:: The Digital Network Camera Surveillance School

As you have read in previous chapters of the Network Video Academy, there is a strong trend towards a move from analogue to digital, networked, server-based surveillance solutions. With this in mind it’s probably not a wise decision to continue to invest in analogue components. On the other hand, you can’t just discard an earlier investment if it works fine and still has a couple of years in it. In this chapter, we will illustrate how you can move step-by-step from analogue to digital.

Benefits of going digital
For the past 20 years, monitoring and surveillance applications have been served by analogue technology. CCTV has traditionally been recorded on VCRs (video cassette recorders), and because of its perceived ease of use and manageable price point, analogue was probably the right choice at the time of purchase. However, the rise of digital technology has laid bare the many shortcomings of analogue solutions. Analogue CCTV systems are generally maintenance intensive, offer no remote accessibility and are notoriously difficult to integrate with other systems. Despite these obvious deficiencies, the end user who has invested in cameras, cables, etc, and is satisfied with the current quality is right to ask, “Why buy new equipment?”

Implementing a digital system does not mean throwing away those trusted (and already paidfor) cameras. With IP-Surveillance, you can still use all the cameras, lenses, and cables in place through this step-by-step migration to digital technology. And if this is not sufficient reason to seriously consider an upgrade, examine the TLV, or time-lapse video, recording component. These systems are highly labour intensive because of the need to change tapes and perform system maintenance. Tape wear and tear is an ever-present problem. Furthermore, the actual quality of the images recorded is often unsatisfactory, particularly if used for official investigations. With the introduction of digital video recorder (DVR) technology, the storage media are no longer dependent on operator intervention or tape quality. And with IP-Surveillance technology, the video server and network server represent the next level of improvement by connecting existing cameras to the network with a video server and then storing the images on the network server.

Step-by-step migration

OK, so how do we do it – and what potential traps do we need to avoid? Let’s start with a typical, analogue solution from the 1990-ies. (Fig 1).

One easy and attractive solution could be to just replace the TLV with a DVR. (Fig 2).

With the spread of digital recording technology, its many advantages have become apparent: ease of use, advanced search capabilities, simultaneous record and playback, no image degradation, improved compression and storage, integration potential, and so on.

It’s likely that you might want to add more cameras to the solution. If they are installed in the same room as, or close to, the DVR – all you have to do is to connect the cameras to the DVR with coax cables.(Fig 3). But what options do you have if you want to connect them directly to the existing network or place the cameras further away from the DVR, on another floor or in another building?

No problem really, you can easily add network cameras to the same network and let a server act as recording unit.

This looks like an obvious and cost-effective solution. But it isn’t, we have actually built ourselves into a dead-end. Now we have all the images at two separate locations and it’s really two separate systems. What we should have done, right from the beginning, is to have made the analogue cameras IP-based through a video server. Lately, most manufacturers of advanced DVRs have added support for connecting network cameras directly to the DVR through the network; this puts an end to any problems with further expansion. (Fig 4).

If this decision had been taken at the start, it would have been much easier to expand with more cameras as well as other applications like access control and remote monitoring. (Fig 5).

Remote accessibility
The main benefit from connecting those analogue cameras to a network is that the user can now see surveillance images from any computer on the network – without the need and expense of additional hardware or software. If you have a port to Internet, you can securely connect from anywhere in the world to view a chosen facility or even a single camera from your surveillance system. By using a Virtual Private Network (VPN) or the company intranet, you can manage passwordprotected access to images from the surveillance system. Similar to secure payment over the Internet, a user’s images and information are kept secure and viewed only by approved personnel.

Unlimited, secure storage

Store as many hours of images as you want – provided you have hard disk capacity. And store and view images off-site in any location in cases where monitoring and storage are mission critical or need back up.

Flexible, pro-active image distribution
Take snapshots of an intruder or incident and send by e-mail to police or appropriate authorities. Also, police or other passwordapproved parties can log on to cameras and view activities around a user’s facilities.

Automatic alerts
The video server can automatically send an e-mail with an alarm image to selected e-mail addresses, so the right people have the information they need to take timely action.

Other application areas
Cameras can send images to more than one resource simultaneously. As an example cameras can be connected to an access control system that records an image every time someone goes in or out through a door, while it at the same time sends images to a server.

Total cost of ownership and performance
At the beginning of this section, we listed the many advantages of digital technology, but it bears repeating that with no further need of time-lapse video equipment, no more tapes and no more tape changing and cataloguing are required. Maintenance costs go way down. And while system performance and results markedly increase, total cost of ownership over time will continue to decrease.

IP-Surveillance provides all the superior functionality of digital technology, plus the tremendous benefits of increased accessibility, storage and distribution of images, and a superior costbenefit picture. At this point, analogue owners are convinced it’s time to make the switch, but what factors need to be taken into consideration?

Factors to consider
At this point, we’ve seen that the transition from an existing analogue system to a high-functioning digital IP-Surveillance system can be done step-by-step and in a cost-effective manner, but there are still a number of factors to consider. What about network bandwidth, bandwidth connections (network, xDSL, ISDN, cellular phone etc.), hard disk storage requirements and software?

Network Bandwidth
If you are using a local network, cameras can be patched through a special dedicated router for the camera, thus eliminating most concerns about bandwidth. However, if images are sent by PSTN, bandwidth considerations do come into play. To get a performance of 30 frames per second, you need a minimum bandwidth of 120 kB/s.

Hard disk space
Hard disk storage requirements are dependent on the frame rate of the video you want to store. If you want to store all video at 30 frames per second (30 fps) as opposed to 1 fps, then that requires 30 times the amount of storage. Each application has different recording and storage needs in terms of video frames per second, and hard disk storage requirements will differ accordingly.

Software applications
A wide variety of software applications can be used. The choice of software to use is governed by the end-user application and their specific needs. An example of application software is Milestone's Xprotect Business product; advanced and highly scalable video surveillance software with built-in motion detection, intelligent PTZ patrolling features, high capacity recording and remote access via the web. Another is management software from SeeTec, software for remote camera configuration and management, direct or automatic control of cameras and accessory equipment, image representation, display and message forwarding.

Conclusion
A digital solution is easier and cheaper than you might think. Even with the enormous growth of CCTV and the recent acceleration in migration to digital video technology, significant hurdles remain for a majority of users in making the switch from analogue to digital video recording. Many end users are still not aware that there is a step-by-step path available to transform existing analogue security systems to digital technology. In terms of education, most end users still need a deeper understanding of the benefits and possibilities of digital and network-based surveillance systems. It is also important to know that in the transition from analogue to digital surveillance systems, no system is too small or too tightly tied to analogue technology, to benefit from digital technology. Even a single analogue camera connected to a video server will provide the user with the full range of advantages that come from digital, networked surveillance.

Consider the ease and cost-effectiveness of a progressive, step-by-step move to digital with IPSurveillance. Now is the right time to take the digital step.