A technique for providing data unit concatenation in a shared communications network is disclosed. The technique establishes a distinction between a first address space and a second address space within one or more shared communications networks, such as a wireless local area network, in a telecommunications system. At a transmitter node, data units arriving from one or more source nodes are packaged together if they are intended a network accessible through a receiver and then are transmitted to the receiver node. During the transfer of data units across the telecommunications system, the addressing mechanism will use either source and destination nodes or transmitter and receiver nodes, depending on the address space relevant at the moment of transmission. The technique increases utilization efficiency, because overhead attributed to headers, acknowledgements and interframe gaps is reduced.