Method for modifying parameter values for long range extension and corresponding node
Systems and methods are disclosed for adjusting Radio Link Monitoring (RLM), Radio Link Failure (RLF) detection, RLF recovery, and/or connection establishment failure detection for wireless devices ( 16 ) in a cellular communications network ( 10 ) depending on mode of operation. In one embodiment, a node ( 14, 16 ) in the cellular communications network ( 10 ) determines whether a wireless device ( 16 ) (e.g., a Machine Type Communication (MTC) device) is to operate in a long range extension mode of operation or a normal mode of operation. The node ( 14, 16 ) then applies different values for at least one parameter depending on whether the wireless device ( 16 ) is to operate in the long range extension mode or the normal mode. The at least one parameter includes one or more RLM parameters, one or more RLF detection parameters, and/or one or more RLF recovery parameters. In doing do, signaling overhead and energy consumption within the wireless device ( 16 ) when operating in the long range extension mode is substantially reduced.
1. A method of operation of a base station in a cellular communications network, comprising:
determining whether a wireless device is to operate in a long range extension mode or a normal mode where the long range extension mode is a mode of operation in which the wireless device is configured to maintain communication with the base station of the cellular communications network over an extended coverage range as compared to a coverage range over which the wireless device is configured to maintain communication with the base station of the cellular communications network in the normal mode of operation; and
applying different values for at least one parameter utilized by the wireless device for radio link monitoring depending on whether the wireless device is to operate in the long range extension mode or the normal mode,
wherein the base station determines that the wireless device is to operate in the long range extension mode in response to a request from the cellular communications network and sends a request causing the wireless device to apply, for each parameter of the at least one parameter, a modified value for the long range extension mode that is different than that which would be applied for the normal mode of operation.
2. The method of claim 1 wherein the at least one parameter comprises at least one of the group consisting of: Qin; transmission parameters of a hypothetical Physical Downlink Control Channel, PDCCH, transmission that would result in a specific value of a Block Error Rate, BLER, value corresponding to Qin; Qout; transmission parameters of a hypothetical PDCCH transmission that would result in a specific value of a BLER corresponding to Qout; T 301 ; T 310 ; T 311 ; N 310 ; N 311 ; T 304 ; T 300 ; a Downlink Control Indication, DCI, format of a hypothetical PDCCH transmission that would result in a specific value of a BLER corresponding to Qout; and a DCI format of a hypothetical PDCCH transmission that would result in a specific value of a BLER corresponding to Qin.
3. The method of claim 1 wherein the at least one parameter utilized by the wireless device for the radio link monitoring comprises at least one threshold for monitoring link quality.
4. The method of claim 1 wherein the at least one parameter utilized by the wireless device for the radio link monitoring comprises a radio link monitoring frequency.
5. The method of claim 1 wherein the at least one parameter utilized by the wireless device for the radio link monitoring comprises at least one of the group consisting of: a threshold measurement for generating an in-sync indication for the wireless device and a threshold measurement for generating an out-of-sync indication for the wireless device.
6. The method of claim 1 further comprising performing a procedure to determine whether the wireless device is to be in the long range extension mode or the normal mode in response to determining that the wireless device is in idle mode, the wireless device has transmitted an RRC Connection Request, the RSRP measured by the wireless device is less than a predefined RSRP threshold, a timer T 300 has expired, and an additional delay has expired.
7. The method of claim 1 further comprising determining whether the wireless device is to operate in the long range extension mode or the normal mode if at least one condition exists of the group consisting of:
the cellular communications network does not receive a response after a predefined number of uplink scheduling grants transmitted to the wireless device;
the cellular communications network does not receive a response after a predefined number of paging requests for the wireless device; and
an uplink received strength of signal for the wireless device is less than a predefined threshold uplink received strength of signal.
8. The method of claim 1 wherein applying the different values for the at least one parameter comprises:
configuring the at least one parameter with the different values depending on whether the wireless device is to operate in the long range extension mode or the normal mode; and
monitoring a radio link between the wireless device and the cellular communications network for failure in accordance with the at least one parameter.
9. A base station for operation in a cellular communications network, comprising:
a wireless interface; and
one or more control and processing circuits associated with the wireless interface and configured to:
determine whether a wireless device is to operate in a long range extension mode or a normal mode where the long range extension mode is a mode of operation in which the wireless device is configured to maintain communication with the base station of the cellular communications network over an extended coverage range as compared to a coverage range over which the wireless device is configured to maintain communication with the base station of the cellular communications network in the normal mode of operation; and
apply different values for at least one parameter utilized by the wireless device for radio link monitoring depending on whether the wireless device is to operate in the long range extension mode or the normal mode,
wherein the base station determines that the wireless device is to operate in the long range extension mode in response to a request from the cellular communications network and sends a request causing the wireless device to apply, for each parameter of the at least one parameter, a modified value for the long range extension mode that is different than that which would be applied for the normal mode of operation.
10. A method of operation of a wireless device in a cellular communications network, comprising:
determining whether the wireless device is to operate in a long range extension mode or a normal mode where the long range extension mode is a mode of operation in which the wireless device is configured to maintain communication with a base station of the cellular communications network over an extended coverage range as compared to a coverage range over which the wireless device is configured to maintain communication with the base station of the cellular communications network in the normal mode of operation; and
applying different values for at least one parameter utilized by the wireless device for radio link monitoring depending on whether the wireless device is to operate in the long range extension mode or the normal mode, wherein:
the wireless device determines that it is to operate in the long range extension mode in response to a request from the cellular communications network; and
applying the different values comprises applying, for each parameter of the at least one parameter, a modified value for the long range extension mode that is different than that which would be applied for the normal mode of operation.
11. The method of claim 10 wherein the at least one parameter comprises at least one of the group consisting of: Qin; transmission parameters of a hypothetical Physical Downlink Control Channel, PDCCH, transmission that would result in a specific value of a Block Error Rate, BLER, value corresponding to Qin; Qout; transmission parameters of a hypothetical PDCCH transmission that would result in a specific value of a BLER corresponding to Qout; T 301 ; T 310 ; T 311 ; N 310 ; N 311 ; T 304 ; T 300 ; a Downlink Control Indication, DCI, format of a hypothetical PDCCH transmission that would result in a specific value of a BLER corresponding to Qout; and a DCI format of a hypothetical PDCCH transmission that would result in a specific value of a BLER corresponding to Qin.
12. The method of claim 10 wherein the at least one parameter utilized by the wireless device for the radio link monitoring comprises at least one threshold for monitoring link quality.
13. The method of claim 10 wherein the at least one parameter utilized by the wireless device for the radio link monitoring comprises a radio link monitoring frequency.
14. The method of claim 10 wherein the request comprises the modified value for the long range extension mode for each parameter of the at least one parameter.
15. The method of claim 10 wherein applying the different values for the at least one parameter comprises:
configuring the at least one parameter with the different values depending on whether the wireless device is to operate in the long range extension mode or the normal mode; and
monitoring a radio link between the wireless device and the cellular communications network for failure in accordance with the at least one parameter.
16. A wireless device for operation in a cellular communications network, comprising:
a wireless interface; and
one or more control and processing circuits associated with the wireless interface and configured to:
determine whether the wireless device is to operate in a long range extension mode or a normal mode where the long range extension mode is a mode of operation in which the wireless device is configured to maintain communication with a base station of the cellular communications network over an coverage extended range as compared to a coverage range over which the wireless device is configured to maintain communication with the base station of the cellular communications network in the normal mode of operation; and
apply different values for at least one parameter utilized by the wireless device for radio link monitoring depending on whether the wireless device is to operate in the long range extension mode or the normal mode, wherein:
the wireless device determines that it is to operate in the long range extension mode in response to a request from the cellular communications network; and
being configured to apply the different values comprises being configured to apply, for each parameter of the at least one parameter, a modified value for the long range extension mode that is different than that which would be applied for the normal mode of operation.