The discipline of engineering which focuses on the design, operation and construction of rail transport systems is known as railway engineering. It is an umbrella field which encompasses principles of several other engineering disciplines such as computer engineering, civil engineering, industrial engineering, electrical engineering, mechanical engineering and production engineering. The most important sub-fields of railway engineering are railway signaling and systems integration. Railway signalling helps to keep the trains clear of each other and directs railway traffic. System integration is a process that combines the component sub-systems into one system. It utilizes various techniques such as business process management, computer networking and enterprise application integration. This book explores all the important aspects of railway engineering in the present day scenario. Some of the diverse topics covered herein address the varied aspects that fall under this category. This book is a complete source of knowledge on the present status of this important field.