A wireless LAN, as the name implies, is a LAN without any wires to connect different nodes in the network, because in these LAN's wireless media or unguided media is used for this purpose.
Most wireless LAN's today work either on Infra-red (IR) or Radio Frequencies (RF). Infra-red devices have a problem of "line of sight", while radio frequencies are more immune to noise etc.
Just like any network a wireless LAN also has to follow a standard, some protocol, some handshaking mechanism. The standards for Wireless LAN's which are most commonly used are 802.11 by IEEE and HiperLAN (used in europe).
Although most wireless LAN cards normally connect directly with your PC and enable you to communicate with other nodes in the network over wireless media, a different approach could be to build a device equipped with a RF-module or simply a FM transmitter/ receiver.This device should be able to communicate with the standard Ethernet LAN cards and transmit their data over radio frequencies using the RF-module.
If in a Ethernet every node is equipped with such a device, the LAN can be safely termed as a wireless LAN.
At the very first look it may seem impossible, but if we consider the fact that in a 802.3 network (Ethernet) the LAN cards don't send any acknowledgments and don't wait for them either, things become pretty simple.
Whenever a LAN card gets some data from the upper layers, it simply frames the packet and sends it on the outgoing link, without caring whether the packet will reach its destination or not, this worrying is done by the upper layers (transport layer) and even if the upper layer is sending some ack or nack it will look just like a normal packet to the LAN card.
So all this proves that the LAN card will show no...
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added: 03/16/2011
CISCO Getting UN-Wired November 19, 2001 "Wireless LANs represent a major area for potential growth in this new economy." Wireless LAN Benefits Study, ) NOP World - Technology, Cisco Systems, September 2001 By Terry Moos, News@Cisco More Information Feature: Putting Wireless LAN Through Its Paces Cisco's Global Deployment Serves as a Testing Ground Video: NOP Confirms Wireless Productivity Gains 56k Broadband Release: Cisco Announces New Independent Study Demonstrating Productivity Gains Achieved Through Wireless LAN Use Study: Wireless LAN Benefits Study Related links: Cisco Technology Innovations: Wireless During the past few years, organizations have been inundated with propositions about the competitive necessity of deploying innovative new technologies. But in this new era of uncertainty in global markets, the decision to implement the latest technologies has to be weighed carefully. Which innovative products and services will help drive business? Which ones will make employees more efficient? How soon will the benefits be realized? With so many choices, investments now require justification - new technology must be tested and proven before implementation. Decision makers need evidence that the investments they make will significantly improve the bottom line. "Current economic conditions have made productivity and profitability the new benchmarks for business success," said Charles Giancarlo, Senior Vice-President and General Manager of Technology Development at Cisco Systems. This need to improve productivity and profitability has fueled the growth of wireless local area network (WLAN) technology in many sectors of the market. The advantages are widely touted: WLAN supplies the characteristics organizations need from a LAN (Ethernet, Token Ring), without wire or cable connections. WLAN provides 'anytime, anywhere' network access, and helps IT departments cut cabling costs and simplify labor-intensive installations. "Wireless networking has been viewed as one of the technologies promising the greatest impact on productivity, but until now, no formal studies existed to substantiate the many benefits of wireless LANs," explained Giancarlo. Wireless LAN Benefits Study Reveals Gains To that end, NOP World - Technology recently polled...
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added: 11/20/2011
Worldwide are rolling out wireless technology. This has created a completely new dimension of computing and business practices that have propelled enterprises to new heights of service and flexibility. Along with these new opportunities and benefits, wireless networks come with their share of unique problems, enterprises must plan and implement an intelligent strategy for wireless networks or risk failure. It is essential for organizations to understand the wireless environment and implement world-class technology solutions that grow with the business. The enterprise of the future is one whose employees are free to perform their job functions from their workplace of choice¡Xwhether from a stationary desk, or while on the move. To improve workforce productivity, most enterprises will leverage wireless technologies to support a mobile environment. Mobile devices for personal use are very popular today, and this trend is carrying over to the enterprise. Within the next few years, all end-user connectivity should be wireless, meaning that every enterprise will operate in a hybrid ¡§wired plus wireless¡¨ environment. Today, the line between computing and telephony on handheld devices is rapidly blurring. Devices that combine the features of mobile phones and PDAs are already popular. Eventually there will be one combined device we carry or wear¡X where we do our scheduling, email, web surfing, videoconferencing, document management and take all of our business and personal calls. This would be a true all-round utility device. With data storage capabilities and network bandwidth steadily improving, it won¡¦t be long before we have the capabilities of today¡¦s high-end desktop computer available in a device that fits into a pocket. In some situations, enterprises are looking into integrating their telephone systems with wireless local area networks. Using technologies like voice-over IP (VoIP), these enterprises aim to reduce the costs associated with elaborate telephone cabling and further leverage the benefits of...
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added: 11/07/2011
Executive Summary Jacks Valley Training Complex (JVTC) is a unique facility that covers 2,000 acres of United States Air Force Academy land, located in Colorado Springs, Colorado. JVTC has several training courses that include an Obstacle Course, Leadership Reaction Course, Confidence Course, Assault Course, and Self Aide and Buddy Care area. These courses are used year round by over 76 military and civilian organizations for munitions training, expanding leadership skills, promoting teamwork opportunities and building confidence. Jacks Valley Training Complex is also home of the Global Engagement summer program. The cadets stationed at the Air Force Academy learn Air Force Expeditionary Force (AFE) training concepts through this program. The AEF training includes a mini airstrip for the cadets to practice parachuting. Over 1,200 customers a year utilize this training facility and annually this number is growing. This massive influx of new customers is causing concerns with the scheduling process. We at LITS Consulting recognize your concerns and have researched and developed a scheduler that will reduce man-hours, centrally locate the scheduling process, and proved training for the scheduler and manuals for the customer. This new scheduling process will be available through the JVTC web site and will allow for a paperless automated scheduling process. The features will include: on line registration, double booking prevention through date authentication, and flexibility to schedule multiple events at one time. Number of Concurrent Users At this time, 20,000 individuals a year utilize Jack Valley Courses. We have 50 users who are in charge of scheduling the Valley for these organizational needs. The customers set up reservations for an organization of twenty to a hundred people. These fifty customers are the point of contact for the Jack's Valley Scheduler. They are the people who answer what dates, times, equipment, and courses their organization needs. Jack's Valley 's new network...
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added: 08/09/2011
Sophie HUANG, Jimmy CHEN Abstract With 6 billion people in the world and only about 800 million telephone lines, access to modern communications service is still a dream for most people. We call this gap as "digital divide?which's between those who have access to the related information technologies in developed countries and those who have not in underdeveloped countries. The digital divide is now an accepted key factor that affects economic, society and knowledge development in both developed and underdeveloped countries. In this paper, we attempt to identify the opportunities to use low-cost wireless solution for telecommunication in underdeveloped countries. 1. Bridging the gap. 1.1 What's the digital divide? There're various definitions of the digital divide with different emphasis. We give the term of digital divide a conclusion from many referenced sources: Digital divide describes that the world can be divided into people who do and people who don't have access to - and the capability to use - modern information technology, such as computer facilities, literacy and use skills, computer literacy skills, or appropriate information content. Internet facilities, telecommunications facilities, information While there is no doubt that information technology has been a benefit to many and helped the business world to prosper, it has also widened the gap between the developed and underdeveloped countries, creating a two-tier world of have and have-nots. Even within developed, there is a gap between cities and rural areas. If we fail to solve the digital divide problem, millions could be left out in the cold. 1.2 Why decreasing the digital divide through wireless? In developed countries the mobile data access is driven by a fundamental need for basic communications services. But they existed a server problem in the rural areas where telecom network are even more scare, and now faced with great challenges to fulfilling universal access objectives and provide advanced communications...
pages: 13 (words: 3391)
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added: 12/23/2011
It's 6:30 the change of classes, and no matter which hallway you take they are filled with students making their way to their next destination. For some it's the last class of the evening and they're rushing off to meet friends or families. The students that are left behind are going to their next class, going to their first class of the evening or have school business at one of the student services office. The hallway past the receptionist desk leads to the admissions office where you might see new students enrolling, or students at the financial aid office waiting to discuss their financial aid with one of the interviewers. Next door to the financial aid office is the student development office where the students there are selecting, dropping and/or adding classes. Across the hall is the business office and the students there are finalizing classes for the coming semester. As you make your way through this crowded corridor you can't help but notice the many conversations that are taking place at one time. There may be conversations between 2 persons or conversations between a group of people but the conversations I notice most in these congested hallways are the conversations of students on their cell phones. As I desperately make my way down the crowded halls of Davenport University trying not to be late for class, I can't help but wonder as I pass these students so deeply engaged in their phone conversations, how did society survive before the invention of the cellular phone. Cell phones or wireless communication is not an invention that was discovered within the last few years, in fact, wireless communication or mobile phones have been around since the 1800s with the invention of the telephone (The Cell Approach 1). Before cell phones, people who needed mobile communications installed...
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added: 01/19/2012
WAP(Wireless Application Protocol) Background In 1995 Ericsson initiated a project which purpose was to develop a general protocol, or rather a concept, for value added services on mobile networks. Theprotocol was named Intelligent Terminal Transfer Protocol (ITTP), and handles the communication between a service node where the service application is implemented and an intelligent mobile telephone. The ambition was to make ITTP a standard for value added services in mobile networks.During 1996 and 1997 Unwired Planet, Nokia, and others, launched additional concepts in the area of value added services on mobile networks. Unwired Planet presented Handheld Device Markup Language (HDML) and Handheld Device Transport Protocol (HDTP). Just as HyperText Markup Language (HTML) used on the WWW, HDML is used for describing content and user interface, but optimised for wireless Internet access from handheld devices with small displays and limited input facilities. In March 1997 Nokia officially presented the Smart Messaging concept, an Internet access service technology specially designed for handheld GSM devices. The communication between the mobile user and the server containing Internet information uses Short Message Service (SMS) and a markup language called Tagged Text Markup Language (TTML). Just like HDML, this language is adapted for wireless communication, i.e. narrowband connections.With a multitude of concepts there was a substantial risk that the market could become fragmented, a evelopment that neither of the involved companies would benefit from. Therefore, the companies agreed upon bringing forth a joint solution. WAP was born... WAP Forum On June 26 1997 Ericsson, Motorola, Nokia, and Unwired Planet took the initiative to start a rapid creation of a standard for making advanced services within the wireless domain a reality. In December 1997 WAP Forum was formally created, and after the release of the WAP 1.0 specifications in April 1998, WAP Forum membership was opened to all. Today (February 1999)...
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added: 12/31/2011
Wireless vs. Cable Imagine fast, consistent, bi-directional speeds (upload and download speeds are uniform) with no busy signals, disconnections or loss of bandwidth. Broadband Wireless eliminates the need for any dedicated phone lines, and therefore reduces your costs, while providing data rates much better than modems. Broadband Wireless supports bandwidth intensive applications such as graphic rich media, animation, Internet phone calls and video conferencing (without breakups), sending and receiving of large email messages or files, and online banking, investing or shopping faster and more productive than ever before (transactions are sent and received instantly), unlike Cable and satellite which typically do not offer enough upstream speed to perform bandwidth intensive applications. In today's day and age of more speed with less hassle, wireless is becoming a more viable option for many companies. This option, while frowned upon in the past, is now more likely because of an implied increase in bandwidth, which amounts to more information begin sent at greater speeds. The argument wireless providers make is as follows: With Broadband Wireless, you will have bandwidth always available, unlike Cable or SDSL. As with any Internet connection the provider is sharing access (bandwidth) with all of it's customers, so your most limiting factor is the amount of bandwidth the ISP has, Cable and SDSL charge low rates for what they call "high speed access", which seems like a good thing, but charging so little means there is not enough money coming in to provide the bandwidth needed for your customers, so typically you will find your connection slows drastically when more users connect and when other people are using it heavily. You seldom actually get the speed they boast you will. You get what you pay for. You'll realize this to be true as more and more cable and SDSL providers are putting...
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added: 06/23/2011
WIRELESS COMPUTER NETWORKING Jennifer Velasco ERAU Abstract Computer technology and use is more in demand today then ever. In an attempt to accommodate computer users, the amount of computer peripherals and accessories is on the rise. This paper will discuss a particular hardware that is on the market today, which is computer wireless networking. Moreover, it will go in depth as to what exactly wireless networking entails, how to configure your computer for wireless networking and some advantages and disadvantages associated with wireless networking so potential users could possible determine if this type of hardware is one that would be suitable for their use. Computer Wireless Networking With computing technology on demand today, there is a wide variety of computer hardware on the market to select from, depending on needs of the user. A specific type of hardware that is of special interest to me is wireless computer networking. I would like to discuss what wireless networking entails, how it works and some advantages and disadvantages associated with the hardware. To begin with, computer wireless networking is basically the ability to link multiple computer systems in a household together without any wires. One may wonder how this could be possible, and this will be discussed later on in this paper. At any rate, this type of technology could be proven useful in a household with a lot of computer users to even a single household user with a desktop PC and a laptop. It all depends on frequency of use for the system, which now and days majority of households depend on computer technology in one way or another. Currently there are four types of wireless networks available: Bluetooth, IrDA, HomeRF (SWAP), and WECA (Wi-Fi). The difference between them is the range from slow and inexpensive to fast and expensive. Bluetooth is not readily available on the market...
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added: 12/19/2011
Introduction Definition: Communications Satellite is a satellite stationed in geosynchronous orbit that acts as a microwave relay station, receiving signals sent from a ground-based station (earth station), amplifying them, and retransmitting them on a different frequency to another ground-based station. Initially used for telephone and television signals, communications satellites can also be used for high-speed transmission of various multimedia services such as data communications, video and graphic image transfer and interactive conferencing. Overview Many satellites now orbit the earth, bringing satellite communications to almost all parts of the globe. To use a satellite all you need is terminal hardware at your station and the leasing of bandwidth. You will need a big receiving dish, if the signal in your area is weak. Forms of satellite networks 1. Information broadcast- This is used for one-way communication. Data can be transmitted simultaneously in real time (as it happens) to a number of sites e.g. a head office in Paris can broadcast monthly sales for figures or news of the new policies to offices across the world. 2. Point-to-point- Allows two way communications between satellite terminals and is ideal for isolated parts of the world. On this network you can have various multimedia services such as data transfer and video conferencing. 3. A hub or star network-Provides two-way communication over shared band width between large numbers of sites. All the information is processed by a central hub e.g. a head office, before being transmitted via satellite to remote sites. 4. Mesh network- enables several terminals to communicate directly without the need for a hub. It is typically used for voice applications. Two factors affecting the use of satellites with computers, however, are propagation delay (the time lag caused by the distance traveled by the signal) and security concerns. Wireless satellite communications solutions Wireless Connectivity Solutions offer residences and businesses a reliable, real time voice...
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added: 12/13/2011