WIRELESS TECHNOLOGY

INTRODUCTION

Now a days, wireless technology are very famous and popular among people. It was established in the field of computer networking technologies for the last three years and today they have grown rapidly and become a very good and useful source of communication among people. There are lots of wireless technologies in use which helps us to compete in the race of computer networking. Wireless technologies make communication easy between different areas.

WIRELESS DEFINITION

Wireless is a term used to describe telecommunications in which electromagnetic waves (rather than some form of wire) carry the signal over part or all of the communication path. Some monitoring devices, such as intrusion alarms, employ acoustic waves at frequencies above the range of human hearing; these are also sometimes classified as wireless.

WIRELESS - CLASSIFICATION

Wireless can be divided into:

Fixed wireless -- the operation of wireless devices or systems in homes and offices, and in particular, equipment connected to the Internet via specialized modemsMobile wireless -- the use of wireless devices or systems aboard motorized, moving vehicles; examples include the automotive cell phone and PCS (personal communications services)Portable wireless -- the operation of autonomous, battery-powered wireless devices or systems outside the office, home, or vehicle; examples include handheld cell phones and PCS unitsIR wireless -- the use of devices that convey data via IR (infrared) radiation; employed in certain limited-range communications and control systems

FIRST WIRELESS TRANSMISSION

The first wireless transmitters went on the air in the early 20th century using radiotelegraphy (Morse code). Later, as modulation made it possible to transmit voices and music via wireless, the medium came to be called "radio." With the advent of television, fax, data communication, and the effective use of a larger portion of the spectrum, the term "wireless" has been resurrected.

EXAMPLES OF WIRELESS EQUIPMENT

Common examples of wireless equipment in use today include:

Cellular phones and pagers -- provide connectivity for portable and mobile applications, both personal and business

Global Positioning System (GPS) -- allows drivers of cars and trucks, captains of boats and ships, and pilots of aircraft to ascertain their location anywhere on earth

Cordless computer peripherals -- the cordless mouse is a common example; keyboards and printers can also be linked to a computer via wireless

Cordless telephone sets -- these are limited-range devices, not to be confused with cell phones

Home-entertainment-system control boxes -- the VCR control and the TV channel control are the most common examples; some hi-fi sound systems and FM broadcast receivers also use this technology

Remote garage-door openers -- one of the oldest wireless devices in common use by consumers; usually operates at radio frequencies

Two-way radios -- this includes Amateur and Citizens Radio Service, as well as business, marine, and military communications

Baby monitors -- these devices are simplified radio transmitter/receiver units with limited range

Satellite television -- allows viewers in almost any location to select from hundreds of channels

Wireless LANs or local area networks -- provide flexibility and reliability for business computer users

WIRELESS TECHNOLOGY IN PEOPLE’S LIFE

Wireless technology is rapidly evolving, and is playing an increasing role in the lives of people throughout the world. In addition, ever-larger numbers of people are relying on the technology directly or indirectly. (It has been suggested that wireless is overused in some situations, creating a social nuisance.) More specialized and exotic examples of wireless communications and control include:

Global System for Mobile Communication (GSM) -- a digital mobile telephone system used in Europe and other parts of the world; the de facto wireless telephone standard in Europe

General Packet Radio Service (GPRS) -- a packet-based wireless communication service that provides continuous connection to the Internet for mobile phone and computer users

Enhanced Data GSM Environment (EDGE) -- a faster version of the Global System for Mobile (GSM) wireless service

Universal Mobile Telecommunications System (UMTS) -- a broadband, packet-based system offering a consistent set of services to mobile computer and phone users no matter where they are located in the world

Wireless Application Protocol (WAP) -- a set of communication protocols to standardize the way that wireless devices, such as cellular telephones and radio transceivers, can be used for Internet access

i-Mode -- the world's first "smart phone" for Web browsing, first introduced in Japan; provides color and video over telephone sets

TYPES OF WIRELESS TECHNOLOGY:

Due to easy approach to the networks and also in many appliances of the daily life, wireless technology are of many types. Some important types of wireless technology are:

(i) Wi-fi technology:

“Wi-fi “is commonly called wireless LAN. It is one of those networks in which high frequency radio waves are used for transmission of data from one place to another. This technology woks on high frequency radio signals.

(ii) Voice communication:

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

(iii) Bluetooth technology:

Bluetooth technology is used to transmit the data from one device to another. Bluetooth is a open wireless technology standard for exchanging data over short distances.

WORKING OF WIRELESS NETWORK:

A wireless network or Wireless Local Area Network (WLAN) serves the same purpose as a wired one — to link a group of computers. Because "wireless" doesn't require costly wiring, the main benefit is that it's generally easier, faster and cheaper to set up.

By comparison, creating a network by pulling wires throughout the walls and ceilings of an office can be labor-intensive and thus expensive. But even when you have a wired network already in place, a wireless network can be a cost-effective way to expand or augment it. In fact, there's really no such thing as a purely wireless network, because most link back to a wired network at some point.

The BasicsWireless networks operate using radio frequency (RF) technology, a frequency within the electromagnetic spectrum associated with radio wave propagation. When an RF current is supplied to an antenna, an electromagnetic field is created that then is able to propagate through space.

The cornerstone of a wireless network is a device known as an access point (AP). The primary job of an access point is to broadcast a wireless signal that computers can detect and "tune" into. Since wireless networks are usually connected to wired ones, an access

point also often serves as a link to the resources available on the a wired network, such as an Internet connection.

In order to connect to an access point and join a wireless network, computers must be equipped with wireless network adapters. These are often built right into the computer, but if not, just about any computer or notebook can be made wireless-capable through the use of an add-on adapter plugged into an empty expansion slot, USB port, or in the case of notebooks, a PC Card slot.

Wireless Technology StandardsBecause there are multiple technology standards for wireless networking, it pays to do your homework before buying any equipment. The most common wireless technology standards include the following:

802.11b: The first widely used wireless networking technology, known as 802.11b (more commonly called Wi-Fi), first debuted almost a decade ago, but is still in use.

802.11g: In 2003, a follow-on version called 802.11g appeared offering greater performance (that is, speed and range) and remains today's most common wireless networking technology.

802.11n: Another improved standard called 802.11n is currently under development and is scheduled to be complete in 2009. But even though the 802.11n standard has yet to be finalized, you can still buy products based on the draft 802.11n standard, which you will be able to upgrade later to the final standard.

All of the Wi-Fi variants (802.11b, g and n products) use the same 2.4 GHz radio frequency, and as a result are designed to be compatible with each other, so you can usually use devices based on the different standards within the same wireless network. The catch is that doing so often requires special configuration to accommodate the earlier devices, which in turn can reduce the overall performance of the network. In an ideal scenario you'll want all your wireless devices, the access point and all wireless-capable computers, to be using the same technology standard and to be from the same vendor whenever possible.

Wireless Speed & RangeWhen you buy a piece of wireless network hardware, it will often quote performance figures (i.e., how fast it can transmit data) based on the type of wireless networking standard it uses, plus any added technological enhancements. In truth, these performance figures are almost always wildly optimistic.

While the official speeds of 802.11b, 802.11g, and 802.11n networks are 11, 54, and 270 megabits per second (Mbps) respectively, these figures represent a scenario that.s simply not attainable in the real world. As a general rule, you should assume that in a best-case scenario you.ll get roughly one-third of the advertised performance.

It's also worth noting that a wireless network is by definition a shared network, so the more computers you have connected to a wireless access point the less data each will be able to send and receive. Just as a wireless network's speed can vary greatly, so too can the range. For example, 802.11b and g officially work over a distance of up to 328 feet indoors or 1,312 feet outdoors, but the key term there is "up to". Chances are you won't see anywhere close to those numbers.

As you might expect, the closer you are to an access point, the stronger the signal and the faster the connection speed. The range and speed you get out of wireless network will also depend on the kind of environment in which it operates. And that brings us to the subject of interference.

Wireless InterferenceInterference is an issue with any form of radio communication, and a wireless network is no exception. The potential for interference is especially great indoors, where different types of building materials (concrete, wood, drywall, metal, glass and so on) can absorb or reflect radio waves, affecting the strength and consistency of a wireless network's signal. Similarly, devices like microwave ovens and some cordless phones can cause interference because they operate in the same 2.4 frequency range as 802.11b/g/n networks. You can't avoid interference entirely, but in most cases it's not significant enough to affect the usability of the network. When it does, you can usually minimize the interference by relocating wireless networking hardware or using specialized antennas.

Data Security on Wireless NetworksIn the same way that all you need to pick up a local radio station is a radio, all anyone needs to detect a wireless network within nearby range is a wireless-equipped computer. There's no way to selectively hide the presence of your network from strangers, but you can prevent unauthorized people from connecting to it, and you can protect the data traveling across the network from prying eyes. By turning on a wireless network's encryption feature, you can scramble the data and control access to the network.

Wireless network hardware supports several standard encryption schemes, but the most common are Wired Equivalent Privacy (WEP), Wi-Fi Protected Access (WPA), and Wi-Fi Protected Access 2 (WPA2). WEP is the oldest and least secure method and should be avoided. WPA and WPA2 are good choices, but provide better protection when you use longer and more complex passwords (all devices on a wireless network must use the same kind of encryption and be configured with the same password).

Unless you intend to provide public access to your wireless network — and put your business data or your own personal data at risk — you should consider encryption mandatory.

TYPES OF WIRELESS NETWORK:

(i) LAN – Local Area Network: LAN connects networking devices within short span of area such as short offices, home, etc.

(ii) WAN – Wide Area Network:

WAN can cover large distance for communication between computers. Internet ia an example of WAN.

(iii) Wireless Local Area Network:

A local area network based on wireless network technology is mostly refered as Wi-Fi. In WLAN, no wires are used but radio signals are the medium for communication. Wireless network cards are required to be installed in the systems for accessing any wireless network around.

(iv) CAN - Campus Area Network:

Networking spanning with multiple LAN’s but smaller than a MAN. This kind of network are mostly used in relatively large universities or local business offices.

EFFECT OF WIRELESS TECHNOLOGY ON HEALTH:

As we all know that electromagnetic field is generated during the data transmission from the wireless devices. Basically health sometimes effected with the wireless devices because different types of microwaves are used in the communication from one place to another. Wireless devices are developed for the sake of convenience and better or faster networking. They have a very good effect on the health because wireless devices can save the time and expense required for typical broadband connection. Wireless devices made the life easier as compared to wired devices. Mobility is the main factor of convenience in the life.

SECURITY:

Security is a major issue of wireless networks. To protect the network, password should be ensured specially when you are browsing the internet and logging in with your secret information.

CONVENIENCE:

It helps in faster searching. You can use your internet facility conveniently. You are free from using wired or cabled networks so you can log in anywhere in the world through signals.

PREVENTION OF WIRELESS NETWORK HACKING:

Where there are different techniques to hack the wireless networks, some protection techniques are also used, that is, by encryption of the wireless traffic of wireless networks, password protection and change the default name and password of SSID.

ADVANTAGES AND DISADVANTAGES OF WIRELESS TECHNOLOGY

Advantages

Mobility – user device can be moved easily within the wireless range Neat and easy Installation – since no cable running here and there, just start up the

wireless device and you’re ready to rumble Less cost for cabling infrastructure and device More user supported – cable device have limited slots whereas wireless does not.

Disadvantages

Relatively lower bandwidth speed – example: although currently 802.11/n could reach 128 Mbps, UTP cable can reach 1 Gbps. And more user mean each bandwidth get smaller. That is why currently wired backbone network is still preferred.

Ease of access means more security also necessary to protect data and/or bandwidth, since people can connect anywhere within range without seeking network plug.

LIMITATIONS:

While entering in website when you use the wireless connection through cell phones, various websites allow you their standard version in which low functionality exists.

WIRELESS TECHNOLOGIES TRENDS IN FUTURE

DLNA

DLNA (Digital Living Network Alliance) is an innovation that is sure to catch the attention of media enthusiasts. It is a communication technology that allows devices to share content over an existing wired/wireless network. DLNA-enabled devices range from smartphones, tablets, televisions, gaming consoles, media players and cameras. Not only does it allows live streaming and easy sharing of music, video, and photos; it even

supports printing over the network. Once connected to the network, DLNA-enabled devices detect each other easily and allow for seamless sharing with no setup required. Many smartphones like Nokia N8, Samsung Galaxy S II, HTC Sensation and Sony Ericsson Xperia Arc S come with DLNA integrated. Media players like Western Digital's TV Live Hub have it too. It can be enabled on most tablets by installing apps.

Wi-Fi DirectTo connect two devices wirelessly, you would typically require a Wi-Fi setup in which a router broadcasts a network and your devices - be it a PC, phone, laptop, netbook, or TV - all connect to the router. The router in turn, acts as starting point, enabling connected devices to communicate with each other.Opposed to this conventional way, with Wi-Fi Direct, compatible devices can connect directly by generating their own wireless network. While most devices across gadget categories (TV, Printers, etc.) have Wi-Fi connectivity in-built as an option, moving forward, Wi-Fi Direct will be the easiest way to share data. Devices like Samsung's Galaxy S/ SII and LG Optimus Black P970 and even printers that can work with Wi-Fi Direct are available in the market.

Near Field Communications

NFC, or Near Field communications is a technology that uses magnetic fields to connect devices. It is a short range wireless technology that can work up till a few centimetres. It is very fast and takes just a second to connect to a NFC-ready device when within range.

It can be used for financial transactions, sharing content, streaming multimedia, initiating multiplayer gaming, pairing Bluetooth and to read various NFC tags for identification, coupons, advertisements and so on. Google’s recently launched 'Wallet' is a great example that highlights the growth of mobile payments via NFC.

Devices such as Samsung's Nexus S, most of the Blackberry OS7 range and new Nokia Symbian range have NFC integrated.

4G

Although 3G is still far from seeing mass adoption, there are already talks of 4G arriving in India next year. LTE, WiMax and HSPA+ are the three technologies that come the aegis of 4G because of their ability to transfer fast data. What matters the most here is that 2G and 3G work for both voice and data while 4G works only for data transfer. The noticeable improvement that 4G would offer over 3G is better coverage area and higher browsing speeds of up to 100mbps (depending upon the device used). Since it works using a wider frequency range of 2 - 8Ghz, data transfer speeds are not that affected by number of users. For 4G a whole set of new devices across categories will be required to be launched in India as there is no device in the market that can actually utilize 4G connectivity.

Wi-Fi 802.11ac

Wi-fi is one of the best wireless technologies for data transfer. Currently in its 4th generation, Wi-Fi is differentiated on the basis of standards – 802.11b, 802.11g and 802.11n - with 802.11n being the latest, capable of speeds of up to 600 Mbps and offering extended range. It works using the 2.4Ghz and 5Ghz channel. Now, Wi-Fi will step into its 5th generation with the 802.11ac standard. The new standard dictates a theoretical maximum transfer speed of up to 3.6 Gbps and uses the 5Ghz channel for data transfers. It will improve upon signal range, will support better connectivity with multiple devices and consume less power - so important for the battery powered smartphones and laptops of tomorrow. This standard will also make it easier to stream full HD videos and transfer large amounts of data between devices wirelessly. Devices featuring this new standard of Wi-Fi are expected to be demonstrated/launched at the upcoming CES 2012 expo by Broadcom and various other device manufacturers.

CONCLUSION: Wireless technologies have faster speed without the involvement of cables. Mobility is the major advantage. Configuration and the installation of the wireless technology is much less as compared to wired technology. So wireless technologies make communication easy between different areas.