管理某一通信系统的功能部件操作的一组规则，如果要实现通信，必须遵循这些规则。 The set of rules governing the operation of functional units of a communication system that must be followed if communication is to be achieved.
基础设施社会或社区正常运作所需要的基本设施，服务和安装设备等，如交通与通信系统，水与电力供给线，以及学校、邮局和监狱等公共机构 The basic facilities, services, and installations needed for the functioning of a community or society, such as transportation and communications systems, water and power lines, and public institutions including schools, post offices, and prisons.
