• Computer Controlled Radio Information System for Public Vehicle Operations

      Go, G. Bie; AEG-Telefunken (International Foundation for Telemetering, 1974-10)
      Radio control centers for Public vehicle operations has long been an essential instrument to control and monitor schedules and operations. However, due to the rapid development of city and urban traffic the capacity limit of the small amount of voice channels is already reached, especially during rush hours. Moreover the dispatchers are overburdened, so that adherence to schedule and safe operations cannot be guaranteed. Data communications is the means to increase the efficiency and the capacity of the existing system. AEG-TELEFUNKEN has conceived an advanced system TELETRANS utilizing computer control and radio monitoring. This system makes improved use of the existing channel capacity without infringing on current FCC regulations. Through the use of co-channel transmission, which is a special type of transmit diversity, large areas with diameters up to 40 km (25 mi.) can be covered. This system is flexible, so that requirements of small and large public transportation authorities can be fulfilled economically.
    • A Transponder for Deep Space Probes-Design and Performance Characteristics

      Go, G. Bie; AEG-Telefunken (International Foundation for Telemetering, 1974-10)
      Deep space probes necessitate the use of coherent ranging transponders. The requirements for this class of transponder can be divided into telemetry, command and ranging requirements. Usually the telemetry requirements are rather straightforward and concern more with hardware design aspects. On the other hand, command requirements generally requires iterative computations to achieve an optimum system design. Ranging requirements are based either on a simple turn-around ranging channel, or on the complex regenerative channel. The design of this transponder is based on the former type of ranging channel. This paper shows the system design for such a transponder and a comparison with measured performance characteristics. Additionally, spurious signal analysis for the ranging operation is dealt with briefly.