Common access technology could help to clear the wireless logjam
Invensys claims that it has an answer to the growing number of industrial wireless communications systems, each of which has its own access technology and security systems. The company has developed a technology which provides a common access point for all open and proprietary wireless systems and offers built-in security functions.
Although the "managed network" technology has been developed by Invensys Process Systems, it is said to be equally applicable to discrete manufacturing environments.
"The good news in the emerging world of wireless technology is that more and more ingenious wireless devices are being introduced all the time," explains Hesh Kagan, Invensys` wireless programme manager, and president of the Wireless Industrial Networking Alliance.
"The bad news is that most of these devices use different, vendor-specific wireless protocols, technologies, and access points to communicate with the wired communications infrastructure," he continues. "This can make it very difficult to utilise effectively the data coming from these devices - and virtually impossible to ensure appropriate levels of security.
"In the wired world, you can coalesce on Ethernet," he adds. "In the wireless world, there`s nothing to coalesce around."
Invensys has been working with other vendors and several large customers to develop its managed wireless network approach, which uses a shared access point technology for all devices and a common security and data model for all wireless frequencies, and for protocols such as WiFi, WiMax, ZigBee, RFID, IEEE 802.15.4 and VoIP (voice over Internet).
At the heart of the technology (illustrated in the diagram above) is a family of access points - one for each protocol - similar to communications multiplexers. "You can rack-and-stack the different protocols," Kagan explains.
He contends that the technology will save customers money both when the wireless systems are being implemented, and while they are being used. The common data model will make it easier to incorporate wireless data into asset performance management applications, while the standardised security model will make it easier to manage wireless infrastructures.
Kagan is confident that other wireless vendors will support the new initiative and expects to announce several big names in the near future. He hopes that the new approach will help to overcome concerns among potential wireless users over issues such as security, incomplete standards, conflicting frequencies, and migration paths.
Because of continuing concerns over the robustness and determinism of wireless systems, Kagan expects the main uses for wireless technologies to continue to be for monitoring rather than control. With wiring in some process plants costing more than $1,000 a foot, he expects cheaper, more flexible wireless technologies to grow in popularity, especially at large sites - but not to replace wired communications completely.
He points out that at greenfield sites, an RFID wireless network is now often the first infrastructure to be installed because it allows items to be tracked during the construction phase.