From 5QI
to the Air.
Follow one packet from a number in a policy — all the way to a lane in the air. The QoS flow model, the standardized 5QI table, GBR vs Non-GBR vs delay-critical, ARP and notification control, reflective QoS, and the full classification chain SDF→PCC→QoS flow→QER→QFI→DRB — narrated and fully animated in colour, explained like an expert.
QoS: From 5QI to the Air — the packet’s journey, in colour
The player screen is a live animation stage — colour-coded QoS flows fire exactly as the narration reaches them. Karaoke subtitles in English, two subtitle modes, and fullscreen.
Every information element in the module
Each message and structured data type the video opens — its interface, direction, purpose and clause. Click any row to open its full Information-Element breakdown. Filter to find any of them.
| Message | Interface | Dir | What it does | Clause |
|---|
Quality of Service, at protocol depth
Everything the video animates, as reference you can scan: how a flow is built, the standardized 5QI table verbatim, the enforcement ceilings, and the full chain from a policy to a lane in the air. All spec-cited.
Non-GBR — it shares
- No reserved bandwidth; flexes with load.
- Governed by aggregate ceilings (AMBR), not a per-flow rate.
- Web, email, background sync, default 5QI 9.
GBR — it reserves
- Bandwidth reserved: a GFBR floor, an MFBR ceiling.
- Voice, video, live streaming.
- Protected — sits outside the shared ceilings.
Delay-critical GBR — it races a clock
- GBR plus a hard, tiny latency deadline.
- Adds a Maximum Data Burst Volume.
- Robots, remote surgery, power-grid protection.
Colour = resource type: Non-GBR · GBR · Delay-critical GBR. Smaller priority = served first. Filter to find a row.
| 5QI | Resource type | Priority | Packet Delay Budget | Packet Error Rate | Max Data Burst | Example service |
|---|
5QI
- a scalar pointing to a set of QoS characteristics
- standardized, or dynamically assigned
ARP
- priority level 1–15
- pre-emption capability
- pre-emption vulnerability
Bit rates (GBR)
- GFBR — guaranteed floor
- MFBR — maximum ceiling
- measured over the averaging window
Control
- Notification control
- Alternative QoS profiles
- RQA · Max Packet Loss Rate
| Ceiling | Scope | Enforced by |
|---|---|---|
| MFBR | one GBR flow | UPF (DL) · UE (UL) |
| Session-AMBR | all Non-GBR flows in a session | UPF (DL) · UE + gNB (UL) |
| UE-Slice-MBR | a device’s aggregate within one slice | gNB |
| UE-AMBR | all a device’s Non-GBR traffic | gNB |
| GFBR | reserved floor per GBR flow | gNB scheduler (reservation) |
SDF
- app traffic, by 5-tuple
PCC rule
- PCF binds SDF→5QI/ARP
QoS Flow
- SMF assigns a QFI
QER
- UPF marks QFI + polices
GTP-U
- QFI in PDU Session Container
DRB
- SDAP maps QFI→bearer→air
RQA
- Reflective QoS Attribute in the profile — the flow is eligible.
RQI
- a bit set on downlink packets, in the PDU Session Container.
UE-derived rule
- the device mirrors it into an uplink rule; a timer expires it. No signalling.
The rule to remember: Quality of Service is not about speed — it is differentiation. The QoS Flow is the unit, the QFI is its name, the 5QI is its menu number, and one chain — SDF, PCC rule, QoS Flow, QER, QFI, DRB — carries a human decision all the way to a photon in the air.
TS 23.501 §5.7 & Table 5.7.4-1 · TS 24.501 §9.11.4.12/13 · TS 23.503 §6.3QoS mastery check
Questions and answers reshuffle every load. 70%+ to consider Module 4 done.