Small cell mobility enhancement

1. A method, comprising:

applying at least one procedure for inter-frequency measurements of at least one carrier, wherein a first procedure is applied when a carrier associated with a first type of cell is to be measured and a second procedure is applied when a carrier associated with a second type of cell is to be measured, wherein the inter-frequency measurements are performed less frequently in the first procedure than in the second procedure; and

performing the inter-frequency measurements according to the applied procedure, when the procedure for the inter-frequency measurements is on.

2. The method of claim 1 , further comprising:

receiving a command to perform the inter-frequency measurement according to the first procedure.

3. The method of claim 1 , further comprising:

obtaining information on whether the non-continuous coverage radio access is available in the current location or not; and

selecting the procedure of the inter-frequency measurement based on whether the non-continuous coverage radio access is available or not.

4. The method of claim 3 , further comprising receiving at least one of following:

a neighbor list containing information on the cells deployed for providing non-continuous coverage radio access in the current location, and

information on physical cell identifications assigned to the cells deployed for providing non-continuous coverage radio access.

5. The method of claim 1 , further comprising:

setting the procedure for the inter-frequency measurements on when the currently serving cell is overloaded or the signal quality and/or the signal power of the current serving cell decreases to a predetermined threshold level, wherein a higher predetermined threshold level is applied for the first procedure than for the second.

6. The method of claim 1 , further comprising:

having the first procedure on continuously.

7. The method of claim 1 , wherein the first type of cell is deployed for providing non-continuous coverage radio access and the second type of cell is deployed for providing continuous coverage radio access.

8. The method of claim 1 , wherein, when discontinuous reception is off and the first procedure is on, a cycle which comprises the following is repetitively carried out:

performing predetermined number of time-separated inter-frequency measurements by applying gap-assisted inter-frequency measurements; and

restraining from performing inter-frequency measurements for a predetermined time duration exceeding the time-separation after the predetermined number of inter-frequency measurements have been done.

9. The method of claim 1 , further comprising, when discontinuous reception is on and the first procedure is on:

restraining from performing inter-frequency measurements in every predetermined discontinuous reception cycle.

10. The method of claim 1 , further comprising:

providing a measurement report indicating that the inter-frequency measurement corresponding to the measurement report has been performed for the carrier associated with the first type of cell.

11. The method of claim 1 , further comprising:

causing a transmission of a proximity indication or a request for a measurement gap configuration to measure the cell deployed for providing non-continuous coverage more accurately than currently.

12. A method, comprising:

providing information about a plurality of procedures for inter-frequency measurements, wherein a first procedure is applied when a carrier associated with a first type of cell is to be measured and a second procedure is applied when a carrier associated with a second type of cell is to be measured, wherein the inter-frequency measurements are performed less frequently in the first procedure than in the second procedure; and thereafter

receiving at least one measurement report comprising results of interfrequency measurements according to the first or the second procedure.

13. The method of claim 12 , further comprising:

providing information of threshold levels for triggering the inter-frequency measurement procedure, wherein the threshold levels are separate for the first procedure and for the second procedure, wherein the first type of cell is deployed for providing non-continuous coverage radio access and the second type of cell is deployed for providing continuous coverage radio access.

14. An apparatus, comprising:

at least one processor and at least one memory including a computer program code, wherein the at least one memory and the computer pro-gram code are configured to, with the at least one processor, cause the apparatus at least to:

apply at least one procedure for inter-frequency measurements of at least one carrier, wherein a first procedure is applied when a carrier associated with a first type of cell is to be measured and a second procedure is applied when a carrier associated with a second type of cell is to be measured, wherein the inter-frequency measurements are performed less frequently in the first procedure than in the second procedure; and

perform the inter-frequency measurements according to the applied procedure, when the procedure for the inter-frequency measurements is on.

15. The apparatus of claim 14 , wherein the apparatus is further caused to:

receive a command to perform the inter-frequency measurement according to the first procedure.

16. The apparatus of claim 14 , wherein the apparatus is further caused to:

obtain information on whether the non-continuous coverage radio access is available in the current location or not; and

select the procedure of the inter-frequency measurement based on whether the non-continuous coverage radio access is available or not.

17. The apparatus of claim 16 , wherein the apparatus is further caused to receive at least one of following:

a neighbor list containing information on the cells deployed for providing non-continuous coverage radio access in the current location, and

information on physical cell identifications assigned to the cells deployed for providing non-continuous coverage radio access.

18. The apparatus of claim 14 , wherein the apparatus is further caused to:

set the procedure for the inter-frequency measurements on when the currently serving cell is overloaded or the signal quality and/or the signal power of the current serving cell decreases to a predetermined threshold level, wherein a higher predetermined threshold level is applied for the first procedure than for the second.

19. The apparatus of claim 14 , wherein the apparatus is further caused to:

have the first procedure on continuously.

20. The apparatus of claim 14 , wherein the first type of cell is deployed for providing non-continuous coverage radio access and the second type of cell is deployed for providing continuous coverage radio access.