Introduction
Network management is concerned with managing overall operations in a networking system. ”different telecommunication networks are designed to satisfy the same needs, they differ in their nature, purpose, architecture and way they work.” (Arpege Group., & Sturt, 1994, p.1).
The major task of the network management is to keep the network moving smoothly, accounting of the resources and effective network management.
In an industry, the network management is used to control the activities of the computer network. The network administrator is a person who takes the overall control of the network system. His main work is to monitor the network system and to prevent the network system from going down. “Network management means deploying and coordinating resources in order to design, plan, administer, analyse, operate and expand communication network to meet service level objective and all times, at reasonable cost and with optimal combination of resources.” (Terplan 1998, p.4).
Closed-circuit television (CCTV)
“Television on intended for only a limited number of viewers as opposed to broadcast TV. CCTV camera: a unit containing imaging devices to produce video signal in the basic bandwidth. A CCTV system or an associated group of systems, together with all necessary hardware, auxiliary lighting, and so on, located at the protected site” (Matchett 2002, p.237).
CCTV is the collection of video cameras to transmit a signal to a specific place and also to a specific region. It is entirely different from Television, in which we use the simplex transmission method. Simplex means only one way communication. CCTV is often used for surveillance in areas that may need monitoring such as IT companies, jails, institutions and military purpose.
In the industrial plant which is not safe and suitable for human activities, CCTV camera system may be used to view the activities from a centralized point of view. CCTV can operate continuously for many hours or only for monitoring a specific event. We can record the video captured by the CCTV in magnetic storage Medias like Digital Video Recorders (DVRs). This method is traditionally used for recording videos with good quality and also it has a capacity to store huge length videos.
“CCTV was first utilized by the United States Military in the 1940s. Closed circuit cameras were set up during the testing of the V2 missile in order to safely monitor the tests. By using CCTV, officials were able to monitor the testing at close range without danger, watching out for defects and other problems that might have otherwise gone undetected.” (History of CCTV 2009)
“Walter Bruch (1908-1990) was a German engineer, famous for inventing the PAL colour television system.” (Walter Bruch Biography n.d.). He implements the CCTV system first. Today the CCTV systems are also used in the launch sites to monitor the rocket flights to find if there is any malfunctioning. Some of the rockets are fitted with CCTV which transmits or sends the pictures of stage separation.
In the case of business street, the New York City was first to implement this CCTV system. The CCTV cameras capture images and send those images to the main central police stations. Nowadays, the CCTV cameras are also used in departmental stores, banks, ATM counters etc in order to discourage theft. In United Kingdom the first place to install CCTV camera was King’s Lynn. Nowadays it is very popular and it is used in all major sectors. (History of CCTV 2009).
Different Types of CCTV Cameras
CCTV cameras can be classified according to the following criteria like the movement of camera, types of images and frames, etc.
First we can see the two types of camera, which can be take whether black and white or colour image Some of the CCTV cameras have the ability to capture images and videos even at low light because it has night vision specialty.
Another classification of CCTV is based on the FPS. FPS means “frames per second” i.e. total number of frames captured and switching to the monitor in one second. Most of the CCTV cameras available today have a capacity to capture videos at 30 Fps. If we capture the video at the rate of 30 fps then the video size will be enormous; so we need larger storage capacity magnetic tapes to store the video captured by the CCTV because the video size will be larger. In the case of ordinary departmental stores we normally use CCTV cameras having 1-6 fps so that its video size will be low and because of this we need only smaller size video tapes to catch and record the captured video.
This classified also into pan and tilt according to its movement. The right left movement is called pan and up-down is called tilt. We can control this camera remotely by using wireless media i.e. Radio Frequency (RF) or wired media like the co-axial cable or Twisted wired cable. CCTV cameras are also used for special purposes like spying, for usage in night etc. Special types of camera called Nanny Cams are used for the Spy works. (How does CCTV work).
Cabling Methods
According to the transmission media used, we can classify the CCTV networks into two types i.e. wired connection (Fixed Cable Connection) and the wireless connection. In a wired connection there is a physical connection between the CCTV camera and the recording device. The most widely used physical media for the CCTV is the co-axial cable. The advantage of using co-axial cable is that it has higher signal carrying capacity. Usually we use RG59 and CAT5 coaxial cable for the CCTV connection. In the wireless connection CCTV there is no physical media between the CCTV and the recording device. In this case we are using the Radio frequency having a frequency of 2.4 GHz. We can connect more than one camera by changing its frequency slightly. The frequency used by the CCTV has the capacity to penetrate through obstacles like concrete beams and walls. The main advantage of using the wireless CCTV camera is that we can implement the camera in any place or areas in the industry where the implementation of a wired CCTV camera is very difficult.
In the Modern CCTV system, Cameras, Monitors, DVR, Keyboard Controllers will be present. The whole activities of the CCTV can be managed by the surveillance software which is installed in the personal computer. A special switcher called the Matrix switcher is used to connect larger group of cameras. The wired connection includes various Medias like the coaxial cables, twisted wired cables, copper cables, optical cables etc. (Choosing the correct coaxial cable for CCTV applications 1996).
Copper cabled based connection
The copper cabled connection is used for connecting the CCTV which is surrounded in areas around 100 m. The working of a CCTV camera which is connected by a copper cable. Here the video signal from the CCTV PTZ camera is fed into a video encoder. This encoder will merge the signal to the Ethernet video stream. The Local Area Network (LAN) will be connected to this video encoder. Any PC which has surveillance software installed on it will be able to view the video broadcasted by the PTZ camera. A video decoder will be present in the CCTV system and this will extract the PTZ control and video signal and these will be sent to the Keyboard controller and the monitor at the CCTV server room. “Using copper category5e/6 standard cables we can interconnect the CCTV system inside a building.. As shown in the figure, from a PTZ camera, the video and control signals will be feed to a video encoder, which merges the video and PTZ signals to a compressed Ethernet video stream. This will be connected to the Local Area Network (LAN) of the building and can be viewed from any PC installed with the CCTV Surveillance software.“ (Technical proposal 2009, p.12).
Single/Multimode Fibre Optic Cables
The Fibre optic cabling is used in areas where the distance between the CCTV and the Server is more than 100 m, such as, if the server is in one building and the CCTV is located in another building. Up to a distance more than 4 km we can use the multimode and by using the single mode fibre optics we can achieve up to 80 km distance. The working of this cabling method is somewhat similar to the copper cabling
The Multimode is “option is good for long distance transmission of Video and Control signals. The video encoder is copper Ethernet, except that this device has fibre ports and converts the Video and PTZ control signals to Ethernet video stream over Optical Fibre. At the receiver end we use a Fibre media converter to convert these signals to copper Ethernet, and we may either connect it to the Local Network as given in figure or directly to the Video decoder.” (Technical proposal 2009, p.13).
Wireless Local Area Networking
In the places where the installation of a wired CCTV network is very difficult, we use the wireless CCTV network methods. In the wireless connection methods there will be no physical connection between the CCTV server and the CCTV camera. In this method the video signals from the CCTV camera is fed into the video encoder. This device will encode the video and this will pass to the outdoor access point. This device will convert the electrical signal into radio signals. At the receiving side there will be another outdoor access point which is connected to the LAN. This device will receive the signal which is transmitted by the first outdoor access point and transmit the signal to the computers which are connected to the LAN. The main advantage of the wireless network CCTV is that we can control a remote CCTV camera from a remote CCTV server. The wireless network uses the 2.4 GHz frequency range. At the receiving side there is also a video decoder which will extract the video signal captured by the CCTV device and this signal will be fed into Keyboard and the CCTV monitor. “The main criteria of wireless network is that, the access points must be in line of sight, without any major hindrance, like metal, concrete etc.. “ (Technical proposal 2009, p.14).
Best Wired Cabling Methods for CCTV Network
The best wired cabling method for the CCTV Network is the Category 5 cabling. The category 5 cable is commonly known as the Cat5 cable. The Cat5e is the advanced version of the cat5 cable. This comes under the category of twisted pair cables. Some cables come under shielded twisted pair and some come under the unshielded twisted pair. It has a data transfer speed of 155Mbits/s. The Cat5e cable gives protection against the noises in the network system. The unwanted signal in the computer network is termed as noise in the Data communication network. The maximum area covered by the Cat5e cable is of 100 m. There are mainly two types of Cat5e conductors; they are standard and the solid conductor forms. The more flexible form is the standard form and there is less chance for the breakage of these cables. The other type i.e. the solid conductor form is not much flexible and is very expensive.
The newer versions of the Cat5e are the category 6 a (Cat6a) and the category 7 a (Cat7a) cables. The Cat6a has the capacity to support a maximum of 10 Gbit/s applications. Also it can be used up to a maximum distance of 100m. About four twisted copper wires are present in the Cat6a cable. This cable uses the “RJ-45” electrical connectors. This gives more resistance against the noises and the electrical impulses. The enhanced version of the Cat6a is the Cat7a cable. This cable has a capacity to operate at a frequency of 1000 MHz. So, we can conclude that Cat5 and its higher version cable are suitable for providing best wireless cabling methods for the CCTV network. (Bryant 1997).
Best Wireless Cabling Methods for CCTV Network
Various wireless cabling methods are used for CCTV networks which include the Microwave, Laser and the RF (Radio Frequency). By using the Microwave transmission technology we can transmit more than one video signal. The main disadvantage of this microwave transmission is that the cost of implementation is much higher. Obstacles between the access points will cause problems to the video signal transmitted. The main advantage is that by using this microwave we can achieve a long distance transmission capacity. Lasers are also used in the wireless data transfer technology but the main defect of using laser system is that, it will cause a serious problem if any obstacles come between the two access points. The best wireless cabling method available today is the RF transmission method. In the RF i.e. Radio Frequency transmission method, a large number of video signal can be sent at the same time without any delay. Also it has got a dedicated frequency range for its transmission. Normally 2.4 GHz is the frequency which is dedicated for the Radio Frequency (RF) transmission.
Bandwidth and Its Calculations
Bandwidth, which is sometimes called pass band width or base band width according to context, is measured in Hertz. Difference between upper cut off frequency and lower cut off frequency in signal spectrum and upper cut off frequency in base band signal is called pass band width. The upper cut off frequency in signal spectrum is called base band bandwidth. Bandwidth also refers to the data rate measured in bit/second in networking. The digital data rate or channel capacity is measured by using bandwidth or frequency. Bandwidth is the main concept of telephone applications and radio communications. For example, bandwidth is the width of an individual spectral line in optics, whereas a range of frequencies occupied by carrier modulated wave in radio communications. Bandwidth is a valuable term in many occasions. For different occasion there are different definitions for band width. One definition is that “bandwidth could be the range of frequencies beyond which the frequency function is zero.” (Bandwidth: overview 2009).
In this case band width of different cameras and the technique to reduce band width of the cameras in the video compression techniques is used to compress the file size of the video file and audio files. It is used to improve the quality of transmission used in this CCTV cameras and its network. Excessive compression reduces the video quality of the CCTV cameras and we can never attain the original quality. In the case of bandwidth, the uncompressed video signal has greater bandwidth in network and to introduce more cameras in the network, larger will be the bandwidth required. It is not simple as we are thinking to know the band width of the CCTV cameras. In the LAN network there will be large number of hosts and we have to think about availability of bandwidth.
We can calculate the bandwidth of CCTV camera by using the lens focal length and viewing angle check the field of view and find dead zones. In this, video should be mpeg-4 or moving jpeg. To calculate bandwidth of CCTV cameras, to know the storage required for the video captured by the camera, we should be aware of some parameters of CCTV camera.
Resolution: It is measured in pixel. We are always using Mega pixel for that. For full HDTV resolution will be 1920×1080 and others having less. The list contains most popular PAL and NTSC camera resolutions (like 352×288 CIF PAL, 704×576 4 CIF PAL) as well as some typical network camera resolutions (like 640×480) including mega pixel resolutions (1280×1024, 1600×1200), HD and full HD resolutions (1920×1080) as well as others. (IP video system design tool 2009)
Compression: Video and audio compression is already mentioned above. It is used to bring out size of video files. But over-compression reduces the quality of the file and it can’t be retransferred. Usually we are using MPEG 4 and moving JPEG (MJPEG) for this.
FPS: Frame per second refers to number of picture captured by the CCTV camera. 5 to 15 fps is the frame rate of the typical CCTV cameras.
And we are using number of cameras, days required, image complexity etc. We are also using units for Frame size-kilobytes, Bandwidth-(Megabits/Second), Disk space –Gigabytes (GB)
“Bandwidth (Mbits) = Frame Size (Kb) * FPS * Cameras * 8 / 1024.”
(IP video system design tool 2009).
Bandwidth:
- = (352×288)*10*4*8/1024
- = 31680 Mbits
- = 31680/1024 Gigabits
- = 30.9375
Here we are taking Frame rate =352×288, frame per rate= 10 fps, Number of cameras= 4.
“To make proper bandwidth planning you should know practical the bandwidth values for your network type. (IP video system design tool 2009).
- 1 Gigabits Ethernet: 500 Mbits/s
- 100 Mbits Fast Ethernet: 55-60 Mbits/s
- 10 Mbits Ethernet: 6-7 Mbits/s
- WIFI 802.11g 54 Mbits: 12-25 Mbits/s.” (IP video system design tool 2009).
In this case network performance will decrease due to the increase in bandwidth, because when bandwidth increases, size of file also increases; so better network should used. Our Network server should be something better media will be good as Cat5e. It is a special type of cable used only for CCTV camera.
In the case of network management, maintaining all operation in network system and administration of the network is important. In case of CCTV cameras, the network management works more efficiently than any other. In this case, network management should be control of the communication between cameras and server computer. The best connection method is the wireless method connection since it will be free to move. And RF frequencies having high frequency are used here. It can penetrate even the concrete walls; though it has a limit of range of area. It is in the range of 150 to 200. But we are taking the case of wired network we should use the cabling method of fibre cable. It should be single or multi mode. Cat5e is the best cabling solution optics fibre.
Network management solution of CCTV in a Hardware Lab (QM440)
The QM440 lab mainly consists of chemical solutions. So in this type of labs there is a possibility of a chemical explosion at any moment. So if we use a CCTV camera in this type of Lab it is better to use a wireless CCTV camera. The wired camera is not used because if, in any case, a chemical explosion happens then there is a chance of the wired network getting burned and the whole CCTV network may go down. There are many types of wireless CCTV available today. We have already mentioned about the various wireless CCTV cameras in the above topics. There are Microwave, Laser and RF wireless CCTV cameras available today. According to our design the best suggestion for the QM440 lab is the RF (Radio Frequency) CCTV camera. It is because, more than one video signal can be transferred from the CCTV to its server at the same time and also there is no problem of any obstacle between the transmitter and the receiver. Since we are using wireless transmission technology there is no risk of fire and also the occurring fault is very less. Configuring the wireless network is not an overhead task. We just have to set the frequency to 2.4 GHz. Since we are using the RF (Radio Frequency) the CCTV transmission can achieve a good transmission capacity and hence give a good performance in case of data transmission and picture quality. Various security measure like Encryption, password locking can be used in this type of CCTV camera systems. By these security measures we can prevent the network camera from being hacked.
Conclusion
In the post modern world, the use of CCTV cameras is mainly for security purposes. In this developing world, technology is also developing according to mankind. The CCTV system has remote eyes to see even in the utter darkness. Live actions can be captured and can be viewed from distant places. The storage media used in this system can store the video captured by the CCTV and it can be used for later viewing. The CCTV system is a very effective tool to fight against crime. The recorded video can be used as evidence in any court of law. Nowadays in all business firms we are using this equipment. Banks, institutions, departmental stores etc are included in that. It is not only useful for avoiding crime, but it has got many other purposes also. In many occasions, we can have the clear view or scene of the incident which is taking place at a farther place. If anybody meets with an accident in the area of CCTV view, we can certainly save the life of the person by taking immediate action. The CCTV systems are widely used in business streets, cities and also for home usage in order to prevent theft and violence. Since the technology is increasing day by day we now have high resolution video with high bandwidth capacity. The cabling methods also contribute much in the data transfer speed. The Cat5e and its higher versions can be used to achieve more data transfer speed in case of wired transmission and the RF method can be used to achieve a higher data transfer speed in case of wireless transmission.
So, by using these two cabling methods we can achieve a higher data transfer speed and also a higher quality video which can be captured by a DVR. The scope of these two cabling methods is increasing and it is being implemented in various sectors.
References
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