In 2009, the Northern Territory Government and the Australian Government committed $8.612 million to establish a Closed Circuit Television (CCTV) system to equip NT Police to monitor and reduce anti-social behaviour on the streets of Darwin.
After a competitive tender, the NT Police Fire and Emergency Services Department chose Darwin-based security company Security & Technology Services (STS) to deliver the project.
The Darwin Street Camera project required STS to integrate 47 existing CCTV cameras deployed at “hotspots” – mass passenger transport systems as well as bus interchanges – with 62 new Pan, Tilt & Zoom cameras. These cameras are installed at popular congregation points at Casuarina, Palmerston and Darwin.
Due to the prohibitive cost of connecting all the cameras with fibre optic cable, STS needed a highly reliable wireless network to allow NT Police personnel to monitor the 109 cameras, control them remotely and record high-resolution vision of any incidents that are of a quality fit for use in a court for prosecution purposes.
Major challenges of transmitting high definition video streams from the cameras to three police stations – plus a fourth remote storage facility – were to avoid network congestion from the large volume of data traffic and to eliminate the risk caused by single points of failure.
The demanding Top End environment delivered difficulties including high year-round heat and humidity plus thousands of lightning strikes a day during the turbulent Wet Season. Another issue was vandalism.
STS selected Australian network specialist MIMP connecting solutions to design and deliver the highly redundant, high performance wireless network to integrate the Darwin Street Camera system. STS also deployed an optical fibre ring network to augment the system’s high-capacity wireless backhaul.
MIMP solution: Australia’s first multicast mesh wireless network
To meet the demanding Darwin climate and operational challenges, MIMP decided the wireless network needed to be self-healing, so it would keep working if part of the network went offline.
MIMP searched internationally to identify the best self-healing network architecture for the Darwin Street Camera project, which covers a total of six square kilometres.
MIMP selected network equipment from Strix Systems, a US-based global leader in wireless mesh networking. Strix Systems exclusive distributor, Wireless Tech (Australia) supported MIMP with pre sales engineering design support in the project. The Strix Access/One Outdoor Wireless System is a modular, in-the-field upgradable system that delivers high throughput and low latency levels.
Strix technology provides high redundancy by using a multicast mesh structure with self-healing capabilities to optimise performance and availability. Multicast mesh is a highly distributed network model where any device can accept and pass on a data packet, even if it’s not on the shortest path from sender to receiver. This rich connectivity maintains data delivery even when devices or even parts of the network became unavailable.
With 128-bit data encryption for security, the system also uses a multi-subnet architecture to route video data streams over diverse data paths via multiple subnetworks. This design effectively created three standalone mesh networks with a fibre backbone.
MIMP GM Allan Aitchison
MIMP General Manager Allan Aitchison said the multicast mesh structure gave the Darwin wireless network both resilience and redundancy. “To our knowledge, this is the first multicast mesh network in Australia,” he said.
“A multicast mesh network provides the richest connectivity and is very robust, because it self-heals if devices disappear off the network. By designing the network so each device accepts messages, even if the device is not on the shortest path from a camera to the police station, it routes data around any disrupted areas, so there’s no single point of failure. Further robustness is added by the use of multiple subnets, so the second and third subnets can continue operating even if one area goes down.”
Mr. Aitchison said the Strix equipment also handled the demanding Darwin environment including heat, humidity, lightning and vandalism. “Strix equipment is in the highest category for handling lightning strikes,” he said.
“Lightning is a huge issue in Darwin during the Wet, when there are as many as 3000 strikes a day, which all tend to hit the top of buildings. As well as lightning protection in the antenna and the equipment itself, Strix wireless units have a heat shield over the radio unit, which also protects them from vandalism.”
MIMP designed, configured and tested the network at its Adelaide head office before sending it to Darwin where it was installed by STS. MIMP technicians then commissioned the network, which went live in December 2009.
Business benefits: High performance CCTV network allows more proactive policing
Strix mounted on a light pole (click image to open higher-res version)
Installation of the CCTV system was funded under the Territory Government’s Anti-social Behaviour Initiative and the Australian Government’s Safer Suburbs Plan. As well as the MIMP-designed multicast mesh Multi Subnet network, STS chose an IP-based camera system from Scottish IP video security specialist IndigoVision.
The CCTV system is operated by a dedicated police monitoring team located in a real-time CCTV control room at the Joint Emergency Services Communications Centre in Berrimah. As well as video data being recorded at this secure remote data storage facility, surveillance capabilities are available at police stations in Casuarina, Darwin and Palmerston.
Cameras are monitored 24 hours a day, seven days a week. Each day, the 109 cameras deliver hundreds of gigabytes of new vision for storage at two locations, one of which is a central repository with 30 terabytes of data storage. Most video data is destroyed after 30 days, although some is retained as evidence for police investigations and prosecutions.
NT Police CCTV Project Administrator Shane Moten said the CCTV network had assisted police to more proactively manage and reduce anti-social behaviour on the streets of Darwin. “Since the system has been live, we have generated hundreds of additional incidents that we might otherwise have missed,” he said.
“It has helped to solve problems that range from recovering stolen property, dealing with assaults and vandalism to identifying multiple persons on different occasions with concealed weapons, which enabled us to direct police to intercept these persons before incidents occurred.
‘As the video operators become more experienced with identifying developing problems, they are able to proactively look for certain things at hotspots for anti-social behaviour and alert police to intervene before a situation becomes bigger.”
STS Managing Director Greg Ireland said the MIMP multicast mesh network had been a critical part of the CCTV system’s success. “The NT Police are very happy with the system,” he said.
“The CCTV system has proved to be very user-friendly. It also provides them with high quality images that they have been able to use to reduce anti-social behaviour and improve community safety.
“We chose MIMP based on their previous experience and the fact that they’d delivered similar projects elsewhere. We had good feedback on the reputation of their company. While it’s fair to say you always have some teething problems, MIMP’s commitment to solving those problems has been very good.
“We also chose MIMP for a similar project in Alice Springs, which says a lot about what we think of them.”
About MIMP connecting solutions www.mimp.com.au
MIMP connecting solutions is an Australian-owned company whose total business focus is the supply, installation and support of high capacity wideband digital transmission systems in the competitive business communications market. Established in June 1985, MIMP connecting solutions has provided and installed in excess of 600 systems throughout Australia. Key clients include the Adelaide Zoo, SA Heart Centre, State and Local Governments, Education, Health, Defence, and large corporations. MIMP connecting solutions is a flexible Adelaide-based organisation with a country-wide network of technicians trained to provide the best onsite and offsite support in the industry.
MIMP connecting solutions
3 Holder Avenue
Richmond, SA 5033, Australia
Phone: 08 8292 5400
Fax: 08 8292 5499
About Wireless Tech (Australia) – Wireless and General IT Stocking Distributor www.wirelesstech.com.au
Wireless Tech (Australia) is an Australian-owned company and one of Australia’s largest stocking distributors for wireless products. Supporting Systems Integrators in the region suppling and supporting Alvarion, D-Link, PepLink, PepWave Strix Systems, Times, Trango, Tropos and Wavion products. Established in 2005, Wireless Tech (Australia) has supported System Integrators by providing stock locally and pre-sales engineering support resulting in over 1,000 successful project deployments across the region.
Wireless Tech (Australia) Pty Ltd
Unit 1, 63-79 Parramatta Road,
Silverwater, NSW 2118, Australia
Phone: +61 2 8741 5080
Fax: +61 2 9648 4500