8. RLC layer

It is at the level of the RLC protocol that the degree of reliability is managed according to the service required . A flow on the radio interface associated with a quality of service is called a Radio Bearer.

• The RLC protocol has 3 modes: TM, UM and AM

  • In TM's Transparent Mode, data delivered by the upper layer is placed by RLC in MAC-SDUs without any additional header. There is therefore no guarantee of transmission reliability or sequential delivery.

  • In Unacknowledged Mode (UM), a data block delivered...