A.SGSN Change(SGSN:Service GPRS Support Node)
B.MS Time Zone Change(MS:Mobile Station)
C.RAT Change(RAT:Radio Access Type)
D.SGSN PLMN ID Change(PLMN:Public Land Mobile Network)
E.QoS Negotiated Change
A.识别面临的风险并赋值
B.识别存在的脆弱性并赋值
C.制定安全措施实施计划
D.检查安全措施有效性