Traffic Engineering Concepts for Cellular Packet Radio Networks
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Reservation - Time Division Multiple Access Protocols for Wireless Personal Communications
tv '2s.\--qq T! Reservation - Time Division Multiple Access Protocols for Wireless Personal Communications Theodore V. Buot B.S.Eng (Electro&Comm), M.Eng (Telecomm) Thesis submitted for the degree of Doctor of Philosophy 1n The University of Adelaide Faculty of Engineering Department of Electrical and Electronic Engineering August 1997 Contents Abstract IY Declaration Y Acknowledgments YI List of Publications Yrt List of Abbreviations Ylu Symbols and Notations xi Preface xtv L.Introduction 1 Background, Problems and Trends in Personal Communications and description of this work 2. Literature Review t2 2.1 ALOHA and Random Access Protocols I4 2.1.1 Improvements of the ALOHA Protocol 15 2.1.2 Other RMA Algorithms t6 2.1.3 Random Access Protocols with Channel Sensing 16 2.1.4 Spread Spectrum Multiple Access I7 2.2Fixed Assignment and DAMA Protocols 18 2.3 Protocols for Future Wireless Communications I9 2.3.1 Packet Voice Communications t9 2.3.2Reservation based Protocols for Packet Switching 20 2.3.3 Voice and Data Integration in TDMA Systems 23 3. Teletraffic Source Models for R-TDMA 25 3.1 Arrival Process 26 3.2 Message Length Distribution 29 3.3 Smoothing Effect of Buffered Users 30 3.4 Speech Packet Generation 32 3.4.1 Model for Fast SAD with Hangover 35 3.4.2Bffect of Hangover to the Speech Quality 38 3.5 Video Traffic Models 40 3.5.1 Infinite State Markovian Video Source Model 41 3.5.2 AutoRegressive Video Source Model 43 3.5.3 VBR Source with Channel Load Feedback 43 3.6 Summary 46 4. -
Reuters Institute Digital News Report 2020
Reuters Institute Digital News Report 2020 Reuters Institute Digital News Report 2020 Nic Newman with Richard Fletcher, Anne Schulz, Simge Andı, and Rasmus Kleis Nielsen Supported by Surveyed by © Reuters Institute for the Study of Journalism Reuters Institute for the Study of Journalism / Digital News Report 2020 4 Contents Foreword by Rasmus Kleis Nielsen 5 3.15 Netherlands 76 Methodology 6 3.16 Norway 77 Authorship and Research Acknowledgements 7 3.17 Poland 78 3.18 Portugal 79 SECTION 1 3.19 Romania 80 Executive Summary and Key Findings by Nic Newman 9 3.20 Slovakia 81 3.21 Spain 82 SECTION 2 3.22 Sweden 83 Further Analysis and International Comparison 33 3.23 Switzerland 84 2.1 How and Why People are Paying for Online News 34 3.24 Turkey 85 2.2 The Resurgence and Importance of Email Newsletters 38 AMERICAS 2.3 How Do People Want the Media to Cover Politics? 42 3.25 United States 88 2.4 Global Turmoil in the Neighbourhood: 3.26 Argentina 89 Problems Mount for Regional and Local News 47 3.27 Brazil 90 2.5 How People Access News about Climate Change 52 3.28 Canada 91 3.29 Chile 92 SECTION 3 3.30 Mexico 93 Country and Market Data 59 ASIA PACIFIC EUROPE 3.31 Australia 96 3.01 United Kingdom 62 3.32 Hong Kong 97 3.02 Austria 63 3.33 Japan 98 3.03 Belgium 64 3.34 Malaysia 99 3.04 Bulgaria 65 3.35 Philippines 100 3.05 Croatia 66 3.36 Singapore 101 3.06 Czech Republic 67 3.37 South Korea 102 3.07 Denmark 68 3.38 Taiwan 103 3.08 Finland 69 AFRICA 3.09 France 70 3.39 Kenya 106 3.10 Germany 71 3.40 South Africa 107 3.11 Greece 72 3.12 Hungary 73 SECTION 4 3.13 Ireland 74 References and Selected Publications 109 3.14 Italy 75 4 / 5 Foreword Professor Rasmus Kleis Nielsen Director, Reuters Institute for the Study of Journalism (RISJ) The coronavirus crisis is having a profound impact not just on Our main survey this year covered respondents in 40 markets, our health and our communities, but also on the news media. -
Network Traffic Modeling
Chapter in The Handbook of Computer Networks, Hossein Bidgoli (ed.), Wiley, to appear 2007 Network Traffic Modeling Thomas M. Chen Southern Methodist University, Dallas, Texas OUTLINE: 1. Introduction 1.1. Packets, flows, and sessions 1.2. The modeling process 1.3. Uses of traffic models 2. Source Traffic Statistics 2.1. Simple statistics 2.2. Burstiness measures 2.3. Long range dependence and self similarity 2.4. Multiresolution timescale 2.5. Scaling 3. Continuous-Time Source Models 3.1. Traditional Poisson process 3.2. Simple on/off model 3.3. Markov modulated Poisson process (MMPP) 3.4. Stochastic fluid model 3.5. Fractional Brownian motion 4. Discrete-Time Source Models 4.1. Time series 4.2. Box-Jenkins methodology 5. Application-Specific Models 5.1. Web traffic 5.2. Peer-to-peer traffic 5.3. Video 6. Access Regulated Sources 6.1. Leaky bucket regulated sources 6.2. Bounding-interval-dependent (BIND) model 7. Congestion-Dependent Flows 7.1. TCP flows with congestion avoidance 7.2. TCP flows with active queue management 8. Conclusions 1 KEY WORDS: traffic model, burstiness, long range dependence, policing, self similarity, stochastic fluid, time series, Poisson process, Markov modulated process, transmission control protocol (TCP). ABSTRACT From the viewpoint of a service provider, demands on the network are not entirely predictable. Traffic modeling is the problem of representing our understanding of dynamic demands by stochastic processes. Accurate traffic models are necessary for service providers to properly maintain quality of service. Many traffic models have been developed based on traffic measurement data. This chapter gives an overview of a number of common continuous-time and discrete-time traffic models. -
Second Grade Teacher Reading Academy
Phonics and Spelling Second Grade Teacher Reading Academy These materials are copyrighted © by and are the property of the University of Texas System and the Texas Education Agency. ©2009 2TRA: Phonics and Spelling Handout 1 (1 of 1) Learning to Read and Spell Alphabet Pattern Meaning The alphabetic principl e Knowledge of spelling or Structural units or groups matches letters, singly or syllable patterns and their of letters, such as prefixes, in combinations, to common pronunciations suffixes, and Greek or sounds in a left-to-right can help students read Latin roots or base words sequence to read and spell and spell words. focus on meaning and the words. morphological characteristics that represent consistent spellings and/or pronunciations (words with similar meanings are often spelled the same and/or pronounced the same). Examples: Examples: Examples: blending together the /ade/ in made, fade, define and definition sounds /s/ /a/ /t/ to read shade, trade or write the word, sat Adapted from Bear, D. R., Invernizzi, M., Templeton, S., & Johnston, F. (2000). Words their way: Word study for phonics, vocabulary and spelling instruction. (2nd ed.). Upper Saddle River, NJ: Merrill. ©2009 University of Texas/Texas Education Agency 2TRA: Phonics and Spelling Handout 2 (1 of 1) Reading Processes in Spanish Los Procesos de Lectura en Español The four reading processes can be applied to both English and Spanish. Decoding - Decodificación In Spanish, it is essential for students to be able to segment, delete, and manipulate individual phonemes. Students learn to blend sounds at the phoneme level to read syllables and words. Example: /s/ /o/ /l/ = sol Sight - Reconocimiento automático de palabras Although the Spanish language has a regular phonetic system, there are certain syllables or spelling patterns that have to be learned so they can be recognized and read automatically. -
Ethernet LAN (Angolul Link Layer) NET
Computer Networks Sándor Laki ELTE-Ericsson Communication Networks Laboratory ELTE FI – Department Of Information Systems [email protected] http://lakis.web.elte.hu Based on the slides of Laurent Vanbever. Further inspiration: Scott Shenker & Jennifer Rexford & Phillipa Gill Last week on Computer Networks Overview What is a network made of? Three main components End-points Switches Links Overview How to share network resources? Resource handling Two different approaches for sharing Reservation On-demand Reserve the needed Send data when needed bandwidth in advance Packet-level multiplexing Flow-level multiplexing Pros & Cons Pros Cons Predictable performance Low efficiency Bursty traffic Short flows Simple and fast switching Complexity of circuit establ./teard. once circuit established Increased delay New circuit is needed in case of failures Implementation Reservation On-demand Circuit-switching Packet-switching e.g. landline phone networks e.g. Internet Packets Overview How to organize the network? Tier-1 ISP Tier-1 ISP IXP Tier-2 ISP Tier-2 ISP Access ISP Access ISP This week How does communication happen? How do we characterize it? Briefly… The Internet should allow processes on different hosts to exchange data everything else is just commentary… Ok, but how to do that in a complex system like the Internet? University net Phone company CabelTV company Enterprise net To exchange data, Alice and Bob use a set of network protocols Alice Bob A protocol is like a conversational convention The protocol defines the order and rules the parties -
Internet Research: Comments on Formulating the Problem
Internet Research: Comments on Formulating the Problem Gathered by Sally Floyd, with contributions from Deborah Estrin, Greg Minshall, Vern Paxson, Lixia Zhang, and others. January 21, 1998 1 Introduction Development and deployment in the infrastructure is of necessity incremental. This note contains a discussion about formulating the research Explicit examined assumptions are better than implicit un- problem for Internet research. examined ones. The goal of this note is to further the discussion of implicit Changes in the Internet can be unanticipated and uncon- and explicit assumptions in network research. In particular, trolled. this note tries to articulate one such set of assumptions for In- The Internet architecture and scale make requirements for ternet research. Each of these assumptions is shared by some global consistency problematic. subset of the network research community, though perhaps Some research problems have their own natural time none of these assumptions are shared universally. The goal scales. of this paper is not to argue the validity of the assumptions, but to articulate them, to invite discussion of con¯icting or shared sets of assumptions, and to consider the implications 3 Discussion of the assumptions of these assumptions in formulating problems in Internet re- search. This process would aim for both a greater convergence Robustness is more important than ef®ciency. of underlying assumptions, and a more explicit and examined Robustness has been one of the great strengths of the Inter- discussion of those assumptions. net, integral to its design from the very beginning [Clark88]. In some sense, this note is in the tradition of Shenker et al.©s One of our overriding assumptions is that it is critical not to paper on ºPricing in Computer Networks: Reshaping the Re- subordinate robustness to the goal of more closely approxi- search Agendaº [Shenker96], which is a discussion about for- mating optimal ef®ciency. -
Third Annual Workshop on Meteorological and Environmental Inputs to Aviation Systems
National Aeronautics and Space Ad ministration NASA CP-2104 PROCEEDINGS: THIRD ANNUAL WORKSHOP ON METEOROLOGICAL AND ENVIRONMENTAL INPUTS TO AVIATION SYSTEMS APRIL 3-5,1979 UNIVERSITY OF TENNESSEE SPACE INSTITUTE EDITORS: DENNIS W. CAMP WALTER FROST FAA-RD-79-49 i APPROVAL PROCEEDINGS: THIRD ANNUAL WORKSHOP ON METEOROLOGICAL AND ENVIRONMENTAL INPUTS TO AVIATION SYSTEMS Edited by Dennis W. Camp and Walter Frost The i formation in this report has been reviewed for t chni a1 content. Review of any information concerning Department of Defense or nuclear energy activities or programs has been made by the MSFC Security Classification Officer. This report, in its entirety, has been deter- mined to be unclassified. ahcmCHARLES A. LUNDQUIST / Director, Space Sciences Laboratory TECHNICAL REPORT STANDARD TITLE PAGE 1 REPORT NO, 12 GOVERNNENT ACCESSION NO. 13 RECIPIENT’S CATALOG NO. Proceedings. Third Annual Workshop on Meteorological and Environmental Inputs to Aviation Systems 6 PERFORMING ORGANIZATION CODE The University of Tennessee Space Institute Tullahoma, Tennessee 37388 12 SPONSORING AGENCY NAME AND ADDRESS Conference Publicat ion istration, Washington, D C 20553 mospheric Administration, The proceedings of a workshop on meteorological and environmental inputs to aviation systems held at The University of Tennessee Space Institute, Tullahoma, Tennessee, Apr.11 3-5, 1979, are reported The workshop was jointly sponsored by NASA, NOAA, and FAA and brought together many disciplines of the aviation communities in round table discussions The -
A DSP GMSK Modem for Mobitex and Other Wireless Infrastructures
A DSP GMSK Modem for Mobitex and Other Wireless Infrastructures Appliation Report Etienne J. Resweber Synetcom Digital Incorporated SPRA139 October 1994 Printed on Recycled Paper IMPORTANT NOTICE Texas Instruments (TI) reserves the right to make changes to its products or to discontinue any semiconductor product or service without notice, and advises its customers to obtain the latest version of relevant information to verify, before placing orders, that the information being relied on is current. TI warrants performance of its semiconductor products and related software to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed, except those mandated by government requirements. Certain applications using semiconductor products may involve potential risks of death, personal injury, or severe property or environmental damage (“Critical Applications”). TI SEMICONDUCTOR PRODUCTS ARE NOT DESIGNED, INTENDED, AUTHORIZED, OR WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT APPLICATIONS, DEVICES OR SYSTEMS OR OTHER CRITICAL APPLICATIONS. Inclusion of TI products in such applications is understood to be fully at the risk of the customer. Use of TI products in such applications requires the written approval of an appropriate TI officer. Questions concerning potential risk applications should be directed to TI through a local SC sales office. In order to minimize risks associated with the customer’s applications, adequate design and operating safeguards should be provided by the customer to minimize inherent or procedural hazards. -
A Survey of Mobile Data Networks
A SURVEY OF MOBILE DATA NETWORKS APOSTOLIS K. SALKINTZIS THE UNIVERSITY OF BRITISH COLUMBIA ABSTRACT The proliferation and development of cellular voice systems over the past several years has exposed the capabilities and the effectiveness of wireless communications and, thus, has paved the way for wide-area wireless data applications as well. The demand for such applications is currently experiencing a significant increase and, therefore, there is a strong call for advanced and efficient mobile data technologies. This article deals with these mobile data technologies and aims to exhibit their potential. It provides a thorough survey of the most important mobile packet data services and technologies, including MOBITEX, CDPD, ARDIS, and the emerging GPRS. For each technology, the article outlines its main technical characteristics, discusses its architectural aspects, and explains the medium access protocol, the services provided, and the mobile routing scheme. istorically, wireless data communications was princi- and have access to external data, wireless data technology pally the domain of large companies with special- plays a significant part because it can offer ubiquitous con- ized needs; for example, large organizations that nectivity, that is, connectivity at any place, any time. For this needed to stay in touch with their mobile sales reason, wireless data technology can be of real value to the Hforce, or delivery services that needed to keep track of their business world since computer users become more productive vehicles and packages. However, this situation is steadily when they exploit the benefits of connectivity. The explosive changing and wireless data communications is becoming as growth of local area network (LAN) installations over the commonplace as its wired counterpart. -
Lecture #9 3G & 4G Mobile Systems E-716-A
Integrated Technical Education Cluster Banna - At AlAmeeria © Ahmad El E-716-A Mobile Communications Systems Lecture #9 3G & 4G Mobile Systems Instructor: Dr. Ahmad El-Banna December 2014 1 Ok, let’s change ! change Ok, let’s 2 E-716-A, Lec#9 , Dec 2014 © Ahmad El-Banna Banna Agenda - Evolution from 2G to 3G © Ahmad El 3G Systems Objectives Alternative Interfaces UMTS , Lec#9 , Dec 2014 Dec Lec#9 , , A - 716 3.5G (HSPA) - E 4G (LTE) 3 Evolution from 2G Banna - 2G IS-95 GSM- IS-136 & PDC © Ahmad El GPRS IS-95B 2.5G HSCSD EDGE , Lec#9 , Dec 2014 Dec Lec#9 , , A - 716 - E Cdma2000-1xRTT W-CDMA 3G EDGE Cdma2000-1xEV,DV,DO 4 TD-SCDMA Cdma2000-3xRTT 3GPP2 3GPP Banna GSM to 3G - High Speed Circuit Switched Data Dedicate up to 4 timeslots for data connection ~ 50 kbps Good for real-time applications c.w. GPRS Inefficient -> ties up resources, even when nothing sent © Ahmad El Not as popular as GPRS (many skipping HSCSD) Enhanced Data Rates for Global Evolution GSM HSCSD Uses 8PSK modulation 9.6kbps (one timeslot) 3x improvement in data rate on short distances GSM Data Can fall back to GMSK for greater distances Also called CSD Combine with GPRS (EGPRS) ~ 384 kbps , Lec#9 , Dec 2014 Dec Lec#9 , , A Can also be combined with HSCSD - GSM GPRS 716 WCDMA - E General Packet Radio Services Data rates up to ~ 115 kbps EDGE Max: 8 timeslots used as any one time Packet switched; resources not tied up all the time 5 Contention based. -
F5 and the Growing Role of GTP for Traffic Shaping, Network Slicing, Iot, and Security
OVERVIEW F5 and the Growing Role of GTP for Traffic Shaping, Network Slicing, IoT, and Security For years, F5 BIG-IP solutions have managed GPRS Tunneling Protocol (GTP) traffic. Now, in part due to EU regulations, GTP traffic growth is much higher than ever before. International trends show that mobile data is increasing, as is the demand for smart and secure GTP traffic handling. In this document, we will explain GTP, where it is typically used, and where BIG-IP solutions provide significant value. What is GTP? GTP is a group of IP-based communication protocols used to carry General Packet Radio Service (GPRS) within GSM, UMTS, and LTE networks. In 3GPP architectures, GTP and Proxy Mobile IPv6-based interfaces are specified on various interface points. GTP in GPRS (2.5G and 3G) Networks GTP is a set of three separate protocols: GTP Control (GTP-C), GTP User (GTP-U), and GTP Prime (GTP’). GTP-C is used within the GPRS core network for signaling between gateway GPRS support nodes (GGSN) and serving GPRS support nodes (SGSN), as demonstrated by the Gn interface on the diagram below. GTP-C allows the SGSN to activate and deactivate a user’s session, adjust quality- of-service parameters, or update sessions when subscribers arrive from another SGSN. HLR MSC Gr Gs luPS Internet Gi Gn SGSN RNC UMTS Radio Network (RAN) GGSN Gb Corporate SGSN PCU GSM Radio Network Network (BSS) Figure 1: GTP in GPRS (2.5G and 3G networks). OVERVIEW | F5 and the Growing Role of GTP 2 GTP-U carries user data within the GPRS core network, and between the radio access network and core network. -
Cox Digital Telephone Rates
No equipment warrantkls aro pwvided under this pian. Customer wilt be charged 'Of servk:e call due to Call Forwarding - Remote Access $ 4.50 N/A faUed self-inmalJ. 20iscovery Tier is tree with the Movie, Variety, $porta & tnfo tiers Of Paquete latino. Call Forwarding on Call Waiting $ 325 N/A 3o1gltal Galeway required. 4Cable modem· rental or purchase required. service may not be available In Call Number Block - per call No charge N/A all areas. 5$41.99 service cal charge may apply 10 non-CSAP custO<Tlf>f; fee Is waived Wservice issue Is Call Retum Last Number Inboun~ $ 3.90 $ 070 relaled to Cox equipmenl. Call Trace N/A $ 1.00 Call Waiting $ 3.45 N/A Rates and programming subte<;t to mange wfthout notK;e. Caller ID $ 7.40 N/A Caller ID Per Use Blocking No charge N/A Long Distance Alert $ 3.15 N/A Line Number Block No charge N/A Cox Digital Telephone Rates i'riority Ringing5 $ 2.70 N/A Calling Packages Distinctive Ring $ 3.50 NlA Cox Unlimited Connection Selective Call Acceptance $ 3.60 N/A '$39.9513-Product Bundle ·$44.9512-Produet Bundle ·$49.951Phone Only Selective Call FOIWarding $ 3.60 N/A Includes unlimited local and nalionwide Cox LO, plus these Selective Call Rej~ion $ 3.60 N/A 16 leatures (Voice Mail is optional): • Call FOIwarding Three Way Calling $ 3.40 $ 0.70 • Call Waiting' Speed Dial 8 • Caller 10· Three-Way Calling 9001976 Restriction No charge N/A • Call Return • Busy Une Redial· Selective Call Acceptance Toll Restriction $ t.50 N/A • Selective Call Rejection • Call Forwarding - Busy Speed Dial 8 $ 1.40 N/A • Call Forwarding - No Answer' Call FOIWarding on Call Waiting Voice Mail $ 4.95 N/A • Priority Ringing' Long Distance Alert • Call Waiting 10 Voice Mail Pager $ 6.95 N/A • Selective Call Forwarding' Voice Mail Home Office, Voice Mall and fax .