GSM Principles and Network Optimization (2nd Edition) mainly starts from the perspective of GSM principles and network optimization. Firstly, the composition, optimization process and wireless interface theory of GSM mobile communication system are introduced, so that users can have a certain theoretical basis for GSM network principle. Then, through the analysis of call processing flow and the introduction of signaling protocol, the BSS part and NSS part of GSM are organically combined, so that readers can have a comprehensive and in-depth understanding of the signaling transmission process of mobile stations and networks with various communication needs. This part is the necessary theoretical knowledge for GSM network optimization. For beginners, this part has a certain depth and difficulty, which needs to be explored step by step in practice in order to understand it deeply. Then, the related knowledge of the actual operation of network optimization is introduced in detail, including the optimization and adjustment of common parameters, some problems that should be paid attention to in network optimization, the handling of network faults, the knowledge of repeater, network testing, exchange optimization and so on. This part is the application and practice of GSM network optimization theory. "GSM Principles and Network Optimization (2nd Edition)" is accompanied by a large number of examples, which allows readers to find a breakthrough to solve problems when facing various difficult network failures.