Quality control and management in mobile networks are based on the use of the key QoS parameters such as bit rate, latency, and packet loss. The 5G Quality of Service (QoS) model is based on the QoS Flows. Each QoS flow has a unique identifier called QoS Flow Identifier (QoI). There are always two types of bearer flows GBR (Guaranteed bit rate) QoS flows and NGBR(Non-Guaranteed bit rate) QoS flows. GBR bearers are used for real-time services such as rich voice and video services which occur in real-time. A GBR bearer has a minimum amount of bandwidth that is always reserved by the network. Non-GBR bearers do not have specific bandwidth allocation e.g file downloads, email, internet access, etc.
5G mobile technologies should significantly improve the QoS given by the previous technologies. 5G is giving an ample amount of data rate, so achieving good quality of service is of utmost importance. Use cases of 5G network include shopping malls, stadiums, virtual reality offices, dense urban information society, teleportation in smart grid network, blindspots, massive deployment of sensors, etc. end-users should be able to experience data rates of at least 1 Gbps in 95% of office locations and at 99% of the busy period. The highest requirement of the data rate is with virtual reality offices. The highest requirement for network latency is for dense urban information society use cases which requires network latency of less than 1 msec. The highest requirement for availability and reliability of a 5G network is traffic safety and efficiency. During the evolution of QoS management mechanisms in 3GPP networks, there was a migration from QoS management at the user equipment level to the QoS management at the network level. QoS management mechanisms in 5G networks should provide video and VOIP traffic prioritization towards web-search traffic and other applications which are tolerant to traffic. All the specifications define a default QoS rule. Every PDU session is required to have a QoS flow associated with such default. The flow remains active for the lifetime of the PDU session. QoS parameters to have defaults.
- 5G QoS Identifier(5GQI)
- Allocation and retention priority (ARP)
- Reflective QoS Attribute
- Notification control
- Flow Bit Rates
- Aggregate Bit Rates
- Default values
- The maximum packet loss rate
5G QoS Identifier
It is an identifier for QoS characteristics that influences scheduling weights, admission thresholds. Queue management, link layer protocol configurations, etc.
Allocation and Retention Priority
It is the information about the priority level, it covers pre-emption vulnerability and capability.
Reflective QoS Attribute
It enables the UE to map Uplink user plane traffic to QoS flows without SMF-provided QoS rules. This is achieved by creating UE-derived QoS rules on the received DL traffic.
It indicates whether notifications are requested from the NG-RAN. It is signaled as a part of the QoS profile.
Flow bit rates
It is the bit rate that is guaranteed by the network to the QoS flow over the Average time window.
Aggregate bit rates
It is the aggregate of the bit rates provided by N-GBR traffic.
These are the default values that are set as per various classes.
The maximum packet loss rate
It indicates the maximum rate for lost packets of the QoS flows that can be tolerated in the uplink and downlink direction.
Advantages of 5G QoS in NR (New Radio)
- It delivers critical information services for mission-critical users or organizations.
- It provides different prioritization levels for various different applications as perusers.
- It provides help to users during disasters and emergency situations such as floods, earthquakes, etc.
- The service is always available for emergency callers.