A wireless network is provided that includes a base station and subscriber stations that communicate with the base station using radio frequency (RF) time division duplex (TDD) signaling. The base station may establish medium access control (MAC) connections with each station. The base station monitors communications with the stations and, in accordance, assigns stations or MAC connections to modulation groups. The base station transmits signals on MAC connections or to stations in a modulation group in adjacent TDD slots within a TDD frame. The base station may receive access requests from the stations, evaluate traffic requirements for the stations, and determine a longest downlink portion for the stations. The base station then allocates downlink and uplink portions of a TDD frame according to the length of the longest downlink portion.

A POTS alternative including an uninterruptible power supply (UPS), a router, a modbus converter for connecting the router to the UPS to monitor conditions of the UPS, a gateway for providing connections to one or more POTS-based customer premises equipment through the modbus converter to the router and directly to the router. The router includes a plurality of SIM cards, each SIM card for connecting to one cellular service provider among a plurality of cellular service providers. The router automatically connecting to a cellular service provider among the plurality of cellular service providers providing the strongest cellular signal and switching from the cellular service provider to a different cellular service providers when the different cellular service provider provides a stronger cellular signal when the cellular service provider no longer provides the strongest cellular signal.