Course 544: GSM System Engineering

This two-day seminar provides a solid grounding in principles of basic GSM system design and RF engineering. Propagation, antenna systems, and traffic engineering principles are thoroughly introduced. Finally, GSM system design, growth, and performance considerations are explored each student receiving example files on disk

Signal Principles

• Modulation
• Bandwidth
• Interference
• Performance

Radio Propagation Basics for GSM

• Frequency and Wavelength
• The Physics of Propagation: Free Space, Reflection, Diffraction
• Local Variability: Rayleigh fading and multipath cancellation
• Area Propagation Models: Okumura, HATA, Cost 231
• Point-to-Point Models: techniques and commercial software
• Analyzing measured data to produce models
• Reliability of Service: using statistics to design for reliability
• Macro-cell Indoor Penetration Considerations and reliability
• Micro-cellular systems and techniques

GSM Air Interface Overview

• GSM Air Interface Basics and Signal RF Characteristics
• How it all works: decoding GSM signals
• Capacity Implications of the Air Interface
• CM, MM, RR (Layer 3 messages)
• LAPDm (Layer 2)
• Radio channel (Layer 1)
• Logical and Physical Channels
• Handover

Antennas for GSM

• Basic Antennas: Isotropic and Dipole radiators
• Concept of Antenna Gain and gain references
• Effective Radiated Power
• Antenna Patterns and Pattern Features
• How Antennas achieve Gain
• Reflector techniques, array techniques
• Families of Antennas used in Wireless: architecture, characteristics
• Collinear vertical antennas
• Horizontal arrays: yagis, log-periodics, etc.
• Implications of propagation driving antenna selection
• Multipath scattering in mobile clutter environment
• Beamwidth and tilt considerations for base station antennas

Basic Principles of Traffic Engineering for GSM

• Terms and Basic Concepts
• Traffic Units (Erlangs, CCS, Minutes)
• Trunks, Circuits, Voice Paths
• Offered Traffic vs. Carried Traffic
• Blocking Probability, Grade of Service
• Basic Operational Concepts
• Using Traffic Tables
• Principle of Trunking Efficiency

GSM Link Budgets and High-Level System Design

• Link Budget basics and application principles
• Traffic Considerations
• Determining Number of Cells Required

Optional Background Material for GSM

• Calculating levels in decibels
• Receiver Basics
• Superheterodyne architecture, frequency conversion, images
• Sensitivity: noise basics
• Dynamic range and intermodulation considerations
• Transmitter Basics
• Linear vs. non-linear amplifier