scope:

The present document specifies the Return Link Encapsulation (RLE) Protocol, which is used to encapsulate and if necessary fragment network layer packets such as for example IP datagrams to allow their transmission over the return link of an interactive satellite network.

RLE has been derived from the Generic Stream Encapsulation (GSE) protocol [1], used in the forward links of interactive and broadcasting satellite networks, which are normally characterized by continuous transmission, limited variability in the size of network layer packets, and large physical layer frames typically capable of carrying more than one network layer packet. RLE was designed to maximize the system efficiency on the return channel, which is in turn characterized by bursty traffic, highly variable size of network layer packets, smaller physical layer bursts, and multiple access constraints.

The RLE protocol is designed to provide three main functionalities which are fully specified in the present document, namely:

• encapsulation;

• fragmentation;

• frame packing.

RLE is today used in DVB-RCS2 [2] as well as in the S-MIM [3] standards.