9 MESSAGE FUNCTIONAL DEFINITIONS AND CONTENTS

04.633GPPPacket Data on Signalling channels Service (PDS) Service Description, Stage 3TS

This section defines the structure of the messages of those layer 3 protocols, that is the PDSS1 and PDSS2 protocols. Both protocols mostly use the same messages, but have different protocol discriminators, cf. GSM 04.07.

NOTE: Two different protocol discriminators are used in order to allow the network different routing.

When a message is only defined for one protocol in one protocol or has restricted use in one protocol (i.e. it is only defined in one direction in one protocol but in both directions in the other protocol), this is defined in the subclause specifying the message. All messages are standard L3 messages as defined in GSM 04.07.

Each definition given in the present subclause includes:

– a brief description of the message direction and use;

– a definition in which protocol(s), PDSS1 and/or PDSS2 the message is defined and in which direction;

– a table listing the information elements permitted to be in that message and their order of their appearance in the message. All information elements that may be repeated are explicitly indicated. Neither the network nor the mobile station is allowed to include information elements in a message which are not specified for the message or to include the information elements in the message in an order different from the specified order. ( V and LV formatted IEs, which compose the imperative part of the message, occur before T, TV, and TLV formatted IEs which compose the non-imperative part of the message, cf. GSM 04.07.) In a (maximal) sequence of consecutive information elements with half octet length, the first information element with half octet length occupies bits 1 to 4 of octet N, the second bits 5 to 8 of octet N, the third bits 1 to 4 of octet N+1 etc. Such a sequence always has an even number of elements.

For each information element the table indicates:

1. if the IE has format T, TV, or TLV, the IEI used by the IE at the indicated position in the message, in hexadecimal notation. If the IEI has half octet length, this is specified by a notation representing the IEI as a hexadecimal digit followed by a "-" (example: B-);

2. the name of the information element (which may give an idea of the semantics of the element). The name of the information element (usually written in italics) followed by "IE" or "information element" is used in GSM 04.08 as reference to the information element within a message;

3. the name of the type of the information element (which indicates the coding of the value part of the IE), and generally, the referenced subsection of subclause 10 describing the value part of the information element;

4. the presence requirement indication (M or O) for the IE as defined in GSM 04.07. (Presence requirement indication C is not used in the present document);

5. the format of the information element (T, V, TV, LV, TLV) as defined in GSM 04.07;

6. the length of the information element (or permissible range of lengths), in octets, in the message. This indication is normative. However, further restrictions to the length of an IE may be specified elsewhere.

c) subsections specifying, where appropriate:

– the meaning of, and

– conditions for;

absence, repeated occurrence, and/or presence for IEs with presence requirement O in the relevant message which together with other conditions specified, define when the information elements shall be included or not, what presence, repeated occurrence, and absence of such IEs means.

Table 9.1/GSM 04.63 summarizes the messages for PDSS1 and PDSS2. A letter D ("downlink") in the column corresponding to one of the two protocols specifies that the message is defined in the direction network to mobile station for that protocol, a letter U ("uplink") specifies that the message is defined in the direction mobile station to network for that protocol; the word "no" specifies that the message is not defined at all for that protocol.

Table 9.1/GSM 04.63: Messages for PDSS1 and PDSS2

Message Reference defined for PDSS1 defined for PDSS2

DATA 9.1 D,U D,U
IMMediate Setup 9.2 no U
RELEASE COMPLETE 9.3 D,U D,U
SETUP 9.4 D,U no
SETUP ACKNOWLEDGE 9.5 D,U D,U
RESUME 9.6 U U
RESUME ACK 9.7 D D

STATUS 9.8 D,U D,U

9.1 DATA

This message is used to send data to the peer entity. See Table 9.2/GSM 04.63.

Message type: DATA.

Protocol/direction: PDSS1 in both directions.

PDSS2 in both directions.

Table 9.2/GSM 04.63: DATA message

IEI information element type / reference presence format length

protocol discriminator protocol discriminator M V 1/2
GSM 04.07, 11.2.1

transaction identifier transaction identifier M V 1/2
GSM 04.07, 11.2.3

message type message type M V 1
10.4

data data M LV 1-249
10.5.3

9.1.1 Data

The length of the data information element (including the length indicator) in the DATA message shall not exceed 251 – L octets where L is the number of octets occupied by all other IEs in the message.

NOTE: This is due to restrictions of layer 2 (which result from restrictions in GSM 08.56). Due to some reasons, usage of long data IE is not recommendable e.g. on the SACCH or if the A or Ap interface has stronger length restrictions.

9.2 IMMEDIATE SETUP

This message is sent by the mobile station to the network in order to initiate the establishment of a PDSS2 connection. See Table 9.3/GSM 04.63.

Message type: IMMEDIATE SETUP.

Protocol/direction: PDSS2 mobile station to network.

Table 9.3/GSM 04.63: IMMEDIATE SETUP message

IEI information element type / reference presence format length

protocol discriminator protocol discriminator M V 1/2
GSM 04.07, 11.2.1

transaction identifier transaction identifier M V 1/2
GSM 04.07, 11.2.3

message type message type M V 1
10.4

spare half octet spare half octet M V 1/2
10.5.5

ciphering key sequence ciphering key sequence M V 1/2
number number
GSM 04.08, 10.5.3.2

mobile station mobile station M LV 4
classmark classmark 2
GSM 04.08, 10.5.1.6

mobile identity mobile identity M LV 2-9
10.5.4

application application M V 1
10.5.1

data data M LV 1-10
10.5.3

9.2.1 Ciphering key sequence number

The ciphering key sequence number shall be set to the value “111“ (no key is available).

9.2.1 Data

The length of the data information element (including the length indicator) in the IMMEDIATE SETUP message shall not exceed N201 – L, where L is the number of octets all other information elements occupy in the message and N201 is as defined in GSM 04.06 for the signalling link used for the transmission of the message.

9.3 RELEASE COMPLETE

This message is sent to the peer entity in order to release the PDSS1 or PDSS2 connection. See Table 9.4/GSM 04.63.

Message type: RELEASE COMPLETE.

Protocol/direction: PDSS1 in both directions.

PDSS2 in both directions.

Table 9.4/GSM 04.63: RELEASE COMPLETE message

IEI information element type / reference presence format length

protocol discriminator protocol discriminator M V 1/2
GSM 04.07, 11.2.1

transaction identifier transaction identifier M V 1/2
GSM 04.07, 11.2.3

message type message type M V 1
10.4

cause cause M LV 2-248
10.5.2

data data M LV 1-248
10.5.3

08 cause 2 cause O TLV 3-248
10.5.2

9.3.1 Data

The length of the data information element (including the length indicator) in the RELEASE COMPLETE message shall not exceed 251 – L octets where L is the number of octets occupied by all other IEs in the message.

NOTE: This is due to restrictions of layer 2 (which result from restrictions in GSM 08.56). Due to some reasons, usage of long data IE is not recommendable e.g. on the SACCH or if the A or Ap interface has stronger length restrictions.

9.3.2 Cause 2

This IE is included in the message, if more than one cause has to be reported; it may be repeated in the message, if further causes have to be reported.

9.4 SETUP

This message is sent by a PDSS1 protocol entity in order to establish a PDSS1 connection. See Table 9.5/GSM 04.63.

Message type: SETUP.

Protocol/direction: PDSS1 in both directions.

Table 9.5/GSM 04.63: SETUP message

IEI information element type / reference presence format length

protocol discriminator protocol discriminator M V 1/2
GSM 04.07, 11.2.1

transaction identifier transaction identifier M V 1/2
GSM 04.07, 11.2.3

message type message type M V 1
10.4

application application M V 1
10.5.1

data data M LV 1-248
10.5.3

9.4.1 Data

The length of the data information element (including the length indicator) in the SETUP message shall not exceed 251 – L octets where L is the number of octets occupied by all other IEs in the message.

NOTE: This is due to restrictions of layer 2 (which result from restrictions in GSM 08.56). Due to some reasons, usage of long data IE is not recommendable e.g. on the SACCH or if the A or Ap interface has stronger length restrictions.

9.5 SETUP ACKNOWLEDGE

This message is sent by a PDSS1 or PDSS2 protocol entity in order to accept establishment of a connection. See Table 9.6/GSM 04.63.

Message type: SETUP ACKNOWLEDGE.

Protocol/direction: PDSS1 in both directions.

PDSS2 in both directions.

Table 9.6/GSM 04.63: SETUP ACKNOWLEDGE message

IEI information element type / reference presence format length

protocol discriminator protocol discriminator M V 1/2
GSM 04.07, 11.2.1

transaction identifier transaction identifier M V 1/2
GSM 04.07, 11.2.3

message type message type M V 1
10.4

data data M LV 1-249
10.5.3

9.5.1 Data

The length of the data information element value part in the SETUP message shall not exceed 251 – L octets where L is the number of octets occupied by all other IEs in the message.

NOTE: This is due to restrictions of layer 2 (which result from restrictions in GSM 08.56). Due to some reasons, usage of long data IE is not recommendable e.g. on the SACCH or if the A or Ap interface has stronger length restrictions.

9.6 RESUME

This message is sent to the peer entity in order to resume the connection. See Table 9.7/GSM 04.63.

Message type: RESUME.

Protocol/direction: PDSS1 in mobile to network direction.

PDSS2 in mobile to network direction.

Table 9.7/GSM 04.639.6: RESUME

IEI information element type / reference presence format length

protocol discriminator protocol discriminator M V 1/2
GSM 04.07, 11.2.1

transaction identifier transaction identifier M V 1/2
GSM 04.07, 11.2.3

message type message type M V 1
10.4

spare half octet spare half octet M V 1/2
10.5.5

ciphering key sequence ciphering key sequence M V 1/2
number number
GSM 04.08, 10.5.3.2

mobile station mobile station M LV 4
classmark classmark 2
GSM 04.08, 10.5.1.6

mobile identity mobile identity M LV 2-9
10.5.4

9.6.1 Ciphering key sequence number

The ciphering key sequence number shall be set to the value "111" (no key is available) in case of PDSS2.

9.7 RESUME ACK

This message is sent to the peer entity in order to acknowledge resumption of the connection. See Table 9.8/GSM 04.63.

Message type: RESUME ACK.

Protocol/direction: PDSS1 in network to mobile direction.

PDSS2 in network to mobile direction.

Table 9.8/GSM 04.63: RESUME ACK

IEI information element type / reference presence format length

protocol discriminator protocol discriminator M V 1/2
GSM 04.07, 11.2.1

transaction identifier transaction identifier M V 1/2
GSM 04.07, 11.2.3

message type message type M V 1
10.4

9.8 STATUS

This message is sent by a PDSS1 or PDSS2 protocol entity in order to inform its peer entity about an error situation. See Table 9.7/GSM 04.63.

Message type: STATUS.

Protocol/direction: PDSS1 in both directions.

PDSS2 in both directions.

Table 9.9/GSM 04.63: STATUS message

IEI information element type / reference presence format length

protocol discriminator protocol discriminator M V 1/2
GSM 04.07, 11.2.1

transaction identifier transaction identifier M V 1/2
GSM 04.07, 11.2.3

message type message type M V 1
10.4

cause cause M LV 2-248
10.5.2

08 cause 2 cause O TLV 3-248
10.5.2

9.8.1 Cause 2

This IE is included in the message, if more than one cause has to be reported; it may be repeated in the message, if further causes have to be reported.

10.1 Overview

Within the Layer 3 protocols defined, every message is a standard L3 message as defined in GSM 04.07.

10.2 Protocol Discriminator

The Protocol Discriminator (PD) and its use are defined in GSM 04.07. GSM 04.08 defines the protocols relating to the PD values:

bits 4 3 2 1
0 0 1 0 PDSS1 protocol
0 1 0 0 PDSS2 protocol.

10.3 Transaction identifier

Bits 5 to 8 of the first octet of every message belonging to the PDSS1 and PDSS2 protocols contain the transaction identifier (TI). The transaction identifier and its use are defined in GSM 04.07.

10.4 Message Type

The message type IE and its use are defined in GSM 04.07. Table 10.1/GSM 04.63 define the value part of the message type IE used in the PDSS1 and PDSS2 protocols.

Table 10.1/GSM 04.63: Message types for PDSS1 and PDSS2

+—————————————————+

| 8 7 6 5 4 3 2 1 |

| |

| 0 x 1 1 0 0 0 0 DATA |

| 0 x 1 1 0 0 0 1 IMMEDIATE SETUP |

| 0 x 1 1 0 0 1 0 RELEASE COMPLETE |

| 0 x 1 1 0 0 1 1 SETUP |

| 0 x 1 1 0 1 0 0 SETUP ACKNOWLEDGE |

| 0 x 1 1 0 1 0 1 RESUME |

| 0 x 1 1 0 1 1 0 RESUME ACK |

| 0 x 1 1 0 1 1 1 STATUS |

+—————————————————+

Bit 8 is reserved for possible future use as an extension bit, see GSM 04.07.

Bit 7 is reserved for the send sequence number in PDSS1 and PDSS2 messages sent from the mobile station. In PDSS1 and PDSS2 messages sent from the network an, bit 7 is coded with a "0". See GSM 04.07.

10.5 Other information elements

For coding of other IEs, the rules defined in GSM 04.08 apply.

10.5.1 Application

The purpose of the application information element is to indicate the application that requested the PDSS1 or PDSS2 connection to the peer entity.

The application information element value part has a length of 1 octets. The value part is coded as shown below:

8 7 6 5 4 3 2 1

+————————————————+

| 1 | application indication |octet 1

| ext | |

+——┴—————————————–+

Figure 10.1/GSM 04.63: application indication information element

Table 10.2/GSM 04.63: application indication information element

application indication (7 bits)

bit 7 6 5 4 3 2 1 0 0 0 0 0 0 0 X.25
0 0 0 0 0 0 1 IP

all other values indicate unknown applications

10.5.2 Cause

The purpose of the cause information element is to describe the reason for generating certain messages and to provide diagnostic information in the event of procedural errors.

The cause information element value part has a minimal length of 1 octets. No upper length limit is specified except for that given by the maximum number of octets in a L3 message (see GSM 04.06); further rules in the present document may further restrict the length of the IE in a message.

The value part is coded as shown below:

8 7 6 5 4 3 2 1

+———————————————–+

| 1 | |

| ext | cause value | octet 1

+—–┴—————————————–|

| |

| diagnostic(s) if any | octet 2*

: :

: : octet N*

+———————————————–+

Figure 10.2/GSM 04.63: cause information element

Table 10.3/GSM 04.63: cause information element

+—————————————————–+

| Cause value (octet 1) |

| Bits |

| 7 6 5 4 3 2 1 |

| 0 0 0 0 0 1 1 Illegal MS |

| 0 0 0 0 1 0 1 IMEI not accepted |

| 0 0 0 0 1 1 0 Illegal ME |

| 0 0 0 1 0 0 0 Service not authorized |

| 0 0 0 1 0 0 1 Application not supported on the |

| protocol |

| 0 0 0 1 0 1 0 RR connection aborted |

| 0 0 1 0 0 0 1 Network failure |

| 0 0 1 0 1 1 0 Congestion |

| 0 1 0 0 0 0 0 Service option not supported |

| 0 1 0 0 0 0 1 Requested service option |

| not subscribed |

| 0 1 0 0 0 1 0 Service option temporarily |

| out of order |

| 0 1 0 0 1 1 0 Call cannot be identified |

| 0 1 1 0 0 0 0 } |

| to } retry upon entry into a new cell |

| 0 1 1 1 1 1 1 } |

| 1 0 1 1 1 1 1 Semantically incorrect message |

| 1 1 0 0 0 0 0 Invalid mandatory information |

| 1 1 0 0 0 0 1 Message type non-existent |

| or not implemented |

| 1 1 0 0 0 1 0 Message type not compatible with |

| the protocol state |

| 1 1 0 0 0 1 1 Information element non-existent |

| or not implemented |

| 1 1 0 0 1 0 1 Message not compatible with |

| the protocol state |

| 1 1 0 1 1 1 1 Protocol error, unspecified |

| |

| Any other value received |

| shall be treated as an unspecific information |

| |

| |

| Diagnostics (octet 2 ff) |

| This field may contain a message or information |

| element |

| |

+—————————————————–+

10.5.3 Data

The purpose of the data information element is to transport data to the peer entity. Within the scope of the present document the content of the data information field is an array of octets.

The data information element has a minimum length of 0 octets. No upper length limit is specified except for that given by the maximum number of octets in a L3 message (see GSM 04.06); further rules in the present document may further restrict the length of the IE in a message.

10.5.4 Mobile identity 2

The purpose of the mobile identity information element is to provide either the international mobile subscriber identity, IMSI, the temporary mobile subscriber identity, TMSI, the international mobile equipment identity, IMEI, the international mobile equipment identity together with the software version number, IEMISV or the Anonymous Mobile Station Identity (AMSI).

The IMSI shall not exceed 15 digits, the TMSI and The AMSI is 4 octets long.

The mobile identity 2 IE is used in the establishment of a PDSS2 connection. The mobile station shall select the mobile identity type as follows: If the application requests it, the AMSI is used. Otherwise the TMSI shall be used if it is available. The IMSI shall be used in cases where no TMSI is available.

The mobile identity information element is coded as shown below:

8 7 6 5 4 3 2 1

+———————————————–+

| | Mobile Identity IEI | octet 1

+—–┴—————————————–|

| |

| Length of mobile identity contents | octet 2

+———————————————–|

| |odd/ | |

| Identity digit 1 |even | Type of identity| octet 3

| |indic| |

+———————–┼—–┴—————–|

| | |

| Identity digit p+1 | Identity digit p | octet 4*

+———————–┴———————–+

Figure 10.3/GSM 04.63: Mobile Identity 2 information element

Table 10.4/GSM 04.63: Mobile Identity information element

+——————————————————–+

| Type of identity (octet 3) |

| Bits |

| 3 2 1 |

| 0 0 1 IMSI |

| 1 0 0 TMSI |

| 1 0 1 AMSI |

| |

| All other values are reserved. |

| |

| Odd/even indication (octet 3) |

| Bit |

| 4 |

| 0 even number of identity digits and also when |

| the TMSI is used |

| 1 odd number of identity digits |

| |

| Identity digits (octet 3 etc.) |

| For the IMSI this field is coded using |

| BCD coding. If the number of identity digits is even |

| then bits 5 to 8 of the last octet shall be filled |

| with an end mark coded as "1111". |

| |

| If the mobile identity is the TMSI then bits 5 to 8 of |

| octet 3 are coded as "1111" and bit 8 of octet 4 is the|

| most significant bit and bit 1 of the last octet the |

| least significant bit. The coding of the TMSI is left |

| open for each administration. |

| |

| If the mobile identity is the AMSI then bits 5 to 8 of |

| octet 3 are coded as "1111" and bit 8 of octet 4 is the|

| most significant bit and bit 1 of the last octet the |

| least significant bit.The coding of the AMSI is further|

| defined in TS GSM 03.03. |

+——————————————————–+

10.5.5 Spare Half Octet

This element is used in the description of messages in section 9 when an odd number of half octet type 1 information elements are used. This element is filled with spare bits set to zero and is placed in bits 5 to 8 of the octet unless otherwise specified.

Annex A (informative):
Change Request History

Change history

SMG No.

TDoc. No.

CR. No.

Section affected

New version

Subject/Comments

SMG#18

5.0.0

ETSI Publication of GTS 04.63

SMG#27

6.0.0

Release 1997 version

SMG#29

7.0.0

Release 1998 version

SMG#31

8.0.0

Release 1999 version