【Introduction to 5G】The difference between QoS control on the 4G and 5G

QoS control based on QCI and ARP

eNodeB side

eNodeB QoS control based on QCI and ARP is only for Non-GBR bearer, GBR bearer to control the rate according to GBR and MBR.

Non-GBR bearer scheduling priority can be based on the QCI scheduling priority control in effect, QCI scheduling priority can be directly configured through the scheduling priority weighting factor parameter. The larger the scheduling priority weighting factor, the higher the scheduling priority the Non-GBR bearer will receive.

For Non-GBR bearers with QCI values from 6 to 9, the scheduling priority of Non-GBR bearers can also be controlled by switching on the ARP-based scheduling priority.

ARP is passed from P-GW to eNodeB when creating a Non-GBR bearer, and then eNodeB maps the ARP to the priority of the Non-GBR bearer. The priority of Non-GBR bearer is divided into four levels: gold, silver, bronze, and iron, which represent the highest priority of scheduling, the second priority of scheduling, the third priority of scheduling, and the fourth priority of scheduling. Different priority levels have different ARP value ranges, as shown in the figure below.

Based on the mapping relationship between ARP and Non-GBR bearer priority, the QoS requirements of different Non-GBR bearers can be guaranteed. For example, three Non-GBR bearers under the same eNodeB, their ARPs are 3 (corresponding to Gold Non-GBR bearer), 10 (corresponding to Silver Non-GBR bearer), 13 (corresponding to Bronze Non-GBR bearer), the three Non-GBR bearer services are browsing the web (QCI of 8), then the eNodeB will give priority to guarantee Gold Non-GBR bearer QoS requirements.

The eNodeB can also determine the load control policy of the service based on ARP, such as setting different access thresholds for Gold/Silver/Bronze/Iron Non-GBR bearers at access and different release thresholds for Gold/Silver/Bronze/Iron Non-GBR bearers at congestion. For details on admission congestion, see Admission Congestion Control.

eNodeB based on QCI and ARP can jointly control the scheduling priority weighting factor of Non-GBR bearer, which can be configured by parameters, and the larger the factor, the higher the scheduling priority of Non-GBR bearer. Where QCI is used to distinguish the services of Non-GBR bearer, ARP is used to distinguish the priority of 

QCI- and ARP-based scheduling priority weighting factor

gNodeB side

gNodeB QCI and ARP-based QoS control are only for Non-GBR bearers. gNodeB controls the rate of GBR bearers according to GBR and MBR.

gNodeB based on QCI and ARP can control the scheduling priority weighting factor of Non-GBR bearers to adjust the scheduling priority of different Non-GBR bearers. gNodeB can be mapped to Non-GBR bearers of different operators, different QCIs, and different ARPs through parameter configuration, and the scheduling priority weighting factor of this Non-GBR bearer can be directly configured through parameters.

If all or part of the ARP of a QCI corresponding to the Non-GBR bearer is not configured with relevant parameters, the scheduling priority of the Non-GBR bearer takes effect in accordance with the QCI-based scheduling priority control, and the scheduling priority of the QCI can also be configured directly through parameters. The larger the scheduling priority weighting factor, the higher the scheduling priority the Non-GBR bearer will receive.

Example of ARP and QCI based scheduling priority for gNodeB

QoS control based on GBR and MBR

GBR and MBR are QoS parameters specific to GBR bearers, GBR rate guarantee and MBR rate control are pin separate GBR bearers.

The base station controls the rate of GBR bearer by comparing the transmission throughput of GBR bearer with the size of GBR/MBR.

• If the GBR bearer transmission throughput is less than GBR, the base station will give priority to the allocation of wireless resources to the GBR bearer use, in order to try to protect the GBR bearer rate to GBR.

• If the transmission throughput of the GBR bearer is greater than the MBR, the base station will suspend the scheduling of the GBR bearer.

• If the transmission throughput of the GBR bearer is between GBR and MBR, the base station keeps the scheduling priority of each GBR bearer unchanged.

GBR bearing rate can be guaranteed, Non-GBR does not get the minimum rate guarantee.

Huawei also supports the configuration of the guaranteed rate for a Non-GBR bearer on the gNodeB to guarantee the minimum rate of a Non-GBR bearer.

The gNodeB controls the rate of the Non-GBR bearer by comparing the transmission throughput of the Non-GBR bearer with the size of the guaranteed rate configured for the Non-GBR bearer.

• If less than, the base station will increase the scheduling priority of the Non-GBR bearer, the radio resources will be allocated to the Non-GBR bearer for use in priority, in order to try to guarantee that the rate of the Non-GBR bearer reaches the guaranteed rate configured to the Non-GBR bearer.

• If not less than, the base station keeps the scheduling priority of each Non-GBR bearer unchanged.

QoS control based on UE-AMBR

UE-AMBR is a QoS parameter specific to Non-GBR bearer, UE-AMBR rate control is for a UE all Non-GBR bearer.

The base station controls the rate of Non-GBR bearers by comparing the transmission throughput of all Non-GBR bearers of a UE with the size of the UE-AMBR.

• If it is greater than, the base station suspends the scheduling of each Non-GBR bearer.

• If it is not greater than, the base station keeps the scheduling priority of each Non-GBR bearer unchanged.

This concludes this chapter, and I hope this knowledge has been helpful to you. Thank you for browsing.