Few things are as inspiring to the practice of engineering as new technologies that break down barriers and enable new possibilities. Take, for instance, the new Nexense platform Rarely does sensing and measurement allow the flexibility to accomplish multiple sensing jobs with a single technology. Yet Nexense does, and thus has inspired great excitement here at Sensors. (The real excitement is yet to come when the technology gets into the hands of engineers in all disciplines.)
 Barbara G. Goode |
Few things are as important for the use of technology, however, as standards. As the most promising open-source scheme for wireless sensor networking, ZigBee (www.zigbee.org) has garnered much attention lately, and thus has become something of a target. Several companies, including Echelon, claim specifically that their proprietary schemes are superior to it. And a recent report from ARC Advisory Group urges manufacturers to explore extensions beyond ZigBee for industrial use.
But that same report says that manufacturing end users will make large deployments of wireless devices using only products based on standards. The report points out that among the many wireless standards available (including IEEE 802.11 WiFi and IEEE 802.15.4—with or without ZigBee), only 802.15.4 ZigBee offers the very low power consumption that long-lived battery-powered industrial products require.
Answering the doubts, Bob Heile of the ZigBee Alliance says that his organization is doing a great deal of work in the demanding industrial space, and that the standard was developed anticipating many real challenges. Now, he says, the Alliance "must do the work of deciding what pieces it actually needs to build in." For instance, there is more than one way to deal with the problem of fading, and the Alliance is testing which approach it wants to adopt for this task.
A number of companies are helping to ensure the adoption of ZigBee by releasing ZigBee-enabled products. For instance, Chipcon (www.chipcon.com) released the first ZigBee system on a chip (SoC) to make it easy for OEMs to incorporate the standard into their designs. And Ember (www.ember.com) announced at press time its own SoC, the 250.
Bob Metcalfe, who serves as chairman and now interim CEO of Ember Corp., told me that at this point in the evolution of wireless sensor networking, the strength of ZigBee has not been fully appreciated. He notes, for instance, that semiconductor manufacturers are still learning about it. He knows this because Ember is approaching manufacturers of microcontrollers (MCUs) in an effort to persuade them to incorporate ZigBee functionality. Ember, he says, is making the opportunity easy for the semiconductor companies: its 260 chip functions as a ZigBee coprocessor to handle mesh processing outside the MCU, and Ember obviates the need for the manufacturers to port software to their MCUs. Metcalfe expects to announce, during the next ZigBee Alliance Open House on December 8, one or more partnerships with microcontroller manufacturers. This advance is valuable for widespread adoption of the standard.
Metcalfe, by the way, had a distinguished career prior to joining Ember, and is known mainly for inventing the now ubiquitous Ethernet networking protocol. He told me that a new technology develops in two phases. During the first phase, vendors focus on making it work properly within their products. During the second phase, which comes within one to three years, manufacturers begin looking outward to make their products connect with those of other vendors.
With wireless sensor networking, we have one foot in phase one and the other foot in phase two. This situation is not comfortable, but necessary.
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Barbara G. Goode Editor in Chief
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