This paper contributes to the management of a network infrastructure formed by distinct wireless access technologies, which are administered by several cooperating mobile operators. These wireless technologies may cover a public area, which at specific times of the day are overwhelmed by a large number of users. A new management solution is proposed that controls the heterogeneous network infrastructure in a distributed way, using policies and metrics, and ensuring a Quality of Service (QoS) level associated with each terminal connection. The QoS level is supported through a novel, vertical and dynamic aggregation of performance information about the wireless access, originated at distinct technologies. A closed innovative control loop among a flexible brokerage service in the network, and agents at the mobile terminals, counteracts any abnormal data load. This allows the terminals to make well-informed decisions about their connections to improve on the QoS offered to the application layer. In this way, depending on the management policies of the brokerage service and the quality metrics, wireless access technologies that by default only offer a best-effort connection service can be enhanced in a very straightforward way. The obtained results highlight the advantages for using this new distributed solution to manage the heterogeneous network infrastructure in several distinct usage scenarios.