1. A radio communication system including a radio terminal that communicates with a radio network, wherein the radio terminal comprises: a communication controller; a memory coupled to the communication controller; a receiver; and a transmitter, wherein the communication controller is configured to: detect radio link failure and store radio link failure related measurement results in a case where the radio link failure is detected, wherein the radio link failure related measurement results are measurement results related to the radio link failure; control the transmitter to transmit, to the radio network, status information indicating that the radio link failure related measurement results are stored in the memory, wherein the status information doesn't contain the radio link failure related measurement results; control the receiver to receive, from the radio network, a report request for requesting a report of the radio link failure related measurement results; and control the transmitter to transmit, to the radio network, the report of the radio link failure related measurement results in response to the report request.

2. The radio communication system according to claim 1, wherein the report of the radio link failure related measurement results include received quality of a cell in which the radio link failure was detected.

3. A radio terminal that communicates with a radio network, the radio terminal comprising: a communication controller; a memory coupled to the communication controller; a receiver; and a transmitter, wherein the communication controller is configured to: detect radio link failure and store radio link failure related measurement results in a case where the radio link failure is detected, wherein the radio link failure related measurement results are measurement results related to the radio link failure; control the transmitter to transmit, to the radio network, status information indicating that the radio link failure related measurement results are stored in the memory, wherein the status information doesn't contain the radio link failure related measurement results; control the receiver to receive, from the radio network, a report request for requesting a report of the radio link failure related measurement results; and control the transmitter to transmit, to the radio network, the report of the radio link failure information related measurement results in response to the report request.

4. The radio terminal according to claim 3, wherein the report of the radio link failure related measurement results include received quality of a cell in which the radio link failure was detected.

5. A radio base station that communicates with a radio terminal, the radio base station comprising: a communication controller; a memory coupled to the communication controller; a receiver; and a transmitter, wherein the communication controller is configured to: control the receiver to receive, from the radio terminal, status information indicating that radio link failure related measurement results stored in the radio terminal, wherein the radio link failure related measurement results are measurement results related to the radio link failure detected by the radio terminal, wherein the status information doesn't contain the radio link failure related measurement results; control the transmitter to transmit, to the radio terminal, a report request for requesting a report of the radio link failure related measurement results; and control the receiver to receive, from the radio terminal, the report of the radio link failure information related measurement results.

6. The radio base station according to claim 5, wherein the report of the radio link failure related measurement results include received quality of a cell in which the radio link failure was detected.

7. A method for a radio terminal communicating with a radio network, the method comprising: detecting radio link failure; storing radio link failure related measurement results in a case where the radio link failure is detected, wherein the radio link failure related measurement results is measurement results related to the radio link failure; transmitting to the radio network, status information indicating that the radio link failure related measurement results are stored in a memory of the radio terminal, wherein the status information doesn't contain the radio link failure related measurement results; receiving, from the radio network, a report request for requesting a report of the radio link failure related measurement results; and transmitting, to the radio network, the report of the radio link failure information related measurement results.

8. The method according to claim 7, wherein the report of the radio link failure related measurement results include received quality of a cell, in which the radio link failure was detected.

WE CLAIM:
1. A radio communication system including a radio terminal that communicates with a radio
network, wherein
the radio terminal comprises:
a communication controller;
a memory coupled to the communication controller;
a receiver; and
a transmitter, wherein
the communication controller is configured to:
detect radio link failure and store radio link failure related measurement results in a case where the radio link failure is detected, wherein the radio link failure related measurement results are measurement results related to the radio link failure;
control the transmitter to transmit, to the radio network, status information indicating that the radio link failure related measurement results are stored in the memory, wherein the status information doesn't contain the radio link failure related measurement results;
control the receiver to receive, from the radio network, a report request for requesting a report of the radio link failure related measurement results; and
control the transmitter to transmit, to the radio network, the report of the radio link failure related measurement results in response to the report request.
2. The radio communication system according to claim 1, wherein the report of the radio link failure related measurement results include received quality of a cell in which the radio link failure was detected.
3. A radio terminal that communicates with a radio network, the radio terminal comprising:

a communication controller;
a memory coupled to the communication controller;
a receiver; and
a transmitter,
wherein the communication controller is configured to:
detect radio link failure and store radio link failure related measurement results in a case where the radio link failure is detected, wherein the radio link failure related measurement results are measurement results related to the radio link failure;
control the transmitter to transmit, to the radio network, status information indicating that the radio link failure related measurement results are stored in the memory, wherein the status information doesn't contain the radio link failure related measurement results;
control the receiver to receive, from the radio network, a report request for requesting a report of the radio link failure related measurement results; and
control the transmitter to transmit, to the radio network, the report of the radio link failure information related measurement results in response to the report request.
4. The radio terminal according to claim 3, wherein the report of the radio link failure related measurement results include received quality of a cell in which the radio link failure was detected.
5. A radio base station that communicates with a radio terminal, the radio base station comprising:
a communication controller;
a memory coupled to the communication controller;
a receiver; and
a transmitter,
wherein the communication controller is configured to:

control the receiver to receive, from the radio terminal, status information indicating that radio link failure related measurement results stored in the radio terminal, wherein the radio link failure related measurement results are measurement results related to the radio link failure detected by the radio terminal, wherein the status information doesn't contain the radio link failure related measurement results;
control the transmitter to transmit, to the radio terminal, a report request for requesting a report of the radio link failure related measurement results; and
control the receiver to receive, from the radio terminal, the report of the radio link failure information related measurement results.
6. The radio base station according to claim 5, wherein the report of the radio link failure related measurement results include received quality of a cell in which the radio link failure was detected.
7. A method for a radio terminal communicating with a radio network, the method comprising:
detecting radio link failure;
storing radio link failure related measurement results in a case where the radio link failure is detected, wherein the radio link failure related measurement results is measurement results related to the radio link failure;
transmitting to the radio network, status information indicating that the radio link failure related measurement results are stored in a memory of the radio terminal, wherein the status information doesn't contain the radio link failure related measurement results;
receiving, from the radio network, a report request for requesting a report of the radio link failure related measurement results; and
transmitting, to the radio network, the report of the radio link failure information related measurement results.
8. The method according to claim 7, wherein the report of the radio link failure related

measurement results include received quality of a cell, in which the radio link failure was detected.