In fixed telecommunications, the term ‘downstream’ refers to the direction of data flow from the network to the end-user. Conversely, the data flow from the end-user to the network is referred to as ‘upstream.’

In the context of radiocommunications, different terminology is used. The terms ‘downlink’ and ‘uplink’ are employed to describe the radio communication links. Specifically, ‘downlink’ signifies the radio link from the network to the end-user, while ‘uplink’ designates the radio link from the end-user to the network. These terms are commonly utilized when discussing wireless communication systems such as mobile networks and satellite communication.