System for adjusting signal transmission timing to prevent signal collisions

In a communication network system, a central equipment unit (l) transmits, over a down link (4), a frame signal carrying subframe information signals addressed to respective terminal equipment units (2, ....2n) on a time-division multiplexing basis. The frame signal consists of a delay measurement window field carrying address information designating one of the terminal equipment units for delay measurement and a data field carrying the subframe information signals (DIl, DI2....) addressed to the terminal equipment units (2, .... 2n). When a terminal equipment unit is polled from the central equipment unit (l) to measure the delay time, it transmits a response signal (RSP) to the central equipment unit after a pre­determined time interval (Tx, To) from the reception timing of the frame signal, such that the response signal arrives at the central equipment unit within the delay measurement window field of the next frame signal. The central equipment unit (l) measures a delay time between the transmission timing of the next frame signal and the reception timing of the response signal (RSP), and transmits transmission timing adjustment information based on the measured delay time, and address information of the terminal equipment unit, in an address field of the next frame signal. The terminal equipment unit (2, .... 2n) transmits a subframe signal to the central equipment unit (l) after a time interval, depending on the transmission timing adjustment information, from the reception timing of a frame signal.