DOCSLIB.ORG

802.11N-Draftstd June2009.Pdf

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
802.11N-Draftstd June2009.Pdf IEEE P802.11n/D11.0, June 2009 1 2 IEEE P802.11n™/D11.0 3 4 5 6 7 Draft STANDARD for 8 9 10 Information Technology— 11 12 13 Telecommunications and information exchange 14 15 between systems— 16 17 18 Local and metropolitan area networks— 19 20 Specific requirements 21 22 23 24 25 26 Part 11: Wireless LAN Medium Access Control 27 28 (MAC) and Physical Layer (PHY) specifications 29 30 31 32 33 Amendment 5: Enhancements for Higher 34 35 36 Throughput 37 38 39 40 41 Prepared by the 802.11 Working Group of the 802 Committee 42 43 Copyright © 2009 by the IEEE. 44 Three Park Avenue 45 46 New York, NY 10016-5997, USA 47 48 All rights reserved. 49 50 51 This document is an unapproved draft of a proposed IEEE Standard. As such, this document is subject to 52 change. USE AT YOUR OWN RISK! Because this is an unapproved draft, this document must not be uti- 53 lized for any conformance/compliance purposes. Permission is hereby granted for IEEE Standards Commit- 54 55 tee participants to reproduce this document for purposes of international standardization consideration. Prior 56 to adoption of this document, in whole or in part, by another standards development organization, permis- 57 sion must first be obtained from the IEEE Standards Activities Department ([email protected]). Other enti- 58 ties seeking permission to reproduce this document, in whole or in part, must also obtain permission from 59 the IEEE Standards Activities Department. 60 61 IEEE Standards Activities Department 62 63 445 Hoes Lane 64 65 Piscataway, NJ 08854, USA Copyright © 2009 IEEE. All rights reserved. i This is an unapproved IEEE Standards Draft, subject to change. Authorized licensed use limited to: Univ of Calif San Diego. Downloaded on October 29, 2009 at 15:52 from IEEE Xplore. Restrictions apply. IEEE P802.11n/D11.0, June 2009 1 Abstract: This amendment defines modifications to both the 802.11 physical layers (PHY) and the 802.11 2 Medium Access Control Layer (MAC) so that modes of operation can be enabled that are capable of much 3 higher throughputs, with a maximum throughput of at least 100 Mb/s, as measured at the MAC data service 4 5 access point (SAP). 6 7 Keywords: Wireless LAN, Medium Access Control, Physical Layer, Radio, Multiple Input Multiple Out- 8 put, MIMO, MIMO-OFDM, High Throughput 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 ii Copyright © 2009 IEEE. All rights reserved. This is an unapproved IEEE Standards Draft, subject to change. Authorized licensed use limited to: Univ of Calif San Diego. Downloaded on October 29, 2009 at 15:52 from IEEE Xplore. Restrictions apply. IEEE P802.11n/D11.0, June 2009 1 Introduction 2 3 (This introduction is not part of IEEE P802.11n/D11.0, Draft Amendment to Standard for Information 4 Technology-Telecommunications and information exchange between systems-Local and Metropolitan 5 networks-Specific requirements-Part 11: Wireless LAN Medium Access Control (MAC) and Physical 6 7 Layer (PHY) specifications: Enhancements for Higher Throughput.) 8 9 10 This amendment specifies enhancements to 802.11 PHY and MAC layers to provide modes of operation with 11 useful data rates substantially higher than those previously available. Significantly higher 802.11 wireless lo- 12 cal area network (LAN) throughput is expected to improve user experiences for current applications and to 13 14 enable new applications and market segments. 15 16 17 Notice to users 18 19 20 Laws and regulations 21 22 Users of these documents should consult all applicable laws and regulations. Compliance with the provisions 23 of this standard does not imply compliance to any applicable regulatory requirements. Implementers of the 24 25 standard are responsible for observing or referring to the applicable regulatory requirements. IEEE does not, 26 by the publication of its standards, intend to urge action that is not in compliance with applicable laws, and 27 these documents may not be construed as doing so. 28 29 30 Copyrights 31 32 33 This document is copyrighted by the IEEE. It is made available for a wide variety of both public and private 34 uses. These include both use, by reference, in laws and regulations, and use in private self-regulation, stan- 35 dardization, and the promotion of engineering practices and methods. By making this document available for 36 use and adoption by public authorities and private users, the IEEE does not waive any rights in copyright to 37 this document. 38 39 40 41 Updating of IEEE documents 42 43 Users of IEEE standards should be aware that these documents may be superseded at any time by the issuance 44 of new editions or may be amended from time to time through the issuance of amendments, corrigenda, or 45 errata. An official IEEE document at any point in time consists of the current edition of the document together 46 47 with any amendments, corrigenda, or errata then in effect. In order to determine whether a given document is 48 the current edition and whether it has been amended through the issuance of amendments, corrigenda, or er- 49 rata, visit the IEEE Standards Association website at http://ieeexplore.ieee.org/xpl/standards.jsp, or contact 50 the IEEE at the address listed previously. 51 52 53 For more information about the IEEE Standards Association or the IEEE standards development process, visit 54 the IEEE-SA website at http://standards.ieee.org. 55 56 57 Errata 58 59 Errata, if any, for this and all other standards can be accessed at the following URL: 60 61 http://standards.ieee.org/reading/ieee/updates/errata/index.html. Users are encouraged to check this URL for 62 errata periodically. 63 64 65 Interpretations Copyright © 2009 IEEE. All rights reserved. iii This is an unapproved IEEE Standards Draft, subject to change. Authorized licensed use limited to: Univ of Calif San Diego. Downloaded on October 29, 2009 at 15:52 from IEEE Xplore. Restrictions apply. IEEE P802.11n/D11.0, June 2009 1 Current interpretations can be accessed at the following URL: 2 http://standards.ieee.org/reading/ieee/interp/index.html. 3 4 5 Patents 6 7 8 Attention is called to the possibility that implementation of this amendment may require use of subject mat- 9 ter covered by patent rights. By publication of this standard, no position is taken with respect to the existence 10 or validity of any patent rights in connection therewith. A patent holder or patent applicant has filed a state- 11 ment of assurance that it will grant licenses under these rights without compensation or under reasonable 12 13 rates, with reasonable terms and conditions that are demonstrably free of any unfair discrimination to appli- 14 cants desiring to obtain such licenses. Other Essential Patent Claims may exist for which a statement of 15 assurance has not been received. The IEEE is not responsible for identifying Essential Patent Claims for 16 which a license may be required, for conducting inquiries into the legal validity or scope of Patents Claims, 17 or determining whether any licensing terms or conditions are reasonable or non-discriminatory. Users of this 18 19 standard are expressly advised that determination of the validity of any patent rights, and the risk of infringe- 20 ment of such rights, is entirely their own responsibility. Further information may be obtained from the IEEE 21 Standards Association. 22 23 24 Participants 25 26 27 At the time this draft Standard was completed, the 802.11 Working Group had the following membership: 28 Bruce Kraemer, Chair 29 Jon Rosdahl and Adrian Stephens, Vice-chairs 30 Stephen McCann, Secretary 31 32 EDITORIAL NOTE—a three column list of voting members of 802.11 on the day the draft was sent for 33 34 sponsor ballot will be inserted 35 36 The following were officers of Task Group n: 37 Bruce Kraemer, Chair 38 Sheung Li, Vice-Chair 39 40 Garth Hillman, Secretary 41 Adrian P. Stephens, Technical Editor 42 43 Contributions to this amendment were received from the following individuals: 44 Abbott, Bill Bjerke, Bjorn de Courville, Marc 45 46 Abraham, Santosh Blakenship, Yufei de Vegt, Rolf 47 Adachi, Tomoko Borges, Daniel Dielacher, Franz 48 Akhmetov, Dmitry Chan, Douglas Doi, Yoshiharu 49 Aldana, Carlos Chang, Jerry Dorsey, John 50 Andrus, Dave Chang, John Douglas, Brett 51 52 Anholt, Micha Chen, Jeng-Hong Ecclesine, Peter 53 Aoki, Tsuguhide Chen, Stephen Engwer, Darwin 54 Asai, Yusuke Chen, Yi-Ming Epstein, Leonid 55 Awater, Geert Chiang, Pei-ju Erceg, Vinko 56 Bagby, David Chin, Francois Eroz, Mustafa 57 58 Banerjea, Raja Chin, Woon Hau Fechtel, Stefan 59 Banerjee, Kaberi Chou, Emily Feinberg, Paul 60 Bansal, Amit Chu, Liwen Fischer, Matthew 61 Basson, Gal Chugg, Keith Frederiks, Guido 62 Batra, Anuj Classon, Brian Fukagawa, Takashi 63 64 Benko, John Coffey, Sean Fung, Patrick 65 Benveniste, Mathilde Convertino, Gabriella Gallizio, Edoardo iv Copyright © 2009 IEEE. All rights reserved. This is an unapproved IEEE Standards Draft, subject to change. Authorized licensed use limited to: Univ of Calif San Diego. Downloaded on October 29, 2009 at 15:52 from IEEE Xplore. Restrictions apply. IEEE P802.11n/D11.0, June 2009 1 Gardner, James Li, Pen Poloni, Angelo 2 Gatti, Devis Li, Sheung Poojary, Neeraj 3 Ghosh, Monisha Li, Yuan Ptasinski, Henry 4 5 Gosteau, Jeremy Liao, Kevin Purkovic, Aleksandar 6 Grandhi, Sudheer Lim, Isaac Qian, Luke 7 Gray, Paul Lin, Alfred Raissinia, Ali 8 Gresset, Nicolas Liu, Albert Ramakrishnan, Sthanunathan 9 Gu, Daqing Liu, Der-Zheng Ramamurthy,
Load more

Recommended publications
  • 2.4/5 Ghz Dual-Band 1X1 Wi-Fi 5 (802.11Ac) and Bluetooth 5.2 Solution Rev
    88W8987_SDS 2.4/5 GHz Dual-band 1x1 Wi-Fi 5 (802.11ac) and Bluetooth 5.2 Solution Rev. 2 — 21 May 2021 Product short data sheet 1 Product overview The 88W8987 is a highly integrated Wi-Fi (2.4/5 GHz) and Bluetooth single-chip solution, specifically designed to support the speed, reliability, and quality requirements of next generation Very High Throughput (VHT) products. The System-on-Chip (SoC) provides both simultaneous and independent operation of the following: • IEEE 802.11ac (Wave 2), 1x1 with data rates up to MCS9 (433 Mbit/s) • Bluetooth 5.2 (includes Bluetooth Low Energy (LE)) The SoC also provides: • Bluetooth Classic and Bluetooth LE dual (Smart Ready) operation • Wi-Fi indoor location positioning (802.11mc) For security, the device supports high performance 802.11i security standards through implementation of the Advanced Encryption Standard (AES)/Counter Mode CBC- MAC Protocol (CCMP), AES/Galois/Counter Mode Protocol (GCMP), Wired Equivalent Privacy (WEP) with Temporal Key Integrity Protocol (TKIP), AES/Cipher-Based Message Authentication Code (CMAC), and WLAN Authentication and Privacy Infrastructure (WAPI) security mechanisms. For video, voice, and multimedia applications, 802.11e Quality of Service (QoS) is supported. The device also supports 802.11h Dynamic Frequency Selection (DFS) for detecting radar pulses when operating in the 5 GHz range. Host interfaces include SDIO 3.0 and high-speed UART interfaces for connecting Wi-Fi and Bluetooth technologies to the host processor. The device is designed with two front-end configurations to accommodate Wi-Fi and Bluetooth on either separate or shared paths: • 2-antenna configuration—1x1 Wi-Fi and Bluetooth on separate paths (QFN) • 1-antenna configuration—1x1 Wi-Fi and Bluetooth on shared paths (eWLP) The following figures show the application diagrams for each package option.
    [Show full text]
  • 802.11 Arbitration
    802.11 Arbitration White Paper September 2009 Version 1.00 Author: Marcus Burton, CWNE #78 CWNP, Inc. [email protected] Technical Reviewer: GT Hill, CWNE #21 [email protected] Copyright 2009 CWNP, Inc. www.cwnp.com Page 1 Table of Contents TABLE OF CONTENTS ............................................................................................................................... 2 EXECUTIVE SUMMARY ............................................................................................................................. 3 Approach / Intent ................................................................................................................................... 3 INTRODUCTION TO 802.11 CHANNEL ACCESS ................................................................................... 4 802.11 MAC CHANNEL ACCESS ARCHITECTURE ............................................................................... 5 Distributed Coordination Function (DCF) ............................................................................................. 5 Point Coordination Function (PCF) ...................................................................................................... 6 Hybrid Coordination Function (HCF) .................................................................................................... 6 Summary ................................................................................................................................................ 7 802.11 CHANNEL ACCESS MECHANISMS ...........................................................................................
    [Show full text]
  • Module 4: Table of Contents
    Data Communications(15CS46) 4th Sem CSE & ISE MODULE 4: TABLE OF CONTENTS INTRODUCTION RANDOM ACCESS PROTOCOL ALOHA Pure ALOHA Vulnerable time Throughput Slotted ALOHA Throughput CSMA Vulnerable Time Persistence Methods CSMA/CD Minimum Frame-size Procedure Energy Level Throughput CSMA/CA Frame Exchange Time Line Network Allocation Vector Collision During Handshaking Hidden-Station Problem CSMA/CA and Wireless Networks CONTROLLED ACCESS PROTOCOL Reservation Polling Token Passing Logical Ring CHANNELIZATION FDMA TDMA CDMA Implementation Chips Data Representation Encoding and Decoding Sequence Generation ETHERNET PROTOCOL IEEE Project 802 Ethernet Evolution STANDARD ETHERNET Characteristics Connectionless and Unreliable Service Frame Format Frame Length Addressing Access Method Efficiency of Standard Ethernet Implementation Encoding and Decoding Changes in the Standard Bridged Ethernet Dept. of ISE,CITECH 1 Data Communications(15CS46) 4th Sem CSE & ISE Switched Ethernet Full-Duplex Ethernet FAST ETHERNET (100 MBPS) Access Method Physical Layer Topology Implementation Encoding GIGABIT ETHERNET MAC Sublayer Physical Layer Topology Implementation Encoding TEN GIGABIT ETHERNET Implementation INTRODUCTION OF WIRELESS-LANS Architectural Comparison Characteristics Access Control IEEE 802.11 PROJECT Architecture BSS ESS Station Types MAC Sublayer DCF Network Allocation Vector Collision During Handshaking PCF Fragmentation Frame Types Frame Format Addressing Mechanism Exposed Station Problem Physical Layer IEEE 802.11 FHSS IEEE 802.11 DSSS IEEE 802.11 Infrared IEEE 802.11a OFDM IEEE 802.11b DSSS IEEE 802.11g BLUETOOTH Architecture Piconets Scatternet Bluetooth Devices Bluetooth Layers Radio Layer Baseband Layer TDMA Links Frame Types Frame Format L2CAP Dept. of ISE,CITECH 2 Data Communications(15CS46) 4th Sem CSE & ISE MODULE 4: MULTIPLE ACCESS 4.1 Introduction When nodes use shared-medium, we need multiple-access protocol to coordinate access to medium.
    [Show full text]
  • Technical Report No
    ENGINEERING FACULTY,UNIVERSITY OF PORTO Technical Report no: 1 Robson Costa Supervisor: Paulo Portugal (Ph.D.) Co-supervisor: Francisco Vasques (Ph.D.) Co-supervisor: Ricardo Moraes (Ph.D.) 2010, September c Robson Costa, 2010 Contents List of Figures ii List of Tables iii List of Abbreviations iv 1 Introduction1 1.1 Benefits . .2 1.2 Challenges . .2 2 IEEE 802.11 Standard4 2.1 IEEE 802.11 Medium Access Mechanisms . .5 2.1.1 DCF - Distributed Coordination Function . .6 2.1.2 PCF - Point Coordination Function . .7 2.1.3 EDCA - Enhanced Distributed Channel Access . .9 2.1.4 HCCA - HCF Controlled Channel Access . 11 3 IEEE 802.11n Amendment 14 3.1 PHY Enhancements . 15 3.1.1 MIMO - Multiple-Input Multiple-Output ................. 15 3.1.2 Channel-bonding . 17 3.2 MAC Enhancements . 18 3.2.1 Frame aggregation . 19 3.2.2 Block ACK . 21 3.2.3 Reverse Direction Protocol . 22 4 Review of Relevant Work 23 4.1 Real-Time communication in IEEE 802.11 . 23 4.1.1 CA - Collision Avoidance . 23 4.1.2 CS - Collision Solver . 26 4.1.3 CR - Collision Reducer . 27 4.2 Comparison of the solutions presented . 30 5 Conclusion 31 References 37 i List of Figures 2.1 Original IEEE 802.11 MAC architecture [1]....................5 2.2 IEEE 802.11e MAC architecture [2].........................5 2.3 Interframe spaces in the DCF and PCF mechanisms [1]. .6 2.4 DCF service [2]....................................6 2.5 PCF service [2]....................................8 2.6 CFP foreshortening [2]................................9 2.7 Interframe spaces in the EDCA mechanism [2].
    [Show full text]
  • C Copyright 2015 Farzad Hessar
    c Copyright 2015 Farzad Hessar Spectrum Sharing in White Spaces Farzad Hessar A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy University of Washington 2015 Reading Committee: Sumit Roy, Chair John D. Sahr Archis Vijay Ghate Program Authorized to Offer Degree: Electrical Engineering University of Washington Abstract Spectrum Sharing in White Spaces Farzad Hessar Chair of the Supervisory Committee: Professor Sumit Roy Electrical Engineering Demand for wireless Internet traffic has been increasing exponentially over the last decade, due to widespread usage of smart-phones along with new multimedia applications. The need for higher wireless network throughput has been pushing engineers to expand network capacities in order to keep pace with growing user demands. The improvement has been multi-dimensional, including optimizations in MAC/Physical layer for boosting spectral efficiency, expanding network infrastructure with reduced cell sizes, and utilizing additional RF spectrum. Nevertheless, traffic demand has been increasing at a much faster pace than network throughput and our current networks will not be able to handle customer needs in near future. While assigning additional spectrum for cellular communication has been a major ele- ment of network capacity increase, the natural scarcity of RF spectrum limits the extend of this solution. On the other hand, researchers have shown that licensed spectrum that is owned and held by a primary user is heavily underutilized. Examples are TV channels in the VHF/UHF band as well as radar spectrum in the SHF band. Hence, a more efficient use of this spectrum is to permit unlicensed users to coexist with the primary owner, i.e.
    [Show full text]
  • 2.4 Ghz/5 Ghz Dual-Band 1X1 Wi-Fi 4 and Bluetooth 5.2 Combo Soc Rev
    88W8977_SDS 2.4 GHz/5 GHz Dual-band 1x1 Wi-Fi 4 and Bluetooth 5.2 Combo SoC Rev. 3 — 13 May 2021 Product short data sheet 1 Product overview The 88W8977 System-on-Chip (SoC) is a highly integrated single-chip solution that incorporates both Wi-Fi® (2.4/5 GHz) and Bluetooth® technology. The System-on-Chip (SoC) provides both simultaneous and independent operation of the following: • IEEE 802.11n compliant, 1x1 spatial stream with data rates up to MCS7 (150 Mbps) • Bluetooth 5.2 (includes Bluetooth Low Energy (LE)) The SoC also provides 3-way coexistence for Wi-Fi, Bluetooth, and ZigBee operation, and indoor location and navigation (802.11mc). The internal coexistence arbitration and a Mobile Wireless Systems (MWS) serial transport interface provide the functionality for connecting an external Long Term Evolution (LTE) or ZigBee device. The device also supports a coexistence interface for co-located Bluetooth/Wi-Fi device arbitration. For security, the device supports high performance 802.11i security standards through the implementation of the Advanced Encryption Standard (AES)/Counter Mode CBC- MAC Protocol (CCMP), Wired Equivalent Privacy (WEP) with Temporal Key Integrity Protocol (TKIP), AES/Cipher-Based Message Authentication Code (CMAC), WPA (AES), and Wi-Fi Authentication and Privacy Infrastructure (WAPI) security mechanisms. For video, voice, and multimedia applications, 802.11e Quality of Service (QoS) is supported. The device also features 802.11h Dynamic Frequency Selection (DFS) for detecting radar pulses when operating in the 5 GHz range. Host interfaces include SDIO 3.0 and high-speed UART interfaces for connecting Wi-Fi and Bluetooth technologies to the host processor.
    [Show full text]
  • Wireless Networks and MAC Protocols
    Wireless Networks and MAC Protocols Embedded Networks 11 1 J. Kaiser, IVS-EOS Some Wireless Technologies Embedded Networks 11 2 J. Kaiser, IVS-EOS Wireless Technology Comparison Chart Standard Fre- Bandwidth Tx-Power Range Goal Application quency (EIRP) 802.11 2,4 GHz <= 600 MBit/s 100 mW 250 m High Data Internet Wlan 5 GHz Rate Sharing, Media Streaming, File Transfer 802.15.1 2,4 GHz <= 2,1 MBit/s 100 mW 100 m Low Power, Handsfree, Bluetooth 2,5 mW 10 m Ease of Use, Cable 1mW 5m Security Replacement 802.15.4 0,8 GHz <= 20 kBit/s 1 mW 10 m Ultra-Low- Sensor Zigbee 0,9 GHz <= 40 kBit/s Power, networks, 2,4 GHz <= 250 kBit/s Timing Remote Guarentees control Embedded Networks 11 3 J. Kaiser, IVS-EOS IEEE 802.11 IEEE 802.11 MAC Layer MAC Architektur: Contention- Free Contention Services Services Point Coordination Function (PCF) (optional) Distributed Coordination Function (DCF) Embedded Networks 11 4 J. Kaiser, IVS-EOS IEEE 802.11 Distributed Coordination Function (DCF) • CSMA/CA Protocol • Collision Avoidance by random backoff procedure (p-persistent) • All Frames are acknowledged, lost Frames are resend • Priority Access by Interframe Space (IFS) => fair arbitration but no real-time support Embedded Networks 11 5 J. Kaiser, IVS-EOS Relationship of different IFSs in 802.11 DIFS DIFS Contention Window PIFS SIFS Busy Medium Backoff-Window Next frame Slot time Defer Access DIFS: DCF Interframe Space PIFS: PCF Interframe Space SIFS: Short Interframe Space Embedded Networks 11 6 J. Kaiser, IVS-EOS IEEE 802.11 Network STA Types ad-hoc network CELL STA STA infrastructure network STA STA CELL CELL DS: Distribution System STA IEEE 802.X AP STA AP Access Point Embedded Networks 11 7 J.
    [Show full text]
  • Local Area Networks: Ethernet
    LANs 1 Local Area Networks: Ethernet Prof. Jean-Yves Le Boudec Prof. Andrzej Duda Prof. Patrick Thiran ICA, EPFL CH-1015 Ecublens [email protected] http://icawww.epfl.ch LANs 2 Objective o Understand shared medium access methods of Ethernet; o Describe network aspects of an Ethernet network; PART A: The CSMA/CD method PART B: Network Aspects (Ethernet) PART C: CSMA/CA and wireless LANs The access method is a way of sharing a common transmission medium (cable, wireless link) between several hosts. Ethernet is built upon the medium access method called CSMA/CD (Carrier Sense Multiple Access/Collision Detection). The network aspects explain how a local area network is built today. We will see that the resulting network is very far away from the original design. LANs 3 Part A: Motivation for LANs o goal: connect computers in same site (building, small campus) o experience from host centric networks:bursty traffic o basic idea: share a cable, no complex software in the end systems o alternatives ? switch based LANs: connection oriented: ATM switch based LANs: connectionless. Switched Ethernet If you want to understand something in the world of local area networks, you should keep in mind the design requirements. Today, they are: •(1) interconnect many pieces of equipment without complex cabling, inside a limited geographical area, and inside one organization •(2a) be easy to manage, in particular, detect cable faults easily. When Ethernet was first conceived, the requirements were a little bit different. The second requirement was replaced by: •(2b) use one shared cable for the entire network.
    [Show full text]
  • UNIT-5 IEEE STANDARDS 1 IEEE Stands
    UNIT-5 IEEE STANDARDS IEEE stands for “Institute of Electrical and Electronics Engineers”. IEEE was founded in the year 1884. Project 802 is one of the famous projects regarding to IEEE. This project contains the features which are lead to the essential development in LAN and its usage. Project 802 sets high-level standards in components that are using in inter-communication between systems. Any manufacturer must follow the standards while preparing the components. IEEE also provides the support for OSI reference model and its supported layers. Especially for Data link layer and Physical layer. According OSI reference model data link layer and physical layer is performing the most of the responsibility in data transfer. Generally LAN is used for connecting limited group of systems in limited area. LAN can provide sharing of resources. LAN concept is also supporting WAN or internet. LAN is one of the mostly used technologies. LAN is having several technologies (versions): 1) Ethernet. 2) Token Ring. 3) Token Bus. 4) ATM LAN. IEEE provides supports for any type of LAN version and also working along with Data link and physical layer. Data Link Layer: The IEEE has subdivided the data link layer into two sub layers: 1) Logical Link Control (LLC). 2) Media Access Control (MAC). IEEE has also created several physical layer standards for different LAN protocols. 1 UNIT-5 IEEE STANDARDS We know that data link control handles framing, flow control, and error control. In IEEE Project 802, flow control, error control, and part of the framing duties are collected into one sub layer called the logical link control.
    [Show full text]
  • Enabling Channel Bonding in High-Density Wlans
    To Overlap or not to Overlap: Enabling Channel Bonding in High-Density WLANs Sergio Barrachina-Mu˜noz∗, Francesc Wilhelmi, Boris Bellalta Wireless Networking (WN), Universitat Pompeu Fabra, Barcelona, Spain Abstract Wireless local area networks (WLANs) are the most popular kind of wireless Internet connection because of their simplicity of deployment and operation. As a result, the number of devices accessing the Internet through WLANs such as laptops, smartphones, or wearables, is increasing drastically at the same time that applications’ throughput requirements do. To cope with these challenges, channel bonding (CB) techniques are used for enabling higher data rates by transmitting in wider channels, thus increasing spectrum efficiency. However, important issues like higher potential co-channel and adjacent channel interference arise when bonding channels. This may harm the performance of the carrier sense multiple access (CSMA) protocol because of recurrent backoff freezing, while making nodes more sensitive to hidden node effects. In this paper, we address the following point at issue: is it convenient for high-density (HD) WLANs to use wider channels and potentially overlap in the spectrum? First, we highlight key aspects of DCB in toy scenarios through a continuous time Markov network (CTMN) model. Then, by means of extensive simulations covering a wide range of traffic loads and access point (AP) densities, we show that dynamic channel bonding (DCB) – which adapts the channel bandwidth on a per-packet transmission – significantly outperforms traditional single-channel on average. Nevertheless, results also corroborate that DCB is more prone to generate unfair situations where WLANs may starve. Contrary to most of the current thoughts pushing towards non-overlapping channels in HD deployments, we highlight the benefits of allocating channels as wider as possible to WLANs altogether with implementing adaptive access policies to cope with the unfairness situations that may appear.
    [Show full text]
  • A Real-Time Multimedia Streaming Protocol for Wireless Networks Hans Scholten, Pierre Jansen, Ferdy Hanssen, Wietse Mank and Arjan Zwikker
    1 A Real-Time Multimedia Streaming Protocol for Wireless Networks Hans Scholten, Pierre Jansen, Ferdy Hanssen, Wietse Mank and Arjan Zwikker University of Twente, Department of Computer Science (EEMCS), Enschede, the Netherlands Email: scholten, jansen, hanssen @cs.utwente.nl Abstract— This paper describes a new token-based specified by passing a period and a required bandwidth to medium access protocol for real-time networks and its the network socket. The scheduler then decides whether implementation on a wireless network. Originally, the the new network configuration is feasible and if it is, the protocol is developed for use in low cost domestic or scheduler calculates a new PEDF schedule for all the home networks that are based on Ethernet hardware. streams in the network. The most important aspects of In contrast to existing protocols the token is assigned to network nodes on basis of a pre-emptive earliest the real-time network protocol will be described next. deadline first (PEDF) schedule of the multimedia streams. For a more detailed explanation see [3] or [4]. The scheduler is distributed over all active nodes in the network. Although other schedulers could be used, PEDF A. The Scheduler is chosen because it has a theoretical bandwidth utilization of one hundred percent and feasibility analysis is very The scheduler is a pre-emptive earliest deadline first simple, so even simple devices can participate in such a scheduler. As the name already indicates, this scheduler network. This is confirmed by simulation experiments and schedules the stream with the earliest deadline first. It is a prototype based on Ethernet hardware.
    [Show full text]
  • IEEE 802.11 Wireless LAN Standard
    IEEE 802.11 Wireless LAN Standard Updated: 5/10/2011 IEEE 802.11 History and Enhancements o 802.11 is dedicated to WLAN o The group started in 1990 o First standard that received industry support was 802.11b n Accepted in 1999 n Focusing on 2.4 GHz unlicensed band n Initially 2 Mbit BW – relatively slow (802.11) 802.11 Standards WiFi Alliance http://www.wi-fi.org/ Read the handout! 802.11 Standards 802.11ac @5GHz with 1.3Gbps Max. Data Rate! http://en.wikipedia.org/wiki/IEEE_802.11 http://www.wi-fi.org/discover-and-learn OSI Model IEEE 802 Protocol Layers Provide an interface to higher layers and perform flow and error control • Encoding/decoding of signals transmission medium IEEE• Preamble 802 generation/removal Protocol Layers (for synchronization) • Bit transmission/reception • Includes specification of the transmission medium • On transmission, assemble data into a frame with address and error detection fields • On reception, disassemble frame and perform address recognition and error detection • Govern access to the LAN transmission medium LLC and MAC are separated: - The logic required to manage access to a shared- access medium not found in traditional layer 2 data link control - For the same LLC, several MAC options may be provided Protocol Architecture o Functions of physical layer: n Encoding/decoding of signals n Preamble generation/removal (for synchronization) n Bit transmission/reception n Includes specification of the transmission medium Protocol Architecture o Functions of medium access control (MAC) layer: n On transmission,
    [Show full text]