System Information Block Type 5 (SIB5) in 5G NR (New Radio) is a critical component of the broadcast system information. It provides essential information pertaining to inter-frequency and inter-RAT (Radio Access Technology) cell reselection. Specifically, SIB5 contains parameters that enable a User Equipment (UE) to identify and evaluate neighboring cells operating on different frequencies or using a different radio access technology, such as LTE. A primary function is to facilitate mobility management by guiding the UE to appropriate cells for handover or cell reselection when the serving cell’s signal quality degrades. Without this information, the UE would be unable to discover and assess alternative suitable cells, leading to potential service interruption.
The significance of SIB5 lies in its role in ensuring seamless connectivity and mobility in heterogeneous network deployments. It facilitates efficient load balancing across different frequencies and radio access technologies. By providing the necessary parameters for cell reselection, SIB5 contributes to improved network performance and user experience. Historically, the concept of system information blocks evolved from earlier cellular technologies. In 5G, the structure and content of SIBs have been optimized to accommodate the advanced features and requirements of the new generation of wireless communication. The careful design and transmission of this information allow the UE to maintain connection while moving through the network.
