Hi,
We need the following Node to be changed to support different PLNN
ENB , MME, HSS,PCRF
ENB should aware of target PLMN so that it adds as part of SIB(But i am not sure while handover UE verifies target ENB PLMN or not) . MME should support handling different PLMN , and PCRF is to charge the different operator policy. HSS to support IMSI and other identity .