Logically, LTE network protocols can be divided into:
- Control plane (responsible for managing the transport bearer)
- User plane (responsible for transporting user traffic).
Control Plane Protocols
Protocol stacks for the control plane:
- PDCP: sublayer performs ciphering and integrity protection.
- RLC, MAC, and PHY: sublayers perform the same functions as in the user plan.
- RRC: performs functions like System Information Broadcast, Paging, RRC connection management, RB control, Mobility Control, and UE measurement reporting and control.
User Plane Protocols
Protocol stacks for the user plane:
PDCP, RLC, MAC, and PHY sublayers (terminated at the eNB on the network side) perform functions like header compression, ciphering, scheduling, ARQ, and HARQ.