When wireless sensors and detectors came on the market decades ago, the devices were known more for missing signals than capturing alarm activity. They were used in a “patch” type of approach, applied when hard-wired devices were impossible. After all, no one wanted to drill holes in five-foot-thick concrete. They needed direct range, help in the way of battery life and, overall, weren’t something end-users could 100 percent count on for alarm supervision or other tasks.
But wireless and its ability to provide convenience to people, places and things has matured. Many problems have been addressed, making radio frequency (RF) devices critical components of an integrated building solution. Extensive research and development has sunk into RF communications, especially for those who can’t do without remote access to data and systems.
Now, it is unusual not to see wireless used in some sort of application, as a whole-system solution, or part of a layered approach to security and automation functions. Wireless has its own “brains,” power and control, allowing devices to operate intuitively and as an important adjunct to the entire system.
The wireless world
According to a 2005 report by the Telecommunications Industry Association, Arlington, Va., Telecommunications Market Review and Forecast, total U.S. spending on wireless communications is expected to grow by 9.3 percent in 2005 to $158.6 billion. The report further predicted the wireless market will reach $212.5 billion by 2008, with a 10 percent compound annual growth rate from 2005 to 2008.
In security applications, wireless RF signaling and communication devices have upped the ante with stronger -transmission and intelligent processing to allow detailed information about the signal received from the site. For example, it can indicate a maintenance issue, problem with the power or where an alarm is located.
The continued deployment of cellular, satellite, global positioning systems, remote viewing and identification functions—e.g., Internet protocol (IP) cameras—has caused manufacturers to address any potential problems with wireless and iron them out with greater signal strength, battery life and intuitive software to alert users to any shortcomings in the device or transmission path.
We have all waited in the grocery line as the checker attempted to scan an uncooperative bar code. With a frozen item, the bar code is less functional and also, if it is crumpled and not a direct-read, there may be problems. Enter the world of the microchip, embedded into items, magnetic stripe/bar code cards and other RF-read items, making the entire process intelligent and quicker to deploy in wireless applications.
In the business sector, wireless networking must be safe, secure and protect sensitive data, personnel records and other high-tech information. This was another problem with wireless when it first came on the scene, especially on an enterprise-wide network. Now, security such as encryption, firewalls and layered levels of intrusion detection protect the network.
But no technology is without limitations or trade-offs. Some imply the transfer speed or rate of data exchange through a wireless port may not be as good as a hard-wired network connection. Reliability concerns even haunt what has become one of the standards in LAN networking, 802.11s, commonly referred to as wireless fidelity (Wi-Fi). These issues and problems continue to be worked out as standards and common protocols emerge with a maturation of technologies.
In the past, RF problems have been attributed to the lack of a strong network. Those maladies have been fixed by additional towers to transmit signals, as well as innovation by hardware and software manufacturers to increase signal strength and provide robust point-to-point coverage.
There is more in the way of problem solvers. Wireless providers have tools to determine the read range of access control systems and even power boosters to extend distance in the field. Cellular and the proliferation of a new breed of Wi-Fi equipment have solved some of the potential angst associated with wireless systems. Wireless relay points, transponders and other devices pass along signals cleanly from area to area.
Even in some retrofit applications, wireless was not always possible because some form of cabling was required from controller points or at least to be able to piggyback on the Ethernet or other network. Enter the mesh network, a wireless phenomenon designed to set up remote access points over a wide area without cabling.
Mesh network technology allows end-users to extend their wireless local area network (LAN) to a larger geographic area.
“A mesh network lets the user deploy an all-wireless system, using the existing Ethernet on the backbone,” said Alain Amar, East Coast sales representative, Teaneck, N.J., for California-based Firetide Inc.
Wireless mesh networks provide access points, commonly referred to as nodes, to route traffic to one another instead of through cable. These access points may be somewhat expensive, but in reality, it may cost even more to run information transport cabling to every access point, especially in a large campus environment with multiple wireless locations.
“The technology enables network appliances and devices to operate over the wireless mesh, providing instant connectivity wherever cabling is too difficult, disruptive or costly to install,” he said.
In the past, security and surveillance cameras were connected to centralized monitoring and recording facilities with hard-wired coaxial cable. The advent of IP addressable cameras offered additional advantages, but they were still limited by how far their network cabling would reach.
“Firetide’s mesh network provides standard Ethernet ports on virtually every wireless node, so any enterprise-grade IP camera can connect to the network. The mesh network can work with any existing network, deploying voice, data and video,” Amar said.
According to Amar, one of the great advantages of using the mesh network is in the deployment of IP-based video surveillance cameras.
“By providing a wireless backbone, mesh networks enable cameras to be installed without pulling cable through walls, trenching for fiber between buildings or drilling holes for cables in older and historic buildings that were not designed for computer networks,” he said.
In addition to IP cameras, the mesh network has special nodes, which provide Ethernet ports to enable many other network devices such as sensors, printers and computers to connect without the need for backbone wiring. Mesh network technology continues to advance—it may soon be guided by a document being initiated through the Wi-Mesh Alliance, a group of representative technology companies that recently proposed such a standard to the Institute of Electrical and Electronics Engineers.
Flexibility in wireless application has also given way to a more problem-free network. Even public safety officers are relying on wireless to beef up security services to the general public.
“The mobile Internet is a new tool for emergency service providers. It provides them with voice, video and data access across any medium, so they can exchange mission-critical information anywhere, anytime and any place,” said Andy Lockhart, vice president for Cisco Systems Northern Europe, San Jose, Calif.
High-security contactless smart cards are also possible with the use of 13.56 MHz wireless, as opposed to the commonly used 125 MHz, a standard in access control for time and attendance, said Robert M. Fee, general manager, Legic Inc., BU North America, Miramar, Fla.
Legic makes the microscopic microprocessors for all-in-one card applications. Fee said the use of the 13.56 MHz contactless smart card allows for flexibility and multiple applications.
“The 13.56 MHz frequency allows for more data over the RF interface. If additional read-range is necessary, boosters (types of power-controllers) can be used to extend the area,” he said. “In addition, new applications can be stored at any time and can be removed as well, allowing for scalability and the ability to plan for future growth. There are literally hundreds of applications from which users can pick and choose. The 13.56 MHz frequency allows for multiple, higher security applications than 125 MHz.”
Special encoding and digital signatures are part of the tiny chips Legic custom-designs for some 50,000 end-users.
Robust and reliable
With advanced transmitters and high sensitivity receivers providing optimal coverage throughout an area, wireless access control is nothing short of robust, said Lester LaPierre, marketing manager, Schlage Wyreless Access Products, IR Security Technologies, West Chicago, Ill.
“Moreover, spread spectrum technology, which sends the same data over many frequencies simultaneously, makes wireless redundant and thus extremely reliable. Finally, special supervision circuits indicate a warning if a signal is interrupted,” he said.
According to LaPierre, RF testing is essential to a successful wireless installation.
“Test kits are available that are purposely detuned to 50 percent power and are recommended to validate systems designs to optimize placement of panel interface modules,” he said. “This ensures reliability prior to installation. Any weak spots are detected and corrections made before implementation, not after. Even in installations with a lot of concrete and steel, there are no problems with wireless access control systems sending and receiving signals.”
Wireless systems and devices continue to emerge as a critical component of an integrated building system. Improved reliability and signal strength characterize the technology, making it nothing short of robust and dependable. EC
O’MARA is the president of DLO Communications in Park Ridge, Ill., specializing in low-voltage. She can be reached at 847.384.1916 or firstname.lastname@example.org.