16-02-2013, 10:55 AM
WIRELESS COMMUNICATIONS
WIRELESS COMMUNICATIONS.ppt (Size: 911.5 KB / Downloads: 48)
Objectives
Explain how the major wireless technologies are used today
Describe various applications of wireless communications technology
Explain the advantages and disadvantages of wireless communications technology
List several different wireless technologies
How Wireless Technology is Used
Wireless
Describes devices and technologies that are not connected by a wire
Wireless communications
Transmission of user data without the use of wires
Wireless data communications technologies include:
Bluetooth
Satellite
Cellular
Bluetooth and Ultra Wide Band (continued)
Bluetooth
Distance: up to 33 feet (10 meters)
Bandwidth: 1 Mbps
Ultra Wide Band
Distance: 150 feet (50 meters)
Bandwidth: 100 Mbps to 2 Gbps
Piconet
Wireless personal area network (WPAN)
Consists of two or more Bluetooth devices that are exchanging data with each other
Satellite Networks
Used to transmit data over very long distance
Repeater
Located in the satellite itself
Simply “repeats” the same signal to another location
Used to transmit data from one earth station to another
Transmission time is approximately 250 milliseconds
Wireless Local Area Networks
Wireless Local Area Network (WLAN)
Extension of a wired LAN
Connecting to it through a device called a wireless access point
Access point (AP)
Relays data signals between all of the devices in the network
Each computer on the WLAN has a wireless network interface card (NIC)
With an antenna built into it
Summary
Wireless communications have become commonplace
Wireless networks and devices are found in all circles of life today
Wireless wide area networks will enable companies of all sizes to interconnect their offices
Without the high cost charged by telephone carriers for their landline connections
WLAN applications are found in a wide variety of industries and organizations Wireless communication disadvantages
Radio signal interference
Security issues
Health risks