公共数据网是一个由电信主管部门或是被广泛认可的私营机构创建和运营的通信网络。该通信网络以向公众提供某种方式的数据传输服务。

比如在中国，中国电信的Chinanet就是一个公共数据网。

A public data network is a network established and operated by a telecommunications administration, or a recognized private operating agency, for the specific purpose of providing data transmission services for the public.

In communications, a PDN is a circuit- or packet-switched network that is available to the public and that can transmit data in digital form. A PDN provider is a company that provides access to a PDN and that provides any of X.25, frame relay, or cell relay (ATM) services. Access to a PDN generally includes a guaranteed bandwidth, known as the committed information rate (CIR). Costs for the access depend on the guaranteed rate. PDN providers differ in how they charge for temporary increases in required bandwidth (known as surges). Some use the amount of overrun; others use the surge duration.