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X2 Signalling TransportinSpecification,LTE,X2

X2 signalling bearer provides the following functions:

Provision of reliable transfer of X2-AP message over X2 interface.

Provision of networking and routeing function

Provision of redundancy in the signalling network

Support for flow control and congestion control

L2 - Data link layer

Support of any suitable data link layer protocol, e.g. PPP, Ethernet

IP layer

The eNB supports IPv6 and/or IPv4

The IP layer of eNB-eNB only supports point-to-point transmission for delivering X2-AP

message.

The eNB supports the Diffserv Code Point marking

Transport layer

SCTP is supported as the transport layer of eNB-eNB signalling bearer.

SCTP refers to the Stream Control Transmission Protocol developed by the Sigtran working

group of the IETF for the purpose of transporting various signalling protocols over IP

network.

There is only one SCTP association established between eNB pairs.

The eNB establishes the SCTP association. The SCTP Destination Port number value

assigned by IANA to be used for X2AP is 36422.

Protocol specification

3GPP TS36.420- Evolved Universal Terrestrial Radio Access Network (E-UTRAN); X2 general

aspects and principles

3GPP TS36.421- Evolved Universal Terrestrial Radio Access Network (E-UTRAN); X2 layer 1

3GPP TS36.422- Evolved Universal Terrestrial Radio Access Network (E-UTRAN); X2 signalling

transport

IETF RFC2460: "Internet Protocol, Version 6 (IPv6) Specification"

http://lteworld.org/category/tags/specificationhttp://lteworld.org/category/tags/specificationhttp://lteworld.org/category/tags/specificationhttp://lteworld.org/category/tags/ltehttp://lteworld.org/category/tags/ltehttp://lteworld.org/category/tags/ltehttp://lteworld.org/category/tags/x2http://lteworld.org/category/tags/x2http://lteworld.org/category/tags/x2http://www.3gpp.org/ftp/Specs/html-info/36420.htmhttp://www.3gpp.org/ftp/Specs/html-info/36420.htmhttp://www.3gpp.org/ftp/Specs/html-info/36420.htmhttp://www.3gpp.org/ftp/Specs/html-info/36421.htmhttp://www.3gpp.org/ftp/Specs/html-info/36421.htmhttp://www.3gpp.org/ftp/Specs/html-info/36421.htmhttp://www.3gpp.org/ftp/Specs/html-info/36422.htmhttp://www.3gpp.org/ftp/Specs/html-info/36422.htmhttp://www.3gpp.org/ftp/Specs/html-info/36422.htmhttp://www.ietf.org/rfc/rfc2460.txthttp://www.ietf.org/rfc/rfc2460.txthttp://www.ietf.org/rfc/rfc2460.txthttp://www.ietf.org/rfc/rfc2460.txthttp://www.3gpp.org/ftp/Specs/html-info/36422.htmhttp://www.3gpp.org/ftp/Specs/html-info/36421.htmhttp://www.3gpp.org/ftp/Specs/html-info/36420.htmhttp://lteworld.org/category/tags/x2http://lteworld.org/category/tags/ltehttp://lteworld.org/category/tags/specification

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IETF RFC791(September,1981): "Internet Protocol"

IETF RFC2474(December 1998): "Definition of the Differentiated Services Field (DS Field) in the

IPv4 and IPv6 Headers"

X2 layer 1inSpecification,LTE,X2

The main functions of X2 interface layer 1 are as following:

Interface to physical medium;

Frame delineation;

Line clock extraction capability;

Layer 1 alarms extraction and generation;

Transmission quality control.

Protocol specification

3GPP TS36.421- Evolved Universal Terrestrial Radio Access Network (E-UTRAN); X2 layer 1

X2 Application Protocol (X2AP)ineNodeB,Specification,E-UTRAN,LTE,X2,X2AP

The X2AP protocol is used to handle the UE mobility within E-UTRAN and provides the followingfunctions:

Mobility Management

Load Management

Reporting of General Error Situations

Resetting the X2

Setting up the X2

eNB Configuration Update

Protocol specification

3GPP TS36.423- Evolved Universal Terrestrial Radio Access Network (E-UTRAN); X2 Application

Protocol (X2AP)

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