By Tom Condon, RPA, FMA
Published in the September 2007 issue of Today’s Facility Manager
Wireless Local Area Networks (WLANs) have been a part of facilities management for years now, and the technology is installed in many buildings. But wireless technology is moving very fast, and there are plenty of changes afoot in these systems located both inside and outside a facility.
First, facility managers should consider how interior wireless systems are evolving. The latest generation of wireless that has been ratified by the Institute of Electrical and Electronics Engineers (IEEE) and deployed is the 802.11g communications protocol. This provides theoretical speeds of 54 Megabits per second (Mbit/sec) and provides better security than previous versions, such as 802.11b.
However, the reality of 802.11g is that the actual throughput (or capacity) is close to half of the theoretical speeds due to design limitations. While it is sufficient for typical administrative work or for surfing the Internet on regular sites, 802.11g has a difficult time handling high bandwidth applications like streaming video.
The answer lies in the next protocol—802.11n, which has been in the works for several years and is expected to be ratified late next year. This new standard brings greater speeds and better range than 802.11g technology. While 802.11g products provide speeds of about 24Mbit/sec, 802.11n is handling real world speeds of 100Mbit/sec to 140Mbit/sec. And the range of 802.11n is more than twice that of 802.11g equipment.
Many vendors are expected to begin selling 802.11n systems later this year. That means we should all go out and buy 802.11n equipment, right? Not quite yet. Until the standard is officially ratified, there is no guarantee the final standard will actually work on 802.11n equipment purchased now. While many manufacturers will state they expect their products to work on 802.11n, there is no way to know if changes will be made to the standard before full ratification. So, facility managers should be forewarned that there is a small chance that what works today may not work after ratification.
There are also big changes occurring in the wireless arena that affect the outside of facilities, such as with campus area Wi-Fi networks. (Note: Often used interchangeably with WLAN, Wi-Fi is a wireless technology brand owned by the Wi-Fi Alliance that refers to WLAN products.) Many facilities with large grounds, such as office campuses, educational institutions, and airports have a difficult time with outdoor wireless systems. Conventional WLAN antenna units are not well suited for the task, because they have low power outputs designed for indoor use and lack weatherproofing.
A new generation of outdoor WLAN antenna systems has arisen to tackle these challenges. Designed specifically for outdoor use, these systems feature weatherproofed, sealed units with a higher power output; in some cases, it can be hundreds of times the power of an indoor unit. This means much greater range, sometimes close to a mile when there is a clear line of sight.
The most notable feature of this new breed of exterior wireless antennas is the ability to create mesh networks. A mesh network is one where the antennas communicate with each other as well as with the users’ computers.
This has an advantage, because you do not need as many connections to the computer network. For example, in a one-half square mile area, 10 antennas might be needed for full coverage. With a conventional system, CAT5 cable is run to every antenna, but with a mesh system the cable only needs to be run to three or four antennas. The antennas without network cables relay data from one to another until it reaches a network connected antenna. This can dramatically reduce the cost of installation, since running CAT5 cable is often the highest single cost for these systems.
Some users are mounting Wi-Fi mesh units in vehicles to create an instant mobile mesh network. The network can be extended to an entire facility campus, connecting people in vehicles, field workers, security staff, and facility managers. One example is to install mobile IP-enabled cameras in security vehicles that transmit live images to the campus operations center. This is valuable in assessing situations not otherwise visible to managers.
Another security application is to provide officers in the field with access to video surveillance. An airport in the Midwest is experimenting with providing laptops to officers so they can access any camera in the airport. Since the surveillance system is digital and network based, this is as simple as giving the officer a laptop, a log-in name, and a password. Through this connection, officers can view cameras and even operate the pan-tilt-zoom functions.
This is proving to be a valuable aid when teams work together. They have been able to track a suspect from one side of the airport to the other without ever getting close enough to alert the suspect.
Mobile field workers using CMMS or other software can also benefit from wireless mesh systems. Workers use a laptop to connect to software applications wirelessly, which eliminates the need for specialized mobile software and handheld devices. This was a real boon for one facility manager who wanted to keep his older CMMS that didn’t have a mobile module, yet wanted field workers to receive and close their own work orders. By combining the value of the security functions with the advantages for mobile CMMS, he was able to justify the cost of the Wi-Fi mesh.
Another emerging Wi-Fi use is with VoIP (Voice over Internet Protocol) phones. Because VoIP works on Wi-Fi networks, field staff can be equipped with Wi-Fi phones to communicate with each other for free. Because the facility owns the network, there are no monthly cell phone charges for communications within the network. This can be taken a step further by connecting the VoIP system to the facility’s PBX (private branch exchange); then, VoIP phones can also communicate with those not on the network.
Some campus facility managers are using Wi-Fi networks to link their control systems (e.g. building automation, SCADA) to remote sites that are not economically feasible with hard wired LANs.
Wi-Fi works for so many applications, because it is vendor independent. Further, the vast majority of modern facility systems communicate over the IP networks that Wi-Fi uses. So before facility managers start digging those trenches or laying that cable, they should investigate wireless LANs and mesh networks. These might be just the technologies their facilities need.
Condon, a Facility Technologist and former facility manager, is one of the contributing authors for BOMI Institute’s revised Technologies in Facility Management textbook. He works for System Development Integration, a Chicago, IL-based firm committed to improving the performance, quality, and reliability of client business through technology.