Difference between LTE & LTE-A

[V250]

There are enough materials which talks about functionality of LTE, LTE-A and also compare LTE & LTE-A. This comparison is mainly based on data throughput, latency and more on broader level.

Can we list down difference w.r.t. protocol layer level. What changes are made on MAC, RLC, PDCP, PHY, RRC layer.

I have not gone through specs of LTE-A as of now, if some one who is aware of these differences can list down, that would be appreciated.

Regards,
V250