A mixed-modem approach to data isolation on a broadband local area network

Isolation can be obtained by using equipment from more than one manufacturer to introduce incompatibility between nonassociated users. The basis for isolation is developed and it is postulated that four layers of isolation will exist when the proper equipment is chosen. An experimental broadband local area network (LAN) was constructed to verify isolation. This independent network allowed variations in operating conditions without causing interference in normal broadband operations. The measured results indicate that a broadband LAN can transmit data of varying sensitivity levels without compromising data security. When combined with certain administrative restrictions, the mixed-modem technique provides a cost-effective method of sharing a broadband network while maintaining isolation of data having different sensitivities