It is important to accurately evaluate and reduce jitter accumulation in long-haul digital repeatered lines. Jitter accumulation caused by random pattern signals has already been analyzed. However, periodic pattern signals such as pseudorandom signals are usually used to measure jitter accumulation. This paper describes the difference between the jitter accumulation for both signals and the necessary conditions to accurately estimate jitter accumulation for random pattern signals by using periodic pattern signals. First, it is shown theoretically that systematic jitter for periodic signals saturates, showing a ripple pattern. The limit of increase is determined by the ratio of tank bandwidth and pattern repetition frequency. Up to a certain number of regenerators determined by the ratio, systematic jitter increases in rough proportion to the\sqrt{N}slope. It is also shown that the equation to estimate random pattern jitter accumulation is determined by the measured value for periodic pattern signals. Second, jitter characteristics are simulated by optical signal circulating experiments. The results are in agreement with the analysis. In addition, the reduction effects on periodic signal jitter accumulation caused by timing signal delay and nonlinearity of the limiter in the timing circuit are shown.

This paper describes the FS-4OOM submarine system which has a total system capacity of 17 280 two-way voice channels. It gives the major system parameters and system design. In addition, it discusses transmission characteristics of the system including the results of a longterm stability test carried out from January 1982 to February 1984 in Sagami Bay, in the Yahatano Sea area off the coast of the Izu Peninsula.

In equalization design of submarine coaxial cable system, the cable attenuation deviation due to pressure in deep sea bottom has significant weight. This paper treats the submarine coaxial cable characteristics pressure dependency. By using an artificial ocean test facility, 1.7 inch submarine coaxial cable attenuation, phase, capacitance and insulator core diameter were studied and their pressure coefficients under a pressure of 0 to 500kgw/cm^{2}at temperatures of 5, 10 and 20°C were obtained. In this study, pressure dependence of polyethylene dielectric constant and dissipation loss were quantitatively analyzed. The attenuation pressure coefficient varies with frequency. For example, cable attenuation in the sea at a depth of 5000 meters is higher than that on the land by 1.09 percent at 10 MHz and by 1.54 percent at 60 MHz at a temperature of 10°C.