, IP-addressable cameras are a very logical step forward. However, in many cases their abilities as a surveillance instrument are limited from the outset due to the camera specification, let alone what limits the network.

Network video servers are more versatile as they form an effective bridge between any standard CCTV camera (or cameras) and an IP network. They have the added benefit of enabling several cameras to share one IP address, but can also form the point of network interface with other relevant sources of security data such as intruder alarms and telemetry, etc. However, their versatility can only be truly exploited if sufficient bandwidth is available.

With many of the new CCTV/IP products, one somehow forms the opinion that an assumption about bandwidth availability has been made which may not be the right one for today's world. The use of the old CCTV transmission equipment mentioned earlier was ultimately limited by restrictions imposed which were outside of the manufacturer's control. However far we may have come technically, there would seem to be a danger of history repeating itself here.

Unlike the early days, though, there exists the opportunity to ensure that the true potential of Ethernet CCTV is fully exploited. That said, this means long term planning, with IT providers and the CCTV industry working together. There are limited signs of that happening thus far. Those operating at the highest levels in both disciplines understand future needs, but it's clear that more planning is now required at ground level.

Bear in mind, also, that the requirements for cost-effective network operation (ie minimum bandwidth usage for the shortest time) are directly at odds with today's CCTV end user needs.

Integration with existing systems In the meantime, IP video servers, IP cameras and many other network CCTV products must somehow integrate with existing CCTV systems to be of any use. By exploiting the limited bandwidth available in the short term, video-over-IP can be deployed as a cost-effective addition to existing installations (perhaps for adding cameras from a new building or providing a single network access point for CCTV, alarms and access control data).

Additionally, wireless Ethernet technology offers good potential for many applications in the short term, with its innate ability to replace costly, unreliable RF links and target covert applications.

The flexibility of networking technology for CCTV usage – rather than the networks themselves – is indeed huge. By adopting a realistic approach to implementing CCTV over the Ethernet, everyone stands to gain valuable experience, thereby enabling the next generation of products and networks to evolve with CCTV integration very much in mind.