BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method used in a wireless communication system, and more particularly, to a method of system information transmission and acquisition in the wireless communication system.

2. Description of the Prior Art

3GPP in 5G new radio (NR) access technology proposes standalone and non-standalone NR cell deployment. Standalone cell can be selected and accessed by a UE without assistance information from other cells, whereas non-standalone cell cannot be selected nor accessed by a UE without assistance information from other cells.

In addition, system information (SI) of 5G NR system includes essential minimum system information, which is fixed scheduled on a physical downlink broadcast channel (e.g., the physical broadcast channel (PBCH) of LTE or the NR-PBCH of 5G NR) and is organized into single system information block (SIB), non-essential minimum SI, which is dynamically scheduled on a physical downlink shared channel (e.g., the physical downlink share channel (PDSCH) of LTE or the NR-PDSCH of 5G NR) and is organized into one or more system information blocks (SIBs), and other SI, which could be periodically broadcast or on-demand, namely requested by the UE.

Fixed scheduled implies the size of the data unit is fixed, the volume of the radio resource to transmit the data unit is fixed, the radio resource location for transmitting the data unit is fixed in frequency domain, and the periodicity is fixed in time domain. Dynamically scheduled implies the size of the data unit could be dynamic, the volume of the radio resource to transmit the data unit could be dynamically arranged by the network, the radio resource location for transmitting the data unit is dynamically arranged by the network side in frequency domain, the periodicity of the present of the radio resource for transmitting the data unit is dynamically arranged by the network in time domain.

Based on the current mechanism, not every NR cell broadcasts SI or the entire SI, and there may be cells in the system on which the UE cannot camp and do not broadcast the entire SI, such as non-standalone cells. However, there is no specification for a UE to determine whether a cell is campable or not, which causes power consumption and time delay in cell selection. Besides, there is no specification for the UE to know SI or SIB is periodically broadcasted or on-demand, and thus the UE may not know how to acquire the SI/SIB.

SUMMARY OF THE INVENTION

It is therefore an objective to provide a method of system information transmission and acquisition to solve the above problem.

The present invention discloses a method of system information transmission for a cell in a wireless communication system. The method comprises broadcasting essential minimum system information of the cell of the wireless communication system with fixed scheduled on a downlink broadcast channel, wherein the essential minimum SI includes scheduling information for non-essential minimum SI of at least one of the cell and an auxiliary cell or a frequency location, the non-essential minimum SI is broadcasted with dynamically scheduled on a downlink shared channel, and the scheduling information includes a time and frequency resource configuration and an availability information for indicating whether the cell broadcasts the non-essential minimum SI.

The present invention discloses a method of system information acquisition for a mobile device in a wireless communication system. The method comprises receiving essential minimum system information of a cell of the wireless communication system with fixed scheduled on a downlink broadcast channel, wherein the essential minimum SI includes a first scheduling information for non-essential minimum SI, and the first scheduling information includes a time and frequency resource configuration and an availability information for indicating whether the cell broadcasts the non-essential minimum SI, and determining whether the cell is campable according to the availability information of the first scheduling information.

These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.

