The ZigBee wireless protocol may not be getting a lot of love in the process automation space, but that doesn't seem to have clouded the vision of its proponents. According to our survey, only 1.47% of our respondents say they used the Zig-Bee protocol. But don't mistake that number as a sign of a failed technology. As this dialog between Control's editor in chief, Walt Boyes, and Cees ["case"] Linkss, founder and CEO of GreenPeak Technologies. GreenPeak is a fabless semiconductor company with a strong focus on wireless for sense and control networks in combination with battery-less technology, targeting communication devices working on ambient energy. Linkss was involved in the establishment of the IEEE 802.11 standardization committee and the Wi-Fi Alliance. He was also instrumental in helping to establish the IEEE 802.15 standardization committee to become the basis for the ZigBee sense and control networking technology and standardization.
Walt Boyes: 1. ZigBee is one of the oldest 802.15.4 protocols, but has been challenged by two standards based protocols, IEC62591-WirelessHART and ISA100.11a. Our most recent survey shows Zigbee as barely in use in the process automation space. What has Zigbee done to make the protocol more competitive in the industrial sensor network arena?
Cees Links: ZigBee has currently four networking protocols, based on top of IEEEE 802.15.4, addressing four main fields of applications:
- ZigBee RF4CE: Addressing consumer electronics,
- ZigBee Pro: For home automation, building automations and early generations of smart energy (1.0 and 1.1).
- ZigBee IP: For Smart Energy 2.0, currently in the final stages of definition,
- ZigBee Green Power (working with ZigBee Pro): for battery-less applications (e.g. self- power switches).
There are other fields of applications under development (working groups in place): retail, healthcare, telecom, lighting.
ZigBee is a volunteer organization, and players in the process automation have rallied around HART and ISA – not around ZigBee. The reason was not so much against ZigBee, but that HART and ISA were already existing organizations. Note that wireless HART and ISA are using IEEE 802.15.4 derivatives, hardened for the process industry.
Frankly, the field of sense and control networks is very large and diverse. It was never intended [to be covered] by ZigBee and also [it is] not logically feasible to have one standard covering all the application fields, as the requirements are very different anyhow. For example, the requirements for a consumer electronics remote control device are totally different from those for process automation.
Walt Boyes: Is building automation, along with whatever the heck the Smart Grid is, Zigbee's sweet spot? If so, why do you think so?
Cees Links: Smart Energy (the capability to manage the energy consumption of equipment in the home and supporting the offering of different energy rates at different periods during the day) is definitely one of the sweet spots of ZigBee. Smart Energy is part of the Smart Grid initiative that helps utilities to manage and control the delivery of energy to the end user in an efficient way. Other sweet sports are RF4CE, Home Automation and Building Automation.
Walt Boyes: It is claimed that Zigbee's protocol is not very cybersecure. Could you comment on that?
Cees Links: This claim in itself is not particularly substantiated. But to be more specific, "different horses for different causes." It may be clear that Smart Energy utilities, who do billing based on energy provided, demand a different level of security for Smart Energy, than a consumer using a remote control for his TV (both using IEEE 802.15.4). Security is a genuine concern in all the workgroups within ZigBee and adequately addressed in (sometimes painful) discussions that lead to the best-in-class solutions for the different application areas, one more secure than the other, but always in trade-off with the application itself and the cost points demanded ("Do not put a bicycle lock on a Ferrari, or a Ferrari lock on a bicycle).
Walt Boyes: Is Zigbee going to be the protocol of choice for the burgeoning home automation market? Why?
Cees Links: The answer to the question is "yes." but the road to get there may be different compared to several PCs that connect to one home router: Wi-Fi (leaning on IP) is not the right comparison, as Wi-Fi is just one application space – providing the consumer at home access to the Internet. ZigBee is addressing multiple and different other application areas, for example, energy management (air comditioning, pool pump, fridge and meter), consumer electronics (TV, STB), lighting control, etc. People will install separate different systems over time that initially do not interoperate, but over time these systems will integrate. This will not necessarily be a peaceful integration. There might be some battle between operators, utilities and/or other contenders (e.g., Google) who will try to create this platform of integration, and maybe we will see several platforms competing for domination.
Walt Boyes: How many Zigbee sensor nodes are currently installed?
Cees Links: No idea, but a wild guess, 30-50 million units and growing rapidly.
Walt Boyes: Does Zigbee have much penetration in the discrete and machine-builder automation space?
Cees Links: No, not that I am aware of.