Among the new ZigBee wireless standard’s many desirable attributes, “low-power” is perhaps the most frequently mentioned. That descriptor sits at the center of the ZigBee Alliance mission statement, and also forms the last two words of the Alliance’s stated objectives. The emphasis is there for good reason: Designed to deliver wireless networking to even the most humble devices—including devices that run on batteries lasting for years—ZigBee has to be extremely power-miserly to meet its objectives.

Yet manufacturers are beginning to introduce ZigBee products distinguished by power ratings, offering radios with 1 mW RF power and “high-power” versions with 100 mW RF power. What gives? Are these manufacturers deviating from the ZigBee specification?

A little clarification is in order. Manufacturers of ZigBee radios with higher RF power create them for very good reasons grounded in the realities of successful wireless applications; they are also faithful to the ZigBee specification and what it means by “low power.” By separating product lines along RF power differences, manufacturers give design engineers an important option for ZigBee implementations. Choosing relative to that option is a matter of matching power capabilities to application needs.