CCTV: Wired and Wireless Networks

In large scale closed circuit television (CCTV) systems, one of the most critical elements is the network.  These CCTV networks have both wired and wireless elements that demand high level design and control parameters in order to maintain the integrity and security of these network sections.

While some dense footprint networks, such as in casinos are primarily wired networks, most large scale networks at large campuses, airports, highways, freight yards, shopping malls, nuclear plants, pipelines, factories, and other critical infrastructure cover multiple locations, acres of land, or many square miles of property built along corridors.  Therefore, a blended network that is composed of optical fibre, coaxial cable, twisted pair, satellite, and microwave are the norm.  No one technology is able to fit every scenario.  So, multiple communication networks are necessary.

A well designed and well built CCTV system allows you to protect your business’ property and assets from theft and protect your employees from those who may wish to harm them.  Whether you need a basic security system consisting of motion sensors or a more elaborate system including wireless services and panic switches, you must assume that a network based upon total customization is required, giving you the ability to cover your entire building or strategically protect entrances and key areas.  A variety of user programming options makes these CCTV installations a perfect solution for a company’s or organization’s specific needs.

Wireless networks do not require expensive ducts or fibre optic networks which saves time, cost, and disruption.  They can be deployed more quickly and negate the need for expensive fibre line rental.

Your wireless infrastructure can offer huge flexibility including re-deployable cameras, mesh, and self healing networks.

Wireless LAN solutions are often more cost effective to deploy than wired networks, with less disruption to stakeholders.

Wireless Network Options

Point to Point Wireless Network

Point to Point solutions are cost-effective wireless Ethernet bridges that range from 100 Mbps to 1.4 Gbps throughput.  The range of products includes throughput-specific and distance-specific plus licenced and licenced exempt spectrum, covering a variety of wireless frequency bands.

Whether licenced or licenced exempt, Point to Point solutions generally require Line of Sight between the transmitter and receiver although advances in wireless transmission protocols have enabled limited Non-Line of Sight performance.  Particularly in 5 GHz, reflection from nearby buildings can be strong enough to offer a radio connection where data can be passed reliably.

Wireless CCTV systems need to be robust and deal with low or high temperatures, air borne salt, and high winds for extended time periods.

Point to Multi-Point Wireless Network

Vendors have delivered Point to Multi-Point networks to municipal authorities, connecting education to local authority corporate networks, or connecting roadside infrastructure such as roadside CCTV cameras and Automatic Number-Plate Recognition (ANPR) [licence plate reading].

Mesh Wireless Network

Wireless mesh solutions are useful as the last mile on a Point to Multi-Point network. They are cost-effective and offer high bandwidth throughput.

Licenced Microwave

Licenced microwave solutions guarantee levels of throughput.  Radio pairs which operate in licenced frequency bands are useful for links that require consistently high throughput (over several kilometres) or are in heavy-interference environments.

Licenced Exempt Wireless

Advances in wireless products have expanded the licenced exempt 5 GHz into 24 GHz, 60 GHz and 80 GHz. With narrow beamwidths, these higher-frequency solutions are extremely focused and result in negligible interference.

Wireless CCTV Networks

CCTV IP Surveillance is a common use of wireless networking, due to the dispersed nature of CCTV networks, the cameras at the remote end of the network need to transmit images continuously.

Wireless transmission can lower capital and ongoing costs as well as giving you more flexibility and control over your network.  It is ideal for re-deployable cameras for events or hotspot areas.  Vendors can advise on the best and most cost-effective solutions on the market for IP cameras, network switching, video storage and video management software.

With text or email alerts, cameras can be streamed to smart phones or tablet PCs over a Wi-Fi network onsite. They can also be viewed and controlled remotely over the Internet.

When qualifying a vendor, wireless IP design services include:

• Network design and architecture
• Wi-Fi product design and testing
• Wireless Surveying
• Wi-Fi equipment configuration
• Penetration testing / Ethical hacking
• Systems Integration services
• Planning Application management
• Network Installation

Resilience

Many methods exist for transmitting video, audio and data signals over wireless networks.  Previously, only analogue methods were available.  They were prone to signal loss in rain or fog.  Now, with the development of systems using mobile phone and IT technology – more reliable digital methods are available.

We can now provide systems which offer what IT professionals call “five nines” reliability – meaning that the wireless connection is 99.999% reliable (i.e. available 99.999% of the time).

Wireless Network Design

Vendors can provide accredited and fully-qualified technical staff who will recommend the wireless systems best suited to fulfilling your requirements.  Solution designs will be provided, with consideration of the following:

• Transmission distance
• Line of Sight availability
• Requirement to travel through buildings
• Need for transmission of video/audio/data
• Bandwidth requirement (e.g. data sent per second)
• Number of signals transmitted within area (congestion)
• Availability and reliability

Wired Network Options

Twisted Pair

The term Structured Cabling System is used to describe organized cable networks designed to facilitate a variety of internal and multi-building communications services, including integrated voice, video and data.  Primarily installed by the data and telecommunications industries, these advanced cable networks have evolved rapidly in the last 10 years, switching from an early reliance on coax, to using other cable media, with the vast majority now using unshielded twisted pair (UTP) cable for the transmission of a variety of communications signals.

The explanation for this major change is simple; UTP offers a technically superior transmission media, it can be used within simple cable network configurations, is commonly available and is cost-effective when compared to coax. For these reasons, CCTV video transmission technology is able to exploit the intrinsic advantages of UTP cable, to offer an extremely effective choice of transmission media vs. coax and optical fibre.

Structured cabling systems’ standards of performance for use with data and telecommunications services are regulated by the International Standards Organization (ISO) and its European counterpart the IEC.  However, when considering their use for the application of stand-alone CCTV video networks, we need only apply their basic principles and methodology to the installation and design of UTP based video cable networks.  In conjunction with high-performance video transmission technology, a myriad of benefits associated with the simpler and superior UTP based cable-networking topology can be exploited.

The evolution of UTP structured cable systems using CAT5e cable for data and telecoms offers designers and specifiers of camera surveillance systems, a major breakthrough in the way CCTV is installed.  With the vast majority of cameras in the world still being connected to the control room via coax, the associated problems are well known and documented, so why do we put up with them?  UTP cable video networks can eradicate these problems, can provide us with a straightforward and unproblematic solution and dramatically reduce overall installation costs.

When designing a CCTV system, the installer will typically run a 25-pair UTP cable bundle video distribution CAT5e ‘backbone’ in the building or site, to conveniently placed central distribution points where they are terminated in a UTP patch block.  From these points, much smaller multi-pair UTP cable bundles can be run to the cameras, carrying video, telemetry and low voltage power signals.

CCTV installers using UTP based structured cabling wiring principles will experience a number of benefits; these can be summed up in two distinct categories.  For example, by running 25-pair UTP cables as a backbone to strategic distribution points in a building we can achieve:

1. Lower cable cost per metre than running multiple coaxes and associated telemetry control cables – i.e. one UTP cable carries all the signals
2. Reduction in the cost of labour due to ease of installing single multi-pair UTP cables, rather than masses of separate coaxial cables
3. Future proof expansion capability.  By installing 25-pair UTP ‘backbone’ cables, additional capacity is catered for, so that at any time in the future, additional cameras / dome cameras can be installed by simply connecting a short UTP cable run to the nearest main distribution point
4. All UTP cables are ‘colour coded’ which makes installation & maintenance easier and quicker
5. UTP cables take up less containment space than is the case with coax.  A 25-pair UTP is the size of just 2 coaxial cables
6. Flexibility of cable runs – multiple signals can be transmitted down the same multiple UTP cable and between several buildings without any induced interference to the video signals
7. Easier transportation to site of much lighter (than coax) UTP cables

By wiring UTP cables in a ‘star’ configuration to individual cameras, other associated benefits include:

1. Only one cable is required from the main distribution point to any given camera – Instead of 2 to 3 as would be the case with coaxial.  This dramatically reduces the amount of cable mass required, associated cost of materials and labour
2. By sending video, telemetry (data) control and power down one UTP cable, costs can be cut to (typically) a quarter of that compared to using coaxial cables
3. By running power from central distribution points, there is no need to install an un-switched fused spur for each camera.  This saves money at each and every camera point

Combining the benefits of using UTP with the features of high-performance video transmission equipment that includes features such as fully-adjustable brightness and sharpness adjustment, hum-bar protection, surge & lightening protection, cross-talk immunity and better noise and interference rejection, the resulting UTP video transmission solution is superior to that of traditional coax based systems.

With the advent of multiple vendors convenient, simple to use, high-quality UTP video transmission equipment, it is now fair to say, that virtually anywhere that short run coaxial or fibre is used, UTP video transmission can now provide a viable and competitive solution.

Optical Fibre

Networking, digital and Internet Protocol (IP) have ushered in unshielded twisted-pair (UTP) cable and high-speed Ethernet, employing IP to carry the digitized video images. In some installations wireless transmission–radio-frequency, microwave, WiFi and mesh nets–play a role. Most enterprise security video designs are not totally wireless. Instead, the technology is applied to meet certain geographic or operational challenges.

And then there is fiber-optic cabling, with its interference immunity, better inherent security, robust distances and huge bandwidth capability.

Until fairly recently, CCTV used technical standards derived from broadcast television and characterizing quality performance of systems likewise derived from the techniques and equipment typically used in the broadcast industry.   The advent of IP based CCTV and newer technologies related to High Definition (HD) TV have considerably widened the scope of surveillance systems.  Consequently, we now see a mix of both analog based and network based technologies, the former using coaxial cable and the latter using Unshielded Twisted Pair (UTP) cable, typically so-called Cat-5 cable.

While coaxial cable is very easy and convenient to use, it does have limitations:

• Link distances are typically restricted hundreds of meters unless in-line amplifiers are used
• Susceptibility to interference from electrical machinery, lightning and other electronic equipment
• Ground loops can cause major problems
• Obviously, there are ways of reducing these issues but eventually coax runs out of puff.

Often it can be inconvenient to install coax cable and if UTP is available then there is a great incentive to use it.  However, similar issues arise when trying to use UTP cables to transmit analog video signals.  Typically, passive or active Balanced-to-Unbalanced converters (Baluns) are used and these can provide reasonable transmission over a few hundred meters (even more with active cable equalization).  The Ethernet systems typically deployed in local area networks are often used to transfer IP based video signals but as with coax and balun based analog systems, these also have severe distance limitations and are susceptible to EMC issues.

Which is where fiber optic technology comes into play: where distance or EMC are a problem fiber is a very straightforward technical fix for many situations.

Excellent quality is now possible, provided the network can handle the increased data rates required for high quality equipment and software. For Standard Definition (SD) video this could be an average of 0.3 to 1.0 Mbps with peaks of 10 Mbps or even greater. However, megapixel cameras can increase this dramatically with average rates of 5 to 10 Mbps for some types.  Most networks will operate at 100 Mbps out of the camera or encoder and feed either directly to a switch located in a central equipment room or to that switch via a backbone network.  This backbone will sometimes be 100 Mbps but more usually it will be Gigabit Ethernet such as the redundant ring network. Clearly the number of megapixel cameras that can be supported on any network will be a lot less than is possible with standard cameras.  Alternatively, larger networks may need to move towards 10 Gbps backbone technology.

Unfortunately, most backbone networks use millimeter (MM) fiber which really isn’t all that good.  The fiber used has changed from the original 50/125 design to 62.5/125 and back to 50/125 over the past 20 years or so:

• Most legacy fiber has been supplied to meet the old FDDI specification (Fiber Distributed Data Interface, an old standard for token ring based backbone networks) and is usually known as OM1.  This is 62.5/125um and has serious limitations in terms of fiber bandwidth, IE 160 MHz/km @ 850nm and 500 MHz/km @ 1300nm.  This is fine if you are running Fast Ethernet over a few kilometers but starts looking a bit shaky once you have Gigabit speeds and really problematical once we are talking 10 Gbps.
• OM2, OM3 and now OM4 50/125um fibers have been developed to improve the performance at 850nm when using VCSEL light sources and these enable 1G and 10G operation over hundreds to several hundred meters. Still somewhat limiting when networks move outside buildings.

Operation at 1300nm over multimode fiber is sometimes needed, eg when using single mode (SM) oriented equipment and some care is needed to ensure reliable operation. We have covered some of the issues in Tech corner that can arise in such situations and the consequent need for Mode Conditioning Patchcords (MCP).

Of course  the other solution to the limitations of MM fibers is just to completely replace them with single mode fiber and single mode equipment.  This enables you to move seamlessly from generation to generation of technology without touching your network backbone cabling.  In fact, to be absolutely sure that your infrastructure does not need any upgrading, also install APC (Angled Physical Contact) connectors on all your new SM fiber with all the benefits APC technology gives you.

There are many different cable types which tend to be divided into those most suitable for either indoor and outdoor deployment.  Most cables used in conventional commercial or industrial outdoor sites do not move once installed so designs such as the loose tube are ideal. The image shows the cross section of a 6-tube design.  It has great flexibility in that the individual tubes can each carry from 1 to 12 individual fibers or, in some designs, from 1 to 6 or more 12-fiber ribbons.  The cable’s central strength member will usually be dielectric (for example, fiber reinforced plastic, FRP) but can also be metallic. The FRP core is usually quite stiff so bending radii of 500mm or so are quite common which means that this design is not so suitable for in building use where a fair degree of flexibility is needed. Some sort of filling is often used inside the tubes to prevent water migration up the cable.  Such fillings can be gels or dry powder that expands in contact with water.

Distribution (or riser) cables used within buildings need to be flexible, strong and must often meet stringent requirements such as low smoke, zero halogen flame and flame retardant.  The most common design is the tight buffer.

The fibers in tight buffer designs typically have a secondary plastic coating (hytrel or nylon) that takes the diameter up from the usual 0.25mm to 0.9mm.  The fibers are then just bundled together and surrounded by Kevlar for strength and then an outer jacket such as PVC or polyurethane is added.

Single tube variants of the loose tube design are also used in buildings as distribution cables.  Such cables have up to 24 fibers in the central tube that will be surrounded by Kevlar and then a plastic jacket and are flexible enough for indoor use.

Usually, cables are terminated in Fiber Optic Breakout Trays (FOBOTs) with the terminated trunk fiber appearing via a through adapter (SC in most Australian installations).  Connection to the equipment is via a patchcord which will be SC at the FOBOT end and commonly ST, SC or LC at the equipment end.

Maintenance

As with any IT network, preventive maintenance is essential to long-term performance.  Due to the criticality of CCTV networks, users cannot be reactive to maintenance issues.  They need to take a proactive approach to the entire CCTV ecosystem.  When performing maintenance or work on any of your CCTV network systems, a technician will need to:

• Check the history of your CCTV network system since its last maintenance service
• Visually inspect all major CCTV components, including cabling and all accessible connections, for signs of tampering, deterioration or damage
• Check all CCTV control equipment (monitors, storage, NVR, Multiplexer, roting and switching gear, etc.)
• Check and clean cameras, lenses, and housings as necessary
• Check lenses for correct field of view and adjust accordingly
• Check pictures for correct field of view and adjust if necessary
• Check and test remote signaling equipment (if applicable)
• Check recording and playback quality
• Check the satisfactory transmission of images to remote centre (where applicable)
• Retrain the users on the use of the CCTV system (if needed)
• Log all test results
• Return the CCTV system to operational status

Whichever network solution that you use in your CCTV network, it is critical to leverage the highest standards for ‘craft’ skills.  It has been our experience that the single biggest point of failure is in the installation.  The standards and the quality of the installation work will most greatly impact longer term performance of these mission critical systems.  Therefore, extra care is required to oversee installation work.  The installation of the connectors is the single biggest point of failure in any network implementation.

Adhering to open architecture and a well known and trusted technical standards is essential to your CCTV network success.

There is an old adage in the systems integration business.  We call it the 10-100-1000 rule.  It can be applied to a project’s time or cost.

“You can pay me ten dollars to do it right upfront.  Or, one hundred dollars to fix it during the installation.  Or, one thousand dollars to correct the deficiencies after the installation.  The choice is yours to select.”

So, if I part with you here with just one first principle, the devil is in the design.  Do your planning and preparation work thoroughly upfront and save yourself from grief downstream.  All too often we see short-cuts taken upfront to save a few dollars.  But, truthfully, this is a ‘fool’s game’ and you will never win by scrimping upfront.  Do it right and do it once.

 

References:

Clearview. (2017). Wireless Networks. Retrieved on April 16, 2018 from, https://clearview-communications.com/products/integrated-security/security-system-networks/wireless-networks

Optical Systems Design. (2018). Fibre Optics for CCTV. Retrieved on April 16, 2018 from, http://osd.com.au/fiber-optics-for-cctv/

Wilson, M. (2011). The use of fiber optics in security and surveillance systems. Cabling Installation & Maintenance. Retrieved on April 16, 2018 from, http://www.cablinginstall.com/articles/print/volume-19/issue-3/features/the-use-of-fiber-optics-in-security-and-surveillance-systems.html

 

About the Author:

Michael Martin has more than 35 years of experience in systems design for broadband networks, optical fibre, wireless and digital communications technologies.

He is a Senior Executive with IBM Canada’s GTS Network Services Group. Over the past 13 years with IBM, he has worked in the GBS Global Center of Competency for Energy and Utilities and the GTS Global Center of Excellence for Energy and Utilities. He was previously a founding partner and President of MICAN Communications and before that was President of Comlink Systems Limited and Ensat Broadcast Services, Inc., both divisions of Cygnal Technologies Corporation (CYN: TSX).

Martin currently serves on the Board of Directors for TeraGo Inc (TGO: TSX) and previously served on the Board of Directors for Avante Logixx Inc. (XX: TSX.V). 

He serves as a Member, SCC ISO-IEC JTC 1/SC-41 – Internet of Things and related technologies, ISO – International Organization for Standardization, and as a member of the NIST SP 500-325 Fog Computing Conceptual Model, National Institute of Standards and Technology.

He served on the Board of Governors of the University of Ontario Institute of Technology (UOIT) and on the Board of Advisers of five different Colleges in Ontario.  For 16 years he served on the Board of the Society of Motion Picture and Television Engineers (SMPTE), Toronto Section. 

He holds three master’s degrees, in business (MBA), communication (MA), and education (MEd). As well, he has diplomas and certifications in business, computer programming, internetworking, project management, media, photography, and communication technology.