How do you implement and manage network slicing and QoS policies for different 5G and IMS use cases?

1 What is network slicing and QoS?

Network slicing is the process of creating multiple virtual networks on top of a shared physical infrastructure. Each network slice can have its own characteristics, resources, and policies, tailored to the specific needs of the service or application. QoS, or quality of service, is the mechanism that ensures that each network slice meets the performance and reliability requirements of the service or application. QoS policies define the parameters and rules for allocating and prioritizing resources, such as bandwidth, latency, jitter, and packet loss, among different network slices and traffic flows.

2 How to implement network slicing and QoS for 5G?

To implement network slicing and QoS for 5G, you need to use the 5G core network architecture and protocols, which are based on the service-based architecture (SBA) and the HTTP/2 protocol. The 5G core network consists of several network functions (NFs) that communicate with each other through standardized interfaces and provide various services, such as authentication, mobility management, session management, policy control, and charging. The network slicing and QoS functions are mainly provided by the network slice selection function (NSSF), the session management function (SMF), and the policy control function (PCF). The NSSF is responsible for selecting the appropriate network slice for each service request based on the subscription profile and the network availability. The SMF is responsible for establishing, modifying, and terminating the network sessions for each network slice and applying the QoS rules. The PCF is responsible for providing the QoS policies and rules to the SMF and other NFs based on the service level agreement (SLA) and the network conditions.

3 How to implement network slicing and QoS for IMS?

To implement network slicing and QoS for IMS, you need to use the IMS core network architecture and protocols, which are based on the SIP protocol and the IP multimedia subsystem (IMS). The IMS core network consists of several functional entities, such as the proxy-call session control function (P-CSCF), the serving-CSCF (S-CSCF), the interrogating-CSCF (I-CSCF), the application server (AS), and the policy and charging rules function (PCRF). The network slicing and QoS functions are mainly provided by the P-CSCF and the PCRF. The P-CSCF is responsible for identifying the network slice for each SIP session based on the access network information and the IMS public user identity (IMPU). The PCRF is responsible for providing the QoS policies and rules to the P-CSCF and other entities based on the SLA and the network conditions.

4 How to manage network slicing and QoS for different use cases?

To manage network slicing and QoS for different use cases, you need to use the network management system (NMS) and the orchestration system (OS) that can monitor, configure, and optimize the network slices and the QoS policies. The NMS is responsible for collecting and analyzing the network performance data, such as the traffic volume, the latency, the packet loss, and the service quality indicators (SQIs), from different network slices and domains. The OS is responsible for creating, modifying, and deleting the network slices and the QoS policies based on the service requirements, the network conditions, and the feedback from the NMS. The NMS and the OS can use the network exposure function (NEF) and the network repository function (NRF) to interact with the 5G core network and the IMS core network.

5 What are some examples of network slicing and QoS use cases?

Network slicing and QoS use cases provide various services for applications such as video streaming, virtual reality, autonomous driving, industrial automation, and remote surgery. Enhanced mobile broadband (eMBB) requires a network slice with high bandwidth, low latency, and high availability. The QoS policies should prioritize the eMBB traffic over other traffic types and allocate sufficient resources to ensure a smooth user experience. Ultra-reliable low-latency communication (URLLC) requires a network slice with ultra-low latency, high reliability, and high security. The QoS policies should guarantee the URLLC traffic with strict deadlines and minimal errors and protect it from any interference or congestion. Voice over LTE (VoLTE) requires a network slice with low latency, high availability, and high quality. The QoS policies should ensure the VoLTE traffic with low jitter, low packet loss, and high priority.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?