The QoS Class Identifier (QCI) is a scalar that is used as a reference to access node-specific parameters that control bearer level packet forwarding treatment (e.g. scheduling weights, admission thresholds, queue management thresholds, link layer protocol configuration, etc.).
The Allocation and Retention Priority (ARP) primarily allows one to decide whether a bearer establishment request can be accepted or rejected in case of resource limitations.
- In addition, the ARP can be used by the eNodeB to decide which bearer(s) to drop during exceptional resource limitations (e.g. at handover).
Each GBR bearer is additionally associated with the following bearer level QoS parameter:
- GBR = Guaranteed Bit Rate, the bit rate that can be expected to be provided by a GBR bearer
- MBR = Maximum Bit rate
Each non-GBR is additionally associated with the following bearer level QoS parameter:
- UE-AMBR = UE Aggregate Maximum Bit Rate (in UL)
- APN-AMBR = APN Aggregate Maximum Bit Rate (in DL)
Understanding QoS Parameters in LTE
In LTE, QoS (Quality of Service) helps manage how data is prioritized and delivered. When you’re using different apps—like video calls or browsing—the network uses QoS parameters to decide which traffic needs faster or more reliable handling.
Main QoS Parameters in LTE
- QCI (QoS Class Identifier): Tells the network what kind of service you’re using, like voice or video. Each QCI has specific handling rules.
- ARP (Allocation and Retention Priority): Helps the network decide which users get resources first, especially when resources are limited.
- GBR (Guaranteed Bit Rate): Ensures a fixed minimum data rate for real-time services like VoIP. If you’re on a voice call, GBR makes sure it doesn’t break or lag.
- MBR (Maximum Bit Rate): Sets the highest data rate allowed for your service. Even if the network is fast, this keeps data within a set limit.
- AMBR (Aggregate Maximum Bit Rate): Limits the total bit rate for all non-GBR services on your device, like general internet browsing or app usage.
How QoS Works for You
So when you’re streaming, calling, or scrolling, QoS makes sure important tasks like calls or real-time video get priority, while less urgent stuff waits its turn. This helps keep your experience smooth, even when the network is busy.