A.2 EHC packet format and parameters
38.3233GPPNRPacket Data Convergence Protocol (PDCP) specificationRelease 17TS
A.2.1 EHC packet format
A.2.1.1 EHC Full Header packet and EHC Compressed Header packet
Figure A.2.1.1-1 and Figure A.2.1.1-2 show the formats of EHC FH packet and EHC CH packet, respectively.
Figure A.2.1.1-1: EHC Full Header packet format
Figure A.2.1.1-2: EHC Compressed Header packet format
A.2.1.2 EHC feedback packet
Figure A.2.1.2-1 shows the format of the EHC feedback packet.
Figure A.2.1.2-1: EHC feedback packet format
A.2.2 Parameters
A.2.2.1 F/C
Length: 1 bit
This field indicates whether the corresponding EHC packet is a FH packet or a CH packet.
Table A.2.2.1-1: F/C field
|
Bit |
Description |
|
0 |
FH packet |
|
1 |
CH packet |
A.2.2.2 CID
Length: 7, or 15 bits. The length of the CID is configured by upper layers (ehc-CID-Length in TS 38.331 [3]).
The CID = "all zeros" indicates that the corresponding Ethernet header is "uncompressed". The EHC decompressor does not establish the EHC context identified by the CID = "all zeros".
Annex B (normative):
Uplink Data Compression Protocol