In LTE only always RRC reconfiguration message is used but why not rab, physical, transport reconfiguration messages?

Question

During attach procedure, UE sends "Attach Request" along with "RRC Connection Setup Complete", eNodeB sends "Attach Accept" along with "RRC Connection Reconfiguration then why UE does not send "Attach Complete" along with "RRC Connection Reconfiguration Complete" message ? What could be the reason for defining the messages so ?

Answer 1

I just answered similar query on queryhome answering here again -

In LTE, RRC CONNECTION RECONFIGURATION is the only message used to perform all logical, transport, and physical channel configurations where as in case UMTS, there exists Transport Channel, Physical Channel and Radio Bearer Reconfiguration messages so to answer your query this is because of the same can is achieved by the single message.

Read more at: http://tech.queryhome.com/23947/lte-what-is-the-use-rrc-connection-reconfiguration-message

Comments

agreed. Even I have same answer :)

Answer 2

Just to add to the previous answer, if you look at 36.336 RRC specs and look for the RRC messages, you can see separate IEs for logical , transport and phy configuration etc.. as part of the RRC setup and reconfiguration message.