This book teaches readers how wireless networks work, why some of their properties impact wireless network performance at the application level, and what both network engineers and application developers can do to cope with these challenges. Internet users increasingly rely on wireless access links for diverse tasks such as web browsing, video conferencing, interactive games, and data sharing. Irrespective of how they access the Internet, they expect good performance and a high quality of experience. Unfortunately, wireless access networks are much more challenging to build than wired networks. In wired networks, signals used for communication are contained in a carefully engineered transmission medium. In contrast, wireless signals travel in our physical environment, where the presence of obstacles, interference, and mobility can affect communication. In addition, network performance can differ significantly across physical environments. As a result, the performance of wireless links is often lower and less predictable than that of wired links. The author structured the book according to the layers in the Internet protocol stack, similar to traditional network books. However, rather than presenting a general description of each layer, the focus is on wireless networks and how they differ from wired networks.
Author(s): Peter Steenkiste
Series: Synthesis Lectures on Mobile & Pervasive Computing
Publisher: Springer
Year: 2023
Language: English
Pages: 130
City: Cham
Contents
About the Author
1 Introduction
1.1 Goals and Intended Audience
1.2 Structure of the Internet
1.2.1 The Protocol Stack
1.2.2 Benefits of the OSI Model
1.3 Outline of the Lecture
2 The Physical Layer: Sending Bits
2.1 The Wireless Spectrum
2.1.1 Wireless Spectrum Use Examples and Trends
2.1.2 Spectrum Allocation
2.1.3 Licensed Versus Unlicensed Spectrum: Implications for Protocols
2.1.4 Supporting Secondary Users
2.1.5 Mobile Users
2.2 Wireless Communication Basics
2.3 How Do Wireless Signals Travel?
2.3.1 The ``Energy'' View
2.3.2 The ``Ray'' View
2.3.3 The ``Frequency'' View
2.4 Fundamental Limit of Throughput
2.5 Signal Strength Attenuation
2.5.1 Free Space Communication
2.5.2 Communication in Real Environments
2.6 The Multi-path Effect
2.6.1 Multi-path Concepts
2.6.2 Multi-path in Practice
2.6.3 Inter-Symbol Interference
2.7 Mobility: Slow and Fast Fading
2.7.1 Slow Fading
2.7.2 Fast Fading
2.7.3 Impact of Frequency and Speed on Fading
2.8 Channel Reciprocity
3 Optimizing Throughput at the PHY Layer
3.1 Modulation
3.1.1 Tradeoffs in Modulation
3.1.2 Quadrature Amplitude Modulation (QAM)
3.2 Combining Modulation and Forward Error Correction
3.3 Variable Bit Rate Protocols
3.4 Bit Rate Adaptation
3.5 Diversity in Space, Time, and Frequency
3.6 Orthogonal Frequency Division Multiplexing (OFDM)
3.6.1 OFDM Concept
3.6.2 OFDM Optimizations
3.6.3 OFDM Implementation and Use
3.7 Antennas
3.7.1 Performance Considerations
3.7.2 Spatial Diversity: More Antennas is Better!
3.8 Beam Forming
3.9 MIMO and Multi-user MIMO
3.9.1 MIMO
3.9.2 MU-MIMO
3.10 Spread Spectrum
3.10.1 Spread Spectrum Concept
3.10.2 Frequency Hopping Spread Spectrum (FHSS)
3.10.3 Direct Sequence Spread Spectrum (DSSS)
3.10.4 Multiple Access Based on Spread Spectrum
4 Wireless Datalink Protocols
4.1 Why so Many Wireless Protocols?
4.2 Datalink Responsibilities
4.2.1 Framing
4.2.2 Logical Link Control
4.2.3 Error Detection and Recovery
4.2.4 Error Recovery
4.2.5 Media Access Control
4.3 WiFi: High Performance in Unlicensed Spectrum
4.3.1 High Level WiFi Architecture
4.3.2 Wireless MAC Challenges
4.3.3 Wifi Protocol Design
4.3.4 The Basic WiFi Protocol
4.3.5 WiFi Versions
4.3.6 mmWave WiFi
4.3.7 Interoperability
4.3.8 Other WiFi Features
4.3.9 Connecting to a Network Using WiFi
4.3.10 WiFi Deployments
4.3.11 Mobility
4.3.12 WiFi for Special Environments
4.4 Cellular: High Performance in Licensed Spectrum
4.4.1 Cellular Versus WiFi
4.4.2 Origins of Cellular Technology
4.4.3 Cellular Generations
4.4.4 Cellular Network Architecture
4.4.5 LTE PHY and Resource Management
4.4.6 Resource Allocation
4.4.7 LTE Advanced
4.4.8 5G
5 IP and TCP
5.1 IP and Mobility
5.1.1 Internet Protocol Basics
5.1.2 Internet Access for Nomadic Users
5.1.3 Internet Access for Mobile Users
5.2 Impact of Wireless on Application Throughput
5.2.1 Bandwidth Sharing in a Network
5.2.2 TCP Basics
5.2.3 TCP Congestion Control
5.2.4 Impact of RTT on Throughput
5.2.5 Establishing a TCP Session
5.2.6 Impact of Packet Loss
5.2.7 Maintaining a TCP Session While Mobile
5.2.8 Multi-path TCP
6 Applications in Wireless and Mobile Networks
6.1 Application-Centric Metrics for Wireless and Mobile Devices
6.2 Availability
6.2.1 Wireless Coverage
6.2.2 Impact on Mobile Users
6.2.3 Disconnection Operation
6.3 Time to Send an Application Data Unit
6.3.1 ADU Delivery Time
6.3.2 Optimizing Content Delivery
6.4 Resource Constrained Mobile Devices
Bibliography
