Wimax

Visit: www.geocities.com/chinna_chetan05/forfriends.html

TITLE : WIMAX THE HAPPENING WIRELESS NETWORK REFERENCES : Casali, S.P., and Williges, R.C., Data Bases of Accommodative Aids for Computer Users with Disabilities, Human Factors, pp 407-422, 32(4), 1990. Edwards, W. K., Mynatt, E. D., Rodriguez, T. The Mercator Project: A Nonvisual Interface to the X Window System. The X Resource. O’Reilly and Associates, Inc. April, 1993. Mynatt, E. Auditory Presentation of Graphical User Interfaces in Kramer, G. (ed), Auditory Display: Sonification, Audification and Auditory Interfaces, Santa Fe. AddisonWesley: Reading MA., 1994.

College : JAYAPRAKASH NARAYAN COLLEGE OF ENGINEERING

ABSTRACT : Wireless telecommunications networks are generally implemented with some type of information transmission system that uses electromagnetic waves, such as radio waves, for the carrier and this implementation usually takes place at the physical level or "layer" of the network. AIM : .

Military research aims to develop self – configuring secure. Wimax aims to expand the reach of wireless networks.

IMPACT OF WIRELESS COMMUNICATION : Wireless networks have significantly impacted the world as far back as World War II. With the use of wireless networks, information could be sent oversees or behind enemy lines easily and quickly and was more reliable. In the modern world the use of firewalls will help with security breaches which can help to fix security problems in some wireless networks that are more vulnerable. People and businesses use wireless networks to send and share data quickly whether it be in a small office building or across the world.

1 Email: [email protected]

Visit: www.geocities.com/chinna_chetan05/forfriends.html

GOALS OF WIRELESS TRANSMISSION : To achieve the business goals and enhansing customer relationships.

INTRODUCTION DEFINATION : The term wireless network may technically be used to refer to any type of network that is wireless, the term is most commonly use to refer to a telecommunications network whose interconnections between nodes is implemented without the use of wires, such as a computer network.

HISTORY : The beginning of wireless started with Guglielmo Marconi as he began working with radio waves (History of Wireless). In 1896, Marconi was successful and obtained a patent and established the Wireless Telegraph and Signal Company, the first radio factory in the world (History of Wireless). By 1901 the first signals were being sent across the Atlantic Ocean (History of Wireless). The military found use for this wireless technology and configured the wireless signals to send data that was heavily encrypted, making it difficult to be cracked, which proved to be especially useful during World War II for the Army and Navy In 1971, researchers at the University of Hawaii developed the world’s first WLAN, or wireless local area network, it was named ALOHAnet (World of Wireless Networking). In 1982, AMPS (Advanced Mobile Phone Service) system specification became the radio telephony standard of the United States. Other countries also developed cellular networks, some used the United States standard meanwhile others used a different standard. GSM networks are now the most used cellular phone networks, especially in North America.

TYPES OF WIRELESS COMMUNICATION : Wireless LAN : One type of wireless network is a wireless LAN, or Local Area Network. Similar to other wireless devices, it uses radio instead of wires to transmit data back and forth between computers on the same network as was the case for ALOHNET.

2 Email: [email protected]

Visit: www.geocities.com/chinna_chetan05/forfriends.html Global System for Mobile Communications It is another type of wireless network. The GSM network is divided into three major systems which are the switching system, the base station system, and the operation and support system (Global System for Mobile Communication) Wi-Fi It is a commonly used wireless network in computer systems which enable connection to the internet or other machines that have Wi-Fi functionalities. Wi-Fi networks broadcast radio waves that can be picked up by Wi-Fi receivers that are attached different computers D-AMPS It stands for Digital Advanced Mobile Phone Service, is an upgraded version of AMPS but it is being phased out due to advancement in technology. The newer GSM networks are replacing the older system. Personal Communication Service It refers to a radio band that can be used by mobile phones in North America. Sprint happened to be the first service to set up a PCS.

APLICATIONS OF WIRELESS COMMUNICATION : Since then wireless networks have continued to develop and its uses have significantly grown. Cellular phones are part of huge wireless network systems. People use these phones daily to communicate with one another. Sending information over seas is only possible through wireless network systems using satellites and other signals to communicate across the world otherwise getting information Emergency services such as the police department utilize wireless networks to communicate important information quickly. People and businesses use wireless networks to send and share data quickly whether it be in a small office building or across the world. In terms of internet connections, are typically slower than those that are directly connected through an Ethernet cable. Though the speed is slower, most things will still move at the same speed except for things like video downloads. Though wireless technology continues to develop, it is now easier to get networks up and running cheaper and faster than ever before.

3 Email: [email protected]

Visit: www.geocities.com/chinna_chetan05/forfriends.html

LATEST TREND : WIMAX A WiMAX system consists of two parts :

A WiMAX TOWER : It is similar in concept to a cell-phone tower - A single WiMAX tower can provide coverage to a very large area -- as big as 3,000 square miles (~8,000 square km). A WiMAX RECIEVER : The receiver and antenna could be a small box or PCMCIA card, or they could be built into a laptop the way WiFi access is today.

APPLICATION AREA OF WIMAX : WiMAX Could Boost Government Security In an emergency, communication is crucial for government officials as they try to determine the cause of the problem, find out who may be injured and coordinate rescue efforts or cleanup operations. A gas-line explosion or terrorist attack could sever the cables that connect leaders and officials with their vital information networks. WiMAX could be used to set up a back-up (or even primary) communications system that would be difficult to destroy with a single, pinpoint attack. A cluster of WiMAX transmitters would be set up in range of a key command center but as far from each other as possible. Each transmitter would be in a bunker hardened against bombs and other attacks. No single attack could destroy all of the transmitters, so the officials in the command center would remain in communication at all times.

4 Email: [email protected]

Visit: www.geocities.com/chinna_chetan05/forfriends.html

How WiMAX Works In practical terms, WiMAX would operate similar to WiFi but at higher speeds, over greater distances and for a greater number of users. WiMAX could potentially erase the suburban and rural blackout areas that currently have no broadband Internet access because phone and cable companies have not yet run the necessary wires to those remote locations.

A WiMAX system consists of two parts:

• •

A WiMAX tower, similar in concept to a cell-phone tower - A single WiMAX tower can provide coverage to a very large area -- as big as 3,000 square miles (~8,000 square km).

A WiMAX receiver - The receiver and antenna could be a small box or PCMCIA card, or they could be built into a laptop the way WiFi access is today.

A WiMAX tower station can connect directly to the Internet using a high-bandwidth, wired connection (for example, a T3 line). It can also connect to another WiMAX tower using a line-of-sight, microwave link. This connection to a second tower (often referred to as a backhaul), along with the ability of a single tower to cover up to 3,000 square miles, is what allows WiMAX to provide coverage to remote rural areas.

Photo courtesy Intel

WiMAX transmitting tower

What this points out is that WiMAX actually can provide two forms of wireless service:

• •

There is the non-line-of-sight, WiFi sort of service, where a small antenna on your computer connects to the tower. In this mode, WiMAX uses a lower frequency range -- 2 GHz to 11 GHz (similar to WiFi). Lower-wavelength transmissions are not as easily disrupted by physical obstructions -- they are better able to diffract, or bend, around obstacles.

There is line-of-sight service, where a fixed dish antenna points straight at the WiMAX tower from a rooftop or pole. The line-of-sight connection is stronger and more stable, so it's able to send a lot of data with fewer errors. Line-of-sight transmissions use higher frequencies, with ranges reaching a possible 66 GHz. At higher frequencies, there is less interference and lots more bandwidth.

WiFi-style access will be limited to a 4-to-6 mile radius (perhaps 25 square miles or 65 square km of coverage, which is similar in range to a cell-phone zone). Through the stronger line-of-sight antennas, the WiMAX transmitting station would send data to WiMAX-enabled computers or routers set up within the transmitter's 30-mile radius (2,800 square miles or 9,300 square km of coverage). This is what allows WiMAX to achieve its maximum range.

Global Area Network The final step in the area network scale is the global area network (GAN). The proposal for GAN is IEEE 802.20. A true GAN would work a lot like today's cell phone networks, with users able to travel across the country and still have access to the network the whole time. This network would have enough bandwidth to offer Internet access comparable to cable modem service, but it would be accessible to mobile, always-connected devices like laptops or next-generation cell phones.

5 Email: [email protected]

Visit: www.geocities.com/chinna_chetan05/forfriends.html

LIMITATIONS OF WIRELESS COMMUNICATION : Security becomes vitally important when your mobile applications traverse wireless networks. This is primarily because the communications signals are openly available as they propagate outside the controlled area of homes or office buildings. Corresponding security threats are the mischievous monitoring of data packets, unauthorized access to network applications, and denial of service (DoS). When you're developing wireless mobile applications, be certain to consider the impacts and solutions for each of these security issues. An experienced hacker or even casual snooper can easily monitor wireless data packets using tools such as AirMagnet and AiroPeek, which fully disclose the contents of wireless data packets. For example, many of us have been successful at monitoring all transactions occurring over the wireless portion of the network several hundred feet away from a building that has a wireless LAN. Of course, the issue here is that just about anyone can read your emails, identify user names and passwords, and so on. In fact, "war drivers" even post their finds on web sites, just for fun. Thus, strongly consider virtual private network (VPN) solutions, especially those based on Secure Sockets Layer (SSL), when developing mobile applications interfacing with public networks. Even though VPNs are not foolproof, they provide an effective means of end-to-end encryption. VPNs are also effective when clients roam across different types of wireless networks because they operate above the dissimilar network connection levels.

CONCLUSION :

6 Email: [email protected]

Visit: www.geocities.com/chinna_chetan05/forfriends.html The benifits of wireless communication is driving the exclusive growth of the wlan market . Wi-Fi protected access (wpa) overcomes the internet fluence of early wireless networks.This approach offers a pragmatic solution to wireless security and can resolve the single largest barrier to wlan deployment for the It managers.

7 Email: [email protected]