无线接入网是指部分或全部采用哪种传输介质连接交换机和用户终端()。
A.蓝牙
B.光纤
C.红外线
D.无线电波
A.4
B.8
C.16
D.32
A.传输层
B.交互层
C.应用层
D.平合层
Bluetooth is a universal radio interface in the(71)frequency hand that enables portable electronic devices to connect and communicate wirelessly via short-range, ad hoc networks. Each unit can simultaneously communicate with up to(72)other units per piconet. Moreover, each unit can simultaneously(73)to several piconets. Eliminates the need for wires, cables and connectors for and between cordless or mobile phones, modems, headsets, PDAs, Computers, printers, projectors, local area networks, and so on, and paves the way for new and completely different devices and applications. Technology Characteristics(74)symbol rate exploits maximum available(75)bandwidth。
A.1.95GHz
B.2.45GHz
C.4.45GHz
D.11.45GHz