Real-time segmentation

A method for use in a receiving apparatus, comprising:

• receiving, on a medium access control (MAC) layer, a MAC layer packet data unit, PDU, including a plurality of MAC layer service data units, SDUs, each of the plurality of MAC layer SDUs including a header indicating a length of each of the MAC layer SDUs,
• determining a length of a last one of the plurality of MAC layer SDUs included in the MAC layer PDU, the length of a last one of the plurality of MAC layer SDUs being equal to the full length of the corresponding SDU packet,
• comparing a length indicated in the header of the last one of the plurality of MAC layer SDUs with the determined length of the last one of the plurality of MAC layer SDUs includes in the MAC layer PDU,
• determining whether the length indicated in the header of the last one of the plurality of MAC layer SDUs is equal to the determined length of the last one of the plurality of MAC layer SDUs, and
• in response to determining that the lengths are not equal, determining that the last MAC layer SDU included in the MAC layer PDU has been segmented into a first SDU part and at least one second SDU part.

A transmitting apparatus, comprising:

• at least one processor, and
• at least one memory for storing instructions to be executed by the processor, wherein
• the at least one memory and the instructions are configured to, with the at least one processor, cause the apparatus at least to perform:
• composing, on a medium access control (MAC) layer, a MAC layer packet data unit, PDU, having a predetermined length, including a plurality of MAC layer service data units, SDUs, each of the plurality of MAC layer SDUs including a header indicating a length of each of the MAC layer SDUs, and
• inserting a certain number of the plurality of the MAC layer SDUs into the MAC layer PDU corresponding to the predetermined length of the MAC layer PDU,
• determining a remaining portion of the MAC layer PDU,
• determining whether a last one of the certain number of the plurality of MAC layer SDUs does not fit completely into the remaining portion of the MAC layer PDU,
• in response to determining the last one of the certain number of the plurality of MAC layer SDUs does not fit completely into the remaining portion of the MAC layer PDU, segmenting the last one of the certain number of the plurality of MAC layer SDUs into a first part and a second part according to the predetermined length of the MAC layer PDU, and
• inserting the first part of the segmented MAC layer SDU into the remaining portion of the MAC layer PDU without changing the header field of the MAC layer PDU such that the header of the MAC layer PDU indicates the original length of the MAC layer SDU.