Mobile telecommunications system method, user equipment and base station for transmitting on demand system information

1. A mobile telecommunications system method for transmitting on demand system information to a user equipment, the mobile telecommunications system method comprising:

first transmitting essential system information;

requesting system information, by the user equipment transmitting a system information request in direct response to receiving the essential system information, based on an idle state of the user equipment; and

second transmitting a handover command, to the user equipment, based on the system information request, wherein

the user equipment transmits the system information request without performing a physical random access channel (PRACH) procedure,

the handover command includes the requested system information,

the first transmitting is performed by periodically broadcasting the essential system information including at least one of reserved uplink grant and uplink grant resource pools, and

the method further comprises broadcasting non-essential system information in a case that the system information request is received, on a pre-allocated resource, simultaneously as a second system information request is received.

2. A user equipment for a mobile telecommunications system, the user equipment comprising:

circuitry configured to:

receive a first transmission including essential system information;

transmit a system information request to the mobile telecommunications system indirect response to receiving the first transmission, based on an idle state of the user equipment; and

receive a handover command, from the mobile telecommunications system and in response to the system information request, wherein

the circuitry transmits the system information request without performing a physical random access channel (PRACH) procedure,

the handover command includes the requested system information,

the first transmission is transmitted from the mobile telecommunications system by periodically broadcasting the essential system information including at least one of reserved uplink grant and uplink grant resource pools, and

in a case that the system information request is received by the mobile telecommunications system on a pre-allocated resource simultaneously as a second system information request is received by the mobile telecommunications system, the mobile telecommunications system broadcasts non-essential system information.

3. The user equipment of claim 2 , wherein the system information is requested within a radio resource establishment procedure.

4. The user equipment of claim 3 , wherein the system information request is included in a radio resource control connection request message.

5. The user equipment of claim 2 , wherein the system information is requested on a pre-allocated resource.

6. The user equipment of claim 2 , wherein the system information request includes at least one of: indication that system information is requested, indication of system information blocks, service related information, and location related information.

7. The user equipment of claim 2 , wherein the system information request includes identification information for identifying the user equipment which requests the system information.

8. The user equipment of claim 2 , wherein the system information request is repeated, if after a predetermined time period, no acknowledgment is received.

9. The user equipment of claim 2 , wherein requesting system information is performed upon detection of at least one of: new service request, mobility, and new physical layer change.

10. The user equipment of claim 2 , wherein the system information request is transmitted within a radio resource control signaling.

11. The user equipment of claim 2 , wherein the system information request is transmitted within a scheduling request.

12. A base station for a mobile telecommunications system, the base station comprising:

circuitry configured to:

first transmit essential system information;

receive a system information request from a user equipment, the system information request based on a radio resource control connection state of the user equipment and being transmitted by the user equipment in direct response to the user equipment receiving the essential system information;

determine whether the radio resource control connection state of the user equipment is an idle state based on the system information request; and

second transmit a handover command, to the user equipment, based on a system information request, wherein

the user equipment transmits the system information request without performing a physical random access channel (PRACH) procedure,

the handover command includes the requested system information,

the circuitry transmits the essential system information by periodically broadcast and the essential system information includes at least one of reserved uplink grant and uplink grant resource pools, and

in a case that the system information request is received, on a pre-allocated resource, simultaneously as a second system information request is received, the circuitry is further configured to broadcast non-essential system information.