QoS model: EPS bearer (4G) vs QoS flow (5G)

Two Generations, Two QoS Approaches

In 4G LTE, Quality of Service is managed through EPS bearers — dedicated logical tunnels between the UE and the PGW. Each bearer carries traffic with a single QoS level identified by a QCI (QoS Class Identifier). If a subscriber needs a new QoS level for a different service, the network must establish an entirely new dedicated bearer with its own GTP tunnel. This bearer-per-service model works but generates significant signaling overhead and wastes tunnel resources when multiple services need fine-grained QoS differentiation on the same connection.