SON assisted optimized RAT selection for UE in a virtualized RAN environment

1. A method of providing Self Organizing Network (SON) assisted optimized Radio Access Technology (RAT) selection for a User Equipment (UE) in a virtualized Radio Access Network (RAN) environment, comprising:

establishing, by a UE, a Signaling Radio Bearer (SRB) and a Data Radio Bearer (DRB) with a virtualized node (VENB);

determining, within a SON module located at a RAN virtualization environment, whether the VENB has reached a data saturation limit for uplink/downlink throughput with at least one UE, wherein the SON module has global visibility of a plurality of virtual cells and their KPIs;

when the VENB has reached the data saturation limit, then determining, at the SON module, if a virtualized 3G function (VRNC) has reached the data saturation limit; and

when the VRNC is determined not to have reached the data saturation limit, then initiating a Long Term Evolution (LTE) to 3G handover procedure for the UE and specifying a target 3G cell.

2. The method of claim 1 further comprising detecting, by the SON, when a UE connected to a 4G CWS cell sees a 3G CWS cell in a certain geographic area.

3. The method of claim 2 wherein the detecting is based on neighbors built by the SON.

4. The method of claim 2 wherein the detecting is based on UE reported Inter-RAT neighbors sent to the SON by the CWS cells.

5. The method of claim 1 further comprising establishing, by the UE, a Signaling Radio Bearer 2 (SRB2) when the UE registers itself with the VENB and at least one Data Radio Bearer (DRB) is setup.

6. The method of claim 1 further comprising the VENB receiving a trigger from the SON to initiate handover to a UMTS Terrestrial Radio Access Network (UTRAN).

7. The method of claim 6 further comprising sending, by the VENB to the MME, a handover required message having identification of the target SON controlled by a 3G cell.

8. The method of claim 7 further comprising sending, by the UE to the MME, a notification to complete the handover signaling when radio link configuration is complete.

9. A system of providing Self Organizing Network (SON) assisted optimized Radio Access Technology (RAT) selection for a User Equipment (UE) in a virtualized Radio Access Network (RAN) environment, comprising:

a UE;

a HetNet Gateway (HNG) including a virtualized node (VENB) in communication with the UE;

wherein the UE establishes a Signaling Radio Bearer (SRB) and a Data Radio Bearer (DRB) with a virtualized node (VENB);

wherein the HNG determines whether the VENB has reached a data saturation limit for uplink/downlink throughput with at least one UE, wherein the HNG has global visibility of a plurality of virtual cells and their KPIs;

when the VENB has reached the data saturation limit, then the HNG determines if a virtualized function (VRNC) has reached a data saturation limit; and

when the VRNC is determined not to have reached the data saturation limit, then the HNG initiates a Long Term Evolution (LTE) to 3G handover procedure for the UE and specifies a target 3G cell.

10. The system of claim 9 further comprising detecting, by the SON, when a UE connected to a 4G CWS cell sees a 3G CWS cell in a certain geographic area.

11. The system of claim 10 wherein the detecting is based on neighbors built by the SON.

12. The system of claim 10 wherein the detecting is based on UE reported Inter-RAT neighbors sent to the SON by the CWS cells.

13. The system of claim 9 further comprising establishing, by the UE, a Signaling Radio Bearer 2 (SRB2) when the UE registers itself with the VENB and at least one Data Radio Bearer (DRB) is setup.

14. The system of claim 9 further comprising the VENB receiving a trigger from the SON to initiate handover to a UMTS Terrestrial Radio Access Network (UTRAN).

15. The system of claim 14 further comprising sending, by the VENB to the MME, a handover required message having identification of the target SON controlled by a 3G cell.

16. The system of claim 15 further comprising sending, by the UE to the MME, a notification to complete the handover signaling when radio link configuration is complete.

17. A non-transitory computer-readable medium containing instructions for a Self Organizing Network (SON) assisted optimized Radio Access Technology (RAT) selection for a User Equipment (UE) in a virtualized Radio Access Network (RAN) environment, when executed, cause a system to perform steps comprising:

establishing, by a UE, a Signaling Radio Bearer (SRB) and a Data Radio Bearer (DRB) with a virtualized node (VENB);

determining, within a SON module located at a RAN virtualization environment, whether the VENB has reached a data saturation limit for uplink/downlink throughput with at least one UE, wherein the SON module has global visibility of a plurality of virtual cells and their KPIs;

when the VENB has reached the data saturation limit, then determining if a virtualized function (VRNC) has reached a data saturation limit; and

when the VRNC is determined not to have reached the data saturation limit, then initiating a Long Term Evolution (LTE) to 3G handover procedure for the UE and specifying a target 3G cell located.

18. The computer-readable medium of claim 17 further comprising instructions for detecting, by the SON, when a UE connected to a 4G CWS cell sees a 3G CWS cell in a certain geographic area.

19. The computer-readable medium of claim 17 further comprising instructions for establishing, by the UE, a Signaling Radio Bearer 2 (SRB2) when the UE registers itself with the VENB and at least one Data Radio Bearer (DRB) is setup.

20. The computer-readable medium of claim 17 further comprising instructions for sending, by the VNB to the MME, a handover required message having identification of the target SON controlled by a 3G cell.