更多"Bluetooth is a universal radio inte"的相关试题:
[单项选择]
Bluetooth is a universal radio interface in the (1) 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 (2) other units per piconet. Moreover, each unit can simultaneously (3) 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 (4) symbol rate exploits maximum available (5) bandwidth。
1（）
A. 1.95GHz
B. 2.45GHz
C. 4.45GHz
D. 11.45GHz
[单项选择]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
[单项选择]Radio and Television
Radio and television were major agents of social change in the 20th century. Radio was once the center for family entertainment and news and television enhanced this revolution by adding sight to sound. Both opened the windows to other lives, to remote areas of the world, and to history in the making. News coverage changed from early and late editions of newspapers to broadcast coverage from the scene. Play-by-play sports broadcasts and live concerts enhanced entertainment coverage. For many, the only cultural performances or sports events they would ever hear or see would come from the speakers or the screens in their living rooms. Each has engaged millions of people in the major historical events that have shaped the world.
If people could look at the sky and see how it is organized into frequency" bands used for different purposes, they would be amazed. Radio waves crisscross (十字形) the atmosphere at the speed of tight, delivering incredible
A. whether they can broadcast cultural performances
B. whether they may attract millions of people in the great historical events
C. whether they open the windows to remote areas of the world
D. whether they may offer sights to the people
