Real-time traffic control for multihomed devices

In this paper we explore delay based congestion and flow control and off-loading of real-time traffic from Wireless Local Area Networks (WLANs) to cellular networks in multi-homed devices. The developed controller is based on an embedded fuzzy expert system. It adjusts transceivers´ traffic flow(s) for prevailing network conditions to achieve maximum throughput in required application dependent delay limits. In wireless networks delay and throughput are dependent on the packet size, packet transmission interval, and the node connection density. Therefore, the controller on the destination node monitors average one-way delay and a change of one-way delay of the incoming traffic. Thereafter it adjusts packet size and transmission interval of the source node by transmitting a control command to the source. If the prevailing level of traffic in networks exceeds its capacity despite of the control actions, devices prepare to do asynchronous traffic off-loading to another access network. The control model was validated by simulating User Datagram Protocol (UDP) traffic in OMNeT++ network simulator.