An example of this technology is in place at the Acuicola Marina fish farm in the Spanish Province of Castellon on the Mediterranean coast. The business offices and a warehouse are located at Burriana, two miles inland, with the fish farm facilities are sited six miles offshore. The valuable fish stock is a target for poachers and Acuicola Marina has always found it difficult to police the offshore facilities. To overcome this, they deployed an IP video system with a wireless network infrastructure consisting of a local Wi-Fi network covering the offshore facilities with a 7 Mbps WiMAX radio link back to the on-shore offices, eight miles away. As well as providing security for the fish stock it also offered them operational benefits with submersible cameras monitoring fish stocks and food distribution.
Mobile Wireless Broadband
This provides high-speed internet access through existing 3G mobile phone networks. It is an established technology that many of us use on our phones to access the internet while on the go. It can be a very powerful tool for law enforcement officers to monitor live and recorded footage from surveillance cameras on a laptop mounted in police vehicles.
This can be demonstrated by the fully integrated municipal video surveillance system that has been developed in the city of Lansing, Mich. In Lansing, the video is streamed at 30fps across various network technologies including SHDSL (single-pair high-speed digital subscriber line), fiber, mesh wireless and mobile 3G broadband. The police department has equipped 60 vehicles -- each with a laptop and with high speed mobile wireless broadband 3G technology that allows officers to view and control any camera in the system.
Satellite broadband access is an expensive communications solution, but is often the only technology available to connect remote areas. Since the data must travel approximately 20,000 miles to reach its destination, latency (or delay) can be more of an issue than with standard radio-based wireless networks. They can also be affected by weather and climatic conditions. However, where traditional network infrastructure is not available, satellite broadband can often be the only solution.
Satellite is part of a surveillance system at the Grand Canyon West Resort in Arizona, and is used to tie together disparate locations of the resort. A distributed IP video system has been deployed at multiple sites, providing an integrated surveillance solution across a wide area. Grand Canyon West is a popular tourist destination on the west side of the canyon owned and operated by the Hualapai tribe. The resort includes Skywalk, which allows visitors step out on a horseshoe-shaped glass bridge that overhangs the Grand Canyon.
Several sites, including Eagle Point (the location of the Skywalk), Guano Point, a hotel, fuel depot and airport, are all centrally monitored from the airport terminal building. The facilities are located several miles apart and are completely standalone with no cabling or infrastructure between them. All the sites are powered by their own generators, and each local IP network is interconnected using a satellite broadband network.
Wireless networks typically have far lower bandwidth than wired networks. A wired network can have an available bandwidth of up to 700 Mb/s, whereas wireless networks typically offer no more than 25 Mb/s. It is therefore paramount to minimize the amount of data transmitted across the wireless portion of the network. This can be achieved by ensuring that the IP video system deployed has the best compression available, is based on a distributed architecture and has features that ensure the minimum amount of video is transmitted at all times.
Deploying H.264-based video compression technology can make a significant difference to the performance of the wireless IP video system. This is particularly important when using increasingly popular high definition (HD) cameras with their higher resolutions and higher bit rates. The data rates from different manufacturers' cameras can vary significantly, even when comparing cameras implementing H.264. With the limited bandwidths available from wireless networks, this is an important consideration.
There are typically two different architectures used by IP video systems: centralized and distributed. A centralized architecture uses a master database usually located in the central control room or head office. A distributed architecture spreads the data around the security management system, and this model generally locates the data close to where it is produced or needed. Normally much more data is transferred across the network to the centralized video and storage servers than would be the case with a distributed system, where video workstations and network video recorders (NVRs) can be located at the edge of the network. Well-designed distributed systems reduce need for large amounts of data to travel large distances, e.g. between the central network and the edge components.