Standard QCI is used for service differentiation. Extended QCI can be used to differentiate service associated with different priorities.
MME send extended QCI index in RAB assignment message. eNodeB can configure extended QCI and can assign radio resource differently according to the different QCI number and different scheduling weight factor.
Extended QCI may be used as operator defined QCI for differentiating service by user type. As an example an operator may have user categories viz. platinum, gold, silver, bronze etc. Operator may define separate Extended QCIs for voice service corresponding to different user categories as below:
Thus operator can create service differentiation by allocating Extended QCIs by user category.