This is the Wild West of wireless, with everyone running to market with their shiny new wireless widget, says Mike Bedell, vice president, worldwide sales, Apprion (www.apprion.com). Thus far, lack of standardization in wireless communications has led to a plethora of single-vendor, proprietary systems, and users are buying them. Why? Bedell says, Because the applications they enable are terrific.
According to a recent report by ON World, the wireless sensor networking market is expected to reach $4.6 billion by 2011, up from approximately $500 million today. Organizations are scrambling to agree on how existing wired sensor protocols will be adapted to wireless applications.
The HART Communication Foundation (www.hartcomm.org) released its standard in June, 2007. WirelessHART builds on established international standards including the HART protocol (IEC 61158), EDDL (IEC 61804-3), IEEE 802.15.4 radio and frequency-hopping, spread-spectrum and mesh-networking technologies. WirelessHART also gives users an alternative method for extracting condition-monitoring and diagnostic information from an existing installed base of HART instrumentation.
Due to be finalized soon, ISA SP100.11a is based on IEEE 802.15.4 and is an open architecture that can be used with components from multiple vendors. It supports multiple protocols on a single wireless infrastructure for condition monitoring, asset management and process automation applications. ISA100 is the umbrella under which wireless protocols and standards will coalesce in order for wireless sensor networks to reach critical mass, says Jay Werb, CTO of Sensicast (www.sensicast.com) and DLL technical editor (for meshlayer) of the ISA100.11a standard.
If your sensors arent committed to a conventional fieldbus protocol, it might be practical to stick with Ethernet. In a WiFi infrastructure, maintenance condition monitoring sensors can work without SP100, WirelessHART, etc., says Hesh Kagan, Hesh Kagan, director, wireless programs, Invensys (www.invensys.com). SP100 has an important quality specification for signal-to-noise ratio, but if the quality is there, theres no reason not to use WAP.