What is S1 interface in 5G?
In LTE networks, X2 and S1 interface are defined as an interfaces between RAN nodes and between RAN and Core Network. 5G is expect to operate in two modes as non -standalone and standalone mode of operation. Interface between RAN and Core Network as S1/NG.
What is the S1 interface?
The S1 interface connects the eNB to the EPC. It can be split into control-plane (S1-MME) and user-plane (S1-U). The S1-MME is a signaling interface which supports a set of functions and procedures between the eNB and the MME.
What is MME interface?
An MME is a critical network function, which deals with the EPC control plane. Its role is to manage sessions, authentication, paging, mobility, bearers and roaming. It manages an eNB and an S-GW through the S1-MME and S11 interfaces respectively, and communicates with HSS through the S6 interface.
What is S1 handover in LTE?
An S1 handover is a fallback for scenarios where X2 interface is not available. The MME and the SGW are involved during the handover procedure. An interesting part of LTE S1 handovers is the indirect tunnel that is established to carry the downlink data during the handover process.
What is S1 bearer?
An S1 bearer is the connection between the eNodeB and the MME/SGW. Finally, the EPS bearer is established between the EPS and the MME and the SGW, and the SGW and the PGW.
What is S1 AP in LTE?
The S1 Application Protocol (S1AP) provides the control plane signalling between E-UTRAN and evolved packet core (EPC). The used interface is S1-MME which is located between eNB and MME. The S1AP protocol provides transport function between UE and MME by offering NAS signalling transport.
What is S1 and X2 interface?
eNodeBs have two interfaces, the X2 interface permits eNodeBs to intercommunicate with each other directly, and the S1 interface permits communication with the “Packet Core”. The X2 is the interconnecting interface between two eNodeBs in LTE network and supports both Control Plane and User Plane.
What is difference between S1 and X2?
The X2 procedure is used to handover a UE from a source (H)eNB to a target (H)eNB for which the MME is unchanged. The S1 procedure is used by the source eNB to initiate a handover through the S1-MME interface, see [4]. This procedure may relocate the MME and/or the S-GW.
What is IMS bearer?
The two default bearer allow redirecting flows to either the IMS operator APN or Internet APN. In this typical example, the Default bearer 1 is used for signalling messages (SIP signalling) related to the IMS network. It uses QCI 5. The Dedicated bearer is used for VoLTE VoIP traffic.
What is default bearer?
Session Management and Mobility The first EPS bearer that is activated when a PDN connection is established in LTE is called the “default bearer”. This bearer remains established during the lifetime of the PDN connection.
What is the S1-U interface in 3GPP?
The S1-U interface is between eNodeB and the SGW. S1-U protocol stack uses the GTP V1 protocol over UDP and IP. The protocol specification for S1-U is in 3GPP TS 36.414 . The control plane signaling is done over the S11 interface.
What is the LTE S1-MME interface?
The LTE S1-MME interface is responsible for delivering signaling protocols between the eNodeB and the MME. S1-MME interface consists of a Stream Control Transmission Protocol (SCTP) over IP and supports multiple UEs through a single SCTP association. It also provides guaranteed data delivery.
What is the difference between s1up and S1-MME?
A GTP tunnel per radio bearer carries user traffic. The S1-UP interface is responsible for delivering user data between the eNodeB and the S-GW. The IP Differentiated Service Code Point (DSCP) marking is supported for QoS per radio bearer. The LTE S1-MME interface is responsible for delivering signaling protocols between the eNodeB and the MME.
The S1 interface includes the S1-CP (control) and S1-UP part (user plane). The signalling transport on S1-CP will be based on SCTP. The signalling protocol for S1 is called S1-AP.