• End-to-end wireless solution
• Extension of existing system, often for a new, hard-to-reach location or remote building
• Temporary solution that requires mobility (for instance, if use of a building will be short-term)
• Undercover security application where wires cannot show
• Retrofit application where wire and cable access is a major cost issue
Solutions That Overcome the Odds
Schlage Wyreless Access seems to have overcome some of the perceived limitations of wireless technology. Until recently, connectivity was accomplished via the existing access control field panel through the reader connection ports. Wyreless has found a way to connect directly onto the existing proprietary RS485 bus using a PIM controller with a custom driver for that manufacturer's protocol.
Wyreless' LaPierre said his company's products use 900 MHz transmission because it is license-free and has no conflict with other devices, and it offers better performance and better range than other frequencies. 900 MHz systems are largely oriented for line-of-sight communications, so a detailed site survey is always recommended to prevent blind spots.
One of the unique features of the Wyreless solution is dynamic channel switching, which automatically switches channels when it encounters interference in harsh RF environments.
Wireless on the Network
One of the leading new entrants into the wireless access control market is Isonas, which has taken a totally different approach to wireless access control. In 2001 the company introduced a TCP/IP-based card reader/controller. This network-attached appliance has begun to receive significant acceptance in the marketplace.
In 2005, Isonas attached 802.11b wireless communication capability to this product using a Lantronix OEM WiPort module. The system can be maintained over the existing network by the IT staff using the Isonas Crystal Matrix Software. The 802.11b transmission format allows them to integrate the wireless version of their card reader directly into a customer's existing infrastructure.
Burkley stated that with existing access control systems, the ISONAS solution drives the cost of implementation down since there is no access control panel; every card reader/controller is essentially a network-attached, stand-alone device that is connected to the host PC over the existing network or corporate backbone. Adding the wireless option to the appliance costs about $300.
Using the Isonas package with other existing access control packages does present a couple of challenges. The existing host system will need to have an appropriate driver installed using the Isonas API to allow for the integration of information to and from the system. Isonas has developed a BACnet driver that should make communications with BACnet-based gateway controllers an attractive opportunity.
Security of Transmission
The age-old question of whether wireless transmission can be compromised must also be addressed.
• In the case of 900 MHz communication, the transmission is encrypted with proprietary encoding, thus making it very difficult to get into. One would need to have the exact model of the equipment installed with the exact same setup to attempt a breach, and then one would need to have intimate knowledge of that specific installation in order to try to penetrate it—a very difficult task indeed.
• In the case of proprietary 2.4 GHz communication, the transmission is encrypted with proprietary encoding; thus, the same criteria as for 900 MHz apply
• In the case of IEEE 802.11b/g 2.4 GHz communication, a different set of criteria for security transmission applies. All the normal requirements of 802.11 communications need to be addressed. Point-to-point MAC addressing, 128-bit WAP or WEA encryption must be put in place to provide for a secure environment.
Test Before You Buy
The best way to ensure that you are going to have a successful implementation is to do a test before committing to the project. Most manufacturers have portable test sets for that very purpose, so it is not too hard to take the proposed system for a test drive (admitted on a very small scale) and check out its performance ahead of time.