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 Edition

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 Edition

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 Edition

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 high-speed fiber optic transmissions CWNA Guide to Wireless LANs, Second Edition

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 Edition

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 if anywhere within range of transmitted radio signal Depending on device CWNA Guide to Wireless LANs, Second Edition

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 Edition

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 Edition

Wireless Local Area Networks (continued) Figure 1-3: Wireless LAN CWNA Guide to Wireless LANs, Second Edition

Wireless Local Area Networks (continued) Figure 1-4: Home wireless LAN CWNA Guide to Wireless LANs, Second Edition

What is a wireless LAN? Wireless LAN (WLAN) - provides all the features and benefits of traditional LAN technologies such as Ethernet and Token Ring, but without the limitations of wires or cables. CWNA Guide to Wireless LANs, Second Edition

http://earlyradiohistory.us/1920au.htm What is a wireless LAN? WLAN, like a LAN, requires a physical medium to transmit signals. Instead of using UTP, WLANs use: Infrared light (IR) 802.11 does include an IR specification limitations, easily blocked, no real 802.11 products (IrDA) Radio frequencies (RFs) Can penetrate ‘most’ office obstructions CWNA Guide to Wireless LANs, Second Edition

What is a wireless LAN? More later! WLANs use the 2.4 GHz and 5-GHz frequency bands. ISM (Industry, Scientific, Medical) license-free (unlicensed) frequency bands. S-Band ISM 802.11b and 802.11g: 2.4- 2.5 GHz C-Band ISM 802.11a: 5.725 – 5.875 GHz CWNA Guide to Wireless LANs, Second Edition

Icons – Wireless Devices and Functions CWNA Guide to Wireless LANs, Second Edition

Icons - Buildings CWNA Guide to Wireless LANs, Second Edition

Icons – Typical Wired Network Devices CWNA Guide to Wireless LANs, Second Edition

Icons – Wireless LAN Antenna CWNA Guide to Wireless LANs, Second Edition

IEEE 802.11 and the Wi-Fi Alliance IEEE LAN/MAN Standards Committee (LMSC) First 802.11 standard released in 1997, several since then Wireless Ethernet Compatibility Alliance (WECA) Advertises its Wi-Fi (wireless fidelity) program Any 802.11 vendor can have its products tested for interoperability Cisco is a founding member CWNA Guide to Wireless LANs, Second Edition

Wi-Fi™ Wi-Fi™ Alliance Wi-Fi’s™ Mission WECA changed its name to Wi-Fi Wireless Fidelity Alliance 170+ members Over 350 products certified Wi-Fi’s™ Mission Certify interoperability of WLAN products (802.11) Wi-Fi™ is the “stamp of approval” Promote Wi-Fi™ as the global standard CWNA Guide to Wireless LANs, Second Edition

Other Wireless Technologies Not discussed in this course: Cellular Bluetooth or PAN (Personal Area Network) 3G (3rd Generation) UWB (Ultra Wide Band) FSO (Free Space Optics) Radio waves off meteor trails! CWNA Guide to Wireless LANs, Second Edition

Why Wireless? CWNA Guide to Wireless LANs, Second Edition

WLAN Evolution Warehousing Retail Healthcare Education Businesses Home Radio Network Speed 860 Kbps 900 MHz 1 and 2 Mbps 2.4 GHz Proprietary 1 and 2 Mbps 11 Mbps 54 Mbps Standards-based 2.4 GHz 5 GHz IEEE 802.11Begins Drafting 802.11 Ratified 802.11a,b Ratified 802.11g Drafted 1986 1988 1990 1992 1994 1996 1998 2000 2002

Current Standards – a, b, g Radio Network Speed 860 Kbps 900 MHz 1 and 2 Mbps 2.4 GHz Proprietary 1 and 2 Mbps 11 Mbps 54 Mbps Standards-based 2.4 GHz 5 GHz IEEE 802.11Begins Drafting 802.11 Ratified 802.11a,b Ratified 802.11g Ratified 1986 1988 1990 1992 1994 1996 1998 2000 2003 802.11a Up to 54 Mbps 5 GHz Not compatible with either 802.11b or 802.11g 802.11b Up to 11 Mbps 2.4 GHz 802.11g 802.11g is backwards compatible with 802.11b, but with a drawback (later) CWNA Guide to Wireless LANs, Second Edition

802.11 PHY (Physical Layer) Technologies Radio Network Speed 860 Kbps 900 MHz 1 and 2 Mbps 2.4 GHz Proprietary 1 and 2 Mbps 11 Mbps 54 Mbps Standards-based 2.4 GHz 5 GHz IEEE 802.11Begins Drafting 802.11 Ratified 802.11a,b Ratified 802.11g Ratified 1986 1988 1990 1992 1994 1996 1998 2000 2003 Infrared light Three types of radio transmission within the unlicensed 2.4-GHz frequency bands: Frequency hopping spread spectrum (FHSS) 802.11b (not used) Direct sequence spread spectrum (DSSS) 802.11b Orthogonal frequency-division multiplexing (OFDM) 802.11g One type of radio transmission within the unlicensed 5-GHz frequency bands: Orthogonal frequency-division multiplexing (OFDM) 802.11a CWNA Guide to Wireless LANs, Second Edition

Major Factors There are four major factors to consider before implementing a wireless network: High availability Scalability Manageability Open architecture CWNA Guide to Wireless LANs, Second Edition

Atmosphere: the wireless medium Wireless signals are electromagnetic waves No physical medium is necessary The ability of radio waves to pass through walls and cover great distances makes wireless a versatile way to build a network. CWNA Guide to Wireless LANs, Second Edition

Electromagnetic Spectrum The Electromagnetic Spectrum Chart The waves differ only in their frequency. All of these waves share some very important characteristics. Travel at the speed of light Obey the equation (frequency) x (wavelength) = c (speed of light). Very different interactions with various materials. Low frequency electromagnetic waves have a long wavelength, while high frequency electromagnetic waves have a short wavelength. Wavelength represents the distance from one peak to the next on the sine wave. CWNA Guide to Wireless LANs, Second Edition

The Electromagnetic Wave Equation CWNA Guide to Wireless LANs, Second Edition

The size of a bit “Speed of the link” or “Speed of the network” Sometimes we forget that the speed of the data always travels near the speed of light: 180,000 miles/second or 300,000 meters/second What changes is the length of the bit. Using the formula: speed of light = frequency x wavelength 1 bps = CWNA Guide to Wireless LANs, Second Edition

Distance versus Speed WLANs are only one usage of the radio frequency (RF) spectrum. CWNA Guide to Wireless LANs, Second Edition

Bluetooth Low-power wireless data and voice transmission technology Bluetooth devices communicate via radio modules Link manager: Software that helps identify other Bluetooth devices, creates links between devices, and sends and receives data Transmit data at up to 1 Mbps over 10 meters Bluetooth devices within range of each other automatically connect Master and slave CWNA Guide to Wireless LANs, Second Edition

Bluetooth (continued) Piconet: Bluetooth network containing a master and at least one slave Figure 1-5: Bluetooth device CWNA Guide to Wireless LANs, Second Edition

Bluetooth Uses devices with small radio transceivers, called radio modules, built onto microprocessor chips Special software, called a link manager, identifies other Bluetooth devices, creates links with them, and sends and receives data Transmits at up to 1 Mbps over a distance of 33 feet and is not impeded by physical barriers Bluetooth products created by over 1500 computer, telephone, and peripheral vendors CWNA Guide to Wireless LANs, Second Edition

Bluetooth Headset The Bluetooth headset automatically establishes a connection with the telephone CWNA Guide to Wireless LANs, Second Edition

Piconet Two or more Bluetooth devices that send and receive data make up a personal area network (PAN), also called a piconet Figure 1-3 shows a Bluetooth network Bluetooth was named after the 10th century Danish King Harold Bluetooth, who was responsible for unifying Scandinavia CWNA Guide to Wireless LANs, Second Edition

Bluetooth Network CWNA Guide to Wireless LANs, Second Edition

Telecommunications Links Integrated Services Digital Networks (ISDN): Transmits at 256 Kbps T-1 lines: Transmit at 1.544 Mbps Cable modems: Use television cable connection Digital subscriber lines (DSL): Use telephone lines WiMax: Signal transmitted between antennas Up to 75 Mbps and over up to 35 miles Fixed Broadband CWNA Guide to Wireless LANs, Second Edition

Telecommunications Links (continued) FSO: Transmit at speeds up to 1.25 Gbps over up to 4 miles Line-of-site transmission Figure 1-6: Free space optics transceiver CWNA Guide to Wireless LANs, Second Edition

Telecommunications Links (continued) Figure 1-7: Wireless office technologies CWNA Guide to Wireless LANs, Second Edition

2G Digital Cellular Personal Digital Assistant (PDA) Hand-held device May include a barcode scanner and keyboard, as shown in Figure 1-6 Data may be transmitted to a terminal using wireless digital cellular technology CWNA Guide to Wireless LANs, Second Edition

Three Standards The second generation (2G) standard sends data at rates up to 14 thousand bits per second (kilobits per second or Kbps) In the future, the third generation (3G) technology may transmit up to 2 Mbps using a universal standard An interim technology known as 2.5 G offers a bandwidth of up to 384 Kbps CWNA Guide to Wireless LANs, Second Edition

Digital Cellular Network CWNA Guide to Wireless LANs, Second Edition

Cellular Telephony Global Systems for Mobile (GSM) communications technology: Coverage includes most of US and parts of Europe and Japan Transmission speeds up to 9.6 Kbps Information transmitted based on Wireless Application Protocol (WAP) Standard way to transmit, format, and display data for devices like cell phones and handheld devices CWNA Guide to Wireless LANs, Second Edition

Cellular Telephony (continued) Figure 1-8: Browsing the World Wide Web CWNA Guide to Wireless LANs, Second Edition

Cellular Telephony (continued) WAP cell phone runs a microbrowser that uses Wireless Markup Language (WML) instead of HTML WAP gateway or proxy: Translates between WML and HTML Figure 1-9: WAP communications CWNA Guide to Wireless LANs, Second Edition

Radio Frequency Identification (RFID) Like an electronic barcode: Can contain larger amounts of updatable information Information transmitted via radio waves Range typically about 1 foot at 5 Mbps Figure 1-10: RFID tag CWNA Guide to Wireless LANs, Second Edition

Fixed Broadband Wireless and Other Alternatives Integrated Service Digital Networks (ISDN)—consist of leased lines that transmit at 256 Kbps Expensive T-1 lines—transmit at 1.544 Mbps Cable modems—use television cable connections Digital subscriber lines (DSL)—have limited availability Fixed broadband wireless—a faster less expensive choice CWNA Guide to Wireless LANs, Second Edition

Fixed Broadband Wireless Fixed broadband transmits as far as 35 miles at speeds up to 1 billion bits per second (gigabits or Gbps) for downloads and 512 Kbps for uploads Uses small custom antenna on roof of each connected building Figure 1-11 shows fixed broadband wireless network CWNA Guide to Wireless LANs, Second Edition

Fixed Broadband Wireless Network CWNA Guide to Wireless LANs, Second Edition

Satellite Transmits data to/from satellite circling the earth A repeater in the satellite simply “repeats” the signal to another location Earth station transmits at one frequency and receives the signal at another frequency Transmission time from one earth station to another is approximately 250 milliseconds See Figure 1-4 CWNA Guide to Wireless LANs, Second Edition

Satellite Frequency Transmission CWNA Guide to Wireless LANs, Second Edition

A Satellite Network CWNA Guide to Wireless LANs, Second Edition

Wireless Technology Categories Table 1-1: Typical wireless technologies CWNA Guide to Wireless LANs, Second Edition

Wireless LAN Applications: Education Educational institutions some of first adopters of WLANs Dramatic advantages in teaching and learning Wireless LAN connections offer students important degree of freedom WLAN technology translates into cost savings for colleges Reduces need for wiring and infrastructure Fewer computer labs necessary CWNA Guide to Wireless LANs, Second Edition

Wireless LAN Applications: Education (continued) Figure 1-11: Campus access point locations CWNA Guide to Wireless LANs, Second Edition

Wireless LAN Applications: Business Wireless LAN technologies have significantly changed how business conducted Meetings not confined to conference rooms Easier to connect to network resources and Internet Can create office in space where traditional infrastructure does not exist CWNA Guide to Wireless LANs, Second Edition

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 Edition

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 Edition

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 Edition

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 Edition

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 Edition

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 Edition

Wireless LAN Applications: Healthcare (continued) Figure 1-12: Video pill CWNA Guide to Wireless LANs, Second Edition

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 Edition

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 Edition

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 Edition

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 Edition

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 Edition

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 Edition

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 Edition

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 Edition