As part of attach procedure, network establishes at least one default bearer. A default bearer can have one of the QCI value ranges from 5-9. There are two categories of bearer in lte network, one is known as GBR bearer and another one is known as non-GBR bearer.
Default bearer is mandatory to establish for an UE and also it is under non-GBR category. Every subscriber may subscribe for different bit rate and eNodeB MAC scheduler consider those things. Reason being, UE-AMBR IE is a mandatory IE within the Initial context setup request messag