交互式电视系统可以从功能角度划分为服务提供者、网络提供者、服务消费者。作为服务提供者的服务器是交互式电视系统中最重要的组成部分。 一、服务器的功能与结构 1.服务器功能 服务器可以向服务消费者提供四种核心服务:内容服务(content service)、应用服务(application service)、流服务(stream service)和网关服务(service gateway)。消费者通过服务网关进入或退 Interactive television systems can be functionally divided into service providers, network providers, and service consumers. The server as a service provider is the most important part of an interactive television system. I. Function and Structure of Server 1. Server Function The server can provide service consumers with four core services: content service, application service, stream service and service gateway. . The consumer enters or withdraws through the service gateway