TABLE OF CONTENTS The UTRAN MAC is not the same protocol task as the GPRS MAC, even though they both have the same name and handle similar tasks in similar ways. The UTRAN MAC can even contain different functionalities depending on whether it supports FDD, TDD, or both modes. The MAC is not a symmetric protocol; the entities in the UE and in the UTRAN are different.
A MAC task contains several different functional entities:
MAC-b handles the broadcast channel (BCH). The UE has one MAC-b, and the UTRAN has one MAC-b for each cell.
MAC-c/sh handles the paging channel (PCH), the forward access channel (FACH), the random access channel (RACH), and the downlink shared channels (DSCH). The common packet channel (UL CPCH) in the FDD mode and uplink shared channel (USCH) in TDD mode are also handled by this entity. One MAC-c/sh exists in each UE and one exists in the UTRAN for each cell.
MAC-d handles dedicated logical channels and the dedicated transport channels. The UE has one MAC-d, and the UTRAN has one MAC-d for each UE with assigned DCHs.
The MAC operates on transport channels (see Section 3.2.2) between the MAC and layer 1. The logical channels are described between MAC and RLC in Section 3.2.1. The internal configuration of the MAC is controlled by the RRC. The MAC is the lowest sublayer in layer 2; it has a thorough understanding of how to manipulate the physical layer.
The services MAC provides...
