g binary data files using electronic mailUS515766021 sept. 199020 oct. 1992Hitachi, Ltd.Communication system including portable terminals and fixed terminalsUS515959229 oct. 199027 oct. 1992International Business Machines CorporationNetwork address management for a wired network supporting wireless communication to a plurality of mobile usersUS517768018 oct. 19885 janv. 1993Hitachi, Ltd.Electronic