Transcripción del resumen original del autor: The WOC 4 "Transmission" Report contains the results of the works carried out during the three-year period 2001-2003 by the Committee members and by three ad hoc study groups, with the aim of describing the experiences of the gas transmission companies in the new scenario of the 21st century. The most important results have been: ; an overview of the gas transmission system to better identify the focal points of the operational performance of transmission pipelines, through the monitoring of new technology developments for improving the safety, the environmental impact and management costs; an IGU website has been developed for this purpose. ; Study Group 4.1 Report: "The international development of Third Party Access and Network Codes" ; Study Group 4.2 Report: "Frame of reference regarding Pipeline Integrity Management System (PIMS)"