EPS Bearer Terminology in LTE
Quality of service
- GBR bearer: Guaranteed bit rate
- Non-GBR bearer: No guaranteed bit rate
- Default bearer
- Established when UE connects to PDN
- Provides always-on connectivity
- Always non-GBR
- Dedicated bearer established later
- Can be GBR or non-GBR
Every EPS bearer
- QoS class identifier (QCI): This is a number which describes the error rate and delay that are associated with the service.
- Allocation and retention priority (ARP): This determines whether a bearer can be dropped if the network gets congested, or whether it can cause other bearers to be dropped. Emergency calls might be associated with a high ARP.