Wireless Fidelity

Abstract - Wireless Fidelity

The technologies used in this field are one of the best in the wireless space. When compared with other fast improving technologies like Bluetooth and 3G, Wi-Fi is seen to have many advantages. We can set up networks at home and office using Wi-Fi. It is fairly easy to set up a Wi-Fi enabled network at home or a small office. Wi- Fi is several times faster than Bluetooth and operates like a high-speed modem.

        There are many security issues that come under Wi-Fi . The main problem that it has till now is that it is easy for hackers to attack the network. The security method that is used now is the WEP (Wired Equivalent Privacy).The new VPN (Virtual Private Network) method seems to correct everything that is wrong with WEP.

The ad-hoc network structure in the 802.11 protocol

 Contents

1.     INTRODUCTION                                                  

2.     IEEE 802.11 ARCHITECTURES                        

3.     BASIC COMPONENTS                                           

4.     OPERATION BASICS                                             

5.     TECHNOLOLGY                                                  

6.     SECURITY                                                          

7.     SPECIAL FEATURES OF Wi-Fi                        

8.     CONCLUSION                                                     

9.     REFERENCES                                                      

Introduction

The Wi-Fi CERTIFIED logo is your only assurance that the product has met rigorous interoperability testing requirements to assure products from  different vendors will work together. The Wi-Fi CERTIFIED logo means that it  is a “safe” buy.

Wi-Fi    certification  comes from  the Wi-Fi  Alliance, a non profit international trade organisation that tests 802.11 based wireless equipment to make sure that it meets the Wi-Fi standard and works with all other manufacturer’s Wi-Fi equipment on the market. The Wi-Fi Alliance (WELA) also has a Wi-Fi certification program for Wi-Fi products that meet interoperability standards. It is an international organisation devoted to certifying interoperability of 802.11 products and to promoting 802.11as the global wireless LAN std across all market segment.

Operation Basics

        When a wireless adapter is turned on, it begins to scan across the wireless frequencies for wireless APs and other wireless clients in ad hoc mode. Assuming that the wireless client is configured to operate in infrastructure mode, the wireless adapter chooses a wireless AP with which to connect. This selection is made automatically by using an SSID and signal strength and frame error rate information. Next, the wireless adapter switches to the assigned channel of the selected wireless AP and negotiates the use of a port. This is known as establishing an association.

Technology

        Wi-Fi uses radio technology called IEEE 802.11b to provide secure ,reliable,fast wireless connectivity. A Wi-Fi network can be used to connect computers to each other, to the internet and to the wired networks.

Wi-Fi Security Options

        IEEE 802.11 contains an encryption option intended to provide confidentiality. The Wired Equivalent Privacy (WEP) option is defined in the 802.11 standard as "protecting authorized users of a Wi-Fi from casual eavesdropping." Recently, this security scheme has come under a great deal of criticism, accompanied by a number of papers which uncover weaknesses and outline how WEP can be defeated. Additionally, tools to exploit these weaknesses are now freely available over the Internet.

Virtual Private Networks

        It provide the most robust security solutions for corporate LANs and are already widely used for intranets and remote access. A VPN typically utilizes a dedicated server that provides both authentication and confidentiality.

CONCLUSION

Wi-Fi use is growing fast in homes, public access areas and business –both large and small. The Wi-Fi alliance is active with many industry organisations and is working closely with manufacturers to make sure that  existing Wi-Fi  gear  is compatable  with wireless technologies developed in the future .

There are real and measurable benefits to using a wireless network Vs a standard wired network. For a home installation customer, the greatest benefit is that there are no wires needed: you don’t need to drill holes in walls and floors; you don’t need to drag cables across rooms or hide them under rugs. One Wi-Fi access point can provide network access for any typically sized home . And if you live in a rental or a historical building, you may not be allowed to drill holes- that makes wireless your only solution. 

Wireless LAN Security

Wireless LAN Security   - Abstract

The availability of inexpensive, easily installed WLAN equipment opens up new pathways for attacks and other security breaches. Unlike wired networks, where eavesdropping on network traffic will be apparent to watchful network administrators WLAN data streams can be passively observed using ordinary WLAN cards without being detected by administrators. Furthermore, the eavesdropper’s device may even be in the parking lot or on the sidewalk—unlike eavesdroppers on wired LANs, WLAN eavesdroppers need not be on site making an electrical connection to the network. Authentication is the foundation technology for protecting networks, servers, client systems, data, and applications from improper disclosure, tampering, destruction, and other forms of interference.

Shared Key Authentication Process

Contents

1. INTRODUCTION 

                                             

2. THREATS TO WLAN ENVIORNMENT   

                 

3. AUTHENTICATION AND ACCESS CONTROL   

        

4. STANDARDIZED ATTEMPTS TO MANAGE                                                    

5. SHORTCOMINGS OF STANDARD

                                  

6. SOLUTIONS 

                     

7. THREATS TO DATA PRIVACY AND INTEGRITY  

    

8. ROGUE ACCESS POINTS    

                               

9. DENIAL OF SERVICE (DOS)     

                           

10. CONCLUSION

Wireless LAN Security - INTRODUCTION

        Wireless local area networks (WLANs) based on the Wi-Fi (wireless fidelity) standards are one of today’s fastest growing technologies in businesses, schools, and homes, for good reasons. They provide mobile access to the Internet and to enterprise networks so users can remain connected away from their desks. These networks can be up and running quickly when there is no available wired Ethernet infrastructure. They can be made to work with a minimum of effort without relying on specialized corporate installers.

Link Layer Protection: 802.1X

        One of the advantages of an 802.1X authentication system compared to a VPN is that the wireless network need not be located outside the firewall. Because the access points won’t forward any data aside from the authentication process itself, there is next-to-no opportunity for wireless attackers to access the wired network, even if they can receive the wireless signals in the parking lot.

DENIAL OF SERVICE (DoS)

        Denial of service (DoS) attacks are possible on any kind of network, not just WLANs.  However, WLANs have some DoS vulnerabilities that they don’t share with other networks. The most brute-force DoS attack is an attack on WLAN radios. 802.11 networks operate on bands at 2.4GHz and 5.8GHz.

Conclusion

If there are unprotected WLANs connected to an enterprise network, it’s crucial that these WLANs be located outside the firewall and other perimeter defenses. Wherever WLANs are attached to the enterprise network, it’s crucial to install and maintain a secure authentication system that is commensurate with the security risks the enterprise faces. In addition, it’s crucial to find and secure any unauthorized access points. In most cases, enterprises will want to update their existing access point firmware and software, client driver software, and authentication servers to the WPA standards, and only purchase WPA-compliant products going forward.         

                                            

Wireless Charging Of Mobile Phones Using Microwaves

The Microwave Region

Microwave wavelengths range from approximately one millimeter (the thickness of a pencil lead) to thirty centimeters (about twelve inches). In a microwave oven, the radio waves generated are tuned to frequencies that can be absorbed by the food. The food absorbs the energy and gets warmer. The dish holding the food doesn't absorb a significant amount of energy and stays much cooler. Microwaves are emitted from the Earth, from objects such as cars and planes, and from the atmosphere.

With mobile phones becoming a basic part of life, the recharging of mobile phone batteries has always been a problem. The mobile phones vary in their talk time and battery standby according to their manufacture and batteries. All these phones irrespective of their manufacturer and batteries have to be put to recharge after the battery has drained out. The main objective of this current proposal is to make the recharging of the mobile phones independent of their manufacturer and battery make. In this paper a new proposal has been made so as to make the recharging of the mobile phones is done automatically as you talk in your mobile phone! This is done by use of microwaves. The microwave signal is transmitted from the transmitter along with the message signal using special kind of antennas called slotted wave guide antenna at a frequency is 2.45 GHz.  

Introduction of Wireless Charging Of Mobile Phones Using Microwaves

The basic addition to the mobile phone is going to be the rectenna. A rectenna is a rectifying antenna, a special type of antenna that is used to directly convert microwave energy into DC electricity.

Its elements are usually arranged in a mesh pattern, giving it a distinct appearance from most antennae. A simple rectenna can be constructed from a Schottky diode placed between antenna dipoles. The diode rectifies the current induced in the antenna by the microwaves.

Rectenna are highly efficient at converting microwave energy to electricity. In laboratory environments, efficiencies above 90% have been observed with regularity. Some experimentation has been done with inverse rectenna, converting electricity into microwave energy, but efficiencies are much lower--only in the area of 1%.With the advent of nanotechnology and MEMS.

It has been theorized that similar devices, scaled down to the proportions used in nanotechnology, could be used to convert light into electricity at much greater efficiencies than what is currently possible with solar cells. This type of device is called an optical rectenna. Theoretically, high efficiencies can be maintained as the device shrinks, but experiments funded by the United States National Renewable energy Laboratory have so far only obtained roughly 1% efficiency while using infrared light. Another important part of our receiver circuitry is a simple sensor.

Sensor Circuitry

The sensor circuitry is a simple circuit, which detects if the mobile phone receives any message signal. This is required, as the phone has to be charged as long as the user is talking. Thus a simple F to V converter would serve our purpose. In India the operating frequency of the mobile phone operators is generally 900MHz or 1800MHz for the GSM system for mobile communication.

Receiver Design  

Rectifies received microwaves into DC current a rectenna comprises of a mesh of dipoles and diodes for absorbing microwave energy from a transmitter and converting it into electric power. Its elements are usually arranged in a mesh pattern, giving it a distinct appearance from most antennae. The diode rectifies the current induced in the antenna by the microwaves. Rectenna are highly efficient at converting microwave energy to electricity. In laboratory environments, efficiencies above 90% have been observed with regularity.

In future rectennass will be used to generate large-scale power from microwave beams delivered from orbiting SPS satellites. The sensor circuitry is a simple circuit, which detects if the mobile phone receives any message signal. This is required, as the phone has to be charged as long as the user is talking. Thus a simple F to V converter would serve our purpose. In India the operating frequency of the mobile phone operators is generally 900MHz or 1800MHz for the GSM system for mobile communication.

Conclusion   

Thus this paper successfully demonstrates a novel method of using the power of the microwave to charge the mobile phones without the use of wired chargers.

Worldwide Inter Operatibility for Microwave Access wimax

Introduction

In recent years, Broadband technology has rapidly become an established, global commodity required by a high percentage of the population. The demand has risen rapidly, with a worldwide installed base of 57 million lines in 2002 rising to an estimated 80 million lines by the end of 2003. This healthy growth curve is expected to continue steadily over the next few years and reach the 200 million mark by 2006. DSL operators, who initially focused their deployments in densely-populated urban and metropolitan areas, are now challenged to provide broadband services in suburban and rural areas where new markets are quickly taking root. Governments are prioritizing broadband as a key political objective for all citizens to overcome the "broadband gap" also known as "digital divide".

  Abstract

WiMAX is a standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL. WiMAX will provide fixed nomadic, portable and, eventually, mobile wireless broadband connectivity without the need for direct line-of-sight with a base station. In a typical cell radius deployment of three to ten kilometers, WiMAX Forum Certified™ systems can be expected to deliver capacity of up to 40 Mbps per channel, for fixed and portable access applications. This is enough bandwidth to simultaneously support hundreds of businesses with T-1 speed connectivity and thousands of residences with DSL speed connectivity. Mobile network deployments are expected to provide up to 15 Mbps of capacity within a typical cell radius deployment of up to three kilometers. It is expected that WiMAX technology will be incorporated in notebook computers and PDAs in 2006, allowing for urban areas and cities to become “Metro Zones” for portable outdoor broadband wireless access.

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There are several ways to get a fast Internet connection to the middle of nowhere. Until not too long ago, the only answer would have been "cable" - that is, laying lines. Cable TV companies, who would be the ones to do this, had been weighing the costs and benefits. However this would have taken years for the investment to pay off. So while cable companies might be leading the market for broadband access to most people (of the 41% of Americans who have high-speed Internet access, almost two-thirds get it from their cable company), they don't do as well to rural areas. And governments that try to require cable companies to lay the wires find themselves battling to force the companies to take new customers. Would DSL be a means of achieving this requisite of broadband and bridging the digital divide?

WiMAX

WiMax delivers broadband to a large area via towers, just like cell phones. This enables your laptop to have high-speed access in any of the hot spots. Instead of yet another cable coming to your home, there would be yet another antenna on the cell-phone tower. This is definitely a point towards broadband service in rural areas.

Wi-Fi

The WiMAX Forum is keen to present 802.16 as complementary to the local area IEEE standard, 802.11 or Wi-Fi. In many ways, this is right—802.16a, as we have seen, provides a low cost way to backhaul Wi-Fi hotspots and WLAN points in businesses and homes, and as uptake of Wi-Fi increases, the requirement for this backhaul will grow too.

Extended Wi-Fi

Some companies are still sticking with Wi-Fi rather than WiMAX as a metro area wireless standard. There are various approaches to extending Wi-Fi's range and capacity, but all are based on proprietary extensions. Their supporters take the view that they can offer a solution now, particularly to the enterprise, but with the speed of development of WiMAX, this argument will not hold weight for very long.

Other Wi-Fi extenders take the approach of fiddling with the media access control layer rather than directing beams in a more efficient way, Vivato's approach and that of many BWA specialists too. Some of these have got prices down to less than initial WiMAX equipment is likely to be, around $300 per subscriber (though WiMAX, starting around $500, is sure to drop to this level rapidly). However, given that these are proprietary technologies from start-ups and still have some limitations compared to WiMAX, it seems unlikely that many operators will choose them rather than waiting 6-9 months for 802.16.

Mobile-Fi

Standards battles are normally conducted in dusty committees and arouse little interest among technology purchasers until the vendors move the specifications into real products and real marketing wars. The IEEE's wireless standards are proving an exception to this.

Conclusion

WiMAX will become the dominant solution in China, the world's largest potential market for broadband users. The standard has already been adopted by the government and will fill in many of the gaps in the sketchy 3G coverage. The hype around Wi-Fi will die down and 802.11 will return to its rightful place as a useful but limited local area technology, fully integrated with WiMAX at the backhaul. WiMAX will be the most significant technology to date in making wireless access ubiquitous and, as more free spectrum is opened up, in creating a major shake-up of the traditional shape of the wireless and mobile communications sector.