A.eNodeB B.MME C.SGW D.PGW
A.UE小區(qū)間切換 B.UE跨系統(tǒng)重選 C.傳輸用戶業(yè)務數(shù)據(jù) D.空中接口參數(shù)
A.MME和SGW B.MME和HSS C.SGW和PGW D.eNodeB和MME