Mobile computing refers to an emerging new computing environment incorporating both wireless and wired high-speed networking technologies. In the near future, it is expected that mobile users will have access to a wide variety of services that will be made available over highspeed networks. The quality of these services in the high-speed networks can be specified in terms of several QoS paameters. The important QoS parameter in mobile computings is the guarantee for seamless communication which is to provide disruption free service to mobile users. A disruption in service could occur due to active handoffs. This paper proposes an extended staggened muticast approach which provides a probabilistic guarantee for disruption free service. The extended staggerd multicast approach estimates mobility direction and mobility velocity for a user. It is possible that data packets for a mobile host are multicasted to not all neighbor cells but a part of neighbor cells on the basis of these information. Therefore, the extended staggered multicast significantly reduces the static network bandwidth usage also provides a probabilistic guarantee for disruption free service.