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 4G/5G 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
- Antennas
- Radio propagation
- Diversity
- Channel coding and modulation
- Multiple access and cellular concept
- Medium access control (MAC) protocols
- Wireless LAN 802.11
- Network architecture and mobility protocols
- 4G and 5G networks
- Security in mobile networks
- Ad hoc networks
- Economic, health, and societal 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.
The course dates, time, and location can be found at the university site. You can also subscribe to the iCalendar feed using your calendar software (e.g., Apple calendar, Outlook, Google calendar).
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.
Handouts and recordings
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 purposely incomplete and will be completed in the lecture. Students should bring printouts of the handouts to the lecture. Scribe and audio recordings are available for most units. The material contains copyrighted material and is not suited for redistribution.
Exercises
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.
Literature
The following textbooks are very useful:
- Schwartz: Mobile Wireless Communications, 2004
- Popovski: Wireless Connectivity, 2020
- Goldsmith: Wireless Communications, 2005
- Molisch: Wireless Communications, 2010
- Black et al.: Introduction to Wireless Systems, 2008
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
- Stüber: Principles of Mobile Communication, 2011
Feedback from Students
“Thank you for this amazing course, I really enjoyed it!,” a student wrote me in the winter 2019/20. “It was amazing, I have never enjoyed a course like this one,” a student wrote in the 2017 evaluation. Further comments in the official evaluations: “Quality of teaching was at the highest level” (2016), “Very nice slides, well structured, well explained and very interesting topics” (2021), “I liked [the] professor’s enthusiasm and approach to topics.” (2021).
Contents and Handouts
Christian Bettstetter giving a lecture
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 (4 hours) 
Antenna types. Production of radio waves; properties of radio waves; energy transport, power density, radiation intensity. Antenna characteristics: directivity and gain, antenna patterns, polarization. Reception power (Friis equation).
3. Radio Propagation (8 hours) Manuscript
- 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 probabilities. Time spread; frequency spread; time-variant behavior (fade rate, fade duration, Markov chain model); frequency-variant behavior; relationships.
- Overview of fading mitigation techniques: Diversity, 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.
5. Channel Coding and Modulation (8 hours)
- 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.
- Duplexing
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)
Introduction to the “Wireless Networks” lecture (1 hour)
9. Network Architecture and Mobility Protocols (7 hours)
- 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. 4G and 5G Networks (4 hours)
- 4G: LTE physical and data-link layer. LTE protocol architecture. LTE system architecture. LTE advanced.
- 5G and beyond: Guest lecture by Frank Fitzek.
11. Security in Mobile Networks (2 hours)
- Security threats and coutermeasures
- Authentication in cellular networks
12. Ad Hoc Networks (6 hours)
- Routing and relaying
- Connectivity and capacity
- Medium access control (Group project)
- IEEE 802.11s (group project)