In source DU 413, RLC functions comprise Automatic Repeat Request (ARQ), sequence numbering and resequencing, segmentation and re-segmentation. MAC functions comprise buffer status, power control, channel quality, Hybrid Automatic Repeat Request (HARM), user identification, random access, user scheduling, and QoS. PHY functions comprise packet formation/deformation, guard-insertion/guard-deletion, parsing/de-parsing, control insertion/removal, interleaving/de-interleaving, Forward Error Correction (FEC) encoding/decoding, channel coding/decoding, channel estimation/equalization, and rate matching/de-matching, scrambling/descrambling, modulation mapping/de-mapping, layer mapping/de-mapping, precoding, Resource Element (RE) mapping/de-mapping, Fast Fourier Transforms (FFTs)/Inverse FFTs (IFFTs), and Discrete Fourier Transforms (DFTs)/Inverse DFTs (IDFTs).

In source CU 415, UPF 431 performs packet routing & forwarding, packet inspection, QoS handling, and PDU termination. ASF 433 supports one or more low-latency applications in UE 401 like augmented reality, machine control, and the like. PDCPF 441 performs security ciphering, header compression and decompression, sequence numbering and re-sequencing, de-duplication. SDAPF 442 performs QoS marking and flow control. RRCF 443 performs authentication, security, handover control, status reporting, Quality-of-Service (QoS), network broadcasts and pages, and network selection.