The term telecommunications is derived from "tele", meaning at a distance, and "communications", meaning exchanging of information. The history of electronic communications has thus far been applied to the exchange of spoken, visual, and or textual information between pairs of people, pairs of machines, and people and machines. The role of telecommunications has been to provide a medium for the exchange of the information, with the burden placed on the communicating people or machines to initiate the communication and to interpret or process the information being exchanged. In this paper we attempt to predict some future trends in telecommunications, reaching into the next century. Such predictions are inevitably incomplete, inaccurate, or both. Nevertheless, it is a useful exercise to try to anticipate these trends, and more importanly the issues and problems that will arise in the future, as a way of focusing near-term research efforts and suggesting opportunities. One of our hypotheses about the future is that telecommunications networks will become much more active in initiating, controlling, and participating in the exchange of information. Our approach will be to first review some particularly important past developments, and then to try to predict the future in two ways: First, by extrapolating present trends and activities, and second, by criticizing current trends and anticipating problems looming on the horizon.

Noise properties in cascaded erbium-doped fiber amplifiers used in subcarrier multiplexed analog video distribution systems are experimentally examined. The noise dependency on signal wavelength is measured for a 4 stage EDFA cascade, and it is shown that an optical narrow bandpass filter is not necessary after each fiber amplifier for signal wavelength of 1.5511.560µm and that optical bandpass filters are necessary for shorter wavelength than 1.551µm to avoid the noise degradation by spontaneous-spontaneous beat noise. Finally, the attainable distribution loss is estimated for AM and FM video distribution systems.

Theoretical and actual experimental investigations are made on a Loop Antenna System (LAS) consisting of N-gap loop antennas. A general formula for the LAS response to an external EM field is derived by using both the method of moments and techniques for transmission-line analysis. Numerical evaluation verifies that the LAS has favorable characteristics, such as invariable response within a wide frequency range. In addition, differences between the LAS method and the present open-field method in the results of measurement are evaluated. It should be noted that the LAS gives a much lower output for an electrical source than for a magnetic source, even if both sources produce the same value with the open-field method. It is concluded that conversion factors for the results from the LAS method to the open-field method strongly depend on the orientation of the source as well as its characteristics. Consequently, new conversion factors are proposed to obtain practical EMI measurements.

In the paper entitled "The effect of varying routing probability in two parallel queues with dynamic routing under a threshold-type scheduling", Kojima et al. derive an expression in the form of a product of powers for the state probabilities of a threshold-type shortest queue problem. In this note it is demonstrated that this expression is essentially more complicated and has the form of an infinite sum of products of powers. In fact, Kojima et al. find the first term in this infinite sum only.

This letter proposes a non-metallic optical fiber cable which contains fiber ribbons inserted into slots, with a high impact resistant sheath which affords protection against shotgun pellets. The protective performance of the materials is investigated experimentally. Based on the results, non-metallic 100-fiber cable with a high impact resistant sheath was manufactured and its performance was evaluated. It is confirmed that this cable has excellent transmission, mechanical and antiballistic characteristics.

We indicate the existence of optimum expanded mode field diameters in thermally-diffused expanded core (TEC) fiber. The optimum ranges under our experimental conditions were from 14µm to 18µm for both 1.3µm-single-mode fiber and 1.55µm-dispersion-shifted fiber. By applying the TEC fiber fabricated in our experimental conditions to a multifiber connector, the connection loss can be reduced to less than 0.2dB without improving fiber and connector ferrule fabrication accuracy.