A [|point-to-point link] is a dedicated link that connects exactly two communication facilities.
Broadcast
Broadcast links connect two or more nodes and support broadcast transmission, where one node can transmit so that all other nodes can receive the same transmission. Ethernet is an example.
Multipoint
Also known as a multidrop link, a multipoint link is a link that connects two or more nodes. Also known as general topology networks, these include ATM and Frame Relay links, as well as X.25 networks when used as links for a network layer protocol like IP. Unlike broadcast links, there is no mechanism to efficiently send a single message to all other nodes without copying and retransmitting the message.
Point-to-multipoint
A point-to-multipoint link is a specific type of multipoint link which consists of a central connection endpoint that is connected to multiple peripheral CEs. Any transmission of data that originates from the central CE is received by all of the peripheral CEs while any transmission of data that originates from any of the peripheral CEs is only received by the central CE.
Private and public
Links are often referred to by terms that refer to the ownership or accessibility of the link.
A private link is a link that is either owned by a specific entity or a link that is only accessible by a specific entity.
Pertaining to GSM and cellular networks, the radio uplink is the transmission path from the mobile station to a base station. Traffic and signalling flowing within the BSS and NSS may also be identified as uplink and downlink.
Pertaining to radiocommunication service, a downlink is the portion of a feeder link used for the transmission of signals from a spaceradio station, space radio system or high altitude platform station to an earth station.
A forward link is the link from a fixed location to a mobile user. If the link includes a communications relay satellite, the forward link will consist of both an uplink and a downlink.
Reverse link
The reverse link is the link from a mobile user to a fixed base station. If the link includes a communications relay satellite, the reverse link will consist of both an uplink and a downlink which together constitute a half hop.
