URLLC Latency Requirements in User and Control Planes

Key Takeaways

• 5G URLLC is responsible for improved reliability and latency in applications such as autonomous vehicles, real-time human-machine collaboration, advanced wearables, augmented or virtual reality, and cloud robotics.

• The URLLC latency requirements of both the user plane and control plane are low enough that they support the development of solutions for latency-critical applications.

5G ultra-reliable low-latency communication (URLLC) is vital when employing wireless connectivity for mission-critical applications

There is unprecedented growth in services and applications requiring connectivity with high reliability, massive device density, lower latency, and improved efficiency. 5G wireless technology capitalizes on the market demand for connectivity with these requirements. 5G ultra-reliable low-latency communication (URLLC) is vital when employing wireless connectivity for mission-critical applications. 5G technology meets URLLC latency requirements both in the user plane and control plane, and is widely used in applications such as intelligent transportation systems, industrial internet, remote surgery, and smart grids. In this article, we will explore URLLC and how it satisfies latency requirements.

Ultra-Reliable Communication

Today, wireless connectivity is a commodity. We are connected all the time, and the number of wireless-enabled applications we use in our daily life is increasing exponentially. The constant presence of wireless connectivity makes it suitable for mission-critical applications. The support provided by wireless connectivity matches that of wired communication systems and is called ultra-reliable communication (URC).

Types of Ultra-Reliable Connectivity

Two types of ultra-reliable connectivity can be deployed in a system:

1. Long-term ultra-reliable communication with a latency greater than 10 ms.
2. Short-term ultra-reliable communication with a latency less than or equal to 10ms. 

Examples of long-term URC use cases are in resilient wireless connections such as remote instruction with high latency budgets or in disaster scenarios. Short-term URC is used for applications involving tight latency requirements.

Let’s take a closer look at URLLC, latency requirements, and applications.

Ultra-Reliable Low-Latency Communication (URLLC)

5G wireless communication technology covers three generic types of connectivity:

• Enhanced mobile broadband (eMBB)
• Ultra-reliable low-latency communication (URLLC) 
• Massive machine-type communication (mMTC)

URLLC is the use case in 5G that targets machines and their connectivity. The data delivery that is successful within a specified time duration refers to the reliability of 5G networks. The entanglement of URLLC and latency requirements in mission-critical applications make 5G technology trustworthy connectivity solutions.

5G URLLC use cases are responsible for the improved reliability and latency in applications such as autonomous vehicles, real-time human-machine collaboration, advanced wearables, augmented or virtual reality, and cloud robotics.

URLLC Latency Requirements

The eMBB, URLLC, and mMTC use cases of 5G extend their capabilities beyond previous mobile communication generations. The capabilities introduced by these use cases include:

• High data rates
• Low-latency
• Spectral efficiency
• Ultra-high reliability
• Low device costs
• Low energy or consumption
• Energy efficiency in networks

The International Telecommunication Union (ITU) and 3GPP have identified requirements for eMBB, URLLC, and MMTC. One such requirement for URLLC is latency.

Latency 

Latency is a key 5G performance indicator and can be evaluated in terms of user plane latency and control plane latency. Latency is associated separately with the user plane and the control plane, respectively. The user plane deals with the actual data transmission experienced by the user, whereas the control plane deals with the signaling and control function.

User plane latency - User plane latency is a parameter measured in ‘ms’ and represents the work of the communication network starting when the source sends a user pocket until it is received at the target destination.

Control plane latency - Control plane latency is the time taken to transition from an idle state (battery efficient state) to the start of continuous data transfer or active state.

The table below shows the URLLC latency requirements.

URLLC Applications

1. Telesurgery: Telesurgery includes remote surgery and remote surgical consultations. In both these use cases, reliable and low-latency network connectivity are required.

2. Intelligent transportation: When vehicles are fully connected, road safety, traffic efficiency services, and automated driving improve. Fully-connected vehicles intelligently react to complex traffic situations by connecting to other vehicles rather than actions based on local information.

3. Factory automation: The fourth industrial revolution identified URLLC as one of the enabling technologies that bring the concept of automation to the industry through networks deployed in factories. End-to-end latency requirements are significant factors in industrial automation, and the 5G URLLC use case supports them much better than traditional wireless technologies. 

URLLC latency requirements of both the user plane and control plane are low enough to support the development of solutions for latency-critical applications in an optimized way. Latency-sensitive systems can be developed by utilizing the URLLC use case of 5G wireless communication technology.

Cadence’s suite of design and analysis tools can assist you in developing 5G connectivity-enabled systems for different use cases such as eMBB, URLLC, and mMTC. Leading electronics providers rely on Cadence products to optimize power, space, and energy needs for a wide variety of market applications. If you’re looking to learn more about our innovative solutions, talk to our team of experts or subscribe to our YouTube channel.