A collapsible access tower has a chassis 10 supporting a pair of road wheels 11 and outriggers 16,17 to impart stability when in use, and a pair of extensible multi-section columns 26,50 carrying a platform 35. The wireless access system includes a wireless access control system configured to maintain an available pool of Media Access Control Identifiers for subsequent use by a base station, remove a portion of the MAC IDs from the available pool, and use the portion of the MAC IDs for wireless communications between a wireless transceiver of the base station and a plurality of user devices. The material-removal system can be mounted on a mobile platform, such as a vehicle. The change-out handle system can be used, for example, for medical solids trapping instruments.