Vertical Application Layer Group

Description

A VAL group is a fundamental concept in the 3GPP Vertical Application Layer (VAL) architecture, introduced in Release 19 to support group-oriented services for vertical industries such as public safety, railway, and industrial automation. It represents a logical collection of VAL UEs (User Equipment) or VAL users that are configured for a specific purpose within a VAL service. This grouping allows the network to apply common policies, manage resources efficiently, and enable group-based communication patterns like group calls, group messaging, and group data sharing.

The VAL group is defined and managed within a VAL system, which is the application-layer infrastructure that provides vertical-specific services. Each VAL group has a unique identity within its home system and can include members from multiple VAL systems, enabling cross-domain and cross-operator group communication. The group structure is maintained by the VAL group management functions, which handle membership, authorization, and group-related policies. The group concept is essential for services that require coordinated actions among multiple users, such as emergency response teams or factory floor workers.

From an architectural perspective, the VAL group is supported by the VAL server, which stores group definitions and enforces group policies. The VAL UE interacts with the VAL server to join or leave groups, send group communications, and receive group-related notifications. The group membership is typically authenticated and authorized based on the VAL user's subscription and service permissions. The group can be static (pre-configured) or dynamic (created on demand), depending on the service requirements.

The VAL group also plays a crucial role in QoS and policy control. The network can apply specific QoS parameters to group communications, ensuring that group traffic receives appropriate treatment. For example, a group of first responders might require high-priority, low-latency communication, while a group of sensors might need reliable but low-bandwidth data transfer. The group concept allows the network to differentiate and manage these requirements efficiently.

In terms of standardization, the VAL group is defined in 3GPP specifications 23.434 (Architecture enhancements for 5G Vertical Application Enablers) and 29.549 (Vertical Application Layer (VAL) service enabler; Protocol and API). These specifications outline the functional architecture, procedures, and APIs for managing VAL groups. The concept has been carried forward unchanged into Release 20, indicating its stability and foundational role in the VAL framework.

Purpose & Motivation

The VAL group concept was created to address the need for efficient group-based communication and management in vertical applications. Prior to Release 19, 3GPP networks lacked a standardized way to handle group-oriented services for vertical industries, leading to fragmented and proprietary solutions. Vertical applications often require coordinated communication among a set of users or devices, such as a team of firefighters, a fleet of vehicles, or a group of industrial robots. Managing these groups individually would be inefficient and complex.

The VAL group provides a standardized abstraction that allows the network to treat a collection of users or devices as a single entity for the purposes of policy, QoS, and communication. This simplifies the management of group services and enables new capabilities like group-based charging, group-level security, and group mobility. It also facilitates interoperability between different vertical systems and operators, as the group concept is defined at the application layer and can span multiple networks.

Furthermore, the VAL group addresses the limitations of previous approaches that relied on multicast/broadcast or point-to-point communication without a unified group management framework. By defining a clear group structure and associated procedures, 3GPP enables vertical industries to deploy scalable and reliable group services over 5G networks. The introduction in Release 19 reflects the growing demand for vertical-specific enablers and the need to integrate vertical applications more tightly with the 5G core.