Method and apparatus for system information acquisition, beam failure recovery and cell reselection

A method of transmitting system information by a base station in a wireless communication system, the method comprising:

• receiving, from a terminal, a request for system information (SI);
• transmitting, to the terminal, an acknowledgement for the request;
• and
• transmitting, to the terminal, a physical downlink control channel (PDCCH) addressed to a SI radio network temporary identifier (RNTI) in a first SI window for a SI message,
• wherein the first SI window is monitored by the terminal for the SI message immediately after receiving the acknowledgement, and
• wherein receiving of a PDCCH is performed in a second SI window which is next to the first SI window in a modification period, in case that the SI message is not transmitted to the terminal by an end of the first SI window.

A terminal of receiving system information in a wireless communication system, the terminal comprising:

• a transceiver configured to transmit and receive a signal;
• and
• a controller configured to:
• transmit, to a base station, a request for system information (SI),
• receive, from the base station, an acknowledgement for the request,
• receive a physical downlink control channel (PDCCH) addressed to a SI radio network temporary identifier (RNTI) in a first SI window for a SI message immediately after receiving the acknowledgement, and
• receive the SI message,
• wherein receiving of a PDCCH is performed in a second SI window which is next to the first SI window in a modification period, in case that the SI message is not received by an end of the first SI window.

A base station of transmitting system information in a wireless communication system, the base station comprising:

• a transceiver configured to transmit and receive a signal;
• and
• a controller configured to:
• receive, from a terminal, a request for system information (SI),
• transmit, to the terminal, an acknowledgement for the request, and
• transmit, to the terminal, a physical downlink control channel (PDCCH) addressed to a SI radio network temporary identifier (RNTI) in a first SI window for a SI message,
• wherein the first SI window is monitored by the terminal for the SI message immediately after receiving the acknowledgement, and
• wherein receiving of a PDCCH is performed in a second SI window which is next to the first SI window in a modification period, in case that the SI message is not transmitted to the terminal by an end of the first SI window.