Wireless control has been around for decdades and, despite some initial concerns about its application for building automation, it looks set to become the de facto solution in the next 10 to 20 years.

A host of technology options are available with a range of different characteristics, depending on the needs of the application. The main ones are:

• Infrared (IR). This is the lowest cost, but has the shortest range, and it requires line-of-sight to work successfully. It offers data rates up to 16 Mbits/s.
• Industrial, Scientific and Medical (ISM) wireless. Low-cost chips and modules, operating in the ranges 315 MHz to 433 MHz and 902 MHz to 928 MHz. Good for simple applications, but no standard protocols.
• Bluetooth. Highly developed, with many profiles, offering data rates up to 3 Mbits/s and distance ranges of 10 m to 100 m. Offers networking capability.
• Wi-Fi. Relatively expensive and powerhungry, but with high data rates (to 54 Mbits/s) and, at 100 m, the longest range.
• Ultra-wideband (UWB). Available as chips and modules with very high data rates (to 480 Mbits/s), but with a range under 10 m, and generally applied only to consumer products.
• ZigBee. The latest technology, with low data rates (up to 250 kbits/s), but with very low power consumption and inherent mesh networking. It has good potential for many applications, leading to high-volume and low-cost production.