X-Band
X-band is the bandwith between 7 GHz to 8 GHz, which usually is used by military satellites.

Yagi Antenna
Yagi Antenna is an antenna type that radiates in only a specific direction. Yagi antennas are used only in point-to-point situations.

ZDO: ZigBee Device Object
ZigBee Device Object (ZDO), a protocol in the ZigBee protocol stack, is responsible for overall device management, and security keys and policies. The ZDO is like a special application object that is resident on all ZigBee nodes. ZDO has its own profile, known as the ZigBee Device Profile (ZDP), which the application end points and other ZigBee nodes can access.

ZigBee
ZigBee, defined in the IEEE 802.15.4, is the technology used in the low data rate Wireless Personal Area Network (WPAN) for home control, building automation industrial automation. ZigBee covers up to 330 feet (about 100 meters) in the bandwidth of 20 to 250 kbps.

Zone Paging
Zone Paging is a feature in many paging systems that allows you to page a specific department or an area without disturbing other people.