Downlink
User Plane Control (UPC)
taking notes from this presentation.
So UPC has five elements (in the repository, you see those 5)
- UE and Cell Control - upcUeDlNrCe, upcUeUlNrCe
- BDO (Baseband Domain Object) Control - DraCtrlNrMdbfCe (shared between uplink and downlink), draDlMdbfCe draUlMdbfCe
upcUe (UE domain) is in the asynchronous domain, not time aware. But Dra is in synchronomous domain (slot timing), called (DRA domain)
PUCCH decides SRS resources (Precious) when a new user joins
DraCtrl
- Sorting and selection fo UE domain requests
- Resource Pooling
- PUCCH / PDCCH configuration and allocation
The slot timer gives that inofrmation.
DraDl
- PDSCH allocation, and this is what you see in the code. They probably have more code because this takes care of the actual data being sent. MIMO
distributor is the prioritizing subsystem, because we have limited OTA slots. The nonprioritized will be returned to the UE domain.
bbRH for resource.
pdcchAlloc decides what user gets what Alloc
event-driven
UPCDL
Radio hardware is the driver of Ericsson profit.
Where we make money is not in software, we make money selling radio hardware.
Physical Channels
Physical Downlink Shared Channel (PDSCH)
- Carries the user data from network to devices.
- Also carries paging information, random access response message and some part of System Information Block
Parameters are configured by Downlink Control Information (DCI) Radio Resource Control (RRC)