| Hard Knock lessons from a vet of CCTV | | | | cable to each camera. The drawbacks to Siamese |
| systems large and little | | | | wire compared to CAT5 wire is it is noticeably |
| When you are looking at designing an IP camera | | | | more expressive. Siamese wires contain more |
| system traditional rules for wiring the cameras | | | | copper, which is a pricey commodity in today's |
| and recording the cameras go out the window. | | | | market. Siamese wire is also more difficult and |
| Below I have listed 3 design traits that have | | | | awkward to install. |
| changed from conventional coaxial-based camera | | | | Benefit 2 : No extra power supply is required for |
| systems to IP based camera systems. | | | | powering the cameras and it simply needs a single |
| Rule one : Infrastructure Design | | | | termination at the camera and switch location. |
| Two years back I was presented with a big | | | | These two extra features lead to the same |
| camera system that needed over ninety cameras | | | | benefits : cost benefits and a more flexible and |
| in a building that was over 750,000 square ft. The | | | | scalable system solution. Scalability and space |
| challenge, using standard camera design, was | | | | necessities are becoming an enlarging concern for |
| wiring each camera back to a central location | | | | many IT departments. When adding a network |
| where the command console was located. In | | | | camera system the potential rack space needed |
| some examples, camera locations were over | | | | for the present as well as future can be |
| 1,500ft from the command center. Since coaxial | | | | extremely critical when designing a system. Using |
| wires limitation for RG59 and RG6 wire are | | | | PoE can reduce space and reduce heavy, inflexible |
| between eight hundred and 1000ft, solving the | | | | bundles of wires. |
| distance limitation problem was critical. Using the | | | | Rule 3 : Centralized or Edge Recording |
| methods open to me at the time, I had a choice | | | | There is no wrong or right when it comes to |
| between fiber optic wire or UTP ( unshielded | | | | using edge recording or centralized recording. Most |
| twisted pair ) wire. Although fiber optics generally | | | | of your call will rely upon your own application and |
| will produce a clearer picture with less distortion, it | | | | existing network infrastructure. A hybrid of the 2 |
| was cost prohibitive for the project. I chose UTP | | | | styles may be the best solution but this can add |
| wire and with an active receiver at the command | | | | further cost and restrict your available camera |
| console and passive transmitter at the camera. | | | | options. In a meeting with a college district, I was |
| This provided for wire runs of nearly 3000ft. UTP | | | | asked about which solution was better. I replied |
| wire is just CAT3 or CAT5 cable ( commonly | | | | that I felt neither was a better solution ; both |
| called Ethernet wire ), which is used for telephone | | | | solutions have their benefits and it depends on the |
| and data networks. One of the 4 pairs of wires | | | | application. During my meeting I described the |
| sends video down the wire. The twisting of the | | | | following advantages and disadvantages of each. |
| wire provides its unique benefits. This gives the | | | | Centralized Recording: |
| cable its name of unshielded twisted pair. At the | | | | Imagine you have a company which has five |
| time, now more than 4 years back, this was the | | | | buildings ranging in size between 10,000 to fifty |
| best solution for the application as it met the | | | | thousand square ft. All 5 of your buildings are |
| criteria for broadcasting the video and met the | | | | found within a large economic park. Each building |
| client's budget. | | | | has a controlled number of fiber optic wires |
| IP Video changes everything. | | | | between them. Your company has a main server |
| Using IP cameras presents a new set of rules for | | | | room found in the biggest of the five buildings. |
| transmitting video. Where before we were able to | | | | The IT department manages the server room |
| transmit a video signal up to 1000ft using coaxial | | | | and there is limited prohibited access to that |
| wire we are now restricted to only 300ft or one | | | | room. The remaining 4 buildings are accessible via |
| hundred meters. At first, this may appear to be a | | | | fiber from the server room. |
| disadvantage. To anyone that is acquainted with | | | | For this example, centralized recording offers you |
| designing a P. C. network it is apparent this layout | | | | the most inexpensive and scalable solution. |
| is essentially a benefit. Imagine the application | | | | Centralized recording works well here. There is a |
| below: | | | | main server room and all the buildings are |
| You have 5 cameras you want installed. They're | | | | connected thru locally owned fiber. Employing a |
| all located along a back wall of the building looking | | | | single recording location is inexpensive because all |
| out to the shipping and receiving area. The | | | | the recorded video is stored at a central location. |
| recorder is found at the front of the building in an | | | | A single server as against 5 servers ( if using |
| IT closet. Under standard video design, all 5 | | | | edge recording ) will record the video, leading to a |
| cameras would have a coaxial wire installed from | | | | serious cost benefits. In each building, PoE |
| the camera to the recorder. In this example, let's | | | | network switches would connect to the cameras. |
| say the distance is a mean of 500ft from the | | | | The fiber optic wire would transmit the video |
| recorder to a camera. Five cameras at 500ft | | | | back to the central server room for recording. |
| each would require 2,500ft of coaxial wire. Using a | | | | This solution is also very scalable. Adding a |
| network solution the following wiring would be | | | | camera to any location in the 5 buildings is as |
| needed. A single wire, generally fiber, would be | | | | simple as connecting a camera to the nearest PoE |
| pulled from the front of the building to the back. | | | | switch. In this actual application, centralized |
| At every end of the fiber, there would be a | | | | recording fits best thanks to the environment and |
| termination point. The termination point at the | | | | infrastructure available. A disadvantage of |
| front of the building would be considered the Main | | | | centralized recording is if a fiber is cut between |
| Distribution Frame or MDF. The point at the rear | | | | any one of the buildings and the server, all the |
| of the building would be the Intermediate | | | | cameras within that building will no longer be |
| Distribution Frame or IDF. An IDF is outlined as a | | | | recorded or be able to be viewed live. In this |
| location between the MDF and the end device, in | | | | example, all the video from these cameras will be |
| this situation the camera. All the cameras would | | | | lost. |
| be wired to the IDF location. For our example, | | | | Edge Recording: |
| we'll say it's an average of 100ft from each | | | | In this example, you have a company office |
| camera to the IDF. We'd require 500ft of | | | | building and a manufacturing plant. The 2 buildings |
| network wire. Conclusion is that rather than pulling | | | | are found about one mile apart from each other. |
| 2500ft of coaxial wire you are installing 500ft of | | | | You've a dedicated T1 connection between the |
| CAT5e wire and 500ft of fiber. | | | | two locations. The T1 is used to share info |
| The Big Bonus behind IP Video | | | | transmission between the 2 sites. Almost all of |
| The chief benefit behind a network solution is | | | | the installed cameras will be at the producing plant |
| scalability, that leads to important long, and short | | | | so that company is able to monitor the plant |
| term savings. When you have 5 locations all with | | | | remotely. The company office will have 4 to six |
| 5 cameras and all 500ft from the recorder, the | | | | cameras installed to view the main entrance and |
| costs add up quickly with traditional systems. In | | | | worker parking area. |
| this scenario the cost savings can actually begin to | | | | For this example, edge recording offers the most |
| add up. Going back to our example for a minute, | | | | cost effective solution for your company. Limited |
| let's say you need to add a new camera to view | | | | connectivity between the 2 locations is the largest |
| the inside shipping door. The infrastructure is | | | | hindrance. The standard IP camera requires about |
| already in effect. Now all that is's needed is pulling | | | | 2Mb per second available bandwidth. The first |
| a single CAT5e wire from the new camera | | | | camera would consume all the available bandwidth |
| location to the IDF. Perhaps this is only 50ft away. | | | | of a T1 connection making centralized recording |
| Using the old design, you'd need to pull another | | | | most unlikely. Edge recording doesn't forestall |
| 500ft of coaxial wire back to the recorder. This | | | | centralized viewing it only stops the recording of |
| adds up to a cable savings and a significant work | | | | the camera centrally. For this example, you would |
| cost reduction. | | | | use two network video recorders. You would |
| Rule 2 : PoE - The'Power' of a Single Cable | | | | scale each recorder to fit the amount of cameras |
| PoE or Power over Ethernet is just the | | | | they're going to be recording. From the client side |
| transmission of power together with info over a | | | | or remote connection, you would be able to |
| standard Ethernet wire. In a Power over Ethernet | | | | configure the system as though it were a single |
| system, a PoE network switch provides up to | | | | connection. The sole difference would be the |
| 15Watts of power to the end device. This can be | | | | refresh speed of the remote cameras. In this |
| a telephone, camera or any other device that sits | | | | example, edge recording supplies the most cheap |
| on a network and needs less than 15 watts of | | | | answer while still meeting the goals of your |
| power. When planning an IP camera system you | | | | company. The downside, in this application, is the |
| need to look for cameras that use this | | | | price of having 2 servers and slower live display |
| technology. There are 2 basic benefits when using | | | | rates of the cameras. |
| PoE for your system layout. | | | | The Rule Summary: |
| Benefit one : just one wire is necessary to each | | | | By reading this, I'm hoping that you are able to |
| camera for both power and video transmission. | | | | see how IP video offers a very different design |
| Vs a standard camera system that uses a | | | | and new features that weren't possible or cost |
| Siamese wire for both video and power. A | | | | prohibitive with a conventional coaxial wire |
| Siamese wire has a coaxial RG59 wire and | | | | system. There are many other benefits when |
| sometimes a 18 gauge two conductor wire | | | | using IP video. The 3 mentioned above are only |
| molded together to form a single wire. This gives | | | | some of the benefits that IP video technology |
| the appearance and simplicity of pulling a single | | | | has provided to the safety industry.. |