Wi-Fi

Introduction

In the new era of generation, the people that involved in working class or students that need a fast output, always searching for a technology that fits their needs and is suitable to bring everywhere. As the demand for this kind of technology increases, the experts invented a good device to promote the immediate access to the internet, anywhere and anytime. And the Wi-Fi is finally born, bringing new thoughts and comfort ability.

Origin and meaning of the term Wi-Fi

The term Wi-Fi suggests Wireless Fidelity has often been used in an informal way. The term Wi-Fi, first used commercially in August 1999, was coined by a brand consulting firm called Interbrand Corporation that had been hired by the Alliance to determine a name that was "a little catchier than 'IEEE 802.11b Direct Sequence'." Interbrand invented Wi-Fi as simply a play on words with Hi-Fi, and also created the yin yang style Wi-Fi logo.

How it works

A Wi-Fi enabled device such as a PC (Personal Computer), game console, mobile phone, MP3 player or PDA (Personal Digital Assistant) can connect to the Internet when within range of a wireless network connected to the Internet. The coverage of one or more interconnected access points are called hotspot that can comprise an area as small as a single room with wireless-opaque walls or as large as many square miles covered by overlapping access points. In addition to restricted use in homes and offices, Wi-Fi can make access publicly available at Wi-Fi hotspots provided either free of charge or to subscribers to various providers. Enthusiasts or authorities who wish to provide services or even to promote business in a given area sometimes provide free Wi-Fi access to attract or assist clients. The Wi-Fi also allows connectivity in peer-to-peer (wireless ad-hoc network) mode, which enables devices to connect directly with each other. This connectivity mode can prove useful in consumer electronics and gaming applications.

Advantages and Challenges

Advantages and Benefits

Wireless network adapters are now built into most laptops. The price of chipsets for Wi-Fi continues to drop, making it an economical networking option included in even more devices. Wi-Fi has become widespread in corporate infrastructures.

Different competitive brands of access points and client network interfaces are inter-operable at a basic level of service making Wi-Fi as a global set of standards. And unlike mobile telephones, any standard Wi-Fi device will work anywhere in the world. Today, the Wi-Fi is widely available in more than 220,000 public hotspots and tens of millions of homes and corporate and university campuses worldwide. The benefits for the users are:

1. Convenience - The wireless nature of such networks allows users to access network resources from nearly any convenient location within their primary networking environment (home or office). With the increasing saturation of laptop-style computers, this is particularly relevant.
2. Mobility - With the emergence of public wireless networks, users can access the internet even outside their normal work environment. Most chain coffee shops, for example, offer their customers a wireless connection to the internet at little or no cost.
3. Productivity - Users connected to a wireless network can maintain a nearly constant affiliation with their desired network as they move from place to place. For a business, this implies that an employee can potentially be more productive as his or her work can be accomplished from any convenient location. For example, a hospital or warehouse may implement Voice over WLAN applications that enable mobility and cost savings.
4. Deployment - Initial setup of an infrastructure-based wireless network requires little more than a single access point. Wired networks, on the other hand, have the additional cost and complexity of actual physical cables being run to numerous locations (which can even be impossible for hard-to-reach locations within a building).
5. Expandability - Wireless networks can serve a suddenly-increased number of clients with the existing equipment. In a wired network, additional clients would require additional wiring.
6. Cost - Wireless networking hardware is at worst a modest increase from wired counterparts. This potentially increased cost is almost always more than outweighed by the savings in cost and labor associated to running physical cables.

Disadvantages

For a given networking situation, wireless LANs may not be desirable for a number of reasons. Most of these have to do with the inherent limitations of the technology.

1. Security - Wireless LAN transceivers are designed to serve computers throughout a structure with uninterrupted service using radio frequencies. Because of space and cost, the antennas typically present on wireless networking cards in the end computers are generally relatively poor. In order to properly receive signals using such limited antennas throughout even a modest area, the wireless LAN transceiver utilizes a fairly considerable amount of power. What this means is that not only can the wireless packets be intercepted by a nearby adversary's poorly-equipped computer, but more importantly, a user willing to spend a small amount of money on a good quality antenna can pick up packets at a remarkable distance; perhaps hundreds of times the radius as the typical user.
2. Reliability - Like any radio frequency transmission, wireless networking signals are subject to a wide variety of interference, as well as complex propagation effects that are beyond the control of the network administrator. Among the most insidious problems that can affect the stability and reliability of a wireless LAN are microwave ovens and analog wireless transmitters such as baby monitors making interference and propagation effects all the more disturbing. As a result, important network resources such as servers are rarely connected wirelessly. Wi-Fi pollution, or an excessive number of access points in the area, especially on the same or neighboring channel, can prevent access and interfere with the use of other access points by others, caused by overlapping channels. This can be a problem in high-density areas, such as large apartment complexes or office buildings with many Wi-Fi access points.
3. Speed - The speed on most wireless networks (typically 1-108 Mbit/s) is reasonably slow compared to the slowest common wired networks (100 Mbit/s up to several Gbit/s). For most users, however, this observation is irrelevant since the speed bottleneck is not in the wireless routing but rather in the outside network connectivity itself. In most environments, a wireless network running at its slowest speed is still faster than the internet connection serving it in the first place. However, in specialized environments, higher throughput through a wired network might be necessary.
4. Radio Emissions - Wireless LANs utilize radio emissions for communication, which can cause interference in other devices and may have potentially deleterious effects on human health. Due to the complex nature of radio propagation at typical Wi-Fi frequencies, particularly the effects of signal reflection off of trees and buildings, Wi-Fi signal strength can only be predicted generally for any given area in relation to a transmitter. This effect does not apply equally to long-range Wi-Fi, since longer links typically operate from towers that broadcast above the surrounding foliage.
5. Reach - Wi-Fi networks have limited range therefore, Wi-Fi performance decreases roughly quadratically as distance increases at constant radiation levels. A number of "no new wires" technologies have been developed to provide alternatives to Wi-Fi for applications where indoor range is more important than mobility.
6. Threats to the user’s account - Wi-Fi networks that are open (unencrypted) can be monitored and used to read and copy data (including personal information) transmitted over the network, unless another security method is used to secure the data, such as a VPN or a secure web page.

The features in the Wi-Fi accessories are very common now to the users who patronize the new technology. Even though there are many hindrances on this service, the demand is still on high due to the different needs of the subscribers.

References:

Switch on for Square Mile wi-fi. [news.bbc.co.uk.] Available at: http://news.bbc.co.uk/2/hi/technology/6577307.stm.