**5.4 Fog-cloud exchange**

This deployment model involves a user device not being aware of the existence of any FN. Instead, the user device interacts with a Cloud operator who then attempts to find an FN near the user. Therefore, the Cloud operator needs to keep track of the user location and discover suitable FN operators that could be used to support the session at a particular location. In this instance, the Cloud operator will always try to complete the user request first; however, if a QoS target is unlikely to be met due to latency constraints, it can outsource the user request to a regional FN. The incentive in this instance is to enable Fog-Cloud exchange contracts to be negotiated between providers.
