A method, effected by an integrated Wi-Fi and small cell, IWS, system, for handing off between a cellular network and a Wi-Fi network, comprising: causing a cellular base station of the cellular network to collect real time performance data related to the cellular network; causing a Wi-Fi access point of the Wi-Fi network to collect real time performance data related to the Wi-Fi network, wherein the cellular base station and the Wi-Fi access point are integrated and co-located at a single physical location or virtually co-located, wherein co-located comprises connected by control and data channels in such a way that control information and data packets of the cellular base station and the Wi-Fi access point may be passed directly to each other; using the real time performance data related to the cellular network and the real time performance data related to the Wi-Fi network collectively for determining whether to handoff traffic of a user equipment from a cellular air interface of the cellular network to a Wi-Fi air interface of the Wi-Fi network, or vice versa; causing the Wi-Fi access point to send data packets to the cellular base station through the data channel, wherein the data packets correspond to traffic of the user equipment that has been handed off from the cellular air interface of the cellular network to the Wi-Fi air interface of the Wi-Fi network, wherein the data packets are further sent by the cellular base station through tunnels established on the cellular network prior to the handoff; intercepting a dynamic host configuration protocol, DHCP, request sent by the user equipment; and responding to the request by sending a cellular network assigned IP address to be used by the user equipment as its IP address on the Wi-Fi network, wherein the cellular network assigned IP address was previously assigned to the user equipment as its IP address on the cellular network. causing a cellular base station of the cellular network to collect real time performance data related to the cellular network; causing a Wi-Fi access point of the Wi-Fi network to collect real time performance data related to the Wi-Fi network, wherein the cellular base station and the Wi-Fi access point are integrated and co-located at a single physical location or virtually co-located, wherein co-located comprises connected by control and data channels in such a way that control information and data packets of the cellular base station and the Wi-Fi access point may be passed directly to each other; using the real time performance data related to the cellular network and the real time performance data related to the Wi-Fi network collectively for determining whether to handoff traffic of a user equipment from a cellular air interface of the cellular network to a Wi-Fi air interface of the Wi-Fi network, or vice versa; causing the Wi-Fi access point to send data packets to the cellular base station through the data channel, wherein the data packets correspond to traffic of the user equipment that has been handed off from the cellular air interface of the cellular network to the Wi-Fi air interface of the Wi-Fi network, wherein the data packets are further sent by the cellular base station through tunnels established on the cellular network prior to the handoff; intercepting a dynamic host configuration protocol, DHCP, request sent by the user equipment; and responding to the request by sending a cellular network assigned IP address to be used by the user equipment as its IP address on the Wi-Fi network, wherein the cellular network assigned IP address was previously assigned to the user equipment as its IP address on the cellular network.