How Physical channel of LTE works in UL & DL?
A distinction has to made between:
- The Physical channel
- The Physical signal
The DL physical channels are:
- Physical DL Shared Channel (PDSCH)
- It is a shared channel used to carry user data, radio & core network, system information (BCH),
- paging message.
- Physical DL Control Channel (PDCCH)
- It is a shared signaling channel to carry the allocation of the resources (PDSCH).
- Physical Broadcast Channel (PBCH)
- It is the channel used to broadcast the system information.
The UL physical channels are:
- Physical Random Access Channel (PRACH)
- It is a shared channel used for the access procedure.
- Physical UL Shared Channel (PUSCH)
- It is a shared channel used to carry user data, radio & core network,
- Physical UL Control Channel (PUCCH)
- It is a shared signaling channel in uplink to allow the UE to request resources on the PUSCH.
Downlink (DL) and Uplink (UL) Physical Channels in LTE
In LTE, the downlink (DL) and uplink (UL) physical channels are used for transmitting data between your device (UE) and the network (eNB). These channels manage the actual radio transmission, ensuring data flows efficiently in both directions.
Downlink Physical Channels (DL)
The downlink channels carry data from the network to your device. The primary downlink physical channels in LTE are:
- Physical Downlink Shared Channel (PDSCH): Used for carrying user data and control information to the UE. It’s the main channel for data transmission in the downlink.
- Physical Broadcast Channel (PBCH): Carries essential system information needed by the UE for initial connection setup and cell identification.
- Physical Downlink Control Channel (PDCCH): Transmits control information to the UE, including scheduling and resource allocation.
Uplink Physical Channels (UL)
The uplink channels are responsible for sending data from your device to the network. The primary uplink physical channels are:
- Physical Uplink Shared Channel (PUSCH): Used for transmitting user data and control information from the UE to the eNB.
- Physical Uplink Control Channel (PUCCH): Transmits control information, including acknowledgments for received downlink data (ACK/NACK) and scheduling requests.
- Physical Random Access Channel (PRACH): Used for initial access or when your device needs to establish a connection with the network.
Function of DL and UL Channels
The downlink channels ensure your device receives data, like web pages or streaming videos, while the uplink channels handle data from your device, such as uploading files or sending messages. Both sets of channels are essential for maintaining seamless communication between your device and the network.