A method for enabling secure communication between a client on an open network and a server apparatus on a secure network. The perimeter element extends adjacent to a sidewall of the sole structure, and the central element is centrally-positioned. That deflection of gravitation and its effects are then used to drive spacecraft an flying vehicles. When computing and regulating the linear loads, one or more of the physical properties affecting the bending of each intermediate roll under load, such as bending rigidity, mass, shape, and material properties, are taken into account. The pre-emptive roaming functionality can be configured to support desired data rates or other QoS levels.