ETSI TS 129 276 V13.0.0 (2016-01)

ETSI TS 1129 276 V13.0.0 (201616-01)
TECHNICAL SPECIFICATIONION
Universal Mobile Telelecommunications System ( (UMTS);
LTE;
3GPP Evolvolved Packet System (EPS);
Optimized handover er procedures and protocols bs between
E-UTRAN accessss and cdma2000 HRPD Accecess;
Stage 3
(3GPP TS 29.2.276 version 13.0.0 Release 13 13)
---------------------- Page: 1 ----------------------
3GPP TS 29.276 version 13.0.0 Release 13 1 ETSI TS 129 276 V13.0.0 (2016-01)
Reference
RTS/TSGC-0429276vd00
Keywords
LTE,UMTS
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE
Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16
Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88
Important notice
The present document can be downloaded from:
http://www.etsi.org/standards-search

The present document may be made available in electronic versions and/or in print. The content of any electronic and/or

print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any

existing or perceived difference in contents between such versions and/or in print, the only prevailing document is the

print of the Portable Document Format (PDF) version kept on a specific network drive within ETSI Secretariat.

Users of the present document should be aware that the document may be subject to revision or change of status.

Information on the current status of this and other ETSI documents is available at

If you find errors in the present document, please send your comment to one of the following services:

No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying

The content of the PDF version shall not be modified without the written authorization of ETSI.

DECT , PLUGTESTS , UMTS and the ETSI logo are Trade Marks of ETSI registered for the benefit of its Members.

3GPP and LTE™ are Trade Marks of ETSI registered for the benefit of its Members and

GSM® and the GSM logo are Trade Marks registered and owned by the GSM Association.

IPRs essential or potentially essential to the present document may have been declared to ETSI. The information

pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found

in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in

respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web

Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee

can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web

This Technical Specification (TS) has been produced by ETSI 3rd Generation Partnership Project (3GPP).

The present document may refer to technical specifications or reports using their 3GPP identities, UMTS identities or

GSM identities. These should be interpreted as being references to the corresponding ETSI deliverables.

The cross reference between GSM, UMTS, 3GPP and ETSI identities can be found under

In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and

"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of

"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.

Intellectual Property Rights ................................................................................................................................ 2

Foreword ............................................................................................................................................................. 2

Modal verbs terminology .................................................................................................................................... 2

Foreword ............................................................................................................................................................. 5

1 Scope ........................................................................................................................................................ 6

2 References ................................................................................................................................................ 6

3 Definitions, symbols and abbreviations ................................................................................................... 7

3.1 Definitions .......................................................................................................................................................... 7

3.2 Abbreviations ..................................................................................................................................................... 7

4 General ..................................................................................................................................................... 7

5 Transmission Order and Bit Definitions................................................................................................... 8

6 S101 Message Header .............................................................................................................................. 8

6.1 Introduction ........................................................................................................................................................ 8

6.2 S101 Message Header ........................................................................................................................................ 8

6A S121 Message Header .............................................................................................................................. 9

6A.1 Introduction ........................................................................................................................................................ 9

6A.2 S121 Message Header ........................................................................................................................................ 9

7 S101 Messages and Message Formats ................................................................................................... 10

7.1 Introduction ...................................................................................................................................................... 10

7.2 Path Management Messages ....................................................................................................................... 10

7.2.1 Introduction................................................................................................................................................. 10

7.2.2 Echo Request message ................................................................................................................................ 11

7.2.3 Echo Response message ............................................................................................................................. 11

7.2.4 Version Not Supported Indication message ................................................................................................ 11

7.3 S101 Messages ................................................................................................................................................. 11

7.3.1 Introduction................................................................................................................................................. 11

7.3.2 Direct Transfer Request message ................................................................................................................ 12

7.3.3 Direct Transfer Response message ............................................................................................................. 13

7.3.4 Notification Request message ..................................................................................................................... 13

7.3.5 Notification Response message .................................................................................................................. 14

7.4 Reliable Delivery of Signalling Messages ........................................................................................................ 14

7.5 Information Elements ....................................................................................................................................... 14

7.5.1 Information Element Assignments ............................................................................................................. 14

7.5.2 Session ID ................................................................................................................................................... 15

7.5.2A Session ID2 ................................................................................................................................................. 15

7.5.3 Cause .......................................................................................................................................................... 15

7.5.4 Recovery ..................................................................................................................................................... 16

7.5.5 HRPD Sector ID ......................................................................................................................................... 16

7.5.6 S101 Transparent Container ....................................................................................................................... 17

7.5.7 Handover Indicator ..................................................................................................................................... 17

7.5.8 Private Extension ........................................................................................................................................ 18

7.5.9 PDN GW PMIP GRE Tunnel Info .............................................................................................................. 18

7.5.10 S103 GRE Tunnel Info ............................................................................................................................... 18

7.5.11 S103 HSGW IP Address ............................................................................................................................. 18

7.5.12 Void ............................................................................................................................................................ 19

7.5.13 Unauthenticated IMSI ................................................................................................................................. 19

7.5.14 EUTRAN Round Trip Delay ...................................................................................................................... 19

7A S121 Messages and Message Formats ................................................................................................... 19

7A.1 Introduction ...................................................................................................................................................... 19

7A.2 Path Management Messages............................................................................................................................. 20

7A.2.1 Introduction................................................................................................................................................. 20

7A.2.2 Echo Request message ................................................................................................................................ 20

7A.2.3 Echo Response message ............................................................................................................................. 20

7A.2.4 Version Not Supported Indication message ................................................................................................ 20

7A.3 S121 Messages ................................................................................................................................................. 21

7A.3.1 Introduction................................................................................................................................................. 21

7A.3.2 RIM Information Transfer .......................................................................................................................... 21

7A.4 Reliable Delivery of Signalling Messages ........................................................................................................ 21

7A.5 Information Elements ....................................................................................................................................... 21

7A.5.1 Information Element Assignments ............................................................................................................. 21

7A.5.2 S121 Transparent Container ....................................................................................................................... 22

7A.5.3 RIM Routing Address ................................................................................................................................. 22

7A.5.4 Private Extension ........................................................................................................................................ 23

8 Path Protocols ......................................................................................................................................... 23

9 Error Handling ........................................................................................................................................ 23

9.1 Protocol Errors ................................................................................................................................................. 23

9.2 Path Failure ...................................................................................................................................................... 23

9.3 Restoration and Recovery ................................................................................................................................ 23

10 Security provided to Communication over the S101/S121 Interface ..................................................... 23

11 IP - The Networking Technology used by S101/S121 ........................................................................... 23

11.1 IP Version ......................................................................................................................................................... 23

11.2 IP Fragmentation .............................................................................................................................................. 24

12 S101 Parameters ..................................................................................................................................... 24

12.1 General ............................................................................................................................................................. 24

12.2 Timers .............................................................................................................................................................. 24

12.3 Others ............................................................................................................................................................... 24

13 S103 Interface Specification .................................................................................................................. 24

13.1 Introduction ...................................................................................................................................................... 24

13.2 S103 Interface .................................................................................................................................................. 24

Annex A (informative): Change history ............................................................................................... 25

History .............................................................................................................................................................. 26

This Technical Specification has been produced by the 3 Generation Partnership Project (3GPP).

The contents of the present document are subject to continuing work within the TSG and may change following formal

TSG approval. Should the TSG modify the contents of the present document, it will be re-released by the TSG with an

y the second digit is incremented for all changes of substance, i.e. technical enhancements, corrections,

z the third digit is incremented when editorial only changes have been incorporated in the document.

The present document specifies the stage 3 of the Evolved Packet System S101and S121 reference points between the

MME and the HRPD Access Network. The S101 interface supports procedures for Pre-Registration, Session

Maintenance and Active handoffs between E-UTRAN and HRPD networks. The S121 interface supports procedures for

It also specifies the S103 interface between the Serving GW and HSGW. This User Plane interface is used to forward

DL data to minimize packet losses in mobility from E-UTRAN to HRPD. Signalling procedures on the S101 interface

The following documents contain provisions which, through reference in this text, constitute provisions of the present

• References are either specific (identified by date of publication, edition number, version number, etc.) or

• For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including

a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same

[6] 3GPP TS 29.274: "Evolved GPRS Tunnelling Protocol for Control Plane (GTPv2-C); Stage 3".

[7] 3GPP2 C.S0024-B: "cdma2000 High Rate Packet Data Air Interface Specification".

[9] 3GPP2 C.S0087-0 v2.0: "E-UTRAN - HRPD and CDMA2000 1x Connectivity and Interworking:

[10] 3GPP TS 24.301: "Non-Access-Stratum (NAS) protocol for Evolved Packet System (EPS); Stage

[11] 3GPP TS 33.402: "3GPP System Architecture Evolution: Security Architecture".

[12] 3GPP TS 36.413: "Evolved Universal Terrestrial Radio Access (E-UTRA) ; S1 Application

[13] 3GPP TS 24.008: " Mobile radio interface Layer 3 specification; Core network protocols; Stage

[15] 3GPP TS 48.018: "General Packet Radio Service (GPRS); Base Station System (BSS) - Serving

For the purposes of the present document, the terms and definitions given in TR 21.905 [1] and the following apply. A

term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905 [1].

For the purposes of the present document, the abbreviations given in TR 21.905 [1] and the following apply. An

abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in

The S101 and S121 reference points are defined between the MME and the HRPD access, enabling interactions

between E-UTRAN Access and cdma2000 HRPD Access. The S101 interface is required to perform procedures related

to optimise HO from the E-UTRAN Access to cdma2000 HRPD Access to allow for pre-registration and handover

signalling with the target system. The S121 interface is required to perform procedures related to RIM information

The S103 interface is defined between the Serving GW and HSGW and supports the forwarding of DL data during

mobility from E-UTRAN to HRPD. Signalling procedures on the S101 interface are used to set up tunnels on the S103

The protocol stack used for the S101 and S121 interfaces shall be based on GTPv2-C, see 3GPP TS 29.274 [6] Figure

The UDP header and port numbers definitions shall be as defined in GTPv2-C, see 3GPP TS 29.274 [6] section 4. 2.1.

The IP header and IP addresses definitions shall be as defined in GTPv2-C, see 3GPP TS 29.274 [6] section 4.2.2.

Layer 1 and Layer 2 requirements shall as defined in GTPv2-C, see 3GPP TS 29.274 [6] sections 4.2.3 and 4.2.4.

Transmission Order and Bit Definitions shall be as defined in GTPv2-C, see 3GPP TS 29.274 [6] section 4.3.

The S101 Message Header is conformant to the GTPv2-C Message Header, see 3GPP TS 29.274 [6] section 5. All S101

messages shall have a header that includes specific parameters. The following list of header parameters are defined for

The S101 header is a variable length header. The minimum length of the S101 header is eight octets. Space has been

reserved for four flags that may be used in the future to signal the presence of additional optional header fields or

- Bit 4 (the T bit) may be set to one to indicate that a TEID is present in the header, as per 3GPP TS 29.274 [6].

The T bit shall be set to zero to indicate that the TEID field shall not be present in any message sent on the S101

If the header fields do not occupy a full eight octets, then spare octets shall be added after the last valid field in the S101

- Version field: This field is used to determine the version of the S101 protocol. The version number shall be set

- Message Type: This field indicates the type of S101 message. The valid values of the message type are defined

in clause 7.1. Note that values chosen for Message Type shall be coordinated with and shall not overlap the

- Length: This field indicates the length in octets of the payload, i.e. the rest of the packet following the

- Sequence Number: This field enables the target system to identify any missing receipt of messages and is used

NOTE 0: (*) This bit is a spare bit. It shall be sent as '0'. The receiver shall not evaluate this bit.

The S121 Message Header is conformant to the GTPv2-C Message Header, see 3GPP TS 29.274 [6] section 5. All S121

messages shall have a header that includes specific parameters. The following header parameters are defined for the

The S121 header is a variable length header. The minimum length of the S121 header is eight octets. Space has been

reserved for four flags that may be used in the future to signal the presence of additional optional header fields or

- Bit 4 (the T bit) indicates whether a TEID is present in the header, as per 3GPP TS 29.274 [6]. The T bit shall

be set to zero to indicate that the TEID field shall not be present in any message sent on the S121 interface.

If the header fields do not occupy a full eight octets, then spare octets shall be added after the last valid field in the S121

- Version field: This field is used to determine the version of the S121 protocol. The version number shall be set

- Message Type: This field indicates the type of S121 message. The valid values of the message type are defined

in clause 7A.1. Note that values chosen for Message Type shall be coordinated with and shall not overlap the

- Length: This field indicates the length in octets of the payload, i.e. the rest of the packet following the

- Sequence Number: This field enables the target system to identify any missing receipt of messages and is used

NOTE 0: (*) This bit is a spare bit. It shall be sent as '0'. The receiver shall not evaluate this bit.

This section is divided into path management which defines the general messages for the pre-configured tunnel and a

section for the specific messages used for information transfer over the control plane.

Table 7.1 specifies GTPv2-C message types that are used across the S101 interface.

ETSI TS 1129 276 V13.0.0 (201616-01)
TECHNICAL SPECIFICATIONION
Universal Mobile Telelecommunications System ( (UMTS);
LTE;
3GPP Evolvolved Packet System (EPS);
Optimized handover er procedures and protocols bs between
E-UTRAN accessss and cdma2000 HRPD Accecess;
Stage 3
(3GPP TS 29.2.276 version 13.0.0 Release 13 13)
---------------------- Page: 1 ----------------------
3GPP TS 29.276 version 13.0.0 Release 13 1 ETSI TS 129 276 V13.0.0 (2016-01)
Reference
RTS/TSGC-0429276vd00
Keywords
LTE,UMTS
ETSI
650 Route des Lucioles
F-06921 Sophia Antipolis Cedex - FRANCE
Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16
Siret N° 348 623 562 00017 - NAF 742 C
Association à but non lucratif enregistrée à la
Sous-Préfecture de Grasse (06) N° 7803/88
Important notice
The present document can be downloaded from:
http://www.etsi.org/standards-search

The present document may be made available in electronic versions and/or in print. The content of any electronic and/or

print versions of the present document shall not be modified without the prior written authorization of ETSI. In case of any

existing or perceived difference in contents between such versions and/or in print, the only prevailing document is the

print of the Portable Document Format (PDF) version kept on a specific network drive within ETSI Secretariat.

Users of the present document should be aware that the document may be subject to revision or change of status.

Information on the current status of this and other ETSI documents is available at

If you find errors in the present document, please send your comment to one of the following services:

No part may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying

The content of the PDF version shall not be modified without the written authorization of ETSI.

DECT , PLUGTESTS , UMTS and the ETSI logo are Trade Marks of ETSI registered for the benefit of its Members.

3GPP and LTE™ are Trade Marks of ETSI registered for the benefit of its Members and

GSM® and the GSM logo are Trade Marks registered and owned by the GSM Association.

IPRs essential or potentially essential to the present document may have been declared to ETSI. The information

pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found

in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in

respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web

Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee

can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web

This Technical Specification (TS) has been produced by ETSI 3rd Generation Partnership Project (3GPP).

The present document may refer to technical specifications or reports using their 3GPP identities, UMTS identities or

GSM identities. These should be interpreted as being references to the corresponding ETSI deliverables.

The cross reference between GSM, UMTS, 3GPP and ETSI identities can be found under

In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and

"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of

"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.

Intellectual Property Rights ................................................................................................................................ 2

Foreword ............................................................................................................................................................. 2

Modal verbs terminology .................................................................................................................................... 2

Foreword ............................................................................................................................................................. 5

1 Scope ........................................................................................................................................................ 6

2 References ................................................................................................................................................ 6

3 Definitions, symbols and abbreviations ................................................................................................... 7

3.1 Definitions .......................................................................................................................................................... 7

3.2 Abbreviations ..................................................................................................................................................... 7

4 General ..................................................................................................................................................... 7

5 Transmission Order and Bit Definitions................................................................................................... 8

6 S101 Message Header .............................................................................................................................. 8

6.1 Introduction ........................................................................................................................................................ 8

6.2 S101 Message Header ........................................................................................................................................ 8

6A S121 Message Header .............................................................................................................................. 9

6A.1 Introduction ........................................................................................................................................................ 9

6A.2 S121 Message Header ........................................................................................................................................ 9

7 S101 Messages and Message Formats ................................................................................................... 10

7.1 Introduction ...................................................................................................................................................... 10

7.2 Path Management Messages ....................................................................................................................... 10

7.2.1 Introduction................................................................................................................................................. 10

7.2.2 Echo Request message ................................................................................................................................ 11

7.2.3 Echo Response message ............................................................................................................................. 11

7.2.4 Version Not Supported Indication message ................................................................................................ 11

7.3 S101 Messages ................................................................................................................................................. 11

7.3.1 Introduction................................................................................................................................................. 11

7.3.2 Direct Transfer Request message ................................................................................................................ 12

7.3.3 Direct Transfer Response message ............................................................................................................. 13

7.3.4 Notification Request message ..................................................................................................................... 13

7.3.5 Notification Response message .................................................................................................................. 14

7.4 Reliable Delivery of Signalling Messages ........................................................................................................ 14

7.5 Information Elements ....................................................................................................................................... 14

7.5.1 Information Element Assignments ............................................................................................................. 14

7.5.2 Session ID ................................................................................................................................................... 15

7.5.2A Session ID2 ................................................................................................................................................. 15

7.5.3 Cause .......................................................................................................................................................... 15

7.5.4 Recovery ..................................................................................................................................................... 16

7.5.5 HRPD Sector ID ......................................................................................................................................... 16

7.5.6 S101 Transparent Container ....................................................................................................................... 17

7.5.7 Handover Indicator ..................................................................................................................................... 17

7.5.8 Private Extension ........................................................................................................................................ 18

7.5.9 PDN GW PMIP GRE Tunnel Info .............................................................................................................. 18

7.5.10 S103 GRE Tunnel Info ............................................................................................................................... 18

7.5.11 S103 HSGW IP Address ............................................................................................................................. 18

7.5.12 Void ............................................................................................................................................................ 19

7.5.13 Unauthenticated IMSI ................................................................................................................................. 19

7.5.14 EUTRAN Round Trip Delay ...................................................................................................................... 19

7A S121 Messages and Message Formats ................................................................................................... 19

7A.1 Introduction ...................................................................................................................................................... 19

7A.2 Path Management Messages............................................................................................................................. 20

7A.2.1 Introduction................................................................................................................................................. 20

7A.2.2 Echo Request message ................................................................................................................................ 20

7A.2.3 Echo Response message ............................................................................................................................. 20

7A.2.4 Version Not Supported Indication message ................................................................................................ 20

7A.3 S121 Messages ................................................................................................................................................. 21

7A.3.1 Introduction................................................................................................................................................. 21

7A.3.2 RIM Information Transfer .......................................................................................................................... 21

7A.4 Reliable Delivery of Signalling Messages ........................................................................................................ 21

7A.5 Information Elements ....................................................................................................................................... 21

7A.5.1 Information Element Assignments ............................................................................................................. 21

7A.5.2 S121 Transparent Container ....................................................................................................................... 22

7A.5.3 RIM Routing Address ................................................................................................................................. 22

7A.5.4 Private Extension ........................................................................................................................................ 23

8 Path Protocols ......................................................................................................................................... 23

9 Error Handling ........................................................................................................................................ 23

9.1 Protocol Errors ................................................................................................................................................. 23

9.2 Path Failure ...................................................................................................................................................... 23

9.3 Restoration and Recovery ................................................................................................................................ 23

10 Security provided to Communication over the S101/S121 Interface ..................................................... 23

11 IP - The Networking Technology used by S101/S121 ........................................................................... 23

11.1 IP Version ......................................................................................................................................................... 23

11.2 IP Fragmentation .............................................................................................................................................. 24

12 S101 Parameters ..................................................................................................................................... 24

12.1 General ............................................................................................................................................................. 24

12.2 Timers .............................................................................................................................................................. 24

12.3 Others ............................................................................................................................................................... 24

13 S103 Interface Specification .................................................................................................................. 24

13.1 Introduction ...................................................................................................................................................... 24

13.2 S103 Interface .................................................................................................................................................. 24

Annex A (informative): Change history ............................................................................................... 25

History .............................................................................................................................................................. 26

This Technical Specification has been produced by the 3 Generation Partnership Project (3GPP).

The contents of the present document are subject to continuing work within the TSG and may change following formal

TSG approval. Should the TSG modify the contents of the present document, it will be re-released by the TSG with an

y the second digit is incremented for all changes of substance, i.e. technical enhancements, corrections,

z the third digit is incremented when editorial only changes have been incorporated in the document.

The present document specifies the stage 3 of the Evolved Packet System S101and S121 reference points between the

MME and the HRPD Access Network. The S101 interface supports procedures for Pre-Registration, Session

Maintenance and Active handoffs between E-UTRAN and HRPD networks. The S121 interface supports procedures for

It also specifies the S103 interface between the Serving GW and HSGW. This User Plane interface is used to forward

DL data to minimize packet losses in mobility from E-UTRAN to HRPD. Signalling procedures on the S101 interface

The following documents contain provisions which, through reference in this text, constitute provisions of the present

• References are either specific (identified by date of publication, edition number, version number, etc.) or

• For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including

a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same

[6] 3GPP TS 29.274: "Evolved GPRS Tunnelling Protocol for Control Plane (GTPv2-C); Stage 3".

[7] 3GPP2 C.S0024-B: "cdma2000 High Rate Packet Data Air Interface Specification".

[9] 3GPP2 C.S0087-0 v2.0: "E-UTRAN - HRPD and CDMA2000 1x Connectivity and Interworking:

[10] 3GPP TS 24.301: "Non-Access-Stratum (NAS) protocol for Evolved Packet System (EPS); Stage

[11] 3GPP TS 33.402: "3GPP System Architecture Evolution: Security Architecture".

[12] 3GPP TS 36.413: "Evolved Universal Terrestrial Radio Access (E-UTRA) ; S1 Application

[13] 3GPP TS 24.008: " Mobile radio interface Layer 3 specification; Core network protocols; Stage

[15] 3GPP TS 48.018: "General Packet Radio Service (GPRS); Base Station System (BSS) - Serving

For the purposes of the present document, the terms and definitions given in TR 21.905 [1] and the following apply. A

term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905 [1].

For the purposes of the present document, the abbreviations given in TR 21.905 [1] and the following apply. An

abbreviation defined in the present document takes precedence over the definition of the same abbreviation, if any, in

The S101 and S121 reference points are defined between the MME and the HRPD access, enabling interactions

between E-UTRAN Access and cdma2000 HRPD Access. The S101 interface is required to perform procedures related

to optimise HO from the E-UTRAN Access to cdma2000 HRPD Access to allow for pre-registration and handover

signalling with the target system. The S121 interface is required to perform procedures related to RIM information

The S103 interface is defined between the Serving GW and HSGW and supports the forwarding of DL data during

mobility from E-UTRAN to HRPD. Signalling procedures on the S101 interface are used to set up tunnels on the S103

The protocol stack used for the S101 and S121 interfaces shall be based on GTPv2-C, see 3GPP TS 29.274 [6] Figure

The UDP header and port numbers definitions shall be as defined in GTPv2-C, see 3GPP TS 29.274 [6] section 4. 2.1.

The IP header and IP addresses definitions shall be as defined in GTPv2-C, see 3GPP TS 29.274 [6] section 4.2.2.

Layer 1 and Layer 2 requirements shall as defined in GTPv2-C, see 3GPP TS 29.274 [6] sections 4.2.3 and 4.2.4.

Transmission Order and Bit Definitions shall be as defined in GTPv2-C, see 3GPP TS 29.274 [6] section 4.3.

The S101 Message Header is conformant to the GTPv2-C Message Header, see 3GPP TS 29.274 [6] section 5. All S101

messages shall have a header that includes specific parameters. The following list of header parameters are defined for

The S101 header is a variable length header. The minimum length of the S101 header is eight octets. Space has been

reserved for four flags that may be used in the future to signal the presence of additional optional header fields or

- Bit 4 (the T bit) may be set to one to indicate that a TEID is present in the header, as per 3GPP TS 29.274 [6].

The T bit shall be set to zero to indicate that the TEID field shall not be present in any message sent on the S101

If the header fields do not occupy a full eight octets, then spare octets shall be added after the last valid field in the S101

- Version field: This field is used to determine the version of the S101 protocol. The version number shall be set

- Message Type: This field indicates the type of S101 message. The valid values of the message type are defined

in clause 7.1. Note that values chosen for Message Type shall be coordinated with and shall not overlap the

- Length: This field indicates the length in octets of the payload, i.e. the rest of the packet following the

- Sequence Number: This field enables the target system to identify any missing receipt of messages and is used

NOTE 0: (*) This bit is a spare bit. It shall be sent as '0'. The receiver shall not evaluate this bit.

The S121 Message Header is conformant to the GTPv2-C Message Header, see 3GPP TS 29.274 [6] section 5. All S121

messages shall have a header that includes specific parameters. The following header parameters are defined for the

The S121 header is a variable length header. The minimum length of the S121 header is eight octets. Space has been

reserved for four flags that may be used in the future to signal the presence of additional optional header fields or

- Bit 4 (the T bit) indicates whether a TEID is present in the header, as per 3GPP TS 29.274 [6]. The T bit shall

be set to zero to indicate that the TEID field shall not be present in any message sent on the S121 interface.

If the header fields do not occupy a full eight octets, then spare octets shall be added after the last valid field in the S121

- Version field: This field is used to determine the version of the S121 protocol. The version number shall be set

- Message Type: This field indicates the type of S121 message. The valid values of the message type are defined

in clause 7A.1. Note that values chosen for Message Type shall be coordinated with and shall not overlap the

- Length: This field indicates the length in octets of the payload, i.e. the rest of the packet following the

- Sequence Number: This field enables the target system to identify any missing receipt of messages and is used

NOTE 0: (*) This bit is a spare bit. It shall be sent as '0'. The receiver shall not evaluate this bit.

This section is divided into path management which defines the general messages for the pre-configured tunnel and a

section for the specific messages used for information transfer over the control plane.

Table 7.1 specifies GTPv2-C message types that are used across the S101 interface.