5G NR Downlink Channels
5G NR Uplink Channels
There are 3 different types of channels:
1. Logical Channels
> Logical Channels are between RLC and MAC layer.
> It is defined by the type of information it carries and is classified into control channel and traffic channels.
2. Transport Channels
> Transport channels are between MAC and Phy layer.
> It will do multiplexing of logical data.
3. Physical Channels
> Phy channels are between 2 Phy layers.
> Phy channels are used to carry data over radio interface.
5G NR Logical channels
Broadcast Control Channel, BCCH:
> It is used to broadcast system information from Network to UE.
> The system information is divided into MIB and SIB
Paging Control Channel, PCCH:
> It is a downlink channel
> It is used to page the UE whose location at cell level is not known to the network.
> It is mapped to PCH transport channel and then to PDSCH Phy channel.
Common Control Channel, CCCH:
> It is used to transmit of common control information to UE WRT Random Access
> This is used prior to RRCConnection establishment.
Dedicated Control Channel, DCCH:
> It is used to send and receive dedicated control information from UE.
> It is used after RRCConnection establishment.
Dedicated Traffic Channel, DTCH:
> It is used to send and receive dedicated traffic information from UE.
5G NR transport channels
Broadcast Channel, BCH:
> It is used to transmit the BCCH system information.
Paging Channel, PCH:
> It is used to transmit the paging information from the PCCH logical channel.
> PCH supports discontinuous reception, DRX, to enable the UE to save battery.
Downlink Shared Channel, DL-SCH:
> It is used to transmit the downlink data in 5G NR.
> It supports dynamic rate adaptation; HARQ, channel aware scheduling, and spatial multiplexing.
Uplink Shared Channel, UL-SCH:
> It is used to transmit the uplink data in 5G NR.
Random-Access Channel, RACH:
> It carries random access preamble.
5G NR physical layer data channels
5G NR Downlink Physical Channels
Physical downlink shared channel, PDSCH
> It will carry shared data on time and frequency domain.
> It supports dynamic scheduling and dynamic link adaptation, modulation, coding scheme, and resources/power allocation.
> It is used for unicast data transmission.
Physical downlink control channel, PDCCH
> It will carry downlink control data.
> It is sued to carry DCI.
> It is used for scheduling the downlink data transmission on PDSCH and uplink data transmission on PUSCH.
Physical broadcast channel, PBCH
> It is used to broadcast MIB.
5G NR Uplink Physical Channels
Physical random access channel, PRACH
> This channel is used during RACH procedure.
Physical uplink shared channel, PUSCH
> It will carry the data from UL-SCH.
Physical uplink control channel, PUCCH
> Used to carry uplink control information.
TS 38. 211