200字英语介绍wireless technology的定义和它的contain包括内容

Wireless communication is the transfer of information over a distance without the use of electrical conductors or "wires".[1] The distances involved may be short (a few meters as in television remote control) or long (thousands or millions of kilometers for radio communications).When the context is clear,the term is often shortened to "wireless".Wireless communication is generally considered to be a branch of telecommunications.
It encompasses various types of fixed,mobile,and portable two-way radios,cellular telephones,personal digital assistants (PDAs),and wireless networking.Other examples of wireless technology include GPS units,garage door openers and or garage doors,wireless computer mice,keyboards and headsets,satellite television and cordless telephones.