What is S1AP protocol?
The S1AP protocol is defined in TS 36.413. The S1AP protocol provides transport function between UE and MME by offering NAS signalling transport. The NAS protocol provides mobility management and session management between the User equipment (UE) and Mobile Management Entity (MME).
What are the main components of EPC?
The three core elements of the EPC are the Mobility Management Entity (MME), Serving Gateway (SGW), and Packet Data Network Gateway (PGW).
Which is the lower layer protocol used by S1AP?
S1 application part (S1AP) is the control-plane signaling protocol between the eNB and the MME [13]. It supports the S1-MME interface and utilizes SCTP in the transport layer. The SCTP protocol is for the control-plane, which guarantees delivery of control/signaling messages between the MME and the eNB.
What is IMS and EPC?
First of all there is the Evolved Packet Core (EPC) and then there is the IP Multimedia Sub-system (IMS), as shown in Figure 3.15. All user data goes through EPC and the data related to the operator IMS services (such Voice over LTE) goes also via IMS while traffic to the normal internet does not.
Can eNB connect to multiple MME?
Each SCTP association between an eNB and an MME can support multiple UEs. The S1-MME is responsible for EPC bearer setup and release procedures, handover signaling, paging, and NAS signaling transport.
What is S1AP protocol used for?
S1AP – S1 Application Protocol. S1AP is used between the eNB and the MME in order to support operations such as E-RAB (E-UTRAN Radio Access Bearer) Management, transfer of UE Context information, NAS Signalling transport, Paging and EPC based mobility.
What is the PPID of S1AP?
S1 Application Protocol (S1AP) E-UTRAN radio network layer signalling protocol for the S1 interface. SCTP: Typically, S1AP uses SCTP as its transport protocol. The the PPID for S1AP traffic is 18.
What is the difference between S1AP and Nas?
The S1AP is transfered over SCTP. The S1AP protocol is defined in TS 36.413. The S1AP protocol provides transport function between UE and MME by offering NAS signalling transport. The NAS protocol provides mobility management and session management between the User equipment (UE) and Mobile Management Entity (MME).
What is S1AP S1-MME?
The used interface is S1-MME which is located between eNB and MME. The services provided by the S1AP are divided to UE associated and non UE associated. The UE associated services are related to one UE and the non UE associated services are related to the whole S1-MME interface.