A fixed broadband wireless data access service providing shared wide-band packet-switched data transport for high speed data access in areas where conventional ADSL service and fiber optic service are unavailable. The wireless data access service is a point-to-multipoint cellular-type network that connects customers to data service providers through the ATM backbone of an existing network. Customers connect to the ATM backbone and data service provider through a cellular grid in which a wireless base station in each cell communicates with the individual customer wireless equipment within its cell site coverage area. The base stations are connected to an ATM backbone switch through wireless and wireline backhaul links. The upstream and downstream bandwidths of the wireless broadband network are engineered in various symmetric and asymmetric configurations to provide a shared packet-switched connection that emulates an uninterrupted, direct wireline ADSL connection. The wireless broadband network employs a data protocol of shared access bandwidth and adaptive asymmetric data rates to support multiuser service sessions by wireless transmission. The wireless broadband network is not network protocol specific and can be applied to wireless asymmetric digital subscriber line service, wireless integrated service digital network over digital subscriber line service, wireless very high bit rate digital subscriber line service, or wireless symmetric or single-line digital subscriber line service.