What is SST (slice/service type)

Slice/Service Type (SST) Explained Technically

In the context of 5th Generation (5G) mobile networks, Slice/Service Type (SST) is a crucial concept for network slicing. Network slicing allows network operators to create virtualized network slices, each tailored to meet the specific requirements of different services or applications. The SST acts as an identifier for these slices, defining their expected behavior and characteristics.

Here's a breakdown of the technical details of SST:

Functionality:

• Slice Identification: The primary function of SST is to identify the type of network slice being utilized. It provides a standardized way for network elements to recognize and differentiate between various slices configured within the 5G core network.
• Service Differentiation: The SST code, typically an 8-bit value, signifies the anticipated service characteristics of the slice. Different SST values map to different service categories with distinct performance requirements.

Standardized SST Values:

The 3rd Generation Partnership Project (3GPP), the organization responsible for developing mobile telecommunication standards, defines a set of standardized SST values:

• eMBB (Enhanced Mobile Broadband - SST value: 1): This slice type caters to services requiring high data rates and large bandwidth, such as video streaming, high-resolution content downloads, and enhanced mobile broadband applications.
• URLLC (Ultra-Reliable Low-Latency Communication - SST value: 2): This slice type prioritizes ultra-low latency and high reliability for mission-critical applications. Examples include autonomous vehicles, industrial automation, and remote surgery.
• mMTC (Massive Machine-Type Communication - SST value: 3): This slice type is designed for massive machine-to-machine (M2M) communication with a focus on efficient device management and low power consumption. Applications include sensor networks, smart metering, and wearables.
• V2X (Vehicle-to-Everything - SST value: 4): This slice type caters to communication needs between vehicles (V2V) and surrounding infrastructure (V2I) for connected car applications. It supports real-time data exchange for improved safety and traffic management.
• HMTC (High-Performance Machine-Type Communication - SST value: 5): This is a newer category introduced in Release 17 of the 3GPP standard. It provides higher data rates and improved reliability compared to mMTC, targeting applications like industrial automation and remote control of machinery.

Benefits of using SST:

• Simplified Slice Management: Standardized SST values enable efficient network slice configuration and management within the 5G core network.
• Service-Aware Routing: The network can leverage the SST information to route traffic onto the most appropriate slice based on its characteristics, ensuring optimal performance for different service types.
• Improved Network Efficiency: Network resources can be allocated more efficiently by tailoring slice configurations to specific service needs.

Additional Considerations:

• The specific implementation of SST might vary slightly depending on network operator configurations and specific service requirements.
• Beyond the standardized values, the 3GPP standard also allows for operator-specific SST values (128-255) for internal network applications.
• Understanding SST is essential for engineers working on 5G network design, implementation, and service development. It plays a key role in enabling the full potential of network slicing for diverse applications and services.