Basic Call Processing - Typical Packet Call                  Home : www.sharetechnote.com

 

 

Basic State Machine

 

Following diagram shows a possible state machine that a UE would go through. The state transition in this post will be about (s0)->(a)-> (b1) -> (c1) -> (d1) -> (e1) -> (f1) -> (g1) -> (h1).  Most of other transition will be described in "Handover" page.

 

 

Note : Intial Registration and Default EPS Bearer Setup procedure would be common to almost all LTE network. Of course, there would be a small variations but overall concept would be almost same. But the procedure after <Idle> would be quite different among Network Operators. Following would be two major variations.

  • Setup RRC Connection, RRC Connection Reconfiguration without creating any dedicated EPS Bearer.(In this case, UE uses the existing Default EPS bearer for traffic).
  • Setup RRC Connection, RRC Connection Reconfiguration with a dedicated EPS Bearer.(In this case, Ue uses the existing Default EPS bearer or Dedicated EPS Bearer depending on situation).

The example test sequence in this case shows the second case,