This sectional specification relates to IEC 61156-1. The cables described herein may be used for various communication systems as well as for analog systems, such as video, that exist or are under development and which may use as many as four pairs simultaneously. In this sense, this sectional specification provides the cable characteristics required by system developers to evaluate new systems as well as to enhance present systems. It covers a cable having four individually screened (STP) pairs. The cable may be provided with a common screen over the cable core. The transmission characteristics are specified up to a frequency of 1 200 MHz and at a temperature of 20 °C. The cables covered by this sectional specification are intended to operate with voltages and currents normally encountered in communication systems. These cables are not intended to be used in conjunction with low impedence sources, for example, the electric power supply of public utility mains.