论文部分内容阅读
日本电报电话公司已成功地对第一套利用通信卫星转播的汽车电话系统进行了检测。如果这项卫星汽车电话业务在90年代中期投入使用,整个日本的车辆将可进行相互的通信联络。同样,沿海的船舶通过电话也可自由地通信。因为整项业务采用数字形式,自然要包括一个纠错电路用以提高语音质量及加密系统,以防被人窃取情报。通信业务将覆盖整个国家及2500公里的海岸线,因而当车辆离开城市到达郊区时也能联系。这个新的系统也使汽车电话系统与海上航运系统连为一体。
The Nippon Telegraph and Telephone Corporation has successfully tested the first car phone system broadcast on communication satellites. If the satellite car phone business was put into operation in the mid-1990s, vehicles across Japan would be able to communicate with each other. Likewise, coastal ships are also free to communicate by phone. Because the entire business is in digital form, it is natural to include an error correction circuit to improve voice quality and encryption systems to prevent theft of intelligence. The communications business will cover the entire country and its 2,500-kilometer coastline, so it can be contacted when vehicles leave the city and reach the suburbs. The new system also allows the car phone system and maritime shipping system as one.