This memo describes a mobile communications use case for congestion exposure (ConEx) with a particular focus on those mobile communication networks that are architecturally similar to the 3GPP Evolved Packet System (EPS). This memo provides a brief overview of the architecture of these networks (both access and core networks) and current QoS mechanisms and then discusses how congestion exposure concepts could be applied. Based on this discussion, this memo suggests a set of requirements for ConEx mechanisms that particularly apply to these mobile networks.