DOCSLIB.ORG

Medium Access Control (MAC)

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Medium Access Control (MAC) 1 Medium Access Control 2 Medium Access Control (1) The Network H2 H4 H1 H3 Broadcast networks have possibility of multiple access (MA) to a channel medium access control describes how we resolve the conflict assume only one channel available for communication additional channels would also be the subject of MAC 3 Medium Access Control (2) The Network H2 H4 H1 H3 4 Medium Access Control (3) The Network H2 H4 H1 H3 5 Medium Access Control (4) The Network H2 H4 H1 H3 assume when two frames overlaps at the Rx then both are lost, and thus both must be retransmitted assumption always be true in LANs in broadcast WANs might not be true 6 ALOHA protocol You can do nothing for MAC . The Network The Network The Network The Network H2 H4 H2 H4 H2 H4 H2 H4 H1 H3 H1 H3 H1 H3 H1 H3 ALOHA is contention based: a host may broadcast whenever necessary higher layers spot errors caused by collisions, and do retransmission 7 Performance of ALOHA H n vulnerable period for -1 start (λt) −λt Pn(t)= e t1 + t2 n! H1 To find p from Poisson Equation - t set t = 2T, λ = µG, n = 0: t2 -1 0 (µ 2T ) − H2 p = G e µG2T t1 + t2 - 0! −µG2T vulnerable period for H2 start p = e µ − S = e µG2T Let t1 = t2 = T µG µS successfully sent per second −µG2T µS = µGe µG sent (including failures) per second p is probability frame has no collisions µST frames are delivered in T µ seconds p = S µG −µG2T ρ = µST = µGe T 8 Is ALOHA good? ρ 6 0.4 0.3 0.2 0.1 0.0 - 0.0 0.5 1.0 1.5 2.0 2.5 3.0 µGT load of 50% gives maximum efficiency of 18% not a very satisfactory performance no way of assuring that even this maximum efficiency is reached 9 Improving basic ALOHA 1. slotted transmission: there are certain specific times when a host may broadcast. 2. carrier sensing: a broadcast is allowed only when the channel is idle. 3. token passing: a host may only broadcast when it holds some sort of token permitting it to do so. 4. distributed queueing: the hosts collaborate to form a queue of hosts ready to send data. 10 Slotted ALOHA n (λt) −λt vulnerable period for H1 start P (t)= e - n n! To find p from Poisson Equation H1 set t = T, λ = µG, n = 0: - t 0 (µ T ) − p = G e µGT H2 0! − - p = e µGT vulnerable period for H2 start µ − S = e µGT µG µS successfully sent per second − µ = µ e µGT µG sent (including failures) per second S G p is probability frame has no collisions µST frames are delivered in T µ p = S seconds µG −µGT ρ = µST = µGe T 11 Is Slotted ALOHA good? ρ 6 0.4 0.3 0.2 0.1 0.0 - 0.0 0.5 1.0 1.5 2.0 2.5 3.0 µGT now load of 100% loading gives maximum efficiency of 36% still not a very satisfactory performance small basic problems as ALOHA 12 Carrier Sensing The Network The Network The Network H2 H4 H2 H4 H2 H4 H1 H3 H1 H3 H1 H3 carrier sensing involves TI - checking that channel is idle H2 before transmission called CSMA U H1 probability TI of avoiding - TI +TP - TCS a collision TP 13 Collision Detection H3 causes collision H2 causes collision H1 H2 H3 H3 H2 H1 - - - - - transmission contention transmission idle transmission host senses the medium to know that its frame is OK transmission stopped as soon as collision occurs → collision detection (CD) MAC protocol called CSMA/CD host must transmit for long enough so as to know frame is OK thus minimum frame length is 2η where η is end-to-end transmission time 14 Worksheet: CSMA/CD A bus based network is being built using CSMA/CD for MAC, a cabling system with signal propagation speeds of 200 × 106ms−1, and a bit rate 1Mbs−1. 1. If two hosts H1, H2 are separated by 2,000m, how long does it take for a signal to travel between them? 2. If H1 has started to broadcast, and H2 starts to broadcast just before the signal from H1 arrives at H2, what will happen? 3. How long, from the time H1 starts transmitting, will it take H1 to find out about the event in question 2? 4. How many bits would be sent in that time? 5. If the data rate were increased to 10Mbs−1, how many bits would have been sent? 15 Length of bus network using CSMA/CD A bus-based network transmits 64 bit frames at 10 Mbs−1, propagation speed c = 200 × 106ms−1 What is the maximum end-to-end length l on the bus? l We know that the end-to-end propagation delay η = 200×106 64 −6 Also, the time to transmit a frame t = 10×106 = 6.4 × 10 Since the time to transmit a frame must be greater than 2η, we have: − 2l 6.4 × 10 6 > 200 × 106 l < 640m 16 Persistence Used slot N N + 1 N + 2 N + 3 1-persistent 1 0 0 p-persistent p (1 − p)p (1 − p)(1 − p)p non-persistent p p p once idle, it broadcasts with probability p → p-persistent CSMA if p = 1 → simply waiting for the channel to be free before broadcasting if p< 1 then wait with probability 1 − p for one frame, before broadcasting with probability p 17 Binary Exponential Back-off The basis of the MAC in Ethernet is 1-persistent CSMA/CD to avoid the poor performance of this protocol when network loads are high, a variation called binary exponential back-off is introduced. minimum frame length is treated as the slot length when the net is idle, a host may attempt to broadcast if a collision occurs, wait either 0 or 1 slots before attempting to broadcast again if another collision occurs waits 0, 1, 2 or 3 slots after c collisions we choose a slot in the range 0 to 2c − 1 for the next attempt upper limit of 1023 is placed on what this range 18 Binary Exponential Back-off (Light Load) Slot Slot Slot Slot 0 1 0 1 0 1 0 1 H2 H2 H2 H2 H1 H1 H1 H1 chances of collisions occurring are slight during transmission only a few hosts waiting to transmit probably only have a few hosts in contention 19 Binary Exponential Back-off (Heavy Load) Slot Slot Slot Slot Slot Slot Slot 0 1 0 1 0 1 0 1 0 1 0 1 0 1 H5 H5 H5 H5 H5 H5 H5 H4 H4 H4 H4 H4 H4 H4 H3 H3 H3 H3 H3 H3 H3 H2 H2 H2 H2 H2 H2 H2 H1 H1 H1 H1 H1 H1 H1 at any one time a number of hosts are likely to be in contention waiting only a few slots would mean a repeat collision is very likely binary exponential back-off algorithm to quickly adapts 20 Problems with CSMA/CD No notion of authority to broadcast collisions are inevitable in the worst case, a particular host may be delayed indefinitely Acceptable for many applications, such as office information systems Unacceptable for real time systems used in applications such as CAM time that a host waits must have a fixed upper bound. bandwidth available to each host must have a fixed lower bound. 21 Token Passing H2 H3 direction logical 6 node outside of ring of H4 logical ring token hosts token H1 H5 Hosts must posses a token in order to broadcast token passed from one host to another host has nothing to send → pass token on immediately host has something to send → sets a timer, and transmits until the timer expires or, it has no more data to send 22 Token Passing Performance No losses due to collisions, and therefore most of bandwidth available for data. η is the average delay between hosts B bits per second network timeout at each host is T The maximum frame size f obeys f = TB The maximum delay d given by d = N (η + T ) 23 IEEE 802 standard for LANs OSI IEEE Network Layer OSI Network Layer 802.2 LLC Sub-layer Data Link Layer 802.1D Bridging Sub-layer 802.3 802.4 802.17 MAC MAC MAC Sub-layer Sub-layer . Sub-layer Physical 802.3 802.4 802.17 Layer Physical Physical Physical Layer Layer Layer 802 standard sets out a framework: logical link control (LLC) sub-layer performs ARQ (802.2) Bridging might be present to link LANs (802.1D) 24 IEEE MAC Addressing byte0 byte1 byte2 byte3 byte4 byte5 I/ U/ local local local OUID OUID OUID G L id id id Each NIC card conforming to IEEE Standards will have 48 bit number written as six colon separated bytes in hex hbytei:hbytei:hbytei:hbytei:hbytei:hbytei I/G bit decides if individual or group address U/L bit decides if universally or locally administered host 00:90:27:A3:32:05 individual globally unique broadcast address FF:FF:FF:FF:FF:FF group locally unique allows for 7 × 1013 hosts 25 IEEE LAN standards Number Common Name Area MAC Topology 802.3 Ethernet LAN 1-persistent CSMA/CD Bus/Tree 802.4 Token Bus LAN Token Passing Bus/Tree 802.5 Token Ring LAN Token Passing Ring 802.6 DQDB MAN Distributed Queue Bus 802.9 isoEthernet LAN Ethernet + ISDN Star/mesh 802.11 WiFi LAN CSMA/CA Cellular 802.12 100BaseVG LAN Handshaking from hub Star/tree 802.15 Bluetooth PAN Adaptive FHSS Cellular 802.16 WiMAX MAN Connection oriented Cellular 802.17 Resilient Packet Ring LAN to WAN Distributed Queue Ring 26 802.3 Ethernet The IEEE 802.3 works over various cables and speeds Code Common Name Cable Len (m) Topology 1 10Base5 Thick Ethernet 2 inch coaxial cable 500 bus 10Base2 Thin Ethernet 75-ohm coaxial cable 180 bus 10BaseT Twisted Pair Ethernet Category 3 UTP 100 star 100Base-TX Fast Ethernet Category 5 UTP 100 star 100Base-FX Fast Ethernet Fibre optic 185 star 1000Base-T Gigabit Ethernet Category 6 UTP (4 pairs) 100 star 10GBase-T 10 Gigabit Ethernet Category 6a UTP (4 pairs) 100 star 10Mbs−1 standards have been in use for many years 100Mbs−1 common 1Gbs−1 common on new computers, hubs still a little expensive 27 10Mbs−1 Ethernet Thick Ethernet: provides longest lengths hosts are attached via transceivers length of drops from the main cable must not exceed 50m.
Load more

Recommended publications
  • 1) What Is the Name of an Ethernet Cable That Contains Two
    1) What is the name of an Ethernet cable that contains two electrical conductors ? A coaxial cable 2) What are the names of the two common conditions that degrade the signals on c opper-based cables? Crosstal and attenuation 3) Which topology requires the use of terminators? Bus 4) Which of the following topologies is implemented only logically, not physical ly? Ring 5) How many wire pairs are actually used on a typical UTP Ethernet network? Two 6) What is the name of the process of building a frame around network layer info rmation? Data encapsulation 7) Which of the connectors on a network interface adapter transmits data in para llel? The System bus connector 8) Which two of the following hardware resources do network interface adapters a lways require? I/O port address and IRQ 9) What is the name of the process by which a network interface adapter determin es when it should transmit its data over the network? Media Access Control 10) Which bus type is preferred for a NIC that will be connected to a Fast Ether net network? PCI 11) A passive hub does not do which of the following? Transmit management information using SNMP 12) To connect two Ethernet hubs together, you must do which of the following? Connect the uplink port in one hub to a standard port on the other 13) Which term describes a port in a Token Ring MAU that is not part of the ring ? Intelligent 14) A hub that functions as a repeater inhibits the effect of____________? Attenuation 15) You can use which of the following to connect two Ethernet computers togethe r using UTP
    [Show full text]
  • Instituto Politécnico Nacional Escuela Superior De Ingeniería Mecánica Y Eléctrica Ingeniería En Comunicaciones Y Electrónica
    INSTITUTO POLITÉCNICO NACIONAL ESCUELA SUPERIOR DE INGENIERÍA MECÁNICA Y ELÉCTRICA INGENIERÍA EN COMUNICACIONES Y ELECTRÓNICA INSTITUTO POLITÉCNICO NACIONAL ESCUELA SUPERIOR DE INGENIERÍA MECÁNICA Y ELECTRICA INGENIERÍA EN COMUNICACIONES Y ELECTRÓNICA Diseño de una RED FAST ETHERNET (IEEE 802.3) en el laboratorio 7 de la Academia de Computación de Ingeniería en Comunicaciones y Electrónica de la Escuela Superior de Ingeniería Mecánica y Eléctrica, Unidad Zacatenco del IPN. TESIS QUE PARA OBTENER EL TITULO DE: INGENIERO EN COMUNICACIONES Y ELECTRONICA PRESENTAN: OSCAR ARTURO GARCIA PÉREZ AL AN NERI N AR ANJO SÁNCHEZ GLORIA RIVERA OJEDA ASESOR: M. EN C. GENARO ZAVALA MEJÍA MEXICO, D.F. 2008 INSTITUTO POLITÉCNICO NACIONAL ESCUELA SUPERIOR DE INGENIERÍA MECÁNICA Y ELÉCTRICA INGENIERÍA EN COMUNICACIONES Y ELECTRÓNICA MEXICO, D.F. 2008 1 INSTITUTO POLITÉCNICO NACIONAL ESCUELA SUPERIOR DE INGENIERÍA MECÁNICA Y ELÉCTRICA INGENIERÍA EN COMUNICACIONES Y ELECTRÓNICA INSTITUTO POLITECNICO NACIONAL ESCUELA SUPERIOR DE INGENIERIA MECANICA Y ELECTRICA INGENIERIA EN COMUNICACIONES Y ELECTRONICA TESIS COLECTIVA CON OPCIÓN A TITULACION TEMA: Diseño de una RED FAST ETHERNET (IEEE 802.3) en el laboratorio 7 de la Academia de Computación de Ingeniería en Comunicaciones y Electrónica de la Escuela Superior de Ingeniería Mecánica y Eléctrica, Unidad Zacatenco del IPN. ASESORES: M. EN. C. GENARO ZAVALA MEJÍA INTEGRANTES: OSCAR ARTURO GARCIA PÉREZ. ALAN NERI NARANJO SÁNCHEZ. GLORIA RIVERA OJEDA. MEXICO, D.F. 2008 2 INSTITUTO POLITÉCNICO NACIONAL ESCUELA SUPERIOR DE INGENIERÍA MECÁNICA Y ELÉCTRICA INGENIERÍA EN COMUNICACIONES Y ELECTRÓNICA AGRADECIMIENTOS En testimonio de gratitud limitada para su apoyo, aliento y estímulo mismos que posibilitaron la conquista de esta meta, y sabiendo también que no existirá una forma de agradecer una vida de sacrificio y esfuerzo, quiero que sientan que el objetivo logrado también es de ustedes y que la fuerza que me ayudo a conseguirlo fue su apoyo.
    [Show full text]
  • The Essential Guide to Audio Over IP for Broadcasters 2 5
    The Essential Guide To Audio OverIP FOR BROADCASTERS Powerful Performance | Powerful Control | Powerful Savings i 1. Why IP for Broadcast Audio? Reasons to Migrate to Audio over IP ..........................................................................................................8 1. Flexibility ..................................................................................................................................................................................8 2. Cost ...........................................................................................................................................................................................8 3. Scalability ................................................................................................................................................................................9 4. Reliability (yes really!) .........................................................................................................................................................9 5. Availability ..............................................................................................................................................................................9 6. Control and Monitoring .....................................................................................................................................................9 7. Network Consolidation ......................................................................................................................................................9
    [Show full text]
  • C:\Andrzej\PDF\ABC Nagrywania P³yt CD\1 Strona.Cdr
    IDZ DO PRZYK£ADOWY ROZDZIA£ SPIS TREFCI Wielka encyklopedia komputerów KATALOG KSI¥¯EK Autor: Alan Freedman KATALOG ONLINE T³umaczenie: Micha³ Dadan, Pawe³ Gonera, Pawe³ Koronkiewicz, Rados³aw Meryk, Piotr Pilch ZAMÓW DRUKOWANY KATALOG ISBN: 83-7361-136-3 Tytu³ orygina³u: ComputerDesktop Encyclopedia Format: B5, stron: 1118 TWÓJ KOSZYK DODAJ DO KOSZYKA Wspó³czesna informatyka to nie tylko komputery i oprogramowanie. To setki technologii, narzêdzi i urz¹dzeñ umo¿liwiaj¹cych wykorzystywanie komputerów CENNIK I INFORMACJE w ró¿nych dziedzinach ¿ycia, jak: poligrafia, projektowanie, tworzenie aplikacji, sieci komputerowe, gry, kinowe efekty specjalne i wiele innych. Rozwój technologii ZAMÓW INFORMACJE komputerowych, trwaj¹cy stosunkowo krótko, wniós³ do naszego ¿ycia wiele nowych O NOWOFCIACH mo¿liwoYci. „Wielka encyklopedia komputerów” to kompletne kompendium wiedzy na temat ZAMÓW CENNIK wspó³czesnej informatyki. Jest lektur¹ obowi¹zkow¹ dla ka¿dego, kto chce rozumieæ dynamiczny rozwój elektroniki i technologii informatycznych. Opisuje wszystkie zagadnienia zwi¹zane ze wspó³czesn¹ informatyk¹; przedstawia zarówno jej historiê, CZYTELNIA jak i trendy rozwoju. Zawiera informacje o firmach, których produkty zrewolucjonizowa³y FRAGMENTY KSI¥¯EK ONLINE wspó³czesny Ywiat, oraz opisy technologii, sprzêtu i oprogramowania. Ka¿dy, niezale¿nie od stopnia zaawansowania swojej wiedzy, znajdzie w niej wyczerpuj¹ce wyjaYnienia interesuj¹cych go terminów z ró¿nych bran¿ dzisiejszej informatyki. • Komunikacja pomiêdzy systemami informatycznymi i sieci komputerowe • Grafika komputerowa i technologie multimedialne • Internet, WWW, poczta elektroniczna, grupy dyskusyjne • Komputery osobiste — PC i Macintosh • Komputery typu mainframe i stacje robocze • Tworzenie oprogramowania i systemów komputerowych • Poligrafia i reklama • Komputerowe wspomaganie projektowania • Wirusy komputerowe Wydawnictwo Helion JeYli szukasz ]ród³a informacji o technologiach informatycznych, chcesz poznaæ ul.
    [Show full text]
  • EDSA-401 ISA Security Compliance Institute – Embedded Device Security Assurance – Testing the Robustness of Implementations of Two Common “Ethernet” Protocols
    EDSA-401 ISA Security Compliance Institute – Embedded Device Security Assurance – Testing the robustness of implementations of two common “Ethernet” protocols Version 2.01 September 2010 Copyright © 2009-2010 ASCI – Automation Standards Compliance Institute, All rights reserved EDSA-401-2.01 A. DISCLAIMER ASCI and all related entities, including the International Society of Automation (collectively, “ASCI”)provide all materials, work products and, information (‘SPECIFICATION’) AS IS, WITHOUT WARRANTY AND WITH ALL FAULTS, and hereby disclaim all warranties and conditions, whether express, implied or statutory, including, but not limited to, any (if any) implied warranties, duties or conditions of merchantability, of fitness for a particular purpose, of reliability or availability, of accuracy or completeness of responses, of results, of workmanlike effort, of lack of viruses, and of lack of negligence, all with regard to the SPECIFICATION, and the provision of or failure to provide support or other services, information, software, and related content through the SPECIFICATION or otherwise arising out of the use of the SPECIFICATION. ALSO, THERE IS NO WARRANTY OR CONDITION OF TITLE, QUIET ENJOYMENT, QUIET POSSESSION, CORRESPONDENCE TO DESCRIPTION, OR NON- INFRINGEMENT WITH REGARD TO THE SPECIFICATION. WITHOUT LIMITING THE FOREGOING, ASCI DISCLAIMS ALL LIABILITY FOR HARM TO PERSONS OR PROPERTY, AND USERS OF THIS SPECIFICATION ASSUME ALL RISKS OF SUCH HARM. IN ISSUING AND MAKING THE SPECIFICATION AVAILABLE, ASCI IS NOT UNDERTAKING TO RENDER PROFESSIONAL OR OTHER SERVICES FOR OR ON BEHALF OF ANY PERSON OR ENTITY, NOR IS ASCI UNDERTAKING TO PERFORM ANY DUTY OWED BY ANY PERSON OR ENTITY TO SOMEONE ELSE. ANYONE USING THIS SPECIFICATION SHOULD RELY ON HIS OR HER OWN INDEPENDENT JUDGMENT OR, AS APPROPRIATE, SEEK THE ADVICE OF A COMPETENT PROFESSIONAL IN DETERMINING THE EXERCISE OF REASONABLE CARE IN ANY GIVEN CIRCUMSTANCES.
    [Show full text]
  • Modern Ethernet
    Color profile: Generic CMYK printer profile Composite Default screen All-In-One / Network+ Certification All-in-One Exam Guide / Meyers / 225345-2 / Chapter 6 CHAPTER Modern Ethernet 6 The Network+ Certification exam expects you to know how to • 1.2 Specify the main features of 802.2 (Logical Link Control) [and] 802.3 (Ethernet): speed, access method, topology, media • 1.3 Specify the characteristics (for example: speed, length, topology, and cable type) of the following cable standards: 10BaseT and 10BaseFL; 100BaseTX and 100BaseFX; 1000BaseTX, 1000BaseCX, 1000BaseSX, and 1000BaseLX; 10GBaseSR, 10GBaseLR, and 10GBaseER • 1.4 Recognize the following media connectors and describe their uses: RJ-11, RJ-45, F-type, ST,SC, IEEE 1394, LC, MTRJ • 1.6 Identify the purposes, features, and functions of the following network components: hubs, switches • 2.3 Identify the OSI layers at which the following network components operate: hubs, switches To achieve these goals, you must be able to • Define the characteristics, cabling, and connectors used in 10BaseT and 10BaseFL • Explain how to connect multiple Ethernet segments • Define the characteristics, cabling, and connectors used with 100Base and Gigabit Ethernet Historical/Conceptual The first generation of Ethernet network technologies enjoyed substantial adoption in the networking world, but their bus topology continued to be their Achilles’ heel—a sin- gle break anywhere on the bus completely shut down an entire network. In the mid- 1980s, IBM unveiled a competing network technology called Token Ring. You’ll get the complete discussion of Token Ring in the next chapter, but it’s enough for now to say that Token Ring used a physical star topology.
    [Show full text]
  • Ethernet Basics Ethernet Basics
    2016-09-24 Ethernet Basics based on Chapter 4 of CompTIA Network+ Exam Guide, 4th ed., Mike Meyers Ethernet Basics • History • Ethernet Frames • CSMA/CD • Obsolete versions • 10Mbps versions • Segments • Spanning Tree Protocol 1 2016-09-24 Ethernet – Early History • 1970: ALOHAnet, first wireless packet-switched network - Norman Abramson, Univ. of Hawaii - Basis for Ethernet’s CSMA/CD protocol - 1972: first external network connected to ARPANET • 1973: Ethernet prototype developed at Xerox PARC - (Palo Alto Research Center) - 2.94 Mbps initially • 1976: "Ethernet: Distributed Packet Switching for Local Computer Networks" published in Communications of the ACM. - Bob Metcalfe and David Boggs - sometimes considered “the beginning of Ethernet” Ethernet goes Mainstream • 1979: DEC, Intel, Xerox collaborate on a commercial Ethernet specification - Ethernet II, a.k.a. “DIX” Ethernet - (Digital Equipment Corporation) • 1983: IEEE 802.3 specification formally approved - Differs from Ethernet II in the interpretation of the third header field • 1987: alternatives to coaxial cables - IEEE 802.3d: FOIRL, Fiber Optic Inter-Repeater Link - IEEE 802.3e: 1 Mbps over Twisted Pair wires (whoopee!) • 1990: Twisted-Pair wiring takes over - IEEE 802.3i: 10 Mbps over Twisted-Pair – 10Base-TX, 10Base-T4 2 2016-09-24 the Future is Now (next chapter) (and Now is so Yesteryear…) 1995 – Now: speed and cabling improvements • 1995: 100Mbps varieties • 1999: 1Gbps on twisted-pair • 2003-2006: 10Gbps on optical fiber and UTP • 2010: 40Gbps, 100Gbps (802.3ba) - optical fiber or twinaxial cable - point-to-point physical topology; for backbones • 2016, September: 2.5GBase-T, 5GBase-T ? - who knows? What Is Ethernet? • Protocols, standards for Local Area Networks » Ethernet II, IEEE 802.3 • Specifies Physical-layer components - Cabling, signaling properties, etc.
    [Show full text]
  • Getting Physical with Ethernet
    ETHERNET GETTING PHYSICAL STANDARDS • The Importance of Standards • Standards are necessary in almost every business and public service entity. For example, before 1904, fire hose couplings in the United States were not standard, which meant a fire department in one community could not help in another community. The transmission of electric current was not standardized until the end of the nineteenth century, so customers had to choose between Thomas Edison’s direct current (DC) and George Westinghouse’s alternating current (AC). IEEE 802 STANDARD • IEEE 802 is a family of IEEE standards dealing with local area networks and metropolitan area networks. • More specifically, the IEEE 802 standards are restricted to networks carrying variable-size packets. By contrast, in cell relay networks data is transmitted in short, uniformly sized units called cells. Isochronous , where data is transmitted as a steady stream of octets, or groups of octets, at regular time intervals, are also out of the scope of this standard. The number 802 was simply the next free number IEEE could assign,[1] though “802” is sometimes associated with the date the first meeting was held — February 1980. • The IEEE 802 family of standards is maintained by the IEEE 802 LAN/MAN Standards Committee (LMSC). The most widely used standards are for the Ethernet family, Token Ring, Wireless LAN, Bridging and Virtual Bridged LANs. An individual working group provides the focus for each area. Name Description Note IEEE 802.1 Higher Layer LAN Protocols (Bridging) active IEEE 802.2
    [Show full text]
  • Body Area Network, Standardization, Analysis and Application
    Body Area Network, Standardization, Analysis and Application Olufemi Ekundayo Bachelor’s Thesis Degree Programme in Information Technology ___. ___. ______ ________________________________ Valitse kohde. SAVONIA-AMMATTIKORKEAKOULU OPINNÄYTETYÖ Tiivistelmä Koulutusala Tekniikan ja liikenteen ala Koulutusohjelma Degree Programme in Information Technology Työn tekijä(t) Ekunday Olufemi Adeola Työn nimi Body Area Networks; Standardization, Analysis and Application Päiväys 28 February 2013 Sivumäärä/Liitteet Ohjaaja(t) Mr. Arto Toppinen, Principal Lecturer Toimeksiantaja/Yhteistyökumppani(t) University of Eastern Finland Tiivistelmä WBAN (Wireless Body Area Network) on sisätiloissa tai ihmiskehon välittömässä läheisyydessä käytettävä lyhyen kantaman langaton tiedonsiirtotapa. Se soveltuu sekä lääketieteellisiin että ei-lääketieteellisiin so- velluksiin. Yleisimmin sitä käytetään lääketieteessä potilaan reaaliaikaisessa diagnosoinnissa. Olemassa olevat lyhyen kantaman tiedonsiirtoteknologiat, kuten Bluetooth, Bluetooth Low Energy (BLE), ZigBee ja Wi-Fi olisivat olleet soveltuvia teknologioita WBAN:lle. Ne ovat kuitenkin suunniteltuja eri käyttötarkoituk- siin. Niitä ei ole optimoitu vähäisen virrankulutuksen käyttötarpeisiin, joka on yksi tärkein perusta WBAN- teknologialla. Siksi uusi standardointi WBAN:lle on tarpeellinen. Tämä opinnäytetyö perehtyy WBAN-teknologiaan ja kuinka ihmiskeho voi lähettää langatonta signaalia, ja siten auttaa potilaan diagnosoinnissa. Opinnäytetyössä selitetään miten eri ihmiskehon asennot vaikutta- vat ulostulosignaaliin,
    [Show full text]
  • Ethernet (IEEE 802.3)
    Computer Networking MAC Addresses, Ethernet & Wi-Fi Lecturers: Antonio Carzaniga Silvia Santini Assistants: Ali Fattaholmanan Theodore Jepsen USI Lugano, December 7, 2018 Changelog ▪ V1: December 7, 2018 ▪ V2: March 1, 2017 ▪ Changes to the «tentative schedule» of the lecture 2 Last time, on December 5, 2018… 3 What about today? ▪Link-layer addresses ▪Ethernet (IEEE 802.3) ▪Wi-Fi (IEEE 802.11) 4 Link-layer addresses 5 Image source: https://divansm.co/letter-to-santa-north-pole-address/letter-to-santa-north-pole-address-fresh-day-18-santa-s-letters/ Network adapters (aka: Network interfaces) ▪A network adapter is a piece of hardware that connects a computer to a network ▪Hosts often have multiple network adapters ▪ Type ipconfig /all on a command window to see your computer’s adapters 6 Image source: [Kurose 2013 Network adapters: Examples “A 1990s Ethernet network interface controller that connects to the motherboard via the now-obsolete ISA bus. This combination card features both a BNC connector (left) for use in (now obsolete) 10BASE2 networks and an 8P8C connector (right) for use in 10BASE-T networks.” https://en.wikipedia.org/wiki/Network_interface_controller TL-WN851ND - WLAN PCI card 802.11n/g/b 300Mbps - TP-Link https://tinyurl.com/yamo62z9 7 Network adapters: Addresses ▪Each adapter has an own link-layer address ▪ Usually burned into ROM ▪Hosts with multiple adapters have thus multiple link- layer addresses ▪A link-layer address is often referred to also as physical address, LAN address or, more commonly, MAC address 8 Format of a MAC address ▪There exist different MAC address formats, the one we consider here is the EUI-48, used in Ethernet and Wi-Fi ▪6 bytes, thus 248 possible addresses ▪ i.e., 281’474’976’710’656 ▪ i.e., 281* 1012 (trillions) Image source: By Inductiveload, modified/corrected by Kju - SVG drawing based on PNG uploaded by User:Vtraveller.
    [Show full text]
  • Traffic Generation
    WHITEPAPER Joan d’Austria, 112 - Barcelona - SP - 08018 Chalfont St Peter - Bucks - UK - SL9 9TR www.albedotelecom.com Ethernet Traffic Generation One of the key features of Ether.Genius / Ether.Sync / Ether.Giga tester fami- lies is the ability to generate traffic with deterministic and random bandwidth profiles. The traffic generation feature can be used to stress the network, sim- ulate user traffic and, if a suitable payload is configured, to measure critical net- work performance parameters like bit errors, packet loss or latency. The above mentioned Ethernet testers manufactured by ALBEDO, have eight in- dependent full featured traffic generators attached to the main test port (Port A). Each traffic flow may be configured with specific encapsulation and ad- dressing parameters thus providing great versatility in all applications requiring Ethernet and IP traffic generation. 1. GENERATION OF ETHERNET TRAFFIC In Ether.Genius / Ether.Sync / Ether.Giga testers, generation of custom Ether- net frames is available for Port A in Ethernet endpoint mode through the Frame, Bandwith profile and Payload settings for each of the eight available traffic flows. This is a short description of the Ethernet traffic generation menus: Figure 1 ALBEDO Ether.Giga is a field tester for Ethernet equipped with all the features to install and maintain Ethernet infrastructures supporting legacy features such as BER and RFC2544 while new test such as eSAM Y.1564. All rights reserved. No part of this document may be stored, copied or transmitted, by any means,
    [Show full text]
  • Wireless LAN & IEEE 802.11
    Wireless LAN & IEEE 802.11 An Introduction to the Wi-Fi Technology Wen-Nung Tsai [email protected] 1 OUTLINE Wi-Fi Introduction IEEE 802.11 IEEE 802.11x difference WLAN architecture WLAN transmission technology WLAN Security and WEP 2 Wi-Fi Introduction Wi-Fi 是 Ethernet 相容的無線通信協定 Wi-Fi技術代號是IEEE 802.11，也叫做 Wireless LAN 適用範圍在 50 到 150 公尺之間， Transmission rate 可到 11Mbps (802.11b) 3 Intended Use Any Time Any Where 隨時隨地都可上網遨遊 Wireless Internet access inside hotel lobbies, conference rooms, etc. Wireless at the Airport Wireless with your Latte? Wireless home networking . 4 Wi-Fi Standard (802.11) Mission: promote 802.11 interoperability as the global wireless LAN standard Wi-Fi Board members include AMD, Apple, Cisco, Compaq, Dell, Epson, Ericsson, Fujistu, Gateway, HP, IBM, Intel, Microsoft, NEC, Nokia, Nortel, Philips, Samsung, Sharp, Sony, TDK, Toshiba, 5 Wi-Fi Market in the News Wireless LAN equipment market $969 Million in 2000 to estimated $4.5 Billion in 2006 In 2001: Microsoft adds 802.11 in Windows XP Major hotel chains install Wi-Fi Internet access Around 500 Starbucks stores offer wireless Internet Microsoft joins WECA board (the 802.11 alliance) Intel Joins WECA board Most PC/Laptop manufacturers offer Wi-Fi 6 Wireless Ethernet Compatibility Alliance (WECA) Mission statement—WECA’s mission is to certify interoperability of Wi-Fi™ (IEEE 802.11b) products and to promote Wi-Fi as the global wireless LAN standard across all market segments Goal—Provide users with a comfort level for interoperability Presently
    [Show full text]