8 Message functional definitions and contents

04.693GPPBroadcast Call Control (BCC) protocolTS

This clause defines the structure of the messages of those layer 3 protocols defined in the present document, that is the BCC protocol.

All messages are standard L3 messages as defined in GSM 04.07.

Each definition given in the present clause includes:

‑ a brief description of the message direction and use;

‑ a definition in which direction the message is defined;

‑ 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 MS 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 subclause of clause 9 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) subclauses 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 in the present document define when the information elements shall be included or not, what presence, repeated occurrence, and absence of such IEs means.

Table 8.1 summarizes the messages for BCC. A letter D ("downlink") specifies that the message is defined in the direction network to mobile station, a letter U ("uplink") specifies that the message is defined in the direction mobile station to network.

Message Reference Direction

DATA 8.1 D,U IMMediate Setup 8.2 no
RELEASE COMPLETE 8.3 D,U U
SETUP 8.4 D,U SETUP ACKNOWLEDGE 8.5 D,U RESUME 8.6 U RESUME ACK 8.7 D

STATUS 8.8 D,U

TABLE 8.1

Messages for BCC

8.1 CONNECT

This message is sent by the network to the calling MS in order to indicate establishment of the requested broadcast call.

See table 8.1.

Message type: CONNECT

Significance: dual

Direction: network to MS

Table 8.1: CONNECT message content

IEI

Information element

Type / Reference

Presence

Format

Length

Broadcast Call control
protocol discriminator

Protocol discriminator
9.1

M

V

1/2

Transaction identifier

Transaction identifier
9.2

M

V

1/2

Connect
message type

Message type
9.3

M

V

1

Broadcast call reference

Call reference
9.4.1

M

V

4

Originator indication

Originator indication
9.4.4

M

V

1/2

Spare half octet

Spare half octet
9.4.5

M

V

1/2

8.2 GET STATUS

This message is sent by the network at any time to solicit a STATUS message from the MS in acknowledged or unacknowledged mode.

See table 8.2.

Message type: GET STATUS

Significance: local

Direction: network to MS

Table 8.2: GET STATUS message content

IEI

Information element

Type / Reference

Presence

Format

Length

protocol discriminator

protocol discriminator
9.1

M

V

1/2

transaction identifier

transaction identifier
9.2

M

V

1/2

message type

message type
9.3

M

V

1

mobile identity

mobile identity
GSM 04.08, 10.5.1.4

O

TLV

3‑10

8.2.1 mobile identity

This IE is included if the network wishes so. If the message is received by the MS in acknowledged mode, it shall be ignored by the MS. If received in unacknowledged mode, it specifies the destination MS, see clause 5.

8.3 IMMEDIATE SETUP

This message is sent by the MS to the network in order to set‑up a broadcast call immediately, i.e. without previous establishment of an MM connection. See table 8.3.

Message type: IMMEDIATE SETUP

Significance: dual

Direction: MS to network

Table 8.3: IMMEDIATE SETUP message content

IEI

Information element

Type / Reference

Presence

Format

Length

protocol discriminator

protocol discriminator
9.1

M

V

1/2

transaction identifier

transaction identifier
9.2

M

V

1/2

message type

message type
9.3

M

V

1

Spare half octet

Spare half octet
9.4.5

M

V

1/2

Ciphering key sequence
number

Ciphering key sequence
number
GSM 04.08, 10.5.1.2

M

V

1/2

Mobile station
classmark

Mobile station
classmark 2
GSM 04.08, 10.5.1.6

M

LV

4

Mobile identity

Mobile identity
GSM 04.08, 10.5.1.4

M

LV

2‑9

Broadcast identity

Call reference

M

V

4

8.3.1 Mobile identity

This IE shall specify the TMSI, if available, and the IMSI else.

8.4 SET PARAMETER

This message is sent by the network at any time to ask the MS for setting of parameters and consequential actions.

See table 8.4.

Message type: SET PARAMETER

Significance: local

Direction: network to MS

Table 8.4: SET PARAMETER message content

IEI

Information element

Type / Reference

Presence

Format

Length

protocol discriminator

protocol discriminator
9.1

M

V

1/2

transaction identifier

transaction identifier
9.2

M

V

1/2

message type

message type
9.3

M

V

1

state attributes

state attributes
9.4.6

M

V

1/2

spare half octet

spare half octet
9.4.6

M

V

1/2

8.5 SETUP

This message is sent by the MS to the network in order to set‑up a broadcast call after establishment of an MM connection.

See table 8.5.

Message type: SETUP

Significance: dual

Direction: MS to network

Table 8.5: SETUP message content

IEI

Information element

Type / Reference

Presence

Format

Length

protocol discriminator

protocol discriminator
9.1

M

V

1/2

transaction identifier

transaction identifier
9.2

M

V

1/2

message type

message type
9.3

M

V

1

Broadcast identity

Call reference
9.4.1

M

V

4

8.6 STATUS

This message is sent by the MS to the network at any time during a call to report certain error conditions listed in clause 8. It shall also be sent in response to a GET STATUS message.

See table 8.6.

Message type: STATUS

Significance: local

Direction: MS to network

Table 8.6: STATUS message content

IEI

Information element

Type / Reference

Presence

Format

Length

protocol discriminator

protocol discriminator
9.1

M

V

1/2

transaction identifier

transaction identifier
9.2

M

V

1/2

message type

message type
9.3

M

V

1

cause

cause
9.4.3

M

LV

2‑248

A‑

call state

call state
9.4.2

O

TV

1

B‑

state attributes

state attributes
9.4.6

O

TV

1

8.6.1 Call state

This IE may always be included in the message. In certain cases identified in the present document, the IE shall be included in the message, e.g., when used in the get status procedure.

8.6.2 State attributes

This IE may always be included in the message. In certain cases identified in the present document, the IE shall be included in the message, e.g., when used in the get status procedure.

8.7 TERMINATION

This message is sent by the network to the MS in order to terminate the connection between the two peer entities in the network and MS and/or to indicate that the broadcast call has been or will be terminated, e.g. as a response to a termination request.

See table 8.7.

Message type: TERMINATION

Significance: dual

Direction: network to MS

Table 8.7: TERMINATION message content

IEI

Information element

Type / Reference

Presence

Format

Length

protocol discriminator

protocol discriminator
9.1

M

V

1/2

transaction identifier

transaction identifier
9.2

M

V

1/2

message type

message type
9.3

M

V

1

cause

cause
9.4.3

M

LV

2‑248

8.8 TERMINATION REJECT

This message is sent by the network to the MS in order to reject a termination request.

See table 8.8.

Message type: TERMINATION REJECT

Significance: dual

Direction: network to MS

Table 8.8: TERMINATION REJECT message content

IEI

Information element

Type / Reference

Presence

Format

Length

protocol discriminator

protocol discriminator
9.1

M

V

1/2

transaction identifier

transaction identifier
9.2

M

V

1/2

message type

message type
9.3

M

V

1

Reject cause

Cause
9.4.3

M

LV

2-248

8.9 TERMINATION REQUEST

This message is sent by the MS to the network in order to request termination of a broadcast call which it had originated.

See table 8.9.

Message type: TERMINATION REQUEST

Significance: dual

Direction: MS to network

Table 8.9: TERMINATION REQUEST message content

IEI

Information element

Type / Reference

Presence

Format

Length

protocol discriminator

protocol discriminator
9.1

M

V

1/2

transaction identifier

transaction identifier
9.2

M

V

1/2

message type

message type
9.3

M

V

1

Broadcast call reference

Call reference
9.4.1

M

V

4