CWNA guide to wireless LANs 2nd ch01

CWNA Guide to Wireless LANs, Second Edition Chapter One It’s a Wireless World Objectives • Describe how wireless technology is used in daily activities • Tell how wireless local area networks are used in applications such as education, business, travel, construction, and other areas • Explain the advantages and disadvantages of wireless technology CWNA Guide to Wireless LANs, Second Edit A Day in the Life of a Wireless User: Home • Hotspots: Locations where wireless data services are available • Wireless local area network (WLAN): Essentially identical to standard local area network (LAN) – Except devices not connected by wires – Can increase productivity CWNA Guide to Wireless LANs, Second Edit A Day in the Life of a Wireless User: Car • Bluetooth wireless standard: Enables short range wireless communication – Used in many small devices CWNA Guide to Wireless LANs, Second Edit A Day in the Life of a Wireless User: Office • Fixed broadband wireless: Wireless transmissions between immobile devices – Typically between office buildings – Utilizes small, customized antennas • Free space optics (FSO): Alternative to highspeed fiber optic transmissions CWNA Guide to Wireless LANs, Second Edit A Day 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 • Such as e-mail servers CWNA Guide to Wireless LANs, Second Edit A Day in the Life of a Wireless User: On Site • Radio frequency identification (RFID) tags: – “Electronic barcodes” – Used to identify items – Can be read anywhere within range of transmitted radio signal • Depending on device CWNA Guide to Wireless LANs, Second Edit A 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 CWNA Guide to Wireless LANs, Second Edit Wireless Local Area 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 adapter) – Performs same basic functions as standard NIC, plus more • Access point (AP): Transfers signals between wireless NICs • Patch cable connects AP to wired LAN or Internet CWNA Guide to Wireless LANs, Second Edit Wireless Local Area Networks (continued) Figure 1-3: Wireless LAN CWNA Guide to Wireless LANs, Second Edit 10 Wireless LAN Applications: Travel • Travel industry perhaps adopted wireless technologies more than any other industry – Many airport terminals provide wireless hotspots – Several large airlines providing wireless capabilities to passengers during flights – Some airlines use WLAN technology to communicate with aircraft on ground – Some airlines use WLAN technology to facilitate maintenance tasks – Some airlines use new wireless data service to send and receive messages CWNA Guide to Wireless LANs, Second Edit 25 Wireless LAN Applications: Construction • Wireless technology has greatly benefited construction industry – Better management of resources – Better management of paperwork • Construction equipment being fitted with wireless terminals – “Smart” equipment – GPS information can provide location information to within centimeters CWNA Guide to Wireless LANs, Second Edit 26 Wireless LAN Applications: Warehouse Management • New products arrive continuously – Must be inventoried and stored • Products being shipped must first be located then transferred to correct location and truck – Mistakes in inventory or inability to locate items can be devastating – Mark inventory with RFID tags • Warehouse management system (WMS) software: Can manage all activities from receiving through shipping – Utilize wireless technology CWNA Guide to Wireless LANs, Second Edit 27 Wireless LAN Applications: Public Safety • Public safety departments using WLANs and GSM to communicate information with public safety vehicles – City-owned buildings equipped with APs – Large volumes of data can be quickly downloaded to vehicles • e.g., building floor plans, photographs of criminal suspects, and maps CWNA Guide to Wireless LANs, Second Edit 28 Wireless LAN Applications: Healthcare • Wireless LAN point-of-care computer systems allow medical staff to access and update patient records immediately – Document patient’s medication administration immediately – Extensive use of RFID tags • Identify healthcare professionals, patients, medications – System verifies that medication being administered to correct patient in correct dosage • Eliminates potential errors and documentation inefficiencies CWNA Guide to Wireless LANs, Second Edit 29 Wireless LAN Applications: Healthcare (continued) • Documentation process takes place at bedside where care delivered – Improves accuracy • Hospital personnel have real-time access to latest medication and patient status information • Wireless technology also used in other medical areas: – e.g., video pills CWNA Guide to Wireless LANs, Second Edit 30 Wireless LAN Applications: Healthcare (continued) Figure 1-12: Video pill CWNA Guide to Wireless LANs, Second Edit 31 Wireless Advantages and Disadvantages: Advantages • Mobility: Primary advantage of wireless technology – Enables individuals to use devices no matter where users roam within range of network – Increasingly mobile workforce is characteristic of today’s business world – WLANs give mobile workers freedom while allowing them to access network resources – “Flatter” organizations: WLANs give team-based workers ability to access network resources needed while collaborating in team environment CWNA Guide to Wireless LANs, Second Edit 32 Wireless Advantages and Disadvantages: Advantages (continued) • Easier and Less Expensive Installation: Installing network cabling in older buildings difficult and costly – Wireless LAN is ideal solution – Eliminating need for cabling results in cost savings • Significant time savings as well – Allows offices to reorganize easily • Increased Reliability: Wireless LAN technology eliminates certain types of cable failures and increases overall network reliability CWNA Guide to Wireless LANs, Second Edit 33 Wireless Advantages and Disadvantages: Advantages (continued) • Disaster Recovery: Documented disaster recovery plan vital to every business – Hot site: Off-site facility that can run business’s operations if primary site is not available • Generally maintained by third party • Expensive – Cold site: Customer provides and installs equipment • Many businesses use cold sites and WLANs as major piece of disaster recovery plan – No consideration given to network cabling CWNA Guide to Wireless LANs, Second Edit 34 Wireless Advantages and Disadvantages: Disadvantages • Security: Wireless signals broadcast in open air – Security for wireless LANs is prime concern • Unauthorized users might access network – War driving • Attackers might view transmitted data • Employees could install rogue access points • Attackers could easily crack existing wireless security – Older wireless products have very weak security features CWNA Guide to Wireless LANs, Second Edit 35 Wireless Advantages and Disadvantages: Disadvantages (continued) • Radio Signal Interference: Signals from other devices can disrupt wireless transmissions – Or wireless device may be source of interference for other devices – e.g., Microwave ovens, elevator motors, photocopying machines, theft protection devices, cordless telephones – Solution: Locate source of interference and remove • Health Risks: Wireless devices emit RF energy – Not known if or to what extent low levels of RF might cause adverse health effects CWNA Guide to Wireless LANs, Second Edit 36 Summary • Wireless devices and technologies enable users to roam almost anywhere and remain connected to data and voice networks • A WLAN, also known as Wi-Fi, functions the same as a standard wired network except devices send radio frequency signals through the air instead of being connected to the network by cabling • Bluetooth devices communicate using small radio transceivers called radio modules that are built into microprocessor chips CWNA Guide to Wireless LANs, Second Edit 37 Summary (continued) • Two popular technologies are WiMax and free space optics (FSO) • Handheld devices can send and receive wireless signals using the Global System for Mobile (GSM) communications technology • RFID tags function as electronic barcodes • Wireless personal area networks (WPANs) cover technologies where the transmission generally extends only a few meters or feet, whereas wireless local area networks (WLANs) are generally restricted to 112 meters (375 feet) CWNA Guide to Wireless LANs, Second Edit 38 Summary (continued) • Wireless LAN applications can be found in industries in which employees need the freedom to conduct business without being confined to a specific location • Wireless LANs have significant advantages, including increased mobility, easier and less expensive network installations, increased network reliability, and disaster recovery • Some of the disadvantages of wireless LANs include security, radio signal interference, and health concerns CWNA Guide to Wireless LANs, Second Edit 39 ... between wireless NICs • Patch cable connects AP to wired LAN or Internet CWNA Guide to Wireless LANs, Second Edit Wireless Local Area Networks (continued) Figure 1-3: Wireless LAN CWNA Guide to Wireless. .. 1-10: RFID tag CWNA Guide to Wireless LANs, Second Edit 20 Wireless Technology Categories Table 1-1: Typical wireless technologies CWNA Guide to Wireless LANs, Second Edit 21 Wireless LAN Applications:... necessary CWNA Guide to Wireless LANs, Second Edit 22 Wireless LAN Applications: Education (continued) Figure 1-11: Campus access point locations CWNA Guide to Wireless LANs, Second Edit 23 Wireless