CSN405 Handout 1_pdf.pdf

Handout 1 Overview of Wireless Standards, Organizations, and Fundamentals Course Name: Wireless Networks Course Code: CSN 405 Notes appended and modified to those accompanying “CWNA Certified Wireless Network Administrator: Official Study Guide”, D. Coleman & D. Westcott, John Wiley & Sons - Sybex,...

Handout 1 Overview of Wireless Standards, Organizations, and Fundamentals Course Name: Wireless Networks Course Code: CSN 405 Notes appended and modified to those accompanying “CWNA Certified Wireless Network Administrator: Official Study Guide”, D. Coleman & D. Westcott, John Wiley & Sons - Sybex, 6th Ed., 2021, Ch. 1 Overview of Wireless Standards and Organizations • • • • • • • • • • History of WLAN FCC ITU-R IEEE IETF Wi-Fi Alliance ISO 802.11 Networking Basics Core, Distribution, and Access Communications Fundamentals 2 History of WLAN  In the 19th century, numerous inventors and scientists, including Michael Faraday, James Clerk Maxwell, Heinrich Rudolf Hertz, Nikola Tesla, David Edward Hughes, Thomas Edison, and Guglielmo Marconi, began to experiment with wireless communications.  These innovators discovered and created many theories about the concepts of electrical magnetic radio frequency (RF). 3 History of WLAN  Wireless networking technology was first used by the US military during World War II to transmit data over an RF medium using classified encryption technology to send battle plans across enemy lines.  The spread spectrum radio technologies often used in today’s WLANs were also originally patented during the era of World War II. 4 History of WLAN  In 1970, the University of Hawaii developed the first wireless network, called ALOHAnet, to wirelessly communicate data between the Hawaiian Islands.  The network used a LAN communication Open Systems Interconnection (OSI) layer 2 protocol called ALOHA on a wireless shared medium in the 400 MHz frequency range. 5 History of WLAN  The technology used in ALOHAnet is often credited as a building block for the Medium Access Control (MAC) technologies of Carrier Sense Multiple Access with Collision Detection (CSMA/ CD) used in Ethernet.  Similar technology called Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) is used in 802.11 radios. 6 History of WLAN • In the 1990s, commercial networking vendors began to produce low-speed wireless data networking products, most of which operated in the 900 MHz frequency band. • The Institute of Electrical and Electronics Engineers (IEEE) began to discuss standardizing WLAN technologies in 1991. 7 History of WLAN • In 1997, the IEEE ratified the original 802.11 standard that is the foundation of the WLAN technologies you are familiar with. • However, other IEEE WLAN technologies also exist. 8 What Does Wi-Fi Mean? • Many people mistakenly assume that Wi-Fi is an acronym for the phrase wireless fidelity (much like hi-fi is short for high fidelity), but Wi-Fi is simply a brand name used to market 802.11 WLAN technology. • Information about the origin of the name can be found at: Wi-Fi Planet 9 FCC • To put it simply, the Federal Communications Commission (FCC) regulates communications within the United States as well as communications to and from the United States. • Established by the Communications Act of 1934, the FCC is responsible for regulating interstate and international communications by radio, television, wire, satellite, and cable. 10 FCC • The FCC and the respective controlling agencies in other countries typically regulate two categories of wireless communications: – licensed spectrum – unlicensed spectrum • The difference is that unlicensed users do not have to go through the license application procedure before they can install a wireless system. 11 FCC Both licensed and unlicensed communications are typically regulated in the following six areas: • • • • Frequency Bandwidth Maximum of the intentional radiator (IR) Maximum equivalent isotopically radiated power (EIRP) • Use (indoor and/or outdoor) • Spectrum sharing rules 12 ITU-R • A global hierarchy exists for management of the RF spectrum worldwide. • The United Nations has tasked the International Telecommunication Union Radiocommunication Sector (ITU-R) with global spectrum management. Link to ITU-R • The ITU-R strives to ensure interference-free communications on land, sea, and in the skies. 13 ITU-R • Inter-American Telecommunication Commission (CITEL) • Link to CITEL 14 ITU-R • European Conference of Postal and Telecommunications Administrations (CEPT) • Link to CEPT 15 ITU-R • Regional Commonwealth in the Field of Communications (RCC) • Link to RCC 16 ITU-R • African Telecommunications Union (ATU) • Link to ATU 17 ITU-R • Asia-Pacific Telecommunity • Link to APT 18 ITU-R • Arab Telecommunications and Information Council of Ministers/League of Arab States (ATICM) • Link to Arab League Online 19 IEEE • The Institute of Electrical and Electronics Engineers (IEEE) is a global professional society with more than 400,000 members. • The IEEE’s mission is to “foster technological innovation and excellence for the benefit of humanity.” To networking professionals, that means creating the standards that we use to communicate. 20 IEEE - 802.11 WLAN Standard  The most recent published version of the WLAN standard, 802.11-2020  The 802.11-2020 standard can be downloaded from: IEEE Standards Association  Clause 9 defines 802.11 frame format  Clause 10 defines MAC sublayer operations 21 IEEE - 802.3 Ethernet 22 IEEE - 802.3 Power over Ethernet (PoE) • 802.3af • 802.3at (PoE+) • 802 .3bt 23 IEEE – 802.1X • IEEE maintains the 802.1X standard for Port Based Network Access Control • The 802.1X standard can be downloaded from: IEEE Standards Association EAP EAP Root CA cert Server cert CLIENT • LDAP: Lightweight Directory Access Protocol • RADIUS: Remote Authentication Dial-In User Service • EAP: Extensible Authentication Protocol AP RADIUS LDAP 24 IEEE Standards Nomenclatures • Big X, not little x • UPPERCASE = standard 802.1X 802.1x • lowercase = amendment 25 IETF • The Internet Engineering Task Force (IETF) is an international community of people in the networking industry whose goal is to make the Internet work better. • The mission of the IETF is “to produce high quality, relevant technical and engineering documents that influence the way people design, use, and manage the Internet in such a way as to make the Internet work better. “ 26 IETF • The IETF creates and maintains standards (RFCs) that specify the implementation of a network-based technology. • Examples: – Generic EAP (Extensible Authentication Protocol) framework (RFC 3748) – Specific EAP implementation such as EAP-TLS (RFC 5216) – RADIUS (RFC 2865) 27 Wi-Fi Alliance • The Wi-Fi Alliance is a global, nonprofit industry association of about 600 member companies devoted to promoting the growth of WLANs. • One of the primary tasks of the Wi-Fi Alliance is to market the Wi-Fi brand and raise consumer awareness of new 802.11 technologies as they become available. 28 Wi-Fi Alliance • The Wi-Fi Alliance’s main task is to ensure the interoperability of WLAN products by providing certification testing. • Products that pass the Wi-Fi certification process receive a Wi-Fi Interoperability Certificate that provides detailed information about the individual product’s Wi-Fi certifications. 29 Generations of Wi-Fi 802.11n 802.11ac 2009 2013 802.11ax 2019 30 ISO 7 Application 6 Presentation • The International Organization for Standardization, or ISO, is a global, nongovernmental organization that identifies business, government, and society needs. 5 Session 4 Transport 3 Network 2 Data Link 1 Physical • The ISO develops standards in partnership with the sectors that will put them to use. • The ISO is responsible for the creation of the Open Systems Interconnection (OSI) model, which has been a standard reference for data communications between computers since the late 1970s. 31 OSI Model 7 Application 6 Presentation 5 Session • Networking 101 • Always remember that Wi-Fi operates at Layer 1 and the MAC sublayer at Layer 2. 4 Transport 3 Network 2 Data Link 802.11 MAC operations 1 Physical Radio Frequency 32 OSI Model 7 Application 6 Presentation RADIUS, Active Directory, DNS, DHCP, NTP, and user applications 5 Session 4 Transport IP address, routing, ports firewalls 3 Network 2 Data Link 1 Physical Wi-Fi: RF and configuration, drivers, WLAN security sessions, WLAN design, VLANs, etc. 33 Core, Distribution, and Access 34 Core, Distribution, and Access • Wi-Fi is typically an access layer networking technology. Root bridge Non-root bridge • An 802.11 bridge link is an example of wireless technology being used at the distribution layer. 35 RF Is Half-Duplex • Simplex: One device is capable of only transmitting, and the other device is capable of only receiving - FM radio is an example of simplex communications. Wi-Fi is half-duplex • Half Duplex: Both devices are capable of transmitting and receiving; however, only one device can transmit at a time. • Full Duplex: Both devices are capable of transmitting and receiving at the same time. 36 OSI Model and 802.11 Phy Certified Wireless Network Administrator: CWNA – PW0-108 The IEEE 802.11-2012 standard defines mechanisms only at the Physical layer and MAC sublayer of the Data-Link layer 37 Core, Distribution, and Access • Core – High-speed backbone – Performs high-speed switching • Distribution – Routes traffic between VLANs and subnets – Wireless bridging between buildings • Access – Delivery of traffic to end user – Typically where 802.11 operates Certified Wireless Network Administrator: CWNA – PW0-108 38 Communications Fundamentals • • • • • • Amplitude Wavelength Frequency Phase Carrier Signals Keying Methods – Amplitude Shift Keying (ASK) – Frequency Shift Keying (FSK) – Phase Shift Keying (PSK) Certified Wireless Network Administrator: CWNA – PW0-108 39 Amplitude and Wavelength • • Wavelength is the distance between similar points on back-to-back waves Typically measured from peak to peak Amplitude is the height, force, or power of the wave Certified Wireless Network Administrator: CWNA – PW0-108 40 Frequency • • • • • Number of waves generated per second One wave = one oscillation Measured in hertz (Hz) Hertz = one oscillation per second 2.4 GHz = 2.4 billion oscillations per second Certified Wireless Network Administrator: CWNA – PW0-108 41 Phase • Relationship between two waves with the same frequency • Measured in degrees • One wavelength = 360 degrees These waves are 90 degrees out of phase Certified Wireless Network Administrator: CWNA – PW0-108 42 Carrier Signal • Data consists of 0 and 1 bits • RF signal can represent data by fluctuating or altering its RF properties • Properties that can be altered – Amplitude – Frequency – Phase Certified Wireless Network Administrator: CWNA – PW0-108 43 Keying Methods • Method of manipulating a signal to represent multiple pieces of data • Three types of keying methods – Amplitude-shift keying (ASK) – Frequency-shift keying (FSK) – Phase-shift keying (PSK) • Two techniques used to represent data – Current state – State transition Certified Wireless Network Administrator: CWNA – PW0-108 44 Keying Techniques • Current State – Current value of the signal is used to distinguish between 0s and 1s – Current value or level at a specific time • State Transition – A change or transition of the signal is used to distinguish between 0s and 1s – Presence of a change or lack of presence of a change determines 0 or 1 Certified Wireless Network Administrator: CWNA – PW0-108 45 Amplitude-Shift Keying (ASK) • Amplitude or height of a signal represents the binary data • Current state technique • One level represents 0 • Different level represents 1 An example of ASK (ASCII code of an upper-case K) Certified Wireless Network Administrator: CWNA – PW0-108 46 Frequency-Shift Keying (FSK) • Frequency of the wave is varied to represent the binary data • Current state technique • One frequency represents 0 • Different frequency represents 1 An example of FSK (ASCII code of an upper-case K) Certified Wireless Network Administrator: CWNA – PW0-108 47 Phase-Shift Keying (PSK) • Phase of the wave is varied to represent the binary data • State transition technique • Change of phase represents 0 or 1 • Lack of phase change represents 1 or 0 An example of PSK (ASCII code of an upper-case K) Certified Wireless Network Administrator: CWNA – PW0-108 48 Multiple Phase-Shift Keying (PSK) • Can encode multiple bits per symbol • Uses four phases, each of which is capable of representing two binary values (00, 01, 10, or 11 Certified Wireless Network Administrator: CWNA – PW0-108 49 Questions Home Work 1. Open your book and go through all the review questions at the end of the chapter. 2. Review the answers by using Appendix A. 50