By Douglas Grant

NETWORK CAMERAS USED FOR MONITORING

Network camera technology certainly does not fall into this CCTV category, these cameras take us into another dimension of surveillance monitoring.  All made possible now with the availability of high-speed Internet access.

With worldwide market acceptance of digital camera technology, monitoring systems have become much more efficient, and support remote monitoring.  The limitations of the older analogue-type of monitoring rooms have been endured long enough.  All the hardware and cabling that go along with the analogue type control rooms have been reduced to small amounts of network cable, powerful servers with CCTV software and large LCD screens used to view multiple camera images.

Using network camera technology, a security operator in a network camera monitoring room is able to view cameras anywhere in the world.

Using this new camera technology, quite a few possibilities are available to you.  The most obvious use is monitoring a camera from your own computer.  Anyone with a computer and access to the Internet could keep an eye on the camera for you as well.  Surveillance software is supported by major manufacturers of PDA devices and their operating systems.

Most commercial locations now have a mobile network in place which means you can not only call but view important projects when you are out of town.  The PDA also allows you to view Web cams anywhere in the world.  Web cams have similar characteristics as the network cameras, the difference is in the connection to the computer, which is via a USB cable, Web cams do not have the same configuration process, nor do they support the same protocols.  Web cams are generally used with applications running on your PC.

The other alternative to self monitoring your network camera is to hire a security business to do this for you.  Combined with the security companies’ patrol service, you will have 24/7 security monitoring and backup patrol attending the scene if it is required.  These companies can monitor your camera from their vehicles as they approach your premises.  Police are able to do the same thing in any emergency if they have the permission to view your cameras.

Network cameras have features that will alert you to any change in the cameras’ field of view, meaning, if anything moves, the recipient can be sent an email with a message and snap shots that inform you there has been movement and the camera has recorded it.  The messages can also be sent to your mobile phone via SMS and to various recipients in your address book.  These new technologies are very useful to anyone using network cameras for video security.  Imagine having your local security company monitoring your premises from the other side of the world, or having your community camera system being watched by security monitoring centers somewhere else in the world.

It won’t be long before local business and councils realize the cost efficiency of the remote monitoring technology available to all of us now thanks to the Internet.

CAMERA IMAGES ON THE NET

Once the images are sent from the network camera out into other larger networks, anyone with the cameras’ IP address and permission to view the images, are able to watch everything going on in the view of the camera.   Special permissions can be given to users to log on and control the camera as well by moving the camera up and down back and forth, zooming in and out.   They can even play back the images that have been stored.

The next logical application for the network monitoring room is going to be monitoring any number of cameras in local and remote places.

The network camera monitoring room will require Internet access to the monitoring rooms’ camera servers.  This service is installed by the ISP or the Telco provider.  The cost of this service is determined by the bandwidth required to download each cameras’ data or images.  The only cabling from the cameras to the control/monitoring room is a network cable from the ISPs’ modem directly to the server, that’s it.  Gone are the days when you needed to cable each and every camera to the system hardware.  All this new technology is making installations easier, rather than more difficult.

To even more simplify the management of the camera system, software developers have been working hard behind the scenes creating Graphic User Interfaces (GUI) which support hundreds of cameras.  (See: Multi-screen Display)

You can’t always view every camera simultaneously, but you do want to be able to group your cameras and be able to drag them onto the screen whenever they are needed.  Of course, it has to be on a Windows platform and we all want to be able to manage the software with a mouse using all the familiar clicks we have come to memorize.

HOW IS IT ALL DONE?

Let’s start at the network camera and work our way through the technical stuff all the way to the operators’ screen that displays the image of the network camera.

The network camera is in part an analogue camera with a digital output.  Before the network camera, we had the analogue camera connected to a video server using a coax cable with BNC connectors.  The video server converted the analogue signal to an Ethernet data signal which we were able to attach to our computers using Cat 5 or 6 network cable.  All these cables have the same connector on either end called an RJ 45 connector.

The network cable has made camera cabling much easier to install.  Instead of buying a camera and a video server as you might have done before the digital camera technology was available you buy a network camera now and it’s:  all-in-one.

In fact, the software that comes with these cameras will support most configurations you could think of without any extra cost, or attached devices.   Let’s imagine we have configured the network camera and given it a unique IP address that works on your network.  You should be able to go to your computer and type in the IP address and see the images using the same browser you use to surf the net.  (See: Camera setup diagram)

If you are still with me at this point you have probably done a bit of networking in your past and understand the configuration procedure of the network camera as you would a computer.  That’s what I want you to understand, each network camera on a network is set up just like you would set up or configure another computer on a network.  All the familiar protocols your computer, laptop and PDA support are used by the network cameras.

If the images are viewed on another network, then permissions and authentication have to be set up as well.  A router is always used when the Ethernet packets/data is asked to leave your LAN (Local Area Network).  The LAN is a network the network, camera is connected or part of, it may be shared with other computers.  If you would like to have others view your network camera, then you must connect or have access to the Internet.  Connecting to a WAN (Wide Area Network), in this case the Internet, will allow others to view your camera images on the Internet.  Connecting to the Internet is the fastest means most of us have to send our network camera pictures to anyone who would like to see the images.  Broadband media such as Cable, DSL, ISDN and Wireless replace older 56 kb dial up PSTN technologies that served us well in the past and will continue to do so in many regions that are without broadband services.

Today we are installing network camera technology for marketing purposes, such as places of interest to the tourist Web surfer, and for the security conscience that need to view their cameras.  This is a relatively new application for network cameras and is being used across the country and into neighbouring countries.  The applications for this network camera technology are endless in the private, retail, tourism, commercial, aviation and military environments.

Todays’ CCTV consultants and security integrators require a good understanding of network integration.  Network cameras are using the Internet Protocol (IP), stands to reason every device along the way, from your network camera to the computer screen viewing your cameras images must support this protocol.  It’s one big network now and everything networkable is on it.  (See: Network Diagram)

CAMERA IMAGE STORAGE

The Old

Remember the old EVR Video Player (Electronic Video Recorder)?  Let’s not forget our humble beginning in audio/video technology.  In fact, it was in the late 1960s this unit was available to the market, it never really recorded any video as the name may suggest, it was a play only stand-alone unit you plugged into your TV set.  Not a big commercial success, like so many video recorders of that time.

The New

Of course now we use current technologies to record video, we depend on the network monitoring room environment with high powered servers to record and store large scale camera systems on computer hard disk.

True network devices support the familiar networking protocols and are accessed without the need to download a manufacturers’ proprietary software.   With this in mind, a 100% digital network monitoring room will have servers that can access large NAS (Network Attached Storage) devices for the storage of large camera systems.

This is where all the images are stored.  Network integrators will recommend these disks have redundancy and may configure the storage system with RAID (Redundant Array of Independent (or Inexpensive) Disks).  This disk arrangement is vital to the safe keeping of the video images.  I recommend and practice installing at least RAID 5 to all storage disks on the server and any remote NAS being used for the video storage.

RAID 5 will protect all your data on these storage disks if one of the disks goes down for any reason you are able to replace it without any data lose.

HOW MUCH STORAGE IS NEEDED?

Before the server and disks are set up for monitoring and recording the cameras system, the storage space has to be estimated, and then installed to specification.  Multiple camera system require enough storage to playback any image over the specified time that was agreed on when the system was designed.  Government departments may require 30-day storage for some or all of the cameras in the system.  Privately monitored systems may only require one to two weeks.  Each storage system will have enough storage based on the average file size of the image; file size is measured in Kilo Bytes. (kB)

Example: Depending on the resolution of each image and the compression technique used, a JPEG file size of approximately 50 kB is acceptable.

Since large scale storage is still an expensive issue, we can reduce the storage component in a few ways.  The first logical way to reduce storage is to:

• Record at a mid-high compression level;
• Configure each camera to record between  4 - 8 frames per second;
• Use motion detection to activate camera recording.

Note: Real time is calculated with 25 or 30 frames per second, depending on the standard you are using.  PAL / NTSC.

I have found these frame rates mentioned above will playback a very good sequence of events for most surveillance camera systems.

• Multiply the size of the image by the rate per second
• Multiply by the number of seconds in a minute = 60 sec.
• Multiply the number of minutes in an hour = 60 min.
• Multiply the number of hours in the day that require recording.  i.e., = 8 hrs.

If seven days of recording are required:

• Seven is multiplied to this result for the estimated storage needed for one camera.
• Multiply the number of cameras to the figure for a final result.
• Convert this figure to Gigabytes, as most hard disks have a GB capacity.
• Add the tolerance and additional space needed for the specified software and RAID used in the storage system.  

You now have enough storage to record all the cameras constantly for 8 hours a day over a period of 7 days.  After the calculation is completed, you may be surprised just how much disk space is required to record all these cameras.  In most cases, the system recording software supports motion detection, a fraction of the storage space is required when you configure the cameras to record on motion rather than constantly.  Playing back a system that incorporates motion detection is much easier to view in playback mode than a constant recording system.  There you have it in a relatively simplistic model.

It’s just the start of much more exciting technology to come...

Douglas Grant is Director of The CCTV Consultant  (www.cctv.com.au).