work Some devices, such as a wireless bar code scanner, operate only on a wire-less network A computer device also has an operating system, such as Windows XP, LINUX, or MAC OS The operating system runs software needed to realize the wireless network application In some cases, the operating system has built-in features that enhance wireless
place to another And when the network does something you aren’t expecting it to do, you will need a basic knowledge of the technology to do any kind of useful troubleshooting How Wireless Networks Work Moving data through a wireless network involves three separate elements: the radio signals, the data format, and the network structure
Wireless Links •Interference / bit errors –More sources of corruption vs wired •Multipath propagation –Signal does not travel in a straight line •(Often) a broadcastmedium –All traffic to everyone nearby •Power trade-offs –Important for mobile, battery-powered devices 4
Wireless, Mobile Networks 6-13 Wireless Link Characteristics (1) important differences from wired link decreased signal strength: radio signal attenuates as it propagates through matter (path loss) interference from other sources: standardized wireless network frequencies (e g , 2 4 GHz) shared by other
Backbone networks: Providing voice services (PSTN, Public Switched Telephone Network), data services (through Internet), and emergency services Wireless networks need to be connected to backbone networks to extend its service capabilities and geographic coverage