Packet Data Convergence Protocol (PDCP) is specified by 3GPP in TS 25.323 for

UMTS The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the In ...

, TS 36.323 for

LTE LTE may refer to: Science and technology * LTE (telecommunication) (Long-Term Evolution), a telephone and mobile broadband standard ** LTE Advanced, an enhancement *** LTE Advanced Pro * Compaq LTE, a line of laptop computers produced by Compaq * ...

and TS 38.323 for 5G. PDCP is located in the Radio Protocol Stack in the UMTS/LTE/5G

air interface The air interface, or access mode, is the communication link between the two stations in mobile or wireless communication. The air interface involves both the physical and data link layers (layer 1 and 2) of the OSI model for a connection. Physi ...

on top of the RLC layer. PDCP provides its services to the RRC and user plane upper layers, e.g. IP at the UE or to the relay at the base station. The following services are provided by PDCP to upper layers: * transfer of user plane data; * transfer of control plane data; * header compression; * ciphering; * integrity protection. The header compression technique can be based on either IP header compression (RFC 2507) or

Robust Header Compression Robust Header Compression (ROHC) is a standardized method to compress the IP, UDP, UDP-Lite, RTP, and TCP headers of Internet packets. The need for header compression In streaming applications, the overhead of IP, UDP, and RTP is 40 bytes f ...

(RFC 3095). If PDCP is configured for ''No Compression'' it will send the IP Packets without compression; otherwise it will compress the packets according to its configuration by upper layer and attach a PDCP header and send the packet. Different header formats are defined, dependent on the type of data to be transported. In LTE, there are e.g. header formats for Control Plane PDCP Data PDU with long PDCP SN (12 bits), for User plane PDCP Data PDU with short PDCP SN (7 bits) and others.

References

External links

* IP header compression * {{IETF RFC, 3095, link=no Robust Header Compression Mobile telecommunications standards 3GPP standards UMTS 5G (telecommunication)