Wireless communication
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Wireless communication involves transmitting voice and data using radio waves instead of wires. It offers freedom from physical connections and allows communication in areas where wiring is not feasible. Various wireless technologies operate at different radio frequencies and include technologies like Wi-Fi, Bluetooth, cellular networks, and satellite communication. While wireless communication provides mobility and flexibility, it also faces challenges such as security issues, infrastructure costs, and signal degradation from obstructions.
Wireless communication
- 2. WHY WIRELESS COMMUNICATION? Freedom from wires. No bunch of wires running from here and there. “Auto Magical” instantaneous communication without physical connection setup e.g.- Bluetooth, Wi-Fi. Global coverage Communication can reach where wiring is infeasible or costly E.g.- rural areas,buildings,battlefield,outerspace. Stay connected,flexiblity to connect multiple devices.
- 3. WHAT IS WIRELESS COMMUNICATION? Transmitting/receiving voice and data using electromagnetic waves in open space. The information from sender to receiver is carried over a well defined channel. Each channel has a fixed frequency bandwidth & capacity(bit rate). Different channels can be used to transmit information in parallel and independently.
- 4. TYPICAL FREQUENCIES FM RADIO 88 MHZ TV BROADCAST 200 MHZ GSM PHONES 900 MHZ GPS 1.2 GHZ PCS PHONES 1.8 GHZ BLUETOOTH 2.4 GHZ Wi-Fi 2.4 GHZ
- 5. How communication takes place? Transmitting Signal Received Signal Satellite Transmitting Antenna Receiving Antenna
- 6. TYPES OF WIRELESS COMMUNICATION? RADIO TRANSMISSION:- easily generated, Omni- directional , travel long distance , easily penetrates buildings. PROBLEMS:- frequency dependent , relatively low bandwidth for data communication , tightly licensed by government. MICROWAVE TRANSMISSION:- widely used for long distance communication , relatively inexpensive. PROBLEMS:- don’t pass through buildings , weather and frequency dependent.
- 7. TYPES CONTINUED…. INFRARED AND MILIMETER WAVES:- Widely used for short range communication , unable to pass through solid objects , used for indoor wireless LANs , not for outdoors. LIGHT WAVE TRANSMISSION:- unguided optical signal such as laser , unidirectional , easy to install , no license required. PROBLEMS:- unable to penetrate rain or thick fog , laser beam can be easily diverted by air.
- 8. Advantages and disadvantages of wireless communication Advantages: Working professionals can work and access Internet anywhere and anytime without carrying cables or wires wherever they go. This also helps to complete the work anywhere on time and improves the productivity. A wireless communication network is a solution in areas where cables are impossible to install (e.g. hazardous areas, long distances etc.) Wireless networks are cheaper to install and maintain Disadvantages: Has security vulnerabilities High costs for setting the infrastructure Unlike wired communication, wireless communication is influenced by physical obstructions, climatic conditions, interference from other wireless devices
- 9. CURRENT WIRELESS SYSTEMS CELLULAR SYSTEM WIRELESS LANs SATELLITE SYSTEM PAGING SYSTEM PANs(BLUETOOTH)
- 10. Cordless Telephone System • Cordless telephone systems are full duplex communication systems. • First generation cordless phone – in-home use – communication to dedicated base unit – few tens of meters • Second generation cordless phone – outdoor – combine with paging system – few hundred meters per station
- 11. Example of Mobile Radio Systems Examples Cordless phone Remote controller Hand-held walkie-talkies Pagers Cellular telephone Wireless LAN Mobile - any radio terminal that could be moves during operation Portable - hand-held and used at walking speed Subscriber - mobile or portable user
- 12. Wireless local area network(WLAN) WLAN connect local computers Range (100 m) confined region Break data into packets Channel access is shared Backbone internet provides best service Poor performance in some application like videos Low mobility
- 13. Satellite system ? Global coverage Optimized for good transmission Expensive base stations. Voice and data transmission Telecommunication application GPS , global telephone connection TV broadcasting , military , weather broadcasting
- 14. Paging system ? Broad coverage for short messages Message broadcast from all base stations Simple terminals Optimized for one way transmission Answer back hard Overtaken by cellular Pager system
- 15. Paging Systems • Conventional paging system send brief messages to a subscriber • Modern paging system: news headline, stock quotations, faxes, etc. • Simultaneously broadcast paging message from each base station. • Large transmission power to cover wide area.