While at the recent Emerson Exchange, I had a chance to catch up with Emerson’s Dr. José A. Gutierrez, an expert in the field of wireless networks. You may recall José from earlier wireless-related posts. His background includes participation in IEEE LAN/MAN, editor-in-chief of the IEEE 802.15 Working Group-Task Group 4, program manager and member of the board of directors of the ZigBee Alliance, and chairman of the Networking Working Group of the ISA SP100 committee, and HART Communications Foundation (HCF) liaison and U.S. international expert for the IEC, among others. He is also a voting member of the ISA100.12, WirelessHART Convergence Subcommittee.
From our in person chat and subsequent phone conversation, I learned that José and his co-author Ludwig Winkel from Siemens are updating their book, Low-Rate Personal Area Networks: Enabling Wireless Sensors with IEEE 802.15.4, with a third edition. It should be printed and available for purchase in about two months.
The third edition adds a new section, which provides detail on the IEC 62591 WirelessHART communications standard. A draft of the book’s introduction shares:
IEC62591/WirelessHART is the only existing international standard designed to provide very high reliability and performance for industrial sensing and actuation applications. This type of application represents the highest level of performance required for the IEEE 802.15.4 standard as it involves extremely low power consumption, guaranteed throughput and latency, and highest level of security. As such, this new section provides more insights on how the IEEE 802.15.4 standard can perform for this type of critical performance uses.
The IEEE 802.15.4 standard, Wireless Medium Access Control (MAC) and Physical Layer (PHY) Specifications for Low-Rate Wireless Personal Area Networks (WPANs), was introduced in 2003 and was chartered:
…to investigate a low data rate solution with multi-month to multi-year battery life and very low complexity. It is operating in an unlicensed, international frequency band. Potential applications are sensors, interactive toys, smart badges, remote controls, and home automation.
It is Amendment E (IEEE 802.15.4e) that adds capabilities to address industrial applications. This amendment adds support for Time Division Multiplexing (TDMA) and Channel Hopping, which are important in providing reliable coexistence with other wireless technologies. In an earlier post, Coexistence and Diversity Techniques for Reliable Wireless, I shared how these diversity techniques provide the reliability required for industrial applications. While the IEEE 802.15.4e standards effort is still evolving, the WirelessHART standard shows how a high performance and reliable industrial standard could be built on the 802.15.4 technology.
In the three years since the WirelessHART standard was introduced, the global acceptance among process manufacturers has grown as have the number of WirelessHART products available from the automation suppliers.
The book provides a great overview of the IEEE 802.15.4 standard, its history, the applications that motivated the need for the standard, and the rationales for some of the design decisions made. If you’re curious about the journey of this important standard and its application in process automation, then you’ll want to add this to your reading list. I’ll give you an update once the book is available.