Mobile operators are seeing significant increases in user data traffic. For some operators, user data traffic has more than doubled annually for several years. Although the data capacity of networks has increased significantly, the observed increase in user traffic continues to outpace the growth in capacity. This is resulting in increased network congestion and in degraded user service experience. Reasons for this growth in traffic include the rapidly increasing use of "smart phones" and the proliferation of data applications that they support, and the use of USB modem dongles for laptops to provide mobile or nomadic Internet access using 3GPP networks. As the penetration of these terminals increases worldwide, this trend of rapidly increasing data traffic is expected to continue and possibly accelerate. Network operators continue to invest in additional network capacity (network entities and connectivity resources) attempting to cope with user data traffic increases that cause user plane congestion. This additional investment is becoming increasingly costly due to the rapid and continuing increases in user data traffic. From a CAPEX or OPEX perspective, this approach is not sufficient. In addition, existing QoS and PCC mechanisms are being deployed but the full effect is still to be seen. It is therefore necessary to study approaches and mechanisms to manage user plane congestion. This TR considers scenarios and use cases where high usage levels lead to user plane traffic congestion in the RAN, and proposes requirements for handling user plane traffic when RAN congestion occurs. The aim is to make efficient use of available resources to increase the potential number of active users while maintaining the user experience. Scenarios that will be considered include handling of user plane traffic when RAN congestion occurs based on: