The LLC SSS defines 8 functional modules
- LLC-QS Queuing, scheduling and active queue management
- LLC-SAR Segmentation and reassembly, to adapt incoming data to a suitable size for the transmission opportunities inside the WF. LLC provide an end-to-end SAR.
- LLC-FWD Waveform internal message forwarding of unicast, broadcast and multicast messages, Multicast and broadcast duplicate detection
- LLC-ARQ procedures to retransmit data on a hop-by-hop basis to increase the end-to-end probability of correct reception (ARQ based on selective NACK for unicast traffic)
- LLC-TM Traffic metering, measurements of arrival rates and other relevant metrics provided for the MAC, NET and management layers
- LLC-FRI Fragmentation and interleaving
- LLC-PTT Queuing of vocoder frames exchanged in the PTT groups and PTT PDU construction