论文部分内容阅读
1 定义视觉电话(visual telephone)业务通常是双向电信业务,它利用宽带模拟交换网络或数字电路同用户终端建立连接,主要用于传输活动的或静止的图像。专用的单向系统,例如监视和某些信息检索系统,或非交换的电视会议业务也可看作视觉电话业务的变种。视觉电话业务也涉及到语音。2应提供的条件装爱视觉电话业务至少应提供如下的基本条件: :)传输活动图像,例如具有中等分辨力的一个人或一小组人的头、肩像. b)传箱有联系的语音. 。)传输图形信息,例如高分辨力的图表和文件(625行或525行). d)使用或不使用分裂屏幕技术的电视会议业务。通常上述业务应该是双向业务,也可以单向操作。
1 Definition The visual telephone service is usually a two-way telecommunication service. It uses a broadband analog switching network or digital circuit to establish connection with a user terminal, mainly for transmitting moving or still images. Dedicated one-way systems, such as surveillance and some information retrieval systems, or non-exchange videoconferencing services can also be considered as variations of the videophone business. Visual telephony business also involves voice. 2 Conditions that should be provided At least the following basic requirements should be provided for video telephony services: :) Transfer of moving images such as the head and shoulders of a person or group of people with medium resolution b) . ) Transmit graphics information such as high-resolution charts and files (625 lines or 525 lines) d) Videoconferencing services with or without split-screen technology. Usually these businesses should be two-way business, you can also operate one-way.