introduction to wireless lans

... in the Life of a Wireless User: Field • Handheld devices used to connect to nearest cell tower – Cell tower connects to local telephone company – Telephone company connects to appropriate resources ... Networks (WLANs) • Wi-Fi (Wireless Fidelity): Based on standard that transmits at up to 11 Mbps • Computers on WLAN must have wireless network interface cards (wireless NIC or Wireless Trang 10Wireless ... 8A Look at Wireless Technologies• Wireless technology woven throughout many aspects of life • Useful to get overview of some current technologies in today’s wireless world Trang 9Wireless Local

Ngày tải lên: 06/02/2018, 09:28

... for the wireless network and a bridge to connect the wireless network with the wired network • A remote wireless bridge is a wireless device designed to connect two or more wired or wireless ... Devices: Remote Wireless Bridge (continued) Figure 2-8: Point-to-point remote wireless bridge Trang 14WLAN Devices: Remote Wireless Bridge (continued) Figure 2-9: Point-to-multipoint remote wireless ... Devices: Wireless Network Interface Card (continued) • A movement towards integrating wireless NICs – Would eliminate need for external wireless NICs • Software drivers necessary to allow wireless

Ngày tải lên: 06/02/2018, 09:28

... Trang 1CWNA Guide to Wireless LANs, Second EditionChapter Three How Wireless Works Trang 2• Explain the principals of radio wave transmissions ... Intentional loss may be necessary to decrease signal strength to comply with standards or to prevent interference – Unintentional loss can be cause by many factors Trang 27Radio Frequency Behavior: ... for WLANs – Limit distance that WLAN can transmit • Transmitter Power Output (TPO): Measure of power being delivered to transmitting antenna • Receive Signal Strength Indicator (RSSI): Used to

Ngày tải lên: 06/02/2018, 09:28

... Trang 1CWNA Guide to Wireless LANs, Second EditionChapter Four IEEE 802.11 Physical Layer Standards Trang 2• List and describe the wireless modulation schemes used in IEEE WLANs • Tell the difference ... FCC has established restrictions on FHSS to reduce interference • Due to speed limitations FHSS not widely implemented in today’s WLAN systems – Bluetooth does use FHSS Trang 11Frequency Hopping ... Supports speeds over 100 Mbps for 802.11a WLANs – Supports speeds over 54 Mbps for 802.11g WLANs Trang 19IEEE 802.11 Physical Layer Standards• IEEE wireless standards follow OSI model, with some

Ngày tải lên: 06/02/2018, 09:28

... themselves – Peer-to-peer or ad hoc mode • BSS more flexible than IBSS in being able to connect to other wired or wireless networks • IBSS useful for quickly and easily setting up wireless network ... • Wireless device sends beacon to all other devices – Devices that previously attempted to send a frame to a sleeping device will send ATIM frame indicating that receiving device has data to ... responsible for controlling access to wireless medium • Channel access methods: Rules for cooperation among wireless devices – Contention: Computers compete to use medium • If two devices send

Ngày tải lên: 06/02/2018, 09:28

... shown to add one to two hours a day of productive time per worker – Enabling worker to respond to customers, partners, and colleagues more quickly • WLANs too often viewed as optional add-on to ... deploying a wireless network • Explain the ways in which to provide user support Trang 3CWNA Guide to Wireless LANs, Second Edition 3 Planning for a Wireless Network • “If you fail to plan, then ... Trang 1CWNA Guide to Wireless LANs, Second EditionChapter Six Planning and Deploying a Wireless LAN Trang 2• Explain the steps for planning a wireless network • Tell how to design a wireless LAN •

Ngày tải lên: 06/02/2018, 09:28

... Survey Tools: Wireless Tools (continued) Figure 7-1: Adjusting AP power levels Trang 10Site Survey Tools: Wireless Tools (continued) Figure 7-2: External antenna connectors Trang 11Site Survey Tools: ... a proposed wireless LAN site to meet design goals • Three categories of tools used – Wireless tools include the access point and notebook computers with a wireless NIC – Measurement tools include ... building layout blueprints as tools • Advisable to create database to store site survey information and generate reports Trang 22Site Survey Tools: Documentation Tools (continued) Trang 23Performing

Ngày tải lên: 06/02/2018, 09:28

... Guide to Wireless LANs, Second EditionChapter Eight Wireless LAN Security and Vulnerabilities Trang 2• Define information security • Explain the basic security protections for IEEE 802.11 WLANs ... 802.11 to encrypt wireless transmissions – “Scrambling” Trang 14WEP: Cryptography• Cryptography: Science of transforming information so that it is secure while being transmitted or stored – ... IEEE 802.11 Security Trang 10Access Control• Intended to guard availability of information • Wireless access control: Limit user’s admission to AP – Filtering • Media Access Control (MAC) address

Ngày tải lên: 06/02/2018, 09:28

... Trang 1CWNA Guide to Wireless LANs, Second EditionChapter Ten Managing a Wireless LAN Trang 3Monitoring the Wireless Network• Network monitoring provides valuable data regarding ... problems • Monitoring a wireless network can be performed with two sets of tools: – Utilities designed specifically for WLANs – Standard networking tools Trang 4WLAN Monitoring Tools• Two classifications ... Ethernet Trang 9WLAN Monitoring Tools (continued)Figure 10-5: Access point event log Trang 10WLAN Monitoring Tools (continued)Trang 11Standard Network Monitoring Tools• Drawbacks to relying solely on

Ngày tải lên: 06/02/2018, 09:28

... how to solve access point problems • Describe the types of wireless device problems and explain how to solve them Trang 3Wired Network Settings for Wireless occasionally need to be adjusted • To ... 1CWNA Guide to Wireless LANs, Second EditionChapter Eleven Network Settings and Wireless LAN Troubleshooting Trang 2• Explain the wired network settings that can be modified in a wireless network ... agent redirects frames to client via care-of-address Trang 17Troubleshooting Wireless Networks• Troubleshooting can be difficult with WLANs – Many factors can impact wireless transmissions •

Ngày tải lên: 06/02/2018, 09:28

... Guide to Wireless LANs, Second EditionChapter Twelve Personal, Metropolitan, and Wide Area Wireless Networks Trang 2• Define a wireless personal area network • List the technologies of a wireless ... features of a wireless wide area network • Discuss the future of wireless networking Trang 3Wireless Personal Area Networks• Wireless networks classified into four broad categories: – Wireless personal ... Bottleneck Trang 27Wireless Metropolitan Area Networks: Free Space Optics • Optical, wireless, point-to-point, line-of-sight wireless technology – Able to transmit at speed comparable to Fiber Optics

Ngày tải lên: 06/02/2018, 09:28

... Trang 1Wireless NetworksLecture 1 Introduction to Wireless Communication Dr Ghalib A Shah Trang 2Data Communication and Networks1 Wireless Communication and Networks, 2 nd Ed., W Stalling. 2 Wireless ... of wireless networks ► Able to carry research in different domains of wireless networks Trang 4Course Syllabus Introduction to wireless communication  Evolution of wireless communication systems ... Course► Basics of wireless communication ► Evolution of modern wireless communication systems ► Wireless Networks ► Research issues in emerging wireless networks ► Adequate knowledge of wireless networks

Ngày tải lên: 05/07/2022, 13:04

... Trang 1Wireless NetworksLecture 2 Introduction to Wireless Communication Dr Ghalib A Shah Trang 3Last Lecture ReviewTrang 4Trans ... transmitted by encoding each data bit into signal elements.  There can be one-to-one correspondence between data elements and signal elements or one-to-multiple/multiple-to-one  Data rate: the rate ... signal is added to a carrier signal  This is the superimposing of the information onto the carrier  In an RF system a modulator generates this information signal  Then it is passed to the transmitter

Ngày tải lên: 05/07/2022, 13:05

... Trang 1Wireless Networks Lecture 3 Introduction to Wireless Communication Dr Ghalib A Shah Trang 5Multiplexing Trang 7 Time­division multiplexing (TDM)► ... 4/3x100)^1/2 + 0 = 41 km. Now suppose that h2 = 10m To achieve same distance, what must be h1? 41 = 3.57(Kh1)^1/2+(13.3)^1/2 h1 = 46.2m Trang 27Propagation Factors  The effect of the Earth’s shape in ... natural noise (solar, galactic, atmospheric) and manmade ► Above 10 GHz, higher attenuation due to atmospheric Trang 18Ground Wave PropagationTrang 19► AM radioTrang 20Sky Wave PropagationTrang

Ngày tải lên: 05/07/2022, 13:05

... having to go to a specific computer lab or the library – To get on the school’s computer network • Wireless technology translates into a cost savings for colleges as well 32 Home Entertainment • Wireless ... Broadband Wireless (continued) • Wireless metropolitan area network (WMAN) – Covers a distance of up to 35 miles – Based on the IEEE 802.16 Fixed Broadband Wireless standard – Uses small custom antennas ... browser • Wireless Application Protocol version 2.0 (WAP2) – Provides a standard way to transmit, format, and display Internet data • For small wireless devices such as cell phones 25 Wireless...

Ngày tải lên: 13/09/2012, 10:52

... Introduction to Wireless Local Loop Introduction to Wireless Local Loop William Webb Artech House Boston • London Library of Congress Cataloging-in-Publication Data Webb, William E Introduction ... text on wireless local loop The intention here is to provide a reference that those new to the area of wireless local loop can consult to understand what it is all about, and to be able to differentiate ... Hence, PTOs are keen to find ways to send video down twisted-pair copper to provide services such as video on demand (VOD) VOD allows a user to view a film at home without having to go to the...

Ngày tải lên: 24/08/2014, 17:22

... cylinder skewing and sector-based sparing with one spare sector per track This needs to be accounted for in mapping logical blocks to the physical sectors Adding all these factors results in the ... 97560 sector size 256 bytes 512 bytes cylinders 1449 1962 tracks per cylinder 19 data sectors per track 113 72 number of zones 1 track skew 34 sectors sectors cylinder skew 43 sectors 18 sectors ... specifications, since the only alternative is to determine them experimentally The information required to determine how much power to apply to the pivot motor and for how long on a particular seek...

Ngày tải lên: 12/09/2012, 14:16

... beginning to the end (for now)    No backing up to read something again (OK to start over) Just as done from the keyboard Writing to a file  Sending output to a file  Done from beginning to end ... fails, it is generally best to stop the program The function exit, halts a program  exit returns its argument to the operating system  exit causes program execution to stop  exit is NOT a member ... flag is an instruction to one of two options ios::fixed is a flag Will be written in fixed-point notation, the way we normally expect to see numbers Calls to setf apply only to the stream named...

Ngày tải lên: 12/09/2012, 22:49

... using complementary metal oxide semiconductor (CMOS) transistors They used no resistors and inductors, and the whole circuit was fabricated by the 20 INTRODUCTION very large scale integration ... may have to tune each of them to correct for manufacturing tolerances, but there is no such need to test the accuracy of the wordlength in digital filters Data on digital filters can be stored on ... the ability to understand the solution to the problems is important but understanding the theory behind them is far more important The following paragraphs are addressed to the instructors teaching...

Ngày tải lên: 13/09/2012, 10:21

... developed for a particular customer or may be developed for a general market Software products may be • •  Generic - developed to be sold to a range of different customers e.g PC software such ... systems that are intended to provide automated support for software process activities CASE systems are often used for method support Upper-CASE  Lower-CASE   • • Tools to support the early process ... engineers should adopt a systematic and organised approach to their work and use appropriate tools and techniques depending on the problem to be solved, the development constraints and the resources...

Ngày tải lên: 14/09/2012, 11:26