Clarification on downlink window state variable

Hello, Clarification required on Downlink window state GPRS_RLC_DL_BSN_RESEND in OSMO-PCU Could you please let us know the significance of the state GPRS_RLC_DL_BSN_RESEND while handling downlink window. Our understanding is that state GPRS_RLC_DL_BSN_RESEND is used in case of retransmission of UNACKED blocks, which can be done without having GPRS_RLC_DL_BSN_RESEND state. Kindly let us know if we are missing something in our understanding. This will help us in enhancing the state variable handling in FANR (FAST ACK NACK REPORTING) feature. We are planning to introduce new state (i.e GPRS_RLC_DL_BSN_TENTATIVE_ACK ) as part of FANR feature implementation. Thanks & Regards, Sangamesh