The present document defines a BSM functional architecture required to provide multimedia Quality of Service to the end user. This architecture identifies the functional elements to allow QoS provision in BSM systems integrated with heterogeneous networks. It includes the interfaces of these elements to other QoS functional elements in adjacent networks and customer equipment@ and in higher or lower protocol layers. The multimedia services targeted are based on the Internet Protocol (IP) and use the QoS capabilities of IP as far as necessary@ without relying on the support of other underlying protocols (such as MPLS). QoS for unicast rather than multicast services is the primary focus. A key feature of the BSM architecture is the SI-SAP. The way in which the QoS functions interact across the SI-SAP is also illustrated in the architecture. The approach adopted is to define the following aspects in sequence: ? the QoS service requirements; ? the global QoS functional and network architecture requirements in which BSM systems will play a role; ? the detailed BSM QoS architecture of main functional blocks (ST's@ etc.). Several architectural cases are illustrated for QoS provision. These cases are intended to show the potential evolution from a simple QoS solution with quasi-static resource allocations to more sophisticated services with dynamic resource reservation.