Data Communication Principles (eBook)

For Fixed and Wireless Networks

Aftab Ahmad (Autor)

eBook Download: PDF

2007 | 1. Auflage
293 Seiten
Springer US (Verlag)
978-0-306-47793-5 (ISBN)

Infos

"Data Communication Principles for Fixed and Wireless Networks" focuses on the physical and data link layers. Included are examples that apply to a diversified range of higher level protocols such as TCP/IP, OSI and packet based wireless networks. Performance modeling is introduced for beginners requiring basic mathematics.

Separate discussion has been included on wireless cellular networks performance and on the simulation of networks. Throughout the book, wireless LANS has been given the same level of treatment as fixed network protocols. It is assumed that readers would be familiar with basic mathematics and have some knowledge of binary number systems. "Data Communication Principles for Fixed and Wireless Networks" is for students at the senior undergraduate and first year graduate levels. It can also be used as a reference work for professionals working in the areas of data networks, computer networks and internet protocols.  

Inhalt

Table of Contents 9
Preface 15
1. Computer Communications Networks - Introduction 18
1.1. Main Components 19
1.1.1. The Computer System 19
1.1.2. The Communications System 20
1.1.3. The Networking System 21
1.1.3.1. Communication Systems Versus Networking Systems 21
1.2. Network Development Example 22
1.2.1. Three Role Players 22
1.2.2. Network Design 23
1.2.2.1. User/IT Staff 25
1.2.2.2. Network Provider 25
1.2.2.3. Network Designer/Vendor 25
1.2.2.4. Relevance of the text to the above role players 25
1.3. Standardization 26
1.3.1. Example 1 - Communication of Voice 26
1.3.2. Example 2 - File Transfer 27
1.3.2.1. Circuit Switching 28
1.3.2.2. Packet Switching 29
1.4. Classification of Networks There are several ways of 29
1.4.1. Local Area Networks (LANs) 29
1.4.2. Wide Area Networks (WANs) 29
1.4.3. Metropolitan Area Networks (MANs) 30
1.5. Network Protocol Architecture 30
1.5.1. Protocols 30
1.5.2. Standards 30
1.5.3. Protocol Architecture 31
1.5.3.1. A Protocol Layer 31
1.6. Example of a Protocol Architecture 31
1.6.1. Open System 32
1.7. Summary 32
1.8. Review Questions 33
2. Network Architectures - Examples 34
2.1. The OSI Reference Model (OSI-RM) 35
2.1.1. OSI-RM Characteristics and Terminology 35
2.1.2. Communications Model within an OSI Node 36
2.1.3. Communications Across the OSI Network 39
2.1.4. Inter-layer communication 40
2.1.4.1. The Role of the Lower Layers 41
2.1.5. OSI-RM Layer Definitions and Functions 42
2.1.5.1. The Physical Layer 42
2.1.5.2. The Data Link Control Layer (DLC) 43
2.1.5.3. The Network Layer (NET) 44
2.1.5.3.1. Datagram or Connectionless Switching 45
2.1.5.3.2. Virtual Circuit (VC) Switching 45
2.1.5.3.3. Circuit Switching (CS) 46
2.1.5.3.4. A Comparison of Switching Schemes 47
2.1.5.3.5. Quality of Service (QoS) 47
2.1.5.4. The Transport Layer (TL) 51
2.1.5.5. The Session Layer 51
2.1.5.6. The Presentation Layer 51
2.1.5.7. The Application Layer 52
2.2. The TCP/IP Protocol Suite 53
2.2.1. The Internet Protocol (IP) 56
2.2.2. The Transmission Control Protocol (TCP) 57
2.2.3. The Application Protocols for the Internet 58
2.2.4. Lower Layers of the Internet 58
2.3. The IEEE Wireless Local Area Network (IEEE WLAN) 59
2.3.1. Local Area Networks 59
2.3.2. Wireless Local Area Networks 60
2.3.3. The Physical Layer (PHY) 62
2.3.3.1. Spread Spectrum Communications 63
2.3.4. The Medium Access Control (MAC) Layer 63
2.3.4.1. Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) 64
2.4. Framework for Studying a Protocol 64
2.5. Standardization of Protocols 65
2.5.1. International Telecommunications Union (ITU) 66
2.5.2. The Internet Society 66
2.5.2.1. Internet Architecture Board (IAB) 66
2.5.2.2. Internet Engineering Steering Group (IESG) 67
2.5.2.3. Internet Engineering Task Force (IETF) 67
2.5.3. International Organization for Standardization (ISO) 67
2.5.4. European Telecommunications Standards Institute (ETSI) 67
2.5.5. American National Standard Institute (ANSI) 67
2.5.6. Institute of Electrical and Electronic Engineers (IEEE) 68
2.6. Summary 69
2.7. Review Questions 70
3. Network and User Data 72
3.1. The Network Data 73
3.2. The Physical Layer Data 74
3.2.1. Sequence of Events and Definitions 74
3.2.2. Modulation of data and signals 84
3.2.2.1. Baseband and Passband Modulations 85
3.2.3. Digital Encoding of Data 87
3.2.4. Non-Return to Zero (NRZ) 88
3.2.5. Multilevel Encoding 89
3.2.5.1. Bipolar-AMI (Alternative Mark-Inversion) Coding 90
3.2.5.2. Multi-level 3 (MLT-3) Coding 90
3.2.6. Manchester Coding 90
3.2.7. General Characteristics of Bit Encoding 91
3.2.8. Zero-substitution and nB/NB Translation 92
3.3. Passband Modulation 93
3.3.1. The Carrier Signal 93
3.3.2. Analog Modulation 94
3.3.2.1. Amplitude Modulation (AM) 95
3.3.2.2. Angle Modulation 96
3.4. Digital Modulation 97
3.4.1. Amplitude Shift Keying (ASK) 97
3.4.2. Frequency Shift Keying (FSK) 98
3.4.3. Phase Shift Keying (PSK) 99
3.4.3.1. Quadrature Phase Shift Keying (QPSK) 99
3.4.3.2. Signal Constellation 100
3.5. The User Data 101
3.5.1. Digital Transmission of Voice 101
3.5.2. The Sampling Theorem 102
3.5.3. Pulse Coded Modulation (PCM) 102
3.5.4. Delta Modulation 108
3.6. Text and Numerical Data 110
3.6.1. ASCII (American National Standard Code for Information Interchange) 111
3.6.1.1. ASCII and Other Standard Organizations 112
3.6.2. ISO 8859-1 (ISO Latin -1) 112
3.6.3. UCS (Universal multiple-octet coded Character Set) 113
3.7. Summary 115
3.8. Review Questions 116
4. The Physical Layer 118
4.1. Channel Impairments 119
4.1.1. Signal Attenuation 119
4.1.1.1. Attenuation and Propagation Loss 119
4.1.2. Delay Distortion 121
4.1.3. Noise 122
4.1.3.1. Thermal Noise 123
4.1.3.2. Crosstalk 123
4.1.3.3. Impulse Noise 123
4.1.4. Multipath 123
4.2. Transmission Media 124
4.3. Cables in data communications 125
4.3.1. Twisted Pair Copper Cables 125
4.3.2. Co-axial Cable 127
4.3.3. Optical Fiber Cable (OFC) 128
4.4. The Wireless Media 128
4.4.1. Characteristics 129
4.4.2. Examples of Wireless Bands 129
4.5. Physical Layer Protocol Example: EIA-232-F 130
4.5.1. Mechanical Characteristics 131
4.5.2. Electrical Characteristics 133
4.5.3. Functional Characteristics 133
4.5.4. Procedural Characteristics 135
4.5.4.1. Call setup for full-duplex connection 135
4.5.4.2. Call setup for half-duplex connection 136
4.5.4.3. Loopback Testing 136
4.5.4.4. The NULL Modem 137
4.5.5. PHY for IEEE Wireless Local Area Network 138
4.5.6. WLAN Types 139
4.5.7. Frequency Hopping Spread Spectrum (FH-SS) for 2.4 GHz Specification 140
4.5.7.1. PLCP for frequency hopping 141
4.5.7.2. The PMD for Frequency Hopping Spread Spectrum 142
4.5.8. Direct Sequence Spread Spectrum (DS-SS) for 2.4 GHz Specification 143
4.5.9. Infrared PHY for IEEE WLAN 144
4.6. The Integrated Services Digital Network (ISDN) PHY 145
4.7. Review Questions 147
5. Data Link Control Layer Functions and Procedures 148
5.1. Data Link Layer Functions 149
5.1.1. Synchronization 149
5.1.2. Addressing Modes 149
5.1.3. Connection setup and termination 150
5.1.4. Error Control 150
5.1.5. Flow Control 150
5.1.6. Link Control and Testing 150
5.1.7. Multiplexing 151
5.2. Synchronization 151
5.2.1. Synchronous Transmission 151
5.2.1.1. Bit Stuffing 152
5.2.2. Asynchronous Transmission 153
5.3. Connection Setup and Termination 156
5.4. Addressing 157
5.5. Error Control 159
5.5.1. Parity bit 161
5.5.2. Block Error Check 163
5.5.3. The Cyclic Redundancy Check (CRC) 163
5.5.3.1. Parity block generation 164
5.5.3.2. Error Detection Procedure 165
5.5.3.3. Polynomial representation of binary numbers 168
5.5.3.4. Implementation of CRC 170
5.5.3.5. How to Decide C(X) 172
5.5.3.6. Error Detection Power of CRC 172
5.5.3.7. Error Recovery Mechanisms 173
5.6. Flow Control 173
5.6.1. Stop-and-Wait (SnW) Flow Control 173
5.6.2. The Sliding-windows (SW) Flow Control Mechanism 175
5.6.3. Link Utilization of Window Flow Control Mechanisms 179
5.6.4. Full-duplex Communications Using Window Flow Control 180
5.7. Flow Control Based Error Recovery Mechanisms 181
5.7.1. Stop-and-Wait ARQ 181
5.7.2. Go-Back-N ARQ 182
5.7.2.1. Full-duplex operation 182
5.7.2.2. Piggybacking 182
5.7.3. Selective Reject ARQ 183
5.7.4. Maximum Window Size 184
5.8. Link Control and Testing 185
5.9. Review Questions 186
6. Data Link Control Layer Protocol Examples 188
6.1. HDLC (High-level Data Link Control) Protocol 189
6.2. HDLC Frame Types 189
6.3. HDLC station types 193
6.3.1. Primary station 193
6.3.2. Secondary station 193
6.3.3. Combined stations 193
6.4. Operation modes 193
6.4.1. Normal Response Mode (NRM) 193
6.4.2. Asynchronous Balanced Mode (ABM) 193
6.4.3. Asynchronous Response Mode (ARM) 194
6.4.4. Extended Modes 194
6.5. The HDLC Frame 194
6.5.1. Flag 194
6.5.2. Address Field 194
6.5.2.1. Extended address format 195
6.5.3. Frame Check Sequence (FCS) 195
6.6. HDLC Protocol Operation 195
6.6.1. Selection of Timeout 196
6.6.2. Connection Setup and Termination 196
6.6.3. Data Exchange 197
6.6.3.1. Half-duplex Connection 198
6.6.3.2. Use of RR and RNR for Busy Condition Notice and Recovery 201
6.6.3.3. Use of REJ and SREJ 201
6.7. Asynchronous Transfer Mode (ATM) Protocol 202
6.7.1. The ATM Cell 203
6.7.1.1. Generic Flow Control (GFC) 203
6.7.1.2. Virtual Path/Channel Identifiers (VPI/VCI) 204
6.7.1.3. Control Bits 206
6.7.1.4. Header Error Control (HEC) 207
6.8. ATM Protocol Procedures 208
6.8.1. Virtual circuit and the frame relay protocol 208
6.8.2. Error Control 209
6.9. Medium Access Control (MAC) Layer for IEEE Wireless LANs 210
6.9.1. Random Access in LANs 211
6.9.2. Collision Avoidance 212
6.9.3. The Distributed Coordination Function (DCF) 213
6.9.3.1. Interframe Spacing (IFS) 214
6.9.4. MAC Frame Structure 214
6.9.5. MAC Frame Types 215
6.10. Review Questions 217
7. Multiplexing and Carrier Systems 218
7.1. Analog and Digital Transmissions 219
7.1.1. Analog and Digital Multiplexing 219
7.1.2. Frequency Division Multiplexing (FDM) 220
7.1.3. Frequency Division Duplexing (FDD) 221
7.1.4. Time Division Multiplexing (TDM) 222
7.1.5. Synchronous TDM 222
7.1.6. Statistical TDM 223
7.1.7. Statistical Versus Synchronous TDM 225
7.1.8. The TDM Switch 226
7.1.8.1. Framing 227
7.1.8.2. Pulse stuffing 228
7.2. Digital Carrier Systems 228
7.3. The DS-1 Carrier System 229
7.3.1. Total Bit Rate 230
7.3.2. Signaling Information 230
7.3.3. Problems with T-1/E-1 Systems 231
7.4. Synchronous Optical Network/ Synchronous Digital Hierarchy 232
7.5. Digital Subscriber’s Line (DSL) 234
7.5.1.8.1. Integration With Telephone 235
7.6. Multiplexing at higher layers 235
7.6.1. Multiple Protocols Per Layer With Connection-oriented Mode 236
7.6.2. Multiple Connections Per Protocol 237
7.7. Review Questions 239
8. The Network and Higher Layer Functions 240
8.1. The Network Layer 241
8.2. Typical Functions of Network layer 242
8.2.1. Connectionless Network Layers 242
8.2.2. Connection-oriented Mode 246
8.3. The End-to-end Layers 247
8.4. X.25 Packet Layer Protocol 249
8.4.1. X.25 Packet Types 250
8.5. Review Questions 253
9. Performance Models for Data Networks 254
9.1. The Network Performance 255
9.2. Performance of the Physical Layer Protocols 256
9.2.1. Performance Improvement at PHY 257
9.2.1.1. Channel Errors 257
9.2.1.2. Receiver Accuracy 258
9.3. Data Link Layer Performance 259
9.3.1. Flow Control Procedures 260
9.3.2. Error Control Procedures 263
9.3.2.1. Performance Models for FEC and BEC 263
9.4. Performance of the MAC Sublayer 265
9.5. Performance of the network and higher layers 266
9.5.1. Connectionless and Connection-oriented Protocols 267
9.5.2. QoS Differentiation in Connectionless Protocols 269
9.5.2.1. Priority Queueing 269
9.5.2.2. Fair Queueing 270
9.5.2.3. Custom Queueing 270
9.5.3. Performance of End-to-end Protocols 271
9.6. System Simulation for Performance Prediction 272
9.6.1. What is Simulation? 272
9.6.1.1. What is a Random Number? 273
9.6.1.2. The Uniform Random Variable 273
9.6.1.3. What is a Pseudorandom Number? 274
9.6.2. Designing a Simulation Program Versus Using a Package 274
9.7. Performance of Wireless and Mobile Networks 274
9.7.1. The Wireless Network Channel 275
9.7.1.1. Propagation Loss 275
9.7.1.2. Interference 275
9.7.1.3. Frequency Selectiveness 276
9.7.1.4. Time Selectiveness 277
9.7.1.5. Multipath 278
9.7.1.6. Diversity 278
9.7.2. Resource Management in Wireless Networks 279
9.7.3. Mobility Management in Mobile Networks 281
9.7.3.1. Handoff 282
9.7.3.2. Registration 282
9.8. Review Questions 283
References 284
Index 290
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7. Multiplexing and Carrier Systems (p.202)

In earlier chapters, we learnt that the channel bandwidth must be greater than or equal to the signal bandwidth for a successful transmission of a data signal. The channel bandwidth sometimes limits the ability of the user equipment to transmit information. Historically, there have been three ways used to achieve higher data rates. One simple way is to use channels with higher bandwidths. The second mechanism is to design modulation and coding mechanisms to use the available bandwidth more efficiently. The bandwidth efficient modulation and coding schemes result in higher data rates per unit bandwidth, thus increasing the data rates achievable in a channel for a given channel bandwidth. This technique has resulted in gradual increase in the data rates of the telephone line MODEM.

The third important factor contributing to the increased data rates is the improvements in cable manufacturing. This has helped in many ways and can be considered as a part of the first mechanism. Not only higher bandwidth cables are available these days, but also there are ways to allow higher data rates on the already existing cable types. This is possible due to the developments in manufacturing cables with fewer impurities and ones using special circuitry to undo many channel impairments. The cable technology has influenced telecommunications to a point that even new protocols have been introduced with reduced processing. An example of such protocols is the frame relay technology that minimizes processing at layer 2 in order to achieve higher end-to-end throughputs.

Most of the long haul telecommunications transmission systems, however, use channels with much higher bandwidths than a single user signal would need. Many users share each of these high-speed channels. Multiplexing is the mechanism used for channel sharing. In this Chapter, we will look at the difference between two types of transmissions once more, the digital and analog transmissions. We will then define multiplexing schemes that can be used with either type of transmission. In the end, we will look into digital multiplexing in greater detail and discuss carrier systems using digital multiplexing. A carrier system is the term used to describe the transmission systems typically used for long-haul communications for private and public networks. These systems provide a set of standard bandwidths or data rates from which a user can choose. The equipment is designed according to the carrier system it will use, conforming to the signal and transmission formats.

Multiplexing is mostly discussed with reference to the physical layer of the OSI-RM. The fact is that all layers make use of multiplexing. It is one of the functions that can be provided at any layer to open more than one simultaneous connections. Our main focus is on multiplexing at the physical layer, but we will also include a section on multiplexing at other layers.

Produkt-Details

• Erscheint lt. Verlag: 8.5.2007
• Sprache: englisch
• Themenwelt: Mathematik / Informatik ► Informatik ► Netzwerke
• Themenwelt: Informatik ► Weitere Themen ► Hardware
• Themenwelt: Technik ► Elektrotechnik / Energietechnik
• Themenwelt: Technik ► Nachrichtentechnik
• ISBN-10: 0-306-47793-9 / 0306477939
• ISBN-13: 978-0-306-47793-5 / 9780306477935