Wireless systems

Why use wireless ?

Because you have to. Warehouses, hospitals, robots, anywhere you cannot connect with wire. Disadvantages: For data, distortion is not tolerated at all: any errors have to be corrected (complicating the data transfer) or restransmitted (slowing the data-rate). The IEEE 802.11a standard is located in the 5.0 GHz Unlicenced National Information Infrastructure frequency band, utilizing Orthogonal-Frequency-Division-Multiplexing modulation with Quadrature Phase-Shift-Keying. This band competes in part with some Cordless Phones but is relatively free from interference and is fast but short-range. IEEE 802.11b is located in the 2.4 GHz Industrial, Scientic and Medical frequency band, utilizing Direct-Sequence-Spread-Spectrum modulation. This band also contains these sources of interference: Bluetooth, Microwave ovens, some Cordless Phones and Amateur Radio, and is slower but of greater range.

Wireless network utilize components similar to wired networks, however wireless networks must convert information signals into a from suitable for transmission the air medium. even though wireless networks directly contribute only to a portion of the overall network infrastructure , attention to all network functions is necessary to counter impairments resulting from the wireless medium.

A wireless network consist of several components that support communications using radio or light waves propagating through and air medium. some of this elements overlap with those of wired networks, but spacial consideration is necessary for all of these components when deploying a wireless network.

Nowadays wireless technologies are very famous and popular among the people and the modern researchers. It was established and came in the field of computer networking technologies from the last three years and today they are grown rapidly and become a very good and useful source of communication among the people and all the technologies of present era. There are lots of wireless technologies now being into use which helps us to compete in the race of computer networking and be up to date in this technological World. Computer networking is a very vast and advanced field which has been implemented on many aspects of technology. In computer networking, there are so many devices which are used for networking purposes. Wireless technologies really provide the convenient and easy approach to communications between different areas that are very behind from the different types of the modern and the latest technologies. Different types of wireless technologies were designed by the scientists because the people who are away from their homes, they can avail such opportunity of using the internet at very high speed and be in touch with others for the sake of their business enhancement in the best possible ways of communication between two places.

Air medium

Air serves many purposes such as providing a basis for speech, enabling air travel and sustaining life. air also provides a medium for propagation of wireless communications signals, which is heart of wireless networking. air is the conduit by which information flows between computer devices and the wireless infrastructure. think of communication through a wireless network as similar to talking to someone. as you move farther apart , is more difficult to hear each other, especially when a load noise is present. wireless information signals also travel through the air, but they have especial properties that enable propagation over relatively long distances. wireless information signals can’t be heard by humans, so it is possible to amplified the signals to a higher level without disturbing human ears.   the quality of transmission, however depends on obstructions  in the air that either lessen or scatter be strength and range of the signals.


What are Benefits of a Wireless Network?

Wireless LANs offer the following productivity, convenience, and cost advantages over wired networks:

  • Mobility: Wireless LAN systems can provide LAN users with access to real-time information anywhere in their organization. This mobility supports productivity and service opportunities not possible with wired networks.There are now thousands of universities, hotels and public places with public wireless connection. These free you from having to be at home or at work to access the Internet.
  • Installation Speed and Simplicity: Installing a wireless LAN system can be fast and easy and can eliminate the need to pull cable through walls and ceilings.
  • Reduced Cost-of-Ownership: While the initial investment required for wireless LAN hardware can be higher than the cost of wired LAN hardware, overall installation expenses and life-cycle costs can be significantly lower. Long-term cost benefits are greatest in dynamic environments requiring frequent moves and changes.
  • Scalability: Wireless LAN systems can be configured in a variety of topologies to meet the needs of specific applications and installations. Configurations are easily changed and range from peer-to-peer networks suitable for a small number of users to full infrastructure networks of thousands of users that enable roaming over a broad area.



  • It’s a bit more difficult to setup properly
  • Risk of ‘outsiders’ accessing your network unless robust security protocols are enabled (eg WPA, WPA2)
  • Significantly slower than a wired network (2 – 50 times slower, see below).
  •  The network can be less stable. Wireless reception may be impaired by a number of factors including large distances or objects between wireless devices, and other wireless networks.


Here are some types of wireless technologies:

Due to the easy approach to the networks and also in many appliances of the daily life wireless technologies are of many types and almost all the technologies that are used in the present era for the sake of better working are designed wirelessly. Some important types of wireless technologies are as follows

  • Wifi technolog

is commonly called as wireless LAN, it is one of those networks in which high frequency radio waves are required for transmission of data from one place to another. WiFi operates on several hundreds feet between two places of data transmission. This technology only works on high frequency radio signals. Otherwise, it will not work properly. Nowadays this technology is used as office or home network and in many electronic devices. Wireless LAN or WiFi is divided into three main parts on which its whole working depends and all of its applications also depend on these parts i.e. infrastructure mode, ad hoc network and mixed network.

  • zigbee technology

type of low cost, low power and wireless technology which is used for the different purposes at ultra low power is known as Zig bee technology. Low power radios on the basis of standard personal wireless networking are used by a protocol to enhance the technology. It offers excellent wireless control path network. It was not proposed or designed for the excellent or high speed data transfer rate applications. But it was designed for working on excellent long battery timings at low cost and also at ultra low power consumption. It is an ideal technology which operates at low power and low cost and used for wireless monitoring and control.

  • Wimax technology

One of the important wireless technologies another technology is present that is called as Wimax technology. It is defined as a type of the wireless networking technology that is required to transmit the information in the form of microwaves through different type of methods of wireless networking from point to point or multi point access top the devices which are portable in nature. Wimax technology is categorized into two types that are Fixed Wimax and the mobile Wimax.

  • Voice communication technology

Voice communication is also the types of wireless technologies. In this types all the types of technologies related to the communication through the voice is included such as communication through different types of cell phones, through different types wireless internet technologies etc

  • Bluetooth technology

Other important type of wireless technology is the Bluetooth technology that is used to transmit the data from one device to another device with the help of mobile phone technology.

  •  Home RF technology

The HomeRF Working Group (RF stands for radio frequency) was an alliance of businesses that developed a standard for wireless data transfer, which is called Shared Wireless Access Protocol (SWAP). SWAP-based networks are usually point-to-point. Some manufacturers do offer access points as an option to increase the effective range of the wireless network, however, they are not necessary. Mostly because this technology lacks an access point, HomeRF networks are significantly cheaper than the other viable wireless network technology, Wi-Fi. The tradeoffs for the lower price tag are speed and distance. This technology attempts to meet a variety of wireless needs in the home, which includes: phones, audio, video, data, gaming and home appliances.

  • IrDA technology

The acronym IrDA stands for the Infrared Data Association. IrDA uses a series of infrared data pulses to transfer data from one device to another. Because IrDA devices use infrared light, the communicating devices must be in direct line of sight with one another.  The original IrDA was designed to operate at at a speed of 115200 bps. Although now you can purchase and install an IrDA-based network, which is capable of transmitting data at speeds of up to 4 megabits per second (Mbps), because of the line of sight requirement you still would need an access point in each room. This is what limits the usefulness of an IrDA network and IrDA technology. IrDA was the earliest wireless technology and it was used for such things as television remote controls, garage door openers, and other more primitive wireless devices. Nowadays it has improved its standards for data transfer speeds and other important features.

  • Wireless USB

is a short-range, high-bandwidth wireless radio communication protocol created by the Wireless USB Promoter Group. Wireless USB is sometimes abbreviated as “WUSB”, although the USB Implementers Forum discourages this practice and instead prefers to call the technology “Certified Wireless USB” to distinguish it from the competing UWB standard. Wireless USB is based on the WiMedia Alliance’s Ultra-WideBand (UWB) common radio platform, which is capable of sending 480 Mbit/s at distances up to 3 metres (9.8 ft) and 110 Mbit/s at up to 10 metres (33 ft). It was designed to operate in the 3.1 to 10.6 GHz frequency range, although local regulatory policies may restrict the legal operating range for any given country.


Wireless USB is used in game controllers, printers, scanners, digital cameras, portable media players, hard disk drives and flash drives. Kensington released a Wireless USB universal docking station in August, 2008. It is also suitable for transferring parallel video streams, while utilizing the Wireless USB over Ultra-wideband bandwidth.