the benefits of IPin CCTV

– a guide

May 2010For other information please contact:

British Security Industry Associationt: 0845 389 3889

f: 0845 389 0761e: info@bsia.co.ukwww.bsia.co.uk

© This document is the copyright of the BSIA and is not to be reproduced without the written consent of the copyright owner.Form No. 299 Issue 1

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Contents

Introduction 3Scope 3Definitions & Terms 4 Analogue system 4 IP system 4Glossary 5Table 1: Advantages and Disadvantages of IP compared to analogue 6 Cost 6 Flexibility 7 Video Quality 8 Support 8 Resilience & Reliability 8 Environmental Factors 8The Effect of Application Geography 9Table 2: Geographical Scenarios Considered 9 Island Site 9 Campus 9 Metropolitan 9 Regional, National, International 9Table 3: Likely Cost/Benefit for Scenarios Considered 10 Island Site 10 Campus 10 Metropolitan 10 Regional, National, International 10Conclusions 11

The BSIA accepts no responsibility for any loss or liability that may arise from reliance on information or expressions of opinion that are contained in this guide. References to other sources of information are for information only and the BSIA takes no responsibility for any material found in them. The information provided in this guide was believed correct at the time of writing but changes to technology, techniques and relative costs can occur rapidly.

© This document is the copyright of BSIA and is not to be reproduced without the consent of the copyright owner.

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IntroductionAt the time of writing, the technical basis for CCTV systems is in a state of transition. Since the 1970s the industry has moved images from point A to point B largely using coaxial cable and the PAL video standard. Since the turn of the century Internet Protocol (IP) networks have become a popular alternative for transmission.

Many systems now incorporate at least elements of IP (a network connection to a Digital Video Recorder being the most common), but there now exists the possibility of an alternative to using the coaxial cable as the primary means to transport video. This can be achieved by using IP cameras, or coaxial cable can be confined to the very edges of a system (by using analogue cameras and IP encoders). End users and system installers are therefore faced with a choice.

It is a common perception that full IP systems are more expensive to install than analogue systems. Is this true, and if so, how much more expensive are they? If it is true, then should organisations pay more for an IP-based system, and why? What are the associated benefits?

What are the factors that affect this choice?

ScopeTo explore typical scenarios in which IP-based CCTV systems may be considered for professional applications and analyse the potential costs and performance benefits of using an IP system.

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Definitions and terms

In order to examine the benefits it is necessary to define what we mean by an IP system and what we mean by an analogue system. These definitions are set out below but it should be noted that what we define as an analogue system may use IP in some way and what we define as IP may have some analogue components. For the purposes of this document analogue and IP systems are defined by the following text and diagrams. The diagrams show analogue transmission and devices in blue and IP transmission and devices in red.

Analogue system

A system which uses analogue cameras, analogue video transmission, analogue matrix switching, analogue displays and records images using either DVR or Tape technology. It is assumed that the DVR has some IP connectivity to allow limited live monitoring and reviewing over an IP network.

IP system

An IP system is assumed to use professional IP cameras (or analogue cameras with IP encoders) that transmit using an IP LAN or WAN, and to record images using a network video recorder. Monitoring and review is achieved using a control and display facility, often a PC with software.

Figure 1 - Typical Analogue CCTV System with DVR

Figure 2 – Typical IP Video system using IP cameras

Figure 3 – Typical IP Video system using analogue cameras and IP Video Encoders

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Glossary

CCTV: Closed circuit television; The term used to describe the overall “closed” system design which transmits video signals from video cameras to only a limited number of defined receivers (monitors or recorders).

Coaxial cable: A common type of cable construction which is used in the transmission of video signals from cameras to receiving equipment. Similar to the cable used to connect televisions to aerials

Communications provider: A company which provides metropolitan or wide area network services to customers; often abbreviated to ‘CP’.

DVR: Digital Video Recorder; A device which stores video information in a digital format, usually on hard disk drives. Coaxial cables carrying analogue PAL video signals are connected to these devices which in turn encode the video signals into digital formats.

Encoded video: A video image which exists as digitally encoded data rather than as a set of physically defined electric characteristics.

IP Decoder: A device which decodes an IP stream into its constituent analogue components, such as video, and audio.

IP Encoder: A device which converts analogue video (often combined with other data such as audio and telemetry) into an IP stream. Some manufacturers refer to IP transmitters rather than encoders.

LAN: Local Area Network; this type of network commonly defines the small geographical area of a local network such as in an office or home.

LLU: Local Loop Unbundling; A means by which communications providers offer data services over BTs existing network using their own equipment installed in the telephone exchange.

NVR: Network Video Recorder; A device which also stores video information in a digital format but rather than the video signal being connected to and encoded by the unit itself, the NVR connects to an IP network on which the pre encoded video signals are already present.

ONVIF: Open Network Video Interface Forum; An organisation set up to define and promote standards for interoperability between IP CCTV devices. See also PSIA.

PSIA: Physical Security Interoperability Alliance; An organisation set up to define and promote standards for interoperability between IP CCTV devices. See also ONVIF.

PAL video: An analogue encoding specification which defines how the video signal is to be electrically encoded for transmission and then decoding by other devices.

TCP/IP: Transmission Control Protocol/Internet Protocol; This is the common term for a standardised set of communications protocols widely used by the internet as well as other networks to communicate across a variety of systems.

WAN: Wide Area Network: This type of network commonly defines multiple LANs and their interconnection whether dedicated or through the internet.

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Table 1: Advantages and Disadvantages of IP comparedto analogue

Advantages Disadvantages

Cost Reduced cabling costs (especially if existing structured cabling or fibre)An IP system can transmit video and control signals over a single CAT 5 cable for distances up to 90 metres. Intermediate switches or extenders can be used for longer distances.For very long runs fibre can be used. Fibre media converters for IP are significantly cheaper than those for video or telemetry data and can typically carry many more signals.

Use of Power over Ethernet (PoE) can reduce cabling and containment costsUsing PoE the power to the camera is transmitted down the same CAT5 cable which will reduce cabling and containment costs. Equipment costs will be higher as PoE switches or midspan injectors are required to inject power into the cable at 48 volts. The cameras selected must support PoE.

Lower cost to distribute video to multiple operatorsOnce an IP stream is on the network it can be distributed to any operator without the need for additional large switching matrices. A control room can be established for the cost of a PC and (if applicable) the licence cost of the software. This means that systems requiring feeds to many operators are more cost effective in IP.

Lower Video Storage CostsThe use of IT industry-standard low cost storage can reduce costs substantially, especially if large numbers of cameras, high quality and frame rates are involved.

Equipment cost can be higherIP cameras are more expensive than their analogue counterparts. If analogue cameras are used then the cost of IP encoders needs to be deducted from any savings. It may also be necessary to provide IP decoders if video is required to be displayed on existing analogue monitors.

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Advantages Disadvantages

Flexibility Amalgamation of SignalsAnalogue video requires a single coaxial cable for each camera signal. In an IP system multiple camera signals are often amalgamated across a single cable subject only to bandwidth constraints.

Can transit existing networksA new dedicated cabling infrastructure is not necessarily required for an IP CCTV system; it can share an existing network provided bandwidth contention issues are addressed.

Less restricted by rangeLargely because of their ability to use existing communications provider’s networks, IP systems allow images to be distributed over larger areas: between cities, regions, and even worldwide.

Modular and ScalableTypically IP systems are conceived as large systems by manufacturers, with small building blocks such as IP cameras, or single channel IP encoders. This makes it easy to expand from a small system to a very large system using the same technology and equipment.

Logical Camera ArrangementsIP systems are normally designed to use logical camera arrangements such that physical camera locations and cabling connections are transparent to the operator when selecting cameras for live viewing or playback.

Remote Access without Loss of FunctionalityIt is often easier to provide remote monitoring and management of systems without loss of functionality.

Easier Systems IntegrationIn the past different systems had to be integrated using a dedicated cabled interface, most commonly using RS232. Using IP, system developers can interface systems together across the IP network, from separate locations (over a wide geographical area) and without dedicated cabling.

Equipment Upgrades and RelocationBecause systems are based upon standard IT infrastructure they are often easier to upgrade. Control rooms can often be relocated without extensive re-cabling.

LatencyLatency in IP systems results mostly from the video encoding and compression and can make PTZ cameras harder to control.

Proprietary video standardsIP systems from different manufacturers are not currently directly compatible (unlike analogue systems which use a common video format (PAL). There are moves to establish a common IP standard (refer to ONVIF and PSIA) which will allow interoperability.

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Note: Some of the disadvantages are being addressed and developments in IP technology may mean that the remaining advantages of analogue over IP will in future be eroded.

Advantages Disadvantages

Video quality

No signal losses (constant video quality)IP is a digital network and the image received is an exact copy of what was sent, provided the integrity of the network is sound.

Progressive ScanAnalogue cameras use the PAL standard which displays odd and even lines alternately fooling the eye into seeing a single image (a phenomenon known as interlacing.) This can be seen as motion blur when displaying the full resolution still image captured from a high motion stream. The progressive scan sensors used by digital IP cameras do not use interlacing and are better at producing stills.

HD Megapixel cameras offer higher resolutionThe resolution that can be achieved by conventional analogue cameras is limited by the PAL video standard. Some IP cameras offer HD and megapixel resolutions.

Poor Low-Light PerformanceEarly IP cameras suffered from poor low-light performance and designers should ensure that selected cameras are suitable for operational requirements.

Inferior Live Image QualityIP systems that encode and compress analogue video signals will always lose quality in the process. When using a quality IP system this loss is not operationally significant, and can be more than compensated for by the improvement in playback quality. When using cheaper, low quality IP systems this difference will be more significant.

Support Better management of devices on network

IP camera parameters can be adjusted remotely

Better diagnostics

Remote engineering services

IP video systems require an additional set of skills to analogue CCTV systems. Engineers still need familiarity with video concepts but also require networking skills.

Resilience & reliability

It is easier to build in resilience and redundancy in mission critical systems by eliminating Single Points of Failure.

Environmental

factorsHeat OutputThe increased functionality and capabilities of full IP systems often require greater processing power which results in more heat dissipation.

NoiseThe greater heat output sometimes requires more cooling so fan noise must be borne in mind when siting equipment in working areas.

SpaceIP systems can require more space than DVRs

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The Effect of Application Geography

The case for IP is largely dependent upon the underlying geography of the application. We have therefore examined the potential and suitability of an IP solution with reference to four distinct geographical scenarios. These scenarios are defined in table 2. Table 3 explores how the cost/benefit analysis varies between the four scenarios.

Table 2: Geographical Scenarios Considered

Island site Campus Metropolitan Regional, National, International

Examples Logistics warehouse, office block, factory, car park.

University, Hospital, Large industrial complex, Airport, Port, Oil refinery, Water treatment works, shopping centre.

Town/City Centre CCTV Scheme, Urban Traffic Control, Collection of Campus Sites or Island Sites.

Rail TOCRegional, National or international network of sites e.g. retail, industrial.

Area covered (typical)

<300m across. 300m>1500m across. 1500m>10km across. >10Km across.

Land ownership

Site wholly owned by end user.

Area in between buildings/equipment sites owned by end user (installation of cable is possible).

Area in between buildings/equipment sites not fully owned by end user (not cost effective to install cable).

Area in between buildings/equipment sites not fully owned by end user (not cost effective to install cable).

Analogue transmission options

RG59 coaxial.

Twisted Pair.

High grade coaxial.

Fibre optic cable, high number of cores.

High integrity Microwave.

Analogue telecommunications services (e.g. RS1000).

Analogue telecommunications services (e.g. RS1000) up to 25 miles.

IP transmission options

CAT5. CAT5.

Fibre optic cable, low number of cores.

IP Wireless transceivers.

IP Wireless transceivers.

IP based telecommunications services.

IP based telecommunications services

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Table 3: Likely Cost/Benefit for Scenarios Considered

Island site Campus Metropolitan Regional, National, International

Transmission (Existing/Shared Network)

Generally inexpensive to install new analogue cabling. If there is no existing cabling savings are not normally enough to counter higher equipment costs.

Cabling between buildings can involve expensive and disruptive civil works so a shared network infrastructure can offer significant savings.

Can be a worthwhile option if organisations have existing wired or wireless networks spanning metropolitan areas.

If organisations have an existing network this can be used to good effect by IP systems.

Transmission (Wireless)

Wireless transmission requirements unusual on island sites due to site size.

If there is no existing network one can often be created using wireless networking.

Wireless transmission can be an ideal solution for metropolitan applications provided clear line of sight can be obtained.

Typically lack of line of sight prevents the use of wireless links over large distances. Can be used up to 25Km if sufficiently tall mounting points available.

Transmission(Communications Provider Networks)

Not required for island sites other than for remote monitoring which can be achieved without full IP.

Not required for island sites other than for remote monitoring which can be achieved without full IP.

CP network connections with sufficient bandwidth for high quality CCTV are expensive to rent and not normally viable for single cameras. Analogue CCTV circuits more expensive to install and can’t be shared but cheaper to rent.

Few organisations own regional networks so CP networks are normally the only option for transmitting video over long distances. IP systems are ideally suited to make efficient use of this expensive bandwidth.

Systems Integration

High security sites may need systems such as intruder, access, fire and CCTV integrated through a common interface. This may be easier using an IP system.

Integration through IP makes the physical proximity of sub-systems largely irrelevant so the larger the site the more of a benefit IP offers.

Integration through IP makes the physical proximity of sub-systems largely irrelevant so the larger the site the more of a benefit IP offers.

Integration through IP makes the physical proximity of sub-systems largely irrelevant so the larger the site the more of a benefit IP offers.

Multiple Monitoring & Review Locations

Not usually a requirement for more than one professional monitoring location and “occasional monitoring” can be achieved using an IP link to a DVR.

IP ideal for systems requiring backup control rooms (e.g. for disaster recovery) as fully featured control can be duplicated easily.

IP ideal for systems requiring backup control rooms (e.g. for disaster recovery) as fully featured control can be duplicated easily.

IP ideal for systems requiring backup control rooms (e.g. for disaster recovery) as fully featured control can be duplicated easily.

System Size(No. of cameras)

No. of cameras can normally be accommodated using DVRs

Whilst the potentially larger number of cameras can still be accommodated using DVRs the management of a large number of these DVRs is not as convenient as IP where the camera location and recorder is transparent to the user.

Whilst the potentially larger number of cameras can still be accommodated using DVRs the management of a large number of these DVRs is not as convenient as IP where the camera location and recorder is transparent to the user.

Whilst the potentially larger number of cameras can still be accommodated using DVRs the management of a large number of these DVRs is not as convenient as IP where the camera location and recorder is transparent to the user.

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Resilience Some redundancy can be achieved with analogue systems but IP may be more cost effective. Consider IP for high security sites.

Redundancy and resilience are better achieved with IP – e.g. using a backup NVR

Redundancy and resilience are better achieved with IP – e.g. using a backup NVR

Redundancy and resilience are better achieved with IP – e.g. using a backup NVR

Likely Cost/Benefit

There can be a business case for IP on a high security island site, or if the disruption of installing new dedicated analogue cabling is an issue. Otherwise IP is typically more expensive.

The option to use wireless or existing/shared network infrastructure and the ease of setting up multiple monitoring points make IP ideal for campus sites. Transmission savings can easily offset the higher cost of equipment.

Systems using wireless IP networks offer the best value for money as install and revenue costs are low. CP IP transmission not yet competitive with analogue fibre services e.g. BTRS1000. If outstation density is high then LLU may be worth considering. Cost/benefit will depend upon individual site circumstances.

IP highly likely to be the most cost effective option for provision of professional quality surveillance with flexibility and resilience.

Island site Campus Metropolitan Regional, National, International

Conclusions

The factors affecting the choice between analogue and IP are complex and varied.

At the time of writing, for a typical 10 camera system on an “island site”, end users will have to pay an initial premium for an IP solution (unless they are able to use existing structured cabling or network.) For small simple systems such as this many end users will continue to choose analogue systems on the basis of price unless they value the future flexibility that IP systems offer. For larger or more complex systems, and particularly where multiple sites need to be connected the business case for IP becomes more compelling, particularly as such systems are often expanded and re-configured over time.

A full IP solution should be seriously considered if:

• The system is mission critical requiring redundancy and resilience• The system is large (more than 100 cameras) or is likely to grow to this size.• The system has more than one manned control point (or is likely to be expanded in this way)• Control points or cameras are likely to be relocated in future• A significant amount of wireless transmission is (or will be) required.• The system makes use of an existing network, or a new network where the network cost can be shared between multiple

applications• The system covers regional, national or international geography where the only transmission options are using

Communications Provider IP networks.