Circuit Switching is problematic because data communications is（），that is， it is typically dominated by short bursts of activity with long periods of（）.

Satellites were launched（）low orbit for weather and military applications.

【Recently， telecommunication carriers has been building All-IP core networks in order to effectively support various kinds of fixed and mobile broadband services，such as up-and down-loading You tube and SNS（Social Networking Services）with rich video file，as well as broadband mobile Internet services. Such All-IP network is called NGN（Next Generation Network），which guarantees secure authentication and QoS such as the bandwidth and the delay. From the service point of view，convergence of fixed and mobile communications，known as FMC（Fixed Mobile Convergence）is becoming a key increasing new services and expanding the market.】 Form the paragraph above，we can see that（）can be defined as a network that can effectively support various kinds of fixed and mobile broadband services，with guaranteed QoS in terms of（）and etc. And the key to develop new services and gain larger market share should be（）

通信科技人员既应遵循一般科技工作者的职业道德，又应遵循通信工作者的职业道德，因此通信科技人员的职业道德具有（）。

科技工作者进行科技活动的出发点和归宿是（）。

同心同德、团结协作，最根本的是增强个人的（）。