Description
Maximum Data Burst Volume (MDBV) is a key parameter within the 5G Quality of Service (QoS) framework, specifically associated with the 5G QoS Identifier (5QI). It quantifies, in bytes, the maximum amount of data that the network is required to handle as a single burst while still meeting the latency and reliability guarantees defined for that 5QI. The MDBV works in conjunction with the Maximum Burst Duration (MBD), which defines the time window for this burst. Essentially, for a given QoS flow, the network must be engineered to ensure that a data burst of size up to the MDBV can be delivered within the MBD without violating the packet delay budget.
Technically, the MDBV is used by the packet scheduler in the Radio Access Network (RAN) and the QoS enforcement mechanisms in the User Plane Function (UPF). When a QoS flow is established, these network elements are aware of its associated 5QI, which carries the MDBV value (either standardized per 5QI or signaled dynamically). The scheduler uses this information to allocate radio resources. For example, for an Ultra-Reliable Low Latency Communication (URLLC) service, a small MDBV (e.g., corresponding to a single industrial control command) and a very short MBD are defined. The scheduler must prioritize these packets and ensure sufficient resources are available instantaneously to clear the burst within the strict time limit.
Its role is fundamental for traffic shaping and admission control. The Session Management Function (SMF) may use the MDBV during QoS flow establishment to determine if the network has sufficient resources to admit a new flow with stringent requirements. In the user plane, it helps prevent scenarios where a large, unexpected burst of data could cause queueing delays for latency-sensitive packets. By defining the 'burstiness' a service can exhibit, MDBV allows the network to plan resource allocation more accurately than with average bit rate parameters alone, which is crucial for the deterministic performance required by industrial IoT, autonomous vehicles, and real-time gaming.
Purpose & Motivation
The MDBV was introduced to address the stringent and deterministic QoS requirements of new 5G use cases, particularly Ultra-Reliable Low Latency Communication (URLLC) and industrial IoT. Previous cellular generations (4G/LTE) primarily used parameters like Guaranteed Bit Rate (GBR) and Maximum Bit Rate (MBR), which are effective for continuous streams (like video) but insufficient for characterizing bursty, latency-critical traffic. A constant bit rate guarantee does not ensure that a sudden burst of data will be delivered within a few milliseconds.
The core problem MDBV solves is providing a quantifiable bound on 'burstiness' for latency-sensitive services. In URLLC scenarios, data transmissions are often sporadic but must be delivered with extreme reliability and minimal delay (e.g., 1 ms). The network needs to know the maximum size of such a burst to reserve the appropriate resources (radio slots, processing capacity) to handle it instantly. Without MDBV, the network would either over-provision resources for the worst-case continuous rate (inefficient) or risk failing to deliver bursts on time (unreliable).
Its creation was motivated by the need to translate application-level requirements (e.g., 'deliver a 200-byte packet within 5 ms with 99.999% reliability') into concrete network parameters that schedulers can act upon. MDBV, together with MBD and Packet Delay Budget (PDB), forms a complete model for bursty latency-sensitive traffic. This enables 5G systems to offer true performance guarantees, moving beyond 'best-effort' or 'prioritized' service towards deterministic connectivity, which is a foundational requirement for vertical industries adopting 5G for mission-critical operations.
Classification
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (54 CRs across 5 releases). Complements the general historical overview above with the evidence-based evolution of this function.
In Release 15, the Maximum Data Burst Volume (MDBV) was introduced as a new QoS parameter for GBR QoS Flows using the Delay-critical resource type, specifically to support URLLC services. It was defined for use within Alternative QoS Profiles, and its relationship with the Guaranteed Flow Bit Rate (GFBR) was clarified. Furthermore, mechanisms for MDBV enforcement were specified to ensure the QoS characteristics for data bursts could be maintained.
- Data Volume Reporting for Option 4/7 TS 23.501CR0661
- 5G QoS fixes for URLLC services related attributes - PDB, PER, MDB, 5QI TS 23.501CR0087
- Handling of maximum supported data rate per UE for integrity protection TS 23.501CR0334
- Clarify the relationship between GFBR and MDBV TS 23.501CR0416
- MDBV Enforcement TS 38.300CR0047
- Relation between SSB and SS-Burst TS 38.300CR0096
+ 2 more changes
In Release 16, the MDBV (Maximum Data Burst Volume) function was enhanced with specific clarifications and mapping configurations tailored for Time Sensitive Communication (TSC) QoS Flows supporting URLLC. Revisions corrected the relationship between MDBV and the Core Network Packet Delay Budget (CN PDB) and addressed the derivation of the MDBV value. These updates provided more precise QoS control for delay-critical GBR QoS Flows, where an Alternative QoS Profile can include the MDBV parameter.
- New clause for URLLC supporting TS 23.501CR0810
- TSC Burst Arrival Time usage and Clock Reference TS 23.501CR1423
- Introduction of QoS Monitoring to assist URLLC Service TS 23.501CR0990
- 5G URLLC: Optimizing Redundancy TS 23.501CR1217
- Clarifications on URLLC support TS 23.501CR1643
- General description and data volume reporting for NR in unlicensed bands TS 23.501CR1845
+ 18 more changes
In Release 17, the MDBV (Maximum Data Burst Volume) function was introduced as a new QoS parameter specifically for GBR QoS Flows using the Delay-critical resource type. This parameter was defined within the framework of Alternative QoS Profiles, enhancing support for URLLC and IIoT services as indicated in the CR titles. The MDBV provides a concrete bound for the volume of data that can be transmitted in a burst, complementing existing latency and reliability guarantees for critical communications.
- Adding the usage of Redundant Transmission Experience analytics for URLLC service TS 23.501CR2581
- Introduction of support of GSMA NG.116 attributes Maximum DL/UL throughput per slice/UE TS 23.501CR2822
- Introduction of Rel-17 IIoT/URLLC to TS 38.300 TS 38.300CR0416
- 5G URLLC Redundant PDU Session correction for NGAP parameters TS 23.501CR3035
In Release 18, the MDBV (Maximum Data Burst Volume) function was enhanced as part of broader URLLC improvements, specifically by introducing support for Jitter Measurement and End of Data Burst reporting to the NG-RAN. This allows for more precise monitoring and feedback related to data burst characteristics, building upon MDBV's existing role as a QoS parameter for Delay-critical GBR QoS Flows. The release also included corrections and clarifications on burst arrival time procedures, such as during handover scenarios.
- RAN feedback for burst sending time adjustment TS 23.501CR3734
- Removing EN on UL scenario of Reactive RAN feedback for burst sending time adjustment TS 23.501CR3872
- Introduction of support for Jitter Measurement and End of Data Burst reporting to the NG-RAN TS 23.501CR3875
- Introduction of Timing Resiliency and URLLC enhancements TS 38.300CR0730
- Introduction of maximum time duration to initiate CG-SDT in Stage-2 [CG-SDT-Enh] TS 38.300CR0743
- Clarifications on NSAC for maximum number of UEs with at least one PDU SessionPDN Connection TS 23.501CR4839
+ 5 more changes
In Release 19, the MDBV (Maximum Data Burst Volume) function was enhanced with new provisioning capabilities to the NG-RAN, including support for provisioning the Data Burst Size and the Time to Next Burst. The release also introduced clarifications and corrections for procedures such as the End of Data Burst Indication and reactive RAN feedback for Burst Arrival Time adaptation, specifically for applications like XR (Extended Reality).
- Support of Data Burst Size provisioning to NG-RAN TS 23.501CR5784
- Support of Time to Next Burst provisioning to NG-RAN TS 23.501CR5785
- KI#5, Update to data burst related TS 23.501CR5922
- Clarification on handling of application ID/predefined PDRs in reporting of usage data volume to EIF TS 23.501CR6438
- Correction on Burst Size for XR TS 38.300CR1078
- Correct to align with RAN for reactive RAN feedback for Burst Arrival Time adaptation TS 23.501CR5478
+ 1 more changes
Explore further
Broader topics and technologies where MDBV plays a role.
Defining Specifications
3GPP specifications that define or reference MDBV, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TS 23.501 vk00 | 5G System Architecture Stage 2 | Rel-20 |
| TR 26.926 vj00 | Traffic Models & Quality Evaluation for Media/XR in 5G | Rel-19 |
| TS 38.300 vj00 | NG-RAN Overall Description | Rel-19 |