Get Back! Backhaul Communications For Surveillance

Government and enterprise locations worldwide are searching for ways to provide increased protection while minimizing costs. The number of video surveillance cameras being installed is expanding rapidly and this increase is not only being driven by rising theft rates but by a host of new threats that range from terrorism to liability. Video surveillance cameras provide a “force multiplier” that enables real-time, cost-effective monitoring, providing greater reach than staff alone could offer. Wireless video surveillance cameras provide the same level of coverage at a significantly lower cost and time to install.

The rapid market growth of video surveillance cameras is being experienced worldwide. China, India, Russia and countries in Latin America are readily embracing this technology, even in the current challenging economic climate. A recent video surveillance systems report by ABI Research* supports these claims as demonstrated by the growth rates shown in the table illustrated above.

Backhaul signaling

Wired as well as wireless connectivity technologies need to be considered for video surveillance cameras. Traditionally, video security cameras have been deployed using wired technologies to backhaul footage to the command center.

Today, wireless video cameras offer some key benefits over their wired counterparts, making them a compelling alternative. First, wireless solutions do not have the high backhaul costs associated with dedicated T1/E1 leased lines or fiber trenching. Not only are wired backhaul technologies expensive, but the installation is costly and must be considered as well. Finally, many wireless video cameras can use integrated broadband WiFi radios, which avoid the additional expense of installing Ethernet connections or co-located backhaul solutions.

Whether the network is wired or wireless, the growing need for video surveillance results in the need for more network bandwidth. This is especially true with a wireless network where bandwidth is at a premium. Additionally, the need for reliability and resiliency must be considered when deciding on a wireless infrastructure to support the video security network. Wireless video security backhaul technologies offer many different alternatives to address issues like the location of the cameras or the bandwidth requirements. Newer technologies and standards are being incorporated into wireless access points, with 802.11n WiFi wireless will allow for better area coverage and bandwidth capacity.

Let’s examine some of the different wireless technologies that should be considered as an alternative to wired infrastructure.

Point-to-multipoint wireless network

A point-to-multipoint (PMP) high site network allows cameras to be deployed in fixed locations across a few square miles. A typical PMP system provides solutions in licensed, unlicensed and managed frequencies ranging from 900 MHz to 5 GHz. The PMP technology will provide good bandwidth capacity for the video cameras over a high-speed wireless backbone that offers an aggregate data rate up to 20 Mbps. The PMP wireless network is easy to deploy and maintain, which makes it cost effective.

Mesh wireless network

A wireless mesh wide area network (MWAN) is a robust, wireless broadband technology that provides high bandwidth for video surveillance and other applications. A mesh wireless system contains access points that are disbursed in zones where many cameras need to provide coverage as well as access throughout a city, municipality or specific geographic area where wireless coverage and video surveillance is needed.

Mesh wireless networks can be deployed in areas that cannot be reached by line-of-sight radios, by utilizing meshing techniques which also provide redundant paths for the camera to connect back to the control center. Mesh solutions utilize the 802.11a/b/g/n WiFi standards, allowing for access to the video from anywhere within the network by using standard, off-the-shelf laptops, PDAs or other WiFi-based clients. Most MWAN products are designed with two radios; a 2.4 GHz radio for 802.11b/g/n client access and a 5 GHz 802.11a/n radio for the backhaul connection which can provide up to 80Mbps. A 4.9 GHz lightly licensed spectrum is also available for public safety use. The second radio is the key to the resiliency since this provides dedicated backhaul used for node-to-node communication, and in turn forms the wireless mesh.

A growing trend for public safety, public transit and fleet management is to provide video surveillance to and from a moving vehicle. Some wireless mesh networks utilize high powered APs and fast handoff technology to provide the coverage and throughput required for video to and from a moving vehicle.

Wireless video surveillance solutions can be more cost-effective and flexible alternatives to wired products. However, it is important to note that these wireless camera options are only as reliable as the networks on which they reside. For most municipalities looking to deploy or expand their video security systems, the backhaul solution of choice will likely leverage both fiber and wireless technologies to maximize the return on the infrastructure and application investments they have made to date and into the future.

Tim Mason is the senior director, Global Solutions Marketing, Wireless Broadband Networks & Enterprise Business, Motorola Inc.