What is the impact of QoS on system capacity?

Hello, Dancing_M.
The E-UTRAN QoS features have the following impact on system capacity:
Admission and congestion control (including air interface and transmission) maximizes system capacity while ensuring the QoS of admitted UEs.
Uplink scheduling and uplink power control maximize uplink capacity while ensuring uplink coverage and eliminating uplink interference.
Downlink scheduling and downlink power control maximize downlink capacity while ensuring downlink coverage.
The LTE system load balancing feature optimizes the inter-cell load and maximizes the intra-RAT load.
Thanks!