While going through some KDDI presentations, came across how they planned and perform Offloading. In fact, even before the deployment of LTE, they were aware that the network capacity would not be enough for the savvy Japanese mobile phone users. They had to start planning for how to offload the users as soon as possible.
au Wi-Fi is their Wi-Fi offloading strategy where they make Wi-Fi hotspots available for the users. They even claim that with Wi-Fi on, the baattery life could be 1.5 times the normal 3G battery life.
UQ WiMAX is another KDDI company that allows users with compatible handsets to offload to WiMAX. KDDI have their own WiMAX branded services as well, see here.
Finally, with the LTE rollout they have different hierarchical cells available that the user could be moved to if one of the layers is congested.