Controlling data-on-demand client access

The present invention proposes a method for controlling a client access DOD service, comprising: receiving a reservation packet, the reservation packet data comprises at least one associated client identifier associated with the at least one code book and at least one level of service associated level code; and the at least one associated code storing at least part of the subscription level in a storage unit; the at least one associated service level code stored in the storage unit; receiving a first service with a subscription level; wherein the subscription level code corresponding to the subscription level, access to the first service. The method further comprises: receiving a service level associated with at least one second service; wherein the at least one associated service level code corresponding to the at least one associated service level, access to at least a portion of the second service.