A mobile terminal comprising: a processor configured to: conduct communications with a base station of first network in accordance with a first set of parameters including a first encryption key; store the first set of parameters used in association with the first network such that the first set of parameters is retained in said mobile terminal even as the processor subsequently conducts communications with a base station of a second network in accordance with a second set of parameters, including a second encryption key, wherein said first and second encryption keys are established in respective registration and/or authentication processes, wherein each network is identified by a respective session identification number /network identification number, wherein the first encryption key is stored in association with a session identification number /network identification number of the first network; recognize a transition from the first network to the second network and thereafter determine if the second set of parameters has been previously stored in said mobile terminal, wherein said processor is configured to recognize the transition from the first network to the second network by a change in the session identification number /network identification number of the network; retrieve the second set of parameters from a memory on the mobile terminal if the second set of parameters has been previously stored; determine if the retrieved second set of parameters remains valid prior to conducting communications in accordance therewith upon detecting a transition from the first network to the second network; determine and store new second set of parameters associated with the second network if the retrieved second set of parameters is not valid; periodically review the validity of the stored first and second sets of parameters by determining if any of the first and second of sets of parameters were stored more than a predetermined time ago; and delete any stored sets of parameters that are no longer valid as they were stored more than the predetermined time ago. conduct communications with a base station of first network in accordance with a first set of parameters including a first encryption key; store the first set of parameters used in association with the first network such that the first set of parameters is retained in said mobile terminal even as the processor subsequently conducts communications with a base station of a second network in accordance with a second set of parameters, including a second encryption key, wherein said first and second encryption keys are established in respective registration and/or authentication processes, wherein each network is identified by a respective session identification number /network identification number, wherein the first encryption key is stored in association with a session identification number /network identification number of the first network; recognize a transition from the first network to the second network and thereafter determine if the second set of parameters has been previously stored in said mobile terminal, wherein said processor is configured to recognize the transition from the first network to the second network by a change in the session identification number /network identification number of the network; retrieve the second set of parameters from a memory on the mobile terminal if the second set of parameters has been previously stored; determine if the retrieved second set of parameters remains valid prior to conducting communications in accordance therewith upon detecting a transition from the first network to the second network; determine and store new second set of parameters associated with the second network if the retrieved second set of parameters is not valid; periodically review the validity of the stored first and second sets of parameters by determining if any of the first and second of sets of parameters were stored more than a predetermined time ago; and delete any stored sets of parameters that are no longer valid as they were stored more than the predetermined time ago.