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Understanding RF Fundamentals and the Radio Design for 11Ac Wireless Networks Brandon Johnson Systems Engineer Agenda
Understanding RF Fundamentals and the Radio Design for 11ac Wireless Networks Brandon Johnson Systems Engineer Agenda • Physics - RF Waves • Antenna Selection • Spectrum, Channels & Channel widths • MIMO & Spatial Streams • Cisco 802.11ac features • Beyond 802.11ac Electromagnetic Spectrum • Radio waves • Micro waves Colour Frequency Wavelength • Infrared Radiation Violet 668-789 THz 380-450nm Blue 606-668 THz 450-495nm • Visible Light Green 526-606 THz 495-570nm • Ultraviolet Radiation Yellow 508-526 THz 570-590nm • X-Rays Orange 484-508 THz 590-620nm • Gamma Rays Red 400-484 THz 620-750nm Radio Frequency Fundamentals λ1 λ • Frequency and Wavelength 2 • f = c / λ c = the speed of light in a vacuum • 2.45GHz = 12.3cm • 5.0GHz = 6cm • Amplitude • Phase * ϕ A1 A2 Radio Frequency Fundamentals • Signal Strength • Wave Propagation • Gain and Amplification – Attenuation and Free Space Loss • Loss and Attenuation – Reflection and Absorption – Wavelength Physics of Waves • In phase, reinforcement • Out of phase, cancellation RF Mathematics • dB is a logarithmic ratio of values (voltages, power, gain, losses) • We add gains • We subtract losses • dBm is a power measurement relative to 1mW • dBi is the forward gain of an antenna compared to isotropic antenna Now we know that …. How? CSMA / CA – “Listen before talk” • Carrier sense, multiple access / open spectrum • (open, low-power ISM bands) no barrier to entry • Energy detection must detect channel available – Clear Channel Assessment • On collision, random back off timer before trying again. -
Logical Link Control and Channel Scheduling for Multichannel Underwater Sensor Networks
ICST Transactions on Mobile Communications and Applications Research Article Logical Link Control and Channel Scheduling for Multichannel Underwater Sensor Networks Jun Li ∗, Mylene` Toulgoat, Yifeng Zhou, and Louise Lamont Communications Research Centre Canada, 3701 Carling Avenue, Ottawa, ON. K2H 8S2 Canada Abstract With recent developments in terrestrial wireless networks and advances in acoustic communications, multichannel technologies have been proposed to be used in underwater networks to increase data transmission rate over bandwidth-limited underwater channels. Due to high bit error rates in underwater networks, an efficient error control technique is critical in the logical link control (LLC) sublayer to establish reliable data communications over intrinsically unreliable underwater channels. In this paper, we propose a novel protocol stack architecture featuring cross-layer design of LLC sublayer and more efficient packet- to-channel scheduling for multichannel underwater sensor networks. In the proposed stack architecture, a selective-repeat automatic repeat request (SR-ARQ) based error control protocol is combined with a dynamic channel scheduling policy at the LLC sublayer. The dynamic channel scheduling policy uses the channel state information provided via cross-layer design. It is demonstrated that the proposed protocol stack architecture leads to more efficient transmission of multiple packets over parallel channels. Simulation studies are conducted to evaluate the packet delay performance of the proposed cross-layer protocol stack architecture with two different scheduling policies: the proposed dynamic channel scheduling and a static channel scheduling. Simulation results show that the dynamic channel scheduling used in the cross-layer protocol stack outperforms the static channel scheduling. It is observed that, when the dynamic channel scheduling is used, the number of parallel channels has only an insignificant impact on the average packet delay. -
Telematics Chapter 3: Physical Layer
Telematics User Server watching with video Chapter 3: Physical Layer video clip clips Application Layer Application Layer Presentation Layer Presentation Layer Session Layer Session Layer Transport Layer Transport Layer Network Layer Network Layer Network Layer Data Link Layer Data Link Layer Data Link Layer Physical Layer Physical Layer Physical Layer Univ.-Prof. Dr.-Ing. Jochen H. Schiller Computer Systems and Telematics (CST) Institute of Computer Science Freie Universität Berlin http://cst.mi.fu-berlin.de Contents ● Design Issues ● Theoretical Basis for Data Communication ● Analog Data and Digital Signals ● Data Encoding ● Transmission Media ● Guided Transmission Media ● Wireless Transmission (see Mobile Communications) ● The Last Mile Problem ● Multiplexing ● Integrated Services Digital Network (ISDN) ● Digital Subscriber Line (DSL) ● Mobile Telephone System Univ.-Prof. Dr.-Ing. Jochen H. Schiller ▪ cst.mi.fu-berlin.de ▪ Telematics ▪ Chapter 3: Physical Layer 3.2 Design Issues Univ.-Prof. Dr.-Ing. Jochen H. Schiller ▪ cst.mi.fu-berlin.de ▪ Telematics ▪ Chapter 3: Physical Layer 3.3 Design Issues ● Connection parameters ● mechanical OSI Reference Model ● electric and electronic Application Layer ● functional and procedural Presentation Layer ● More detailed ● Physical transmission medium (copper cable, Session Layer optical fiber, radio, ...) ● Pin usage in network connectors Transport Layer ● Representation of raw bits (code, voltage,…) Network Layer ● Data rate ● Control of bit flow: Data Link Layer ● serial or parallel transmission of bits Physical Layer ● synchronous or asynchronous transmission ● simplex, half-duplex, or full-duplex transmission mode Univ.-Prof. Dr.-Ing. Jochen H. Schiller ▪ cst.mi.fu-berlin.de ▪ Telematics ▪ Chapter 3: Physical Layer 3.4 Design Issues Transmitter Receiver Source Transmission System Destination NIC NIC Input Abcdef djasdja dak jd ashda kshd akjsd asdkjhasjd as kdjh askjda Univ.-Prof. -
Cellular Wireless Networks
CHAPTER10 CELLULAR WIRELESS NETwORKS 10.1 Principles of Cellular Networks Cellular Network Organization Operation of Cellular Systems Mobile Radio Propagation Effects Fading in the Mobile Environment 10.2 Cellular Network Generations First Generation Second Generation Third Generation Fourth Generation 10.3 LTE-Advanced LTE-Advanced Architecture LTE-Advanced Transission Characteristics 10.4 Recommended Reading 10.5 Key Terms, Review Questions, and Problems 302 10.1 / PRINCIPLES OF CELLULAR NETWORKS 303 LEARNING OBJECTIVES After reading this chapter, you should be able to: ◆ Provide an overview of cellular network organization. ◆ Distinguish among four generations of mobile telephony. ◆ Understand the relative merits of time-division multiple access (TDMA) and code division multiple access (CDMA) approaches to mobile telephony. ◆ Present an overview of LTE-Advanced. Of all the tremendous advances in data communications and telecommunica- tions, perhaps the most revolutionary is the development of cellular networks. Cellular technology is the foundation of mobile wireless communications and supports users in locations that are not easily served by wired networks. Cellular technology is the underlying technology for mobile telephones, personal communications systems, wireless Internet and wireless Web appli- cations, and much more. We begin this chapter with a look at the basic principles used in all cellular networks. Then we look at specific cellular technologies and stan- dards, which are conveniently grouped into four generations. Finally, we examine LTE-Advanced, which is the standard for the fourth generation, in more detail. 10.1 PRINCIPLES OF CELLULAR NETWORKS Cellular radio is a technique that was developed to increase the capacity available for mobile radio telephone service. Prior to the introduction of cellular radio, mobile radio telephone service was only provided by a high-power transmitter/ receiver. -
Enterprise Best Practices for Ios Devices On
White Paper Enterprise Best Practices for iOS devices and Mac computers on Cisco Wireless LAN Updated: January 2018 © 2018 Cisco and/or its affiliates. All rights reserved. This document is Cisco Public. Page 1 of 51 Contents SCOPE .............................................................................................................................................. 4 BACKGROUND .................................................................................................................................. 4 WIRELESS LAN CONSIDERATIONS .................................................................................................... 5 RF Design Guidelines for iOS devices and Mac computers on Cisco WLAN ........................................................ 5 RF Design Recommendations for iOS devices and Mac computers on Cisco WLAN ........................................... 6 Wi-Fi Channel Coverage .................................................................................................................................. 7 ClientLink Beamforming ................................................................................................................................ 10 Wi-Fi Channel Bandwidth ............................................................................................................................. 10 Data Rates .................................................................................................................................................... 12 802.1X/EAP Authentication .......................................................................................................................... -
Medium Access Control Layer
Telematics Chapter 5: Medium Access Control Sublayer User Server watching with video Beispielbildvideo clip clips Application Layer Application Layer Presentation Layer Presentation Layer Session Layer Session Layer Transport Layer Transport Layer Network Layer Network Layer Network Layer Univ.-Prof. Dr.-Ing. Jochen H. Schiller Data Link Layer Data Link Layer Data Link Layer Computer Systems and Telematics (CST) Physical Layer Physical Layer Physical Layer Institute of Computer Science Freie Universität Berlin http://cst.mi.fu-berlin.de Contents ● Design Issues ● Metropolitan Area Networks ● Network Topologies (MAN) ● The Channel Allocation Problem ● Wide Area Networks (WAN) ● Multiple Access Protocols ● Frame Relay (historical) ● Ethernet ● ATM ● IEEE 802.2 – Logical Link Control ● SDH ● Token Bus (historical) ● Network Infrastructure ● Token Ring (historical) ● Virtual LANs ● Fiber Distributed Data Interface ● Structured Cabling Univ.-Prof. Dr.-Ing. Jochen H. Schiller ▪ cst.mi.fu-berlin.de ▪ Telematics ▪ Chapter 5: Medium Access Control Sublayer 5.2 Design Issues Univ.-Prof. Dr.-Ing. Jochen H. Schiller ▪ cst.mi.fu-berlin.de ▪ Telematics ▪ Chapter 5: Medium Access Control Sublayer 5.3 Design Issues ● Two kinds of connections in networks ● Point-to-point connections OSI Reference Model ● Broadcast (Multi-access channel, Application Layer Random access channel) Presentation Layer ● In a network with broadcast Session Layer connections ● Who gets the channel? Transport Layer Network Layer ● Protocols used to determine who gets next access to the channel Data Link Layer ● Medium Access Control (MAC) sublayer Physical Layer Univ.-Prof. Dr.-Ing. Jochen H. Schiller ▪ cst.mi.fu-berlin.de ▪ Telematics ▪ Chapter 5: Medium Access Control Sublayer 5.4 Network Types for the Local Range ● LLC layer: uniform interface and same frame format to upper layers ● MAC layer: defines medium access .. -
MIMO Channel Modeling and Capacity Analysis for 5G Millimeter
M. K. Samimi, S. Sun, T. S. Rappaport, “MIMO Channel Modeling and Capacity Analysis for 5G Millimeter-Wave Wireless Systems,” in the 10th European Conference on Antennas and Propagation (EuCAP’2016), April 2016. MIMO Channel Modeling and Capacity Analysis for 5G Millimeter-Wave Wireless Systems Mathew K. Samimi, Shu Sun, and Theodore S. Rappaport NYU WIRELESS, NYU Tandon School of Engineering [email protected], [email protected], [email protected] modeling approach in which the spatially fading MIMO chan- Abstract—This paper presents a 3-D statistical channel model nel coefficients are obtained from the superposition of cluster of the impulse response with small-scale spatially correlated subpath powers across antenna array elements. However, random coefficients for multi-element transmitter and receiver antenna arrays, derived using the physically-based time cluster - note that small-scale spatial fading distributions and spatial spatial lobe (TCSL) clustering scheme. The small-scale properties autocorrelation models are not specified to simulate local area of multipath amplitudes are modeled based on 28 GHz outdoor effects [3], [4]. The effects of spatial and temporal correlations millimeter-wave small-scale local area channel measurements. of multipath amplitudes at different antenna elements affect The wideband channel capacity is evaluated by considering MIMO capacity results, and must be appropriately modeled measurement-based Rician-distributed voltage amplitudes, and the spatial autocorrelation of multipath amplitudes for each pair from measurements to enable realistic multi-element antenna of transmitter and receiver antenna elements. Results indicate simulations. that Rician channels may exhibit equal or possibly greater capacity compared to Rayleigh channels, depending on the Work in [5] demonstrates the importance of spatial and tem- number of antennas. -
Physical Layer Compliance Testing for 1000BASE-T Ethernet
Physical Layer Compliance Testing for 1000BASE-T Ethernet –– APPLICATION NOTE Physical Layer Compliance Testing for 1000BASE-T Ethernet APPLICATION NOTE Engineers designing or validating the 1000BASE-T Ethernet 1000BASE-T Physical Layer physical layer on their products need to perform a wide range Compliance Standards of tests, quickly, reliably and efficiently. This application note describes the tests that ensure validation, the challenges To ensure reliable information transmission over a network, faced while testing multi-level signals, and how oscilloscope- industry standards specify requirements for the network’s resident test software enables significant efficiency physical layer. The IEEE 802.3 standard defines an array of improvements with its wide range of tests, including return compliance tests for 1000BASE-T physical layer. These tests loss, fast validation cycles, and high reliability. are performed by placing the device under test in test modes specified in the standard. The Basics of 1000BASE-T Testing While it is recommended to perform as many tests as Popularly known as Gigabit Ethernet, 1000BASE-T has been possible, the following core tests are critical for compliance: experiencing rapid growth. With only minimal changes to IEEE 802.3 Test Mode Test the legacy cable structure, it offers 100 times faster data Reference rates than 10BASE-T Ethernet signals. Gigabit Ethernet, in Peak 40.6.1.2.1 combination with Fast Ethernet and switched Ethernet, offers Test Mode-1 Droof 40.6.1.2.2 Template 40.6.1.2.3 a cost-effective alternative to slow networks. Test Mode-2 Master Jitter 40.6.1.2.5 Test Mode-3 Slave Jitter 1000BASE-T uses four signal pairs for full-duplex Distortion 40.6.1.2.4 transmission and reception over CAT-5 balanced cabling. -
Understanding Mmwave for 5G Networks 1
5G Americas | Understanding mmWave for 5G Networks 1 Contents 1 Introduction ..................................................................................................................................................... 6 2 Status of Millimeter Wave Spectrum ............................................................................................................. 9 2.1 Regional Status ........................................................................................................................................... 9 2.2 Global Millimeter Wave Auctions .............................................................................................................12 3 Millimeter Wave Technical Rules in the United States ...............................................................................15 3.1 Licensed Spectrum ..................................................................................................................................15 3.2 Lightly Licensed .......................................................................................................................................16 3.3 Unlicensed Spectrum ..............................................................................................................................17 4 Millimeter Wave Challenges and Opportunities ..........................................................................................19 4.1 Losses in Millimeter Wave .......................................................................................................................19 -
6.02 Notes, Chapter 15: Sharing a Channel: Media Access (MAC
MIT 6.02 DRAFT Lecture Notes Last update: November 3, 2012 CHAPTER 15 Sharing a Channel: Media Access (MAC) Protocols There are many communication channels, including radio and acoustic channels, and certain kinds of wired links (coaxial cables), where multiple nodes can all be connected and hear each other’s transmissions (either perfectly or with some non-zero probability). This chapter addresses the fundamental question of how such a common communication channel—also called a shared medium—can be shared between the different nodes. There are two fundamental ways of sharing such channels (or media): time sharing and frequency sharing.1 The idea in time sharing is to have the nodes coordinate with each other to divide up the access to the medium one at a time, in some fashion. The idea in frequency sharing is to divide up the frequency range available between the different transmitting nodes in a way that there is little or no interference between concurrently transmitting nodes. The methods used here are the same as in frequency division multiplexing, which we described in the previous chapter. This chapter focuses on time sharing. We will investigate two common ways: time division multiple access,orTDMA , and contention protocols. Both approaches are used in networks today. These schemes for time and frequency sharing are usually implemented as communica tion protocols. The term protocol refers to the rules that govern what each node is allowed to do and how it should operate. Protocols capture the “rules of engagement” that nodes must follow, so that they can collectively obtain good performance. -
(12) United States Patent (10) Patent No.: US 8,521,103 B2 Zhang Et Al
USOO8521 1 03B2 (12) United States Patent (10) Patent No.: US 8,521,103 B2 Zhang et al. (45) Date of Patent: *Aug. 27, 2013 (54) METHOD AND SYSTEM FOR A GREEDY (56) References Cited USER GROUP SELECTION WITH RANGE REDUCTION IN TOD MULTUSER MMO U.S. PATENT DOCUMENTS DOWNLINK TRANSMISSION 6,052,596 A 4/2000 Barnickel 6,131,031 A 10/2000 Lober et al. (75) Inventors: Chengjin Zhang, La Jolla, CA (US); 6,728.307 B1 4/2004 Derryberry et al. Jun Zheng, La Jolla, CA (US); Pieter (Continued) van Rooyen, San Diego, CA (US) FOREIGN PATENT DOCUMENTS (73) Assignee: Broadcom Corporation, Irvine, CA CN 1574685 A 2, 2005 (US) EP 1265389 A2 12/2002 EP 1505741 A2 2, 2005 (*) Notice: Subject to any disclaimer, the term of this WO WO 2005/06O123 A1 6/2005 past list: sited under 35 OTHER PUBLICATIONS is- Behrouz. Farhang-Boroujeny et al., “Layering Techniques for Space spent is Subject to a terminal dis Time Communication in Multi-User Networks.” Proceedings of the IEEE Vehicular Technology Conference, vol. 2, pp. 1339-1343, IEEE (21) Appl. No.: 13/534,492 (2003). Continued (22) Filed: Jun. 27, 2012 ( ) (65) Prior Publication Data Primary Examiner — Tuan H Nguyen US 2012/O269104A1 Oct. 25, 2012 (74) Attorney, Agent, or Firm — Sterne, Kessler, Goldstein • 1-a-s & Fox PL.L.C. Related U.S. Application Data (63) Continuation of application No. 13/074,692, filed on (57) ABSTRACT continuationMar. 29, 2011, of applicationnow Pat. No. No. 8,233,848, 1 1/231.701, which filed is on a CertaiCertain aspects off a methodhod and system ffor processing signalsignal Sep. -
Structure of IEEE 802.11 Packets at Various Physical Layers
Appendix A: Structure of IEEE 802.11 Packets at Various Physical Layers This appendix gives a detailed description of the structure of packets in IEEE 802.11 for the different physical layers. 1. Packet Format of Frequency Hopping Spread-spectrum Physical Layer (FHSS PHY) The packet is made up of the following elements (Figure A.1): 1.1 Preamble It depends on the physical layer and includes: – Synch: a sequence of 80 bits alterning 0 and 1, used by the physical circuits to select the correct antenna (if more than one are in use), and correct offsets of frequency and synchronization. – SFD: start frame delimiter consists of a pattern of 16 bits: 0000 1100 1011 1101, used to define the beginning of the frame. 1.2 Physical Layer Convergence Protocol Header The Physical Layer Convergence Protocol (PLCP) header is always transmitted at 1 Mbps and carries some logical information used by the physical layer to decode the frame: – Length of word of PLCP PDU (PLW): representing the number of bytes in the packet, useful to the physical layer to detect correctly the end of the packet. – Flag of signalization PLCP (PSF): indicating the supported rate going from 1 to 4.5 Mbps with steps of 0.5 Mbps. Even though the standard gives the combinations of bits for PSF (see Table A.1) to support eight different rates, only the modulations for 1 and 2 Mbps have been defined. – Control error field (HEC): CRC field for error detection of 16 bits (or 32 bits). The polynomial generator used is G(x)=x16 + x12 + x5 +1.