Daily demand for data and nonstop applications utilization, data flow and processing are always a challenge for the telecom industry and future network design. These same issues are now carrying over to the automotive industry where 5G is expected to boost services and safety features on next generation vehicles.
It is important for telecom engineers to understand the purpose of ultra-reliable and low latency communications (uRLLC), as latency is defined as the time or delay the signal takes to transport from point to point. That vital parameter is a key indicator for measuring the network performance and boosting the maximum data for all 5G applications and services.
At the moment, 400 mobile operators in 130 countries are deploying 5G for commercial or testing purposes. uRLLC in 5G is concentrated on an ultra-responsive connection with ultra-low latency. The data rate is not expected to be very high in uRLLC but offers high mobility, which has wide applications such as future vehicle systems, signaling automation and reflection on smart cities design.
Wide applications in same frequency resources
Vehicle applications require full delivery of connectivity with 99.9999% availability, security and are ultra-responsive with 1 millisecond latency or lower. Such requirements draw a challenge for current infrastructure and request huge adjustments to the system design to align with 5G needs. First, uRLLC existence with eMBB has an evolving challenge for system design to serve the various applications in the same spot and same physical resource as eMBB requires a bigger data traffic rate. The 5G GNode base station is handling the traffic of automated cars using uRLLC to download or watch a movie on a smartphone or laptop located inside the same car with the same high data rate.
Such requirements in the same radio spectrum lead 5G technology to use several transmission time intervals (TTI) to achieve the required spectral efficiencies (SE) for all applications. Such splitting of TTI will overload the control signaling and might suffer or bottleneck the control channel (CCH) capacity. So, future transport mobile services need to be designed to deliver uRLLC for multiple users at the same time.
uRLLC and AI
Typically, the conventional mobile design and infrastructure are based on high reliability with common frequency management. However, to achieve the evolving application's goals in future vehicles and transport systems, the network design must consider artificial intelligence (AI), which needs a worthy offset of stockpiling, algorithm and computational capabilities, and be linked with big data to maintain an effective transportation system.
Such AI integration to mobile networks will boost network resource efficiency and network management.
The uRLLC challenge, in that case, is big data operation with real-time for a massive number of applications and devices with the highest reliability and low latency. Accordingly, 3GPP set the standards to grant the desired goals including:
- Handover, which defines what service is transferred from one station to another. A main issue for uRLLC is defining a lossless concept and ensuring that source sends/receives the up link (UL) or down link (DL) directly or indirectly to the destination.
- User mobility, which means keeping UE application uninterrupted and providing maximum reliability to ensure vehicle safety, which serves automation and autonomy.
- Quality of services (QOS), which means each service is tagged by a quality flow identifier (QFI) in the End to End (E2E) path of the signal. As QOS is dynamic based on the situation, in this case, it ensures the vehicles' transmission latency is minimized.
Autonomous vehicles
As advances in technology keep evolving and many new concepts are emerging such as vehicle-to-X communication (V2X), where many subclasses are developed accordingly to cover the various applications including vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I).
Automated driving and autonomous vehicle concepts have attracted attention, taking into consideration capability and services. Such vehicles demand a seamless availability to sensor data where vehicles could achieve high safety standards and fewer accidents with rising speed maneuvers.
V2V
V2V ensures safety and better traffic control via V2V communication, which disseminates warning messages when entering intersections or departing highways, entering hazardous locations with accidents reported ahead and obstacle discovery, forward collision and pre-crash warnings.
The settings of the uRLLC signal on every car must be accurately determined, which in most cases and tests are set to be 32 bytes.
V2I
V2I is an interaction that facilitates a car to send/receive information with street field components as radio frequency identification (RFID) systems, speed meters or any other readers. V2I is bidirectional wireless communication where data is transferred from infrastructure to vehicle and vice versa over an ad hoc network.
The roadside units (RSUs) are composed of the same radio transceiver (dedicated short-range communication (DSRC)), an application processor and an interface to the V2I communication network. These are usually mounted on interchanges, intersections and patrol stations. RSUs are mainly responsible for private data transfer and message prioritization management to and from the vehicle. The severities of such messages are set according to their impact and safety consequences. The highest severity is safety and preventing accidents, while the lowest severity is logical notifications and entertainment functions.
Conclusion
Due to the evolving needs of data inside vehicle applications, uRLLC is considered a way to meet the needs of the next generation of cars both for driving functions and entertainment. 3GPP is continuously developing framework standards to cope with the automotive suppliers’ needs, specifically in handover, user mobility and quality of services. Next generation vehicles and transportation systems will rely on 5G networks and uRLLC signals to maintain the safety standards.
