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Chapter 1:WIRELESS COMMUNICATION SYSTEMS : - Coggle Diagram
Chapter 1:WIRELESS COMMUNICATION SYSTEMS
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1.1 Background of wireless communications
Fixed and Mobile wireless communication
The information carried is defined as channel
Parallel and independently.
Transmitting and receiving voice and data
Why Radio Wave ?
easy to generate
can travel long distance
can penetrate buildings
can used for indoor and outdoor communication
can travel in all direction
can be narrowly focused at high frequency.
FIXED WIRELESS COMMUNICATION
unlike mobile wireless
portable wireless which tend to be battery-powered
Laser Bridge
efficiency and bandwidth
CHARACTERISTICS WIRELESS COMMUNICATION
fixed
parallel
well defined channel.
electromagnetic waves
MOBILE WIRELESS COMMUNICATION
Allows the Receiver to roam from place to another
can be located anywhere
FIXED VS MOBILE WIRELESS COMMUNICATION
MOBILE WIRELESS COMMUNICATION
Receiver can roam
Example: Cellular Phones
Receiver located anywhere within transmitter’s range
FIXED WIRELESS COMMUNICATION
Transmitting antenna focuses energy directly toward receiving antenna
Point-to-point link result
Transmitter, receiver locations do not move
Example: Satellite, Cordless Phones
ADVANTAGES
INCREASED RELIABILITY
EASIER INSTALLATION
FLEXIBILITY & MOBILITY
LESS EXPENSIVE INSTALLATION
DISASTER RECOVERY / EMERGENCY ALERTS
CAPABILITY
DISADVANTAGES
SECURITY
HEALTH RISKS
RADIO SIGNAL INTERFERENCE
HIGHER STARTING COST
RELATIVELY LOWER BANDWIDTH SPEED
LIMITED SPECTRUM
1.2 Wireless communication categories
WIRELESS PERSONAL AREA NETWORK (WPAN)
low-range wireless network
without using a hard-wired connection.
Example: Bluetooth, ZigBee and Infrared
ISM (Industrial, Scientific and Medical) frequency bands:
2.4 GHz band (2.4 … 2.4835 GHz)
5.8 GHz band (5.725 … 5.850 GHz)
WIRELESS LOCAL AREA NETWORK (WLAN)
Wi-Fi or WiFi is a technology that allows many electronic devices to exchange data
Mainly operational frequency using the 2.4 GHz (12 cm) UHF and 5 GHz (6 cm) SHF for Industrial Scientific Medical
IEEE 802.11 standards.
Medium Access Control (MAC) and Physical Layer (PHY)
Ethernet, but without the limitations of wires or cables.
High –speed wireless technology
Two or more WLAN-enabled devices
WIRELESS METROPOLITAN AREA NETWORK (WMAN)
Also known as a Wireless Local Loop (WLL).
Based on the IEEE 802.16 standard.
Wireless MAN is long range area network
defined as the network that providing a much larger coverage in wide area place
WiMAX is fixed, portable access and mobile devices.
WORLDWIDE INTEROPERABILITY FOR MICROWAVE ACCESS (WIMAX)
radio frequency technology that uses licensed and unlicensed bands
Based on IEEE 802.16
802.16-2004 is also known as 802.16d, which refers to the working party that has developed that standard
1.3 Bluetooth Communication
Bluetooth (IEEE 802.1.15)
Bluetooth wireless technology is an open specification for a low-cost, low-power, short-range radio technology for ad-hoc wireless communication
Bluetooth is designed to connect devices of different function such as telephone, computer, camera and printer when they are short distance.
Bluetooth is WPAN standard that operates in the 2.4 GHz ISM band at data rate 1 Mbps.
Piconet
Can have until 8 station ( 1 Master, 7 Slaves)
All slaves stations synchronize their clock and hopping sequence with the Master.
Small net
Scatternet
A devices can be slave in one Piconet and master of another Piconet. (Master /Slave)
Piconets are combined to form Scatternet.
1.4 Radio Frequency Identification (RFID)
Automated data collection technology that utilizes radio-frequency waves to transfer data
RFID is the use of wireless magnetic fields to transmit data, for automatically identifying and tracking tags attached to the objects.
Tag is a device used to transmit information such as a serial number to the reader
An antenna attached to the reader to communicate with transponders
In order to move data from a single node to the local network and/or to the global network
TYPE OF RFID
RFID passive
no internal power source and instead are powered by the electromagnetic energy
RFID semi active
Semi-active RFID tags use internal batteries to power their circuits.
RFID active
battery-powered RFID tags that continuously broadcast their own signal.
FAR FIELD
microwave and UHF
NEAR FIELD
LF and HF
