Patent ID: 7058802
Filing Date: 2006-06-06
Classification: H04N

Abstract:
1. A communication session management method for providing a transmission service having a plurality of service-levels, each service-level being associated with a separate quality-of-service (QOS), the method comprising: preparing data for transmission at one of the plurality of service-levels by uniquely associating a service-level encryption key with said one of the plurality of service-levels; encrypting said data with said service-level encryption key to form encrypted data uniquely associated with said one of the plurality of service-levels; transmitting said encrypted data uniquely associated with said one of the plurality of service-levels to users entitled to said one of the plurality of service-levels; determining that communication load at said one of the plurality of service-levels exceeds a threshold; in response to a result of the determining step, downgrading to an available service-level that is lower in the QOS hierarchy than said one of the plurality of service-levels; and distributing to the users entitled to said one of the plurality of service-levels decryption key derivation information for decrypting said encrypted data, wherein said decryption key derivation information is comprised in an entitlement control message (ECM) and said downgrading step is supported in one of the following modes: an automatic mode; and a mode in which downgrade is made upon confirmation by a user.