What is FMS and BITMAP fields in PDCP status PDU?

Question

This status PDU is it necessary in pdcp? if yes when it is required?

Answer 1

I believe you are talking about PDCP Status Report which has FMS and BITMAP -

FMS
PDCP SN of the first missing PDCP SDU

BITMAP
• The MSB of the first octet of the type "Bitmap" indicates whether or not the PDCP SDU with the SN (FMS + 1) modulo 4096 has been received and, optionally decompressed correctly.
• The LSB of the first octet of the type "Bitmap" indicates whether or not the PDCP SDU with the SN (FMS + 8) modulo 4096 has been received and, optionally decompressed correctly.

For more detail please look at http://www.eventhelix.com/lte/presentations/3GPP-LTE-PDCP.pdf

Comments

thank you salil agrawal