what is wireless?
This page describes the term wireless,its network,its channel,its applications,wireless technologies,standards and wireless operators. Wireless is the term used to refer to "anything without wire or cable." Information which needs to be sent Transmitter t on the other side will be converted to the form suitable for the medium to be propagated. This information which is in different form will be retrieved back on the receive side. Information can be in any form voice, data, video, image and so on.
History of wireless starts with Bell who in 1880 along with his colleague Tainter invented photo phone. The system demonstrated by Bell had limitations. After this wireless came into public use in 1896 when Marconi demonstrated wireless telegraph. This came to reality due to Maxwell's prediction of existence of electromagnetic waves.
How it works?
Electromagnetic wave is the medium by which two or more entities communicate unlike cable in the case of wired communication.
Electromagnetic wave or signal is used as a means to transmit information. An EM signal is a function of time, but it can be expressed as a function of frequency also. This frequency domain view is very important to analyze the frequency components of the signal. Viewed as a function of time, an EM signal can be either analog or digital. This EM signal can be transmitted to space and received from space using Antenna.
An antenna can be defined as an electrical conductor or system of conductors used either for radiating EM energy into space or for collecting EM energy from space. There are different antennas designed to transmit and receive different frequency bands.Let us understand what wireless network composed of.
The basic components in the wireless network are Transmitter, Receiver and channel. Transmitter and Receiver combined are often called as Transceiver. Channel is the medium through which information in the form of EM waves pass through to reach the other end of the system. Based on channel there are limitations for different technologies to work efficiently. As mentioned above when Bell demonstrated it had assumed good atmosphere. We see live example of wireless with all the living creatures hearing organs which listens without any wires but works with certain limitations.
Wireless channel models
There are various wireless channel models based on transmitter and receiver systems location, distance and mobility. Due to this different technologies have been designed to exchange information efficiently between transmitter and receiver devices. There are various types of channels based on location,distance and mobility between transmitter and receiver. Time variant and Time invariant channels based on trasnmitter and receiver is fixed and mobile respectively. There are slow and fast fading channels based on speed of Tx and Rx and so on.
2. Home automation
3. Telephone or Mobile
4. AM/FM Radio
7. Space exploration
8. Wireless internet
9. Remote control
10. Wireless navigation systems
12. Wireless inventory systems
5. Cellular-GSM, CDMA, HSPA, LTE, Read more on LTE
6. WLAN, Read More
7. WPAN or Zigbee,Read More on Zigbee
8. WiMAX, Read More
9. WirelessHART, Read More
10. M2M, Read More
3. Cellular-3GPP, Read More on 3G and 4G standards for cellular
4. Wireless Local Area Network-IEEE 802.11, Read More
5. Wireless Personal Area Network-IEEE 802.15, Read More
6. Wireless Metropolitan Area Network-IEEE 802.16, Read More
Major Wireless Network Service Provider-Internet Service Provider
AT&T | Nextel | Verizon wireless| ViryaNet
LTE and other wireless service operator throughout the world
India Airtel | India Aircel | India Reliance | India Tata Indicom | India Tikona Digital | India Vodaphone
UK O2 | UK Broadband | UK Vodafone
USA AT&T Mobility | USA Clearwire | USA Sprint | USA T-Mobile USA | USA US Cellular |USA Verizon Wireless
This page explains what are the various applications of wireless medium and covers standards and provide useful reference links.