Pico Cell-Selection/Handover for TDM EICIC Heterogenous Networks

1. Apparatus, comprising: at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured, with the at least one processor, to cause the apparatus to perfoim at least the following: check if a first received cell range extension received from a first cell is larger than 0; check if a second received cell range extension received from a second cell is larger than 0, wherein the second cell is different from the first cell; set, if both the first received cell range extension and the second received cell range extension are larger than 0, a first modified cell range extension based on the first received cell range extension and a second modified cell range extension based on the second received cell range extension, wherein for at least one combination of values of the first and second received cell range extensions at least one of the first and second modified cell range extensions is different from the respective received cell range extension, and set, if at least one of the first received cell range extension and the second received cell range extension is equal to 0, the first modified cell range extension equal to the first received modified cell range extension and the second modified cell range extension equal to the second received cell range extension; select one of the first cell and the second cell for cell selection and/or handover based on a comparison of a sum of a first signal strength indicator from the first cell and the first modified cell range extension and a sum of a second signal strength indicator from the second cell and the second modified cell range extension.

2. The apparatus according to claim 1 , wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to attach the apparatus to the selected cell.

3. The apparatus according to claim 1 , wherein the first and second signal strength indicators are respective reference signal received powers or wherein the first and second signal strength indicators are respective reference signal received qualities.

4. The apparatus according to claim 1 , wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to set, if both the first received cell range extension and the second received cell range extension are larger than 0, the first modified cell range extension and the second modified cell range extension such that an absolute value of a difference between the first modified cell range extension and the second modified cell range extension is not larger than a threshold.

5. The apparatus according claim 4 , wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further: to compare which of the first received cell range extension and the second received cell range extension is the larger one; to set, if the first received cell range extension is not smaller than the second received cell range extension, the first modified cell range extension equal to the minimum among the first received cell range extension and a sum of the second received cell range extension and the threshold, and to set, if the first received cell range extension is smaller than the second received cell range extension, the second modified cell range extension equal to the minimum among the second received cell range extension and a sum of the first received cell range extension and the threshold.

6. The apparatus according to claim 4 , wherein the threshold is 0.

7. The apparatus according to claim 1 , wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus further to set, if both the first received cell range extension and the second received cell range extension are larger than 0, the first modified cell range extension equal to a the first received cell range extension multiplied by a factor and the second modified cell range extension equal to the second received cell range extension multiplied by the factor, wherein the factor is less than 1.

8. User equipment comprising an apparatus according to claim 1 .

9. A method performed by an apparatus, the method comprising the apparatus: checking if a first received cell range extension received from a first cell is larger than 0; checking if a second received cell range extension received from a second cell is larger than 0, wherein the second cell is different from the first cell; setting, if both the first received cell range extension and the second received cell range extension are larger than 0, a first modified cell range extension based on the first received cell range extension and a second modified cell range extension based on the second received cell range extension, wherein for at least one combination of values of the first and second received cell range extensions at least one of the first and second modified cell range extensions is different from the respective received cell range extension, setting, if at least one of the first received cell range extension and the second received cell range extension is equal to 0, the first modified cell range extension equal to the first received modified cell range extension and the second modified cell range extension equal to the second received cell range extension; and selecting one of the first cell and the second cell for cell selection and/or handover based on a comparison of a sum of a first signal strength indicator from the first cell and the first modified cell range extension and a sum of a second signal strength indicator from the second cell and the second modified cell range extension.

10. The method according to claim 9 , further comprising attaching the apparatus performing the method to the selected cell.

11. The method according to claim 9 , wherein the first and second signal strength indicators are respective reference signal received powers or wherein the first and second signal strength indicators are respective reference signal received qualities.

12. The method according to claim 9 , wherein, if both the first received cell range extension and the second received cell range extension are larger than 0, the first modified cell range extension and the second modified cell range extension are set such that an absolute value of a difference between the first modified cell range extension and the second modified cell range extension is not larger than a threshold.

13. The method according claim 12 , further comprising the apparatus comparing which of the first received cell range extension and the second received cell range extension is the larger one; and wherein, if the first received cell range extension is not smaller than the second received cell range extension, the first modified cell range extension is set equal to the minimum among the first received cell range extension and a sum of the second received cell range extension and the threshold, and, if the first received cell range extension is smaller than the second received cell range extension, the second modified cell range extension is set equal to the minimum among the second received cell range extension and a sum of the first received cell range extension and the threshold.

14. The method according to claim 12 , wherein the threshold is 0.

15. The method according to claim 9 , wherein, if both the first received cell range extension and the second received cell range extension are larger than 0, the first modified cell range extension is set equal to a the first received cell range extension multiplied by a factor and the second modified cell range extension is set equal to the second received cell range extension multiplied by the factor, wherein the factor is less than 1.

16. A computer program product comprising a non-transitory computer-readable storage medium bearing computer program code embodied therein for use with a computer, the computer program code comprising code for performing at least: checking if a first received cell range extension received from a first cell is larger than 0; checking if a second received cell range extension received from a second cell is larger than 0, wherein the second cell is different from the first cell; setting, if both the first received cell range extension and the second received cell range extension are larger than 0, a first modified cell range extension based on the first received cell range extension and a second modified cell range extension based on the second received cell range extension, wherein for at least one combination of values of the first and second received cell range extensions at least one of the first and second modified cell range extensions is different from the respective received cell range extension, setting, if at least one of the first received cell range extension and the second received cell range extension is equal to 0, the first modified cell range extension equal to the first received modified cell range extension and the second modified cell range extension equal to the second received cell range extension; and selecting one of the first cell and the second cell for cell selection and/or handover based ona comparison of a sum of a first signal strength indicator from the first cell and the first modified cell range extension and a sum of a second signal strength indicator from the second cell and the second modified cell range extension.

17. The computer program product according to claim 16 , wherein the first and second signal strength indicators are respective reference signal received powers or wherein the first and second signal strength indicators are respective reference signal received qualities.

18. The computer program product according to claim 16 , wherein, if both the first received cell range extension and the second received cell range extension are larger than 0, the first modified cell range extension and the second modified cell range extension are set such that an absolute value of a difference between the first modified cell range extension and the second modified cell range extension is not larger than a threshold.

19. The computer program product according to claim 16 , wherein the code is further for performing: comparing which of the first received cell range extension and the second received cell range extension is the larger one; and wherein, if the first received cell range extension is not smaller than the second received cell range extension, the first modified cell range extension is set equal to the minimum among the first received cell range extension and a sum of the second received cell range extension and the threshold, and, if the first received cell range extension is smaller than the second received cell range extension, the second modified cell range extension is set equal to the minimum among the second received cell range extension and a sum of the first received cell range extension and the threshold.