NG-RAN and 5G-NR. Frédéric Launay
by the 3GPP standard, allowing us to define:
1 – the type of resource (Guaranteed Bit Rate or not): GBR or non-GBR;
2 – priority;
3 – the maximum transmission delay within the 5GS mobile network;
4 – the residual error rate.
5 The standardization of the 5QI value makes it possible to indicate how the flow is processed on each element of the user’s plan, in order that processing is consistent between the entities of the 5G core network and of the NG-RAN access.
The 5QI indicator is identical to the QCI (QoS Class Identifier) indicator for the 4G network for non-critical services (indicator from 1 to 80). New QCI values (81–85) have been defined in the case of URLLC services to guarantee speed and critical delay (delay critical GBR).
Table 1.2. 5G QoS characteristics
| 5QI | Type | Priority | Packet Delay Budget | PLER | Services |
|---|---|---|---|---|---|
| 1 | GBR | 2 | 100 ms | 10−2 | Conversational Voice |
| 2 | 4 | 150 ms | 10−3 | Conversational Video (Live Streaming) | |
| 3 | 3 | 50 ms | 10−3 | Real Time Gaming, V2X messages | |
| 4 | 5 | 300 ms | 10−6 | Non-Conversational Video (Buffered Streaming) | |
| 65 | 0.7 | 75 ms | 10−2 | Mission Critical user plane Push To Talk voice (e.g. MC-PTT) | |
| 66 | 2 | 100 ms | 10−2 | Non-Mission-Critical user plane Push To Talk voice | |
| 75 | 2.5 | 50 ms | 10−2 | V2X messages | |
| 5 | Non-GBR | 1 | 100 ms | 10−6 | IMS Signaling |
| 6 | 6 | 300 ms | 10−6 | Video (Buffered Streaming) TCP-Based (e.g. www, email, chat, ftp, p2p, etc.) | |
| 7 | 7 | 100 ms | 10−3 | Voice, Video (Live Streaming), Interactive Gaming | |
| 8 | 8 | 300 ms | 10−6 | Video (Buffered Streaming) TCP-Based (e.g. www, email, chat, ftp, p2p, etc.) | |
| 9 | 9 | 300 ms | 10−6 | Video (Buffered Streaming) TCP-Based (e.g. www, email, chat, ftp, p2p, etc.). Typically used as default bearer | |
| 69 | 0.5 | 60 ms | 10−6 | Mission Critical delay sensitive signaling (e.g. MC-PTT signaling) | |
| 70 | 5.5 | 200 ms | 10−6 | Mission Critical Data (e.g. example services are the same as QCI 6/8/9) | |
| 79 | 6.5 | 50 ms | 10−2 | V2X messages | |
| 80 | 6.8 | 10 ms | 10–6 | Low latency eMBB applications (TCP/UDP-based); Augmented Reality | |
| 82 | Delay Critical GBR | 1.9 | 10 ms | 10−4 | Discrete Automation (small packets) |
| 83 | 2.2 | 10 ms | 10−4 | Discrete Automation (big packets) | |
| 84 | 2.4 | 30 ms | 10−5 | Intelligent Transport Systems | |
| 85 | 2.1 | 5 ms | 10−5 | Electricity Distribution-high voltage |
The ARP parameter allows the NG-RAN node to choose whether the bearer establishment request should be made or rejected in the event of congestion.
The QFI value is coded on 6 bits. The 5QI value is set between 1 and 85. For any 5QI value less than or equal to 64, the QFI indicator and 5QI can be the same.
When the mobile is in the RRC_CONNECTED state, the management of QoS rules is delegated to the 5G-NR radio interface.
A user’s plane traffic in a PDU session with the same QFI flag is handled with the same traffic routing rules (e.g. sequencing rules, admission level).
The role of the radio node is to configure one or more radio data bearers (RAB: Radio Access Bearer) and to perform a mapping between the QFI and the bearer(s) from a TFT flow filtering template (Traffic Flow Template).
For uplink, there are two ways to control the mapping between the radio bearers and the QoS of IP flows:
1 – reflective QoS for which the mobile replicates QoS rules received in downlink (configuration of the TFT flow policy rules);
2 – explicit configuration for which the uplink