Abstract: A turntable comprising a hub assembly including a first hub and a second hub rotatable with respect to the first hub about an axis, and an extension member releasably coupled to the second hub. The extension member rotates with the second hub about the axis when the extension member is coupled to the second hub. The extension member extends from the second hub radially outward from the axis.

Abstract: Messages are delivered in a communications network by monitoring an arrival rate of messages destined for a geographical area within a short time period. Then, upon reaching a threshold, a multicast group is established for routing the messages to the geographical area. Network devices responsible for delivering the messages join the multicast group and the messages are delivered to the geographical area upon establishment of the multicast group.