IP Masterclass [Part 1] - Getting to grips with the IP revolution

This is the first in a series of articles designed to introduce the principles, the issues, and the language of IP in CCTV. It is written specifically for installers – the people who are at the sharp end of turning the potential of the hardware products into real-world systems that fit the user's requirements.

With each of the subjects we cover in the series, we will start from the beginning. We realise that the language of IP – gigabytes and Kbps, jpegs and wavelets, LANs and WANs – sometimes seems designed to confuse rather than to inform. It is of course the language of computers and IT, and some experts in that field appear keen to keep the mystery. It's our job here to de-mystify, and to put these buzzwords in a context where they can be understood – they are after all essential to the subject, and once understood, the simplest way of talking about it.

Why is IP knowledge vital?
Having said what these articles will address, let us talk about why. The CCTV industry is undergoing the most fundamental technology change of its lifetime. While most of the changes in the past have been extensions of existing technologies, the impact of IP technology is without doubt revolutionary.

The market forecasts showing very strong growth of IP product sales have been widely publicised, with specific figures for sales in the UK and the US. The detail of these figures can be argued, but there is general agreement that in something like five years time more than half the sales of CCTV products will be in IP technology. Whether the reality turns out to be three years or seven, the picture is clear – CCTV installers who cannot work with IP technology will face a severely declining market in the very near future.

So why is the industry so excited about IP technology? What is it that justifies the description of "revolutionary"?

IP technology is truly revolutionary because it both extends the boundaries of existing applications dramatically, and it also makes feasible applications that would not have been considered with conventional CCTV systems.

The following benefits show why IP products are taking a rapidly increasingly market share, and opening up new application areas:

• Ease of communications – the fundamental benefit of IP is the ease with which images can be viewed remotely – from another building, from another city, from another country or continent, using an existing private and/or public data network and therefore needing no major investment in communications
  
• Use of the installed base of PC screens for viewing – IP not only benefits from the existing communications networks; it also benefits from the existing base of PCs, almost all of which can view images, eliminating the need for new monitors
  
• The cost advantages of the huge PC industry – IP solutions will continue to benefit from the economies of scale being produced by the huge world-wide PC industry
  
• Search recordings more intelligently – there are many quicker ways to find a specific recorded image compared to trawling through hundreds of conventional VHS tapes
  
• Management and integration in companies – having many more options for remote viewing and remote operation of CCTV means staff can be located more flexibly, with operational and financial benefits
  
• More convenient storage medium – with greater capacity and there is no physical handling, labelling or need to change tapes on a daily basis as the system takes care of all the housekeeping
  
• Integration with other security systems – IP opens the door to far simpler links to other security systems such as access control or computerised management systems.

A brief working explanation of IP
Now we come to the biggest problem of understanding IP technology. The fact that it is revolutionary, and not just simply an extension of existing CCTV, means that installers need to get to grips with a number of new ideas to work effectively with the technology.

In the past many innovations, for example dome cameras, have been essentially a progression of existing technology. Their manufacture required solving new problems, and they required specific knowledge and training to deploy and install to best advantage, but the concepts are familiar to installers. With IP technology, there are many new concepts to grasp, a new language to learn, and new issues to consider in the design of systems. But there are, of course, enormous new opportunities and advantages to be gained.

So what is "IP"? The letters stand for "Internet Protocol". However, like so many IT "explanations", that may well confuse you further, so we'll try again.

Standard TV has from the start worked with an "analogue" signal – a wavy pattern or series of patterns like those we see on instruments such as ECGs. To produce this signal, a camera takes in light through the lens onto the Charged Couple Device, which has a number of pixels with which to capture the picture. This information is converted into an analogue signal, transmitted down the cable, and then displayed at the monitor or recorded with a VCR, with the picture built up from the signal, pixel by pixel.

With IP technology, the process of capturing the image in pixels using the Charged Couple Device remains essentially the same. It is the way that the analogue signal is coded for transmission that is different. Instead of using the fluctuations of a wave form to express the value of a pixel, the information is converted into a series of noughts and ones and sent around the network in small packets of information in a set manner as described by the Internet Protocol.

Is IP the same thing as digital? No. IP is just one of the standards used for digital communication across a network, and has been adopted as the preferred standard for communications across the Internet. Just as there were two video formats, VHS and Betamax, thanks to the Internet and developments in the IT world, IP Technology may well become the dominant digital technology in our industry. We will cover this in more detail later in the series.

It is worth noting that progressing from analogue to digital is a development path that has been chosen by many industries, and not just CCTV. The music industry, telephone networks, public TV, and the photography industries are just a few examples where new developments are, in the main, digital. As is of course, the Internet – without doubt one of the most powerful drivers of technology directions.

Data volumes: fundamental issue of IP
The coming articles in this series will deal with the specific areas of IP that installers need to know about – cameras, servers, compression standards, storage, and more. In this introduction we will tackle first the subject of units and volumes – the simple subject of bits and bytes.

Installers of analogue CCTV systems have not needed to consider transmission and storage volumes in great detail. For transmission, the standard coax cable adequately carries the (large) signal. Storage, while limited by the capacity of a three hour VCR tape, required a simple calculation based on time lapsing and the number of cameras being multiplexed.

"Going Digital" suddenly changes all of this. The old rules do not apply. With digital technology, the issue of data volumes is always a key design and installation concern, both for communication networks (where transmission capacity is called bandwidth) and for storage. That is why understanding the volume units of digital technology – bits and bytes – is an essential to all installers, and why we explain it here from the beginning.

The basics of bits and bytes
The basic digital unit is the "bit". It's either a nought or a one, and any digital application – CCTV picture, music CD, or human voice on the phone – is converted to a series of noughts and ones.

A single bit is so small that on its own it has no meaning. Bits only mean something when they are grouped together into bytes. A byte is a block of eight related bits. A byte can store the values of a single pixel.

Once you have understood one bit and one byte, then all the kilos and megas and gigas are easy to understand, because they are simply multiples of the bits and bytes. The table on the previous page shows how they are used. But before moving to that, we highlight a potential source of confusion.

Storage volumes are usually stated in bytes (shortened to capital B) and communications capacities are stated in bits (shortened to small b), usually as bits per second (bps). So a disk of 800 megabyte capacity is written as 800MB, and a communications line of capacity 48 kilobits per second is written 48Kbps.

However, you need to remember that 48 Kilobits per second is only 6 Kilobytes per second (eight bits to a byte), and to always be absolutely sure whether you are talking bits or bytes – because the use of b for bit and B for Byte is not always followed.

What's coming later
As we said at the start, these articles are intended to introduce to installers the principles, the issues, and the language of IP in CCTV. To do that, we will cover the following topics over the coming months:

• cameras, servers, and compression methods
  
• software
  
• public and private data networks
  
• storage
  
• applications of IP systems
  
• the future of IP.

ethernetcctv.com is the IP division of Video Imaging Supplies Limited. Being an authorised distributor for leading IP equipment brands, such as Axis Communications, Baxall, JVC Professional, Indigo Vision and Sony, ethernetcctv.com is for today's professional CCTV installer looking to harness the benefits that IP security solutions can bring.