The lectures “Mobile Communications” and “Wireless Networks” give an introduction to mobile communication systems. Students gain a fundamental understanding of the principles behind wireless communications and networking. Current technologies — such as LTE and IEEE 802.11 — are discussed as examples. Lectures are complemented by group projects. Tutorial courses are offered by teaching assistants. The content is structured in a bottom-up manner, starting from physical layer, then covering higher layers and networking concepts.
Outline and Schedule
The lectures are structured as follows:
- Introduction and overview
- Radio propagation
- Channel coding and modulation
- Multiple access and cellular concept
- Medium access control (MAC) protocols
- Wireless LAN 802.11
- Network architecture and mobility protocols
- LTE networks
- Security in mobile networks
- Ad hoc networks
- Economic, health, and social aspects
Mobile Communications (Chapters 1-8) is taught in the winter semester (Oct-Jan). Wireless Networks (Chapters 9-12) is taught in the summer semester (Mar-Jun). Each course has 4 ECTS.
Requirements and Related Courses
Both lectures and accompanying exercise courses are intended for senior bachelor students and master students in information and communications engineering or informatics, and first year PhD students in engineering who have a master from a different area. Participants should have passed the bachelor lectures Computer Networks and Network Programming, Communications Engineering, and Stochastics.
Students focusing on networks and communications are encouraged to take the following lectures in the following order: Mobile Communications and Pervasive Computing in the winter semester; Sensor Networks, Wireless Networks, Information Theory, and Simulation of Networked Systems in the summer semester; Signal Processing for Communications and a seminar or project in the winter semester; and Advanced Wireless Communications and Stochastic Modeling and Analysis of Networked Systems in the summer semester.
The handouts for the lectures are available via the links on the course outline shown below. For didactic reasons, the text on the handouts is on purpose incomplete and will be completed in the lecture. Students should bring printouts of the handouts to the lecture. The handouts contain copyrighted material and are not suited for redistribution.
An accompanying exercise course is offered for better understanding, in order to train and deepen the content presented in the lecture. This course includes a set of problems to be solved.
The following textbooks are very useful:
- Schwartz: Mobile Wireless Communications, 2004
- Stüber: Principles of Mobile Communication, 2011
- Goldsmith: Wireless Communications, 2005
- Black et al.: Introduction to Wireless Systems, 2008
- Molisch: Wireless Communications, 2010
Further literature is recommended in some chapters, e.g.:
- Balanis: Antenna Theory: Analysis and Design, 2005
- Eberspächer, Vögel, Bettstetter, Hartmann: GSM: Architecture, Protocols, and Services, 2008
- Cox: An Introduction to LTE, 2012
- Koodli, Perkins: Mobile Inter-networking with IPv6, 2008
- Perkins (Ed.): Ad Hoc Networking, 2001
Feedback from Students
- “It was amazing, I have never enjoyed a course like this one,” a student wrote in the 2017 evaluation.
- “Quality of teaching was at the highest level,” a student wrote in the 2016 evaluation.
Contents and Handouts
1. Introduction and Overview (2 hours)
History of wireless communications. Different kinds of mobility. Overview and classification of current wireless technologies. Key challenges in mobile and wireless systems. Transmission chain.
2. Antennas (3 hours)
Antenna types. How are radio waves generated? Energy and power aspects of radio waves. Directivity and gain. How much power is received at a certain distance?
3. Radio Propagation (8 hours)
- Path Loss and Shadowing: Propagation in free space. Path loss models. Shadow fading. Group project.
- Multipath Propagation: Small-scale fading models: Rayleigh, Rice, Nakagami fading and outage probabilitites. Time spread; frequency spread; time-variant behavior (fade rate, fade duration, Markov chain model); frequency-variant behavior; relationships.
- Overview of Fading Mitigation Techniques: Diversity schemes, equalization, spread-spectrum communications, error control and interleaving, multicarrier modulation.
4. Diversity (2 hours)
Concepts und design space. Time diversity, frequency diversity, spatial diversity. Diversity combining schemes: Selection combining, maximum ratio combining; comparison; and outage probabilies. Other diversity and multiple antenna techniques. Diversity in practice.
- Representation of signals: Fourier series and transform. Bandwidth. Sampling and quantization.
- Channel Coding: Block coding. Convolutional coding. Coding gain. Channel coding in practice. Group project.
- Digital Modulation: Linear modulation. Coherent demodulation. Modulation in practice. Spead spectrum modulation.
6. Multiple Access and Cellular Concept (2.5 hours)
- TDMA, FDMA, CDMA, and SDMA
- Cellular concept and channel reuse
- Group project “Orthogonal Frequency Division Multiplexing (OFDM)”
7. Medium Access Control (MAC) Protocols (3 hours)
- Basic concepts and throughput analysis
- ALOHA and Slotted ALOHA
- CSMA and CSMA/CA
8. Wireless LAN 802.11 (1 hour)
- Architecture of cellular networks: General architecture. System components in GSM, UMTS, and LTE.
- Mobility in cellular networks: Addressing and location updating. Routing to mobile users. Roaming and handover.
- Mobility in the Internet: Addressing and mobility problem. Autoconfiguration. Device mobility with Mobile IP. Service mobility. Group project.
10. LTE Networks (2 hours)
Physical and data-link layer. Protocol architecture. System architecture. LTE advanced.
11. Security in Mobile Networks (2 hours)
Security threats and coutermeasures. User authentication in GSM. User and network authentication in UMTS.