Bandwidth-based configuration of measurement gaps

1. A method of configuring measurement gaps during which a wireless device is to perform one or more measurements of one or more neighbor cells on one or more non-serving frequencies, the method comprising:

obtaining information that identifies, for each of a plurality of candidate non-serving frequencies, one or more measurement bandwidths over which one or more corresponding measurements on that non-serving frequency are to be performed;

selecting a subset of the candidate non-serving frequencies based on the measurement bandwidths;

configuring measurement gaps during which the wireless device is to perform one or more measurements on the selected non-serving frequencies.

2. The method of claim 1 , wherein:

the wireless device is configured to receive or measure signals from a serving cell over a serving-cell bandwidth;

the selecting comprises selecting the subset based on the measurement bandwidths in relation to the serving-cell bandwidth.

3. The method of claim 2 , wherein the selecting comprises preferentially selecting, for inclusion in the subset, candidate non-serving frequencies on which the most neighbor cells are to be measured over a measurement bandwidth that does not exceed a defined threshold set based on the serving-cell bandwidth.

4. The method of claim 3 , wherein the defined threshold is set to be larger than the serving-cell bandwidth.

5. The method of claim 2 , wherein the selecting comprises preferentially selecting, for inclusion in the subset, candidate non-serving frequencies on which the most neighbor cells are to be measured over a bandwidth equal to the serving-cell bandwidth.

6. The method of claim 1 , wherein:

the wireless device is configured to receive or measure signals from a serving cell on a serving-cell frequency over a serving-cell bandwidth;

measurements on a reference cell serve as a reference for the measurements;

the method further comprises determining whether or not to select the subset also based on the serving-cell bandwidth, depending on whether or not the reference cell is on the serving-cell frequency.

7. The method of claim 1 , wherein the selecting comprises preferentially selecting, for inclusion in the subset, candidate non-serving frequencies on which the most neighbor cells are to be measured over a measurement bandwidth that does not exceed a defined maximum bandwidth.

8. The method of claim 1 , wherein the selecting comprises:

determining a majority measurement bandwidth for each candidate non-serving frequency, wherein the majority measurement bandwidth for a given candidate non-serving frequency is the measurement bandwidth over which the majority of measurements on that non-serving frequency are to be performed; and

preferentially selecting, for inclusion in the subset, candidate non-serving frequencies that have the greatest majority measurement bandwidth.

9. The method of claim 1 , wherein the selecting and configuring are performed responsive to determining that measurement gaps cannot be configured using a single measurement gap pattern for performing measurements on all of the candidate non-serving frequencies.

10. The method of claim 1 , wherein the obtaining, selecting, and configuring are performed responsive to receiving, from the wireless device, a request that identifies the candidate non-serving frequencies and that requests configuration of the measurement gaps.

11. The method of claim 1 , wherein the measurements comprise positioning measurements that are to be used for determining the geographic position of the wireless device.

12. The method of claim 11 , wherein:

the method is implemented in a Long Term Evolution (LTE) network;

the positioning measurements are performed on Positioning Reference Signals (PRS).

13. The method of claim 11 , wherein the positioning measurements comprise any one or more of:

Reference Signal Time Difference (RSTD) measurements for Observed Time Difference of Arrival (OTDOA);

Receive-Transmit (Rx-Tx) time difference measurements;

Timing Advance (TA) measurements;

received signal strength measurements;

received signal quality measurements.

14. The method of claim 1 :

wherein the one or more measurements comprise one or more of:

intra-frequency measurements;

inter-frequency measurements;

intra-RAT measurements;

inter-RAT measurements;

wherein an inter-frequency or inter-RAT measurement comprises either an intra-band measurement or an inter-band measurement.

15. The method of claim 1 , wherein the wireless device requires measurement gaps in order to perform the one or more measurements on the one or more non-serving frequencies.

16. The method of claim 1 , wherein:

the method further comprises configuring a measurement pattern for the wireless device to perform the one or more measurements;

the measurement pattern indicates low-interference subframes in which the wireless device is to perform the measurements.

17. A radio network node for configuring measurement gaps during which a wireless device is to perform one or more measurements of one or more neighbor cells on one or more non-serving frequencies, the radio network node comprising:

a communications interface;

one or more processing circuits operatively connected to the communications interface;

wherein the one or more processing circuits are configured to cause the network node to:

obtain information that identifies, for each of a plurality of candidate non-serving frequencies, one or more measurement bandwidths over which one or more corresponding measurements on that non-serving frequency are to be performed;

select a subset of the candidate non-serving frequencies based on the measurement bandwidths;

configure measurement gaps during which the wireless device is to perform one or more measurements on the selected non-serving frequencies.