QoS handled by the Scheduler and CORE Network

Can you guide me to some content where I can read on QoS handled by the scheduler and core network? What part is taken care of by the core network and by the scheduler? How does this communication happen between the core and scheduler?

What do you mean by scheduler?
Do you mean the radio scheduler?

It’s about MAC scheduler.

The eNodeB and CN share the information from the EPS Bearer defined for the UE, and this means things like, QCI characteristics, ARP, MBR, GBR, etc… The eNB will ensure and enforce these rules, for instance, will consider the packet delay budget when deciding for how long it can hold a DL packet on buffer.

If you want to learn about Qos and Bearers, see this:

LTE QoS: SDF and EPS Bearer QoS