Time to seriously consider IP

The most common question that I and my colleagues are regularly asked is: “What is the break-even point where the number of cameras to be installed makes it cost effective to consider an IP/network solution instead of a system which is connected by a conventional analogue infrastructure?” Some people quote this as 20 cameras, some at 30, but in fact there is no simple answer to this question as there are so many factors that have to be taken into consideration, many of which will be affected by your operational requirements.

Asking the right questions

This article is therefore intended to suggest a wide ranging number of questions that your system designer needs to address before a decision can be made as to whether or not to go for an IP/network based system. These are:
Do you intend to have one or more operators watching the live video around the clock, and if so, will all the operators be located in a single control room?
Other than security personnel located in your control room, do you have colleagues who if authorised to do so, would wish to have remote access to the live or recorded video?
Will the surveillance system be used for purposes other than security, e.g. health and safety compliance or management information, footfall management, parking control, etc?
Except when there is an incident that needs to be more closely observed, do you wish to be able to capture very high resolution recognition or even identification grade images of all activity in the field of view of the cameras, or will image quality, which enables an operator to just verify that an incident is taking place, be sufficient?
Do you need every second of video from all the cameras to be recorded 24/7?
Will you want to store recorded video for one week, one month, or even longer?
What is the bandwidth capacity of your existing network?
Will your network manager allow the surveillance system to share the available bandwidth with whatever else is being transmitted around the network?
Will the surveillance system be expected to interact with other security systems, e.g. access control, intruder alarms, perimeter protections systems, etc?
When you have the answers to these questions, and perhaps some others that are specific to your requirements, your system designer should be able to make some recommendations on how your system should be structured to match your requirements.

Now, let’s tke a look at some of the key advantages of an IP based surveillance system.
There is potential for substantial savings on cabling installation costs as an existing network can be used instead of installing totally new cables. A single network cable is also able to carry video, audio and data, as well as provide telemetry and Power over Ethernet (PoE).
You have the opportunity to control and monitor the system from anywhere on the network.
Mission critical video recording can be stored at any location on the network and retrieved from any PC by an authorised user. A high level of redundancy can therefore be introduced by choosing to simultaneously record and store video at multiple locations.
Also, IP based surveillance systems allow users to gain maximum benefit from the latest generation of high definition cameras.

A hybrid approach
More often than not, the solution that is likely to be the most cost effective, as well as being fit for purpose, is likely to be a hybrid system where the best of both technologies are deployed. A hybrid system allows both IP and analogue cameras to be controlled from the same device and additional cameras can be hooked up at any time without the need for new long cable runs.
The recent advances in both cameras and digital video recording technology favour a hybrid approach. The WiseNet1 DSP chipset, for example, which has been incorporated into a large number of widely available analogue cameras and domes, provides technology that is ideal for a hybrid surveillance system. This includes a practical time and cost saving feature such as BNC and Ethernet outputs so that video can be transmitted via coaxial cabling as well as over a network.
The H.264, MPEG4, MJPEG and JPEG compression methods incorporated into the WiseNet1 DSP provides users with the ability to simultaneously transmit images to multiple locations at various frame rates and at different resolutions including 1.3megapixel (1280 x 1024), 16.9 HD (1280 x 720), QVGA (320 x 240), SVGA (800x 600) and VGA (640 x 480).
With such a wide range of compression methods and resolutions to choose from, a number of different users, if authorised, will be able to simultaneously monitor live images at one location, record video evidence at another or view live and recorded images on a smartphone. At the same time JPEG images of an incident can be attached to an alarm e-mail notification with the additional facility of storing pre and post-alarm images on a camera’s internal SD memory card.
One of the most impressive features of the WiseNet1 DSP is its Intelligent Video Analytics capability, which includes Disappearing, Appearing, Cross Line and Enter/Exit detection. It also has a Scene Change tampering function which creates an alert if, for example, paint is sprayed on a camera lens or there is an unauthorised manual change of a camera angle.
The cameras and domes that incorporate the WiseNet1 DSP chipset are also likely to utilise a 1/3” Progressive Scan Mega CMOS. Progressive Scan prevents motion artefacts spoiling the quality of video of fast moving objects which can occur with standard CCTV cameras using the traditional interlacing method of processing video frames.
Full duplex bi-directional audio provides the option of interactive communication between a camera’s location and a control room.

Hybrid network friendly digital recording
The latest generation of DVR and NVRs, both of which can sit very effectively within a hybrid surveillance solution, capitalise on high level H.264 compression to ensure superb picture quality, whilst minimising hard drive space and bandwidth requirements.  
A wide choice of four, eight and sixteen channel models are available each offering a long list of installer and operator friendly features, making it possible to pick the perfect unit for the application at hand. For example, data from ATM, POS or access control devices can be captured with the text data saved along with associated images to be played back if required at a later date.
Dual codec operation delivers different streams for both high performance recording and optimised transmission, whilst a built-in web-server allows live and playback viewing options with the ability to back up incidents via a web browser.


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