Selecting the correct CCTV transmission and recording system for use in remote monitoring applications will critically affect the efficiency, operation and level of police response that a site can expect. We asked Jon Martin, Chief Technical Officer for UK based CCTV transmission manufacturer, Teleprecision, to explain the systems and technology currently available. In his first article, Jon discusses the appropriate use of 3G networks in remotely monitored CCTV applications.
Remote monitoring - effective and economical
Remote monitoring is an increasingly popular means of managing sites nationwide. It is effective because trained operators can take appropriate action to site incidents and alarms as they happen. They can ask intruders to leave a site or request a police or emergency service response to a verified, genuine incident. Remote monitoring is an economical security option because operators focus only on critical site incidents. This allows them to efficiently manage multiple sites simultaneously, reducing the monitoring cost per site.
The police have recognised the effectiveness of remotely monitored CCTV systems and endorse “BS 8418: Installation and remote monitoring of detector activated CCTV systems code of practice”. This standard aims to reduce false alarms and unnecessary police call out by setting monitoring station, CCTV transmission equipment and site installation guidelines. BS8418 compliant CCTV equipment will warn of a network connection failure between the site and the monitoring station. If managed correctly, 3G can provide the prime network connection between a monitoring station and site. 3G also provides a very effective secondary or backup connection that enables continuous site monitoring, even after primary network failure. BS8418 compliance is key to ensuring an immediate police response to site incidents and often results in reduced insurance premiums.
Wide Area Networks (WANs) connect the remote monitoring station to the site via the internet. They include:
ASDL or cable broadband
Telephone or a private network (e.g. fibre optic)
3G mobile phone network
Detector activated CCTV systems automatically alert operators to site incidents as they happen. Operators do not watch sites continuously but respond to alerts viewing only relevant images and data, enabling a quick response. For this to work, the WAN connection must be “always on”, when broadband, or available for instant dial-up, when using telephone networks.
3G networks – the cost of “airtime”
3G networks were originally designed for mobile phone use. They happily transmit intermittent, large quantities of small amounts of data on demand, such as when making phone calls or sending emails. Minimal “airtime” is required. Traditional CCTV applications, by comparison, transmit large amounts of data continuously. 3G network “airtime” is an expensive option when used in this way.
3G networks – detector activated CCTV transmission
When 3G networks are used for detector activated, remotely monitored CCTV systems, data transmission and airtime costs become less significant. This is because airtime is only used when an incident occurs, using mobile phone technology in the way it was originally designed. However, the 3G network must remain “available”, even if no data is being transmitted. This enables alarms and site incident responses to be immediate.
Although 3G functionality of this type exists on third party routers, it is far more reliable if it is built in to the CCTV transmission equipment itself. Teleprecision transmission equipment also frequently checks for network failure and offers additional facilities including remote or automatic rebooting, which reduces the likelihood of an engineer call out to reboot a failed router.
Fixed IP address
All network devices connected to the internet have a unique IP address – their electronic location. Remotely monitored CCTV systems require that the transmission equipment used at the monitoring station and at each monitored site has a “fixed” IP address. CCTV images can only be transmitted from the site to the monitoring station when the monitoring station IP address is known to the site. Likewise, a video “guard tour”, for example, can only be set up when the IP address of the site is known to the monitoring station.
It’s easy to arrange a fixed IP address on a cable broadband network. However, when a mobile phone network is used for internet access, technical limitations usually mean that a “dynamic” IP address is allocated by the network infrastructure for the duration of the connection - this is not adequate for security applications.
Machine-to-machine airtime providers
CCTV transmission equipment manufacturers use specialist “machine-to-machine” (M2M) 3G airtime providers, such as Wireless Logic and Vianet, to address the IP address issue. A fixed IP address is allocated to the 3G connection, mirroring its cable broadband equivalent. Again, this is usually more reliable when built in to the transmission equipment. Even with an M2M provider, using 3G networks for CCTV transmission is more expensive than cable broadband, however tariffs are more favourable than their “domestic” rivals.
Where should 3G be used?
A text book BS8418 compliant CCTV transmission system would use cable broadband as the primary network, with 3G as backup. Data transmission costs are kept low, it will operate in an “always on” capacity and the 3G will switch on in an emergency. However, in applications where a cable broadband network is unavailable, such as distant buildings, construction sites and rapid deployment CCTV systems, 3G is now a viable option. Detector activated, remotely monitored CCTV systems, endorsed by the police, mean 3G can operate in an essentially “standby” capacity, only transmitting data when required. Where 3G is the primary monitoring network, it is important that the system selected continually checks the integrity of the 3G network and warns of any failure.
Companies are increasingly looking to remote monitoring for site security and management. 3G network technology has a vital role to play in this. In order for 3G to be an effective addition to CCTV transmission products, it must comply with BS 8418, meet monitoring station technical requirements and avoid excessive airtime costs.