Sign in Subscribe

urllc 3gpp

Last updated on 


URLLC (Ultra-Reliable Low-Latency Communication) is a term used in the context of 3GPP (3rd Generation Partnership Project) standards to define a set of communication requirements for applications that demand extremely low latency and high reliability. URLLC is particularly important in the context of 5G networks, where it enables use cases such as industrial automation, autonomous vehicles, and critical infrastructure.

Here's a technical explanation of URLLC in the 3GPP context:

  1. Latency Requirements:
    • URLLC aims to achieve extremely low communication latency, typically in the order of milliseconds. The latency requirements are stringent to support applications that rely on real-time communication, such as industrial automation where quick responses are critical.
  2. Reliability Requirements:
    • URLLC demands ultra-high reliability to ensure that communication is almost error-free. This is essential for applications where even a small amount of data loss or delay could have severe consequences, such as in remote surgery or autonomous vehicles.
  3. Communication Architecture:
    • URLLC utilizes the 5G NR (New Radio) air interface, which is part of the 5G standard defined by 3GPP. The air interface includes features like advanced modulation schemes, massive MIMO (Multiple-Input Multiple-Output), and beamforming to enhance the reliability and throughput of communication.
  4. Numerology and Frame Structure:
    • URLLC operates with specific numerology and frame structures. Numerology refers to the subcarrier spacing and slot duration used in the communication. URLLC may use numerologies with shorter subcarrier spacing to achieve lower latency. The frame structure defines how data is organized into frames for transmission.
  5. Mini-Slots:
    • To further reduce latency, URLLC introduces the concept of mini-slots. These are smaller time intervals within a slot that allow for quicker transmission of small amounts of data. Mini-slots enhance the flexibility of scheduling and reduce the time it takes to initiate communication.
  6. Grant-Free Access:
    • URLLC supports grant-free access, where devices can transmit data without waiting for explicit permission from the network. This is particularly useful for sporadic and low-latency communication scenarios, such as sensor devices reporting critical information.
  7. Harq (Hybrid Automatic Repeat reQuest) Enhancements:
    • URLLC introduces enhancements to the HARQ mechanism, which is responsible for error detection and correction. These enhancements aim to make the error recovery process more efficient and faster.
  8. Quality of Service (QoS) Profiles:
    • URLLC defines specific QoS profiles that are optimized for low latency and high reliability. These profiles ensure that the network prioritizes URLLC traffic appropriately, meeting the requirements of critical applications.
  9. Network Slicing:
    • Network slicing is a key concept in 5G, including URLLC. It involves creating dedicated virtual networks (slices) tailored to specific use cases. URLLC can benefit from network slicing by having a dedicated slice with optimized parameters for ultra-reliable and low-latency communication.

URLLC in the 3GPP context is a set of specifications and enhancements within the 5G standard to meet the stringent requirements of applications demanding ultra-reliable, low-latency communication. It involves a combination of advanced communication techniques, network architecture optimizations, and protocol enhancements to achieve its goals.