Handoff of (i) a mobile wirelessly communicating device--a mobile--between (ii) as plurality of stationary base stations within cells within a domain of (iii) a stationary gateway router all within (iv) a communications network based on the Internet Protocol (IP) is without interchange of control and responsive to the mobile, only. The gateway router assigns to the mobile at a time before the handoff IP addresses suitable for the mobile to connect to the gateway router through all the plurality of base stations of the domain. Unilaterally deriving a handoff decision to switch base stations, the mobile directs its wireless communications link to a new base station where signal level registration is performed. Responsive to a link layer trigger at the new base station, the gateway router is informed of the handoff, and both the router and the mobile independently construct the mobile's new IP address.