A method of sending, to a policy control unit (100, 100-1 - 100-3) of a mobile communications network, congestion information for a plurality of mobile entities (400-1 - 400-8), each one of the plurality of mobile entities (400-1 - 400-8) being connected to a respective radio access network of the mobile communications network and associated with the policy control unit (100, 100-1 - 100-3), the congestion information indicating congestion of the respective radio access network, the method comprising a congestion monitoring unit: - retrieving an identity of the policy control unit (100, 100-1 - 100-3), wherein said retrieving of the identity of the policy control unit (100, 100-1 - 100-3) comprises: - the congestion monitoring unit sending a request message for transmitting congestion information of a given mobile entity (400-1 - 400-8) to a policy control unit (100, 100-1 - 100-3), including congestion information and an identity of a given mobile entity (400-1 - 400-8) of the plurality of mobile entities (400-1 - 400-8), wherein the request message is routed by a Diameter Routing Agent, DRA to the policy control unit (100, 100-1 - 100-3), and - the congestion monitoring unit receiving a response message including the identity of the policy control unit (100, 100-1 - 100-3) associated with the given mobile entity (400-1 - 400-8), - aggregating the congestion information for at least some of the plurality of mobile entities (400-1 - 400-8) based on the respective mobile entities (400-1 - 400-8) being associated with the policy control unit (100, 100-1 - 100-3), and - sending a message (411-1, 411-3) including the aggregated congestion information to the policy control unit (100, 100-1 - 100-3), wherein said sending of the message (411-1, 411-3) employs the retrieved identity of the policy control unit (100, 100-1 - 100-3) to route the message (411-1, 411-3) to the policy control unit (100, 100-1 - 100-3). - retrieving an identity of the policy control unit (100, 100-1 - 100-3), wherein said retrieving of the identity of the policy control unit (100, 100-1 - 100-3) comprises: - the congestion monitoring unit sending a request message for transmitting congestion information of a given mobile entity (400-1 - 400-8) to a policy control unit (100, 100-1 - 100-3), including congestion information and an identity of a given mobile entity (400-1 - 400-8) of the plurality of mobile entities (400-1 - 400-8), wherein the request message is routed by a Diameter Routing Agent, DRA to the policy control unit (100, 100-1 - 100-3), and - the congestion monitoring unit receiving a response message including the identity of the policy control unit (100, 100-1 - 100-3) associated with the given mobile entity (400-1 - 400-8), - the congestion monitoring unit sending a request message for transmitting congestion information of a given mobile entity (400-1 - 400-8) to a policy control unit (100, 100-1 - 100-3), including congestion information and an identity of a given mobile entity (400-1 - 400-8) of the plurality of mobile entities (400-1 - 400-8), wherein the request message is routed by a Diameter Routing Agent, DRA to the policy control unit (100, 100-1 - 100-3), and - the congestion monitoring unit receiving a response message including the identity of the policy control unit (100, 100-1 - 100-3) associated with the given mobile entity (400-1 - 400-8), - aggregating the congestion information for at least some of the plurality of mobile entities (400-1 - 400-8) based on the respective mobile entities (400-1 - 400-8) being associated with the policy control unit (100, 100-1 - 100-3), and - sending a message (411-1, 411-3) including the aggregated congestion information to the policy control unit (100, 100-1 - 100-3), wherein said sending of the message (411-1, 411-3) employs the retrieved identity of the policy control unit (100, 100-1 - 100-3) to route the message (411-1, 411-3) to the policy control unit (100, 100-1 - 100-3).