| 摘要 |
A telecommunications data transmission system includes a transmission network having a plurality of nodes, a plurality of access nodes and a plurality of subscriber terminals connected to access nodes. The telecommunications data transmission system is adapted to support provision of multimedia telecommunications services and employ a resource reservation protocol. The resource reservation protocol is unique in that it permits users to specify a preference for a multiplicity of levels of QoS and to reserve a plurality of resource types. A user's preference, with regard to QoS, is recorded by elements of a Price Vector, each element of which corresponds to a notional "price" that a user is prepared to pay for a given level of said multiplicity of levels of QoS. A set of possible resource values for each resource type is recorded by the elements of a Resource Vector, each element of which corresponds to an available resource level for a given one of said plurality of resource types. The Price Vector is merged with the Resource Vector to produce a Downgrade Vector specifying resource levels, supported by a given application, which a user is prepared to accept in a descending order of user preference. The Downgrade Vectors are propagated through the transmission network, from node to node, in resource reservation messages. |
