9 Contents of information elements value parts

04.693GPPBroadcast Call Control (BCC) protocolTS

The figures and text in this clause describe the contents of Information Elements (IE) value parts. The structure of an IE as composed of Information Element Identifier (IEI), length, and value part is defined in GSM 04.07.

9.1 Protocol Discriminator

The Protocol Discriminator (PD) and its use are defined in GSM 04.07.

9.2 Transaction identifier

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

9.3 Message Type

The message type IE and its use are defined in GSM 04.07. Table 9.1 define the value part of the message type IE used in the BCC protocol.

Table 9.1: Message types for BCC

8

7

6

5

4

3

2

1

0

x

1

1

0

0

0

1

IMMEDIATE SETUP

0

x

1

1

0

0

1

0

SETUP

0

x

1

1

0

0

1

1

CONNECT

0

x

1

1

0

1

0

0

TERMINATION

0

x

1

1

0

1

0

1

TERMINATION REQUEST

0

x

1

1

0

1

1

0

TERMINATION REJECT

0

x

1

1

1

0

0

0

STATUS

0

x

1

1

1

0

0

1

GET STATUS

0

x

1

1

1

0

1

0

SET PARAMETER

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 BCC messages sent from the MS. In BCC messages sent from the network an, bit 7 is coded with a "0". See GSM 04.07.

9.4 Other information elements

For coding of other IEs, the rules defined in GSM 04.07 annex B apply.

9.4.1 Call Reference

The Call Reference information element identifies the broadcast call reference or broadcast Id of a broadcast call. It is coded as shown below. It is a type 3 information element.

<call reference> ::= reference { 0 spare_4 | { 1 priority spare_1 } }

Attributes

The information element defines a reference which, depending on the situation, is to be interpreted as a broadcast call reference or as a broadcast id. If the priority field is present in <call reference>, the information element also specifies a priority.

Field contents

The field of the call reference information element are coded as shown in table 9.2.

Table 9.2: call reference information element

reference (27 bits)

This field contains the 27 bit binary encoding (with leading zeroes) of the number the decimal encoding of which (with leading zeroes) is the broadcast call reference or the broadcast id (see GSM 03.03).

priority (3 bits)

3

2

1

0

0

0

reserved

0

0

1

call priority level 4

0

1

0

call priority level 3

0

1

1

call priority level 2

1

0

0

call priority level 1

1

0

1

call priority level 0

1

1

0

call priority level B

1

1

1

call priority level A

spare_4 (4 bits)

This field shall be ignored

spare_1 (1 bit)

This field shall be ignored

9.4.2 Call state

The call state information element identifies a state, and, if applicable, a sub‑state of the broadcast call protocol at the MS side. It is coded as defined below. It is a type 1 information element.

<call state> ::= state

Attributes

The state field defines an integer N in the range 0..15. The call state information element defines a call state or a sub‑state of state U2, ACTIVE, of the BCC protocol.

Field contents

See table 9.3.

Static conditions

The values 12 to 15 of integer N are reserved.

Table 9.3: call state information element

state (4 bits)

This field contains the 4 bit encoding (with leading zeroes) of an integer N = 0, …, 15. The state or substate associated to integer N is defined below:

N

state

0

U0

1

U1

2

U2

3

U3

4

U4

5

U5

6

U0.p

7

U6

All other values are reserved.

9.4.3 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 is a type 4 information element. Its value part has a minimal length of 1 octet. The maximum length is given by the maximum number of octets in a L3 message (see GSM 04.06).

The value part is coded as shown below:

<cause > ::= 1 cause_part [ diagnostics ]

| 0 cause_part <cause>

Attributes

The cause_part field defines a non‑negative integer N. If more than one cause_part fields are present in <cause>, the information element indicates an unspecific cause; otherwise, it indicates a cause as defined by N.

Field contents

The fields of the information element are coded as shown in table 9.4.

Table 9.4: cause information element

cause_part (7 bits)

This field contains the 7 bit encoding (with leading zeroes) of a non‑negative integer which

specifies a cause as defined below:

N

cause

3

Illegal MS

5

IMEI not accepted

6

Illegal ME

8

Service not authorized

9

Application not supported on the protocol

10

RR connection aborted

17

Network failure

22

Congestion

30

Response to GET STATUS

32

Service option not supported

33

Requested service option not subscribed

34

Service option temporarily out of order

38

Call cannot be identified

48 ‑ 63

retry upon entry into a new cell

81

Invalid transaction identifier value

95

Semantically incorrect message

96

Invalid mandatory information

97

Message type non‑existent or not implemented

98

Message type not compatible with the protocol state

99

Information element non‑existent or not implemented

100

Message type not compatible with the protocol state

112

Protocol error, unspecified

Any other value received shall be treated as an unspecific cause.

Diagnostics

This field contains a message or information element.

9.4.4 Originator indication

The originator indication information element informs the broadcast call control entity in the MS whether it is the calling user. It is a type 1 information element.

The value part is coded as shown below:

<originator indication> ::= spare_3 OI

Attributes

The IE defines whether the MS is the originator of the broadcast call.

Field contents

The fields of the information element are coded as shown in table 9.5.

Table 9.5: originator indication information element fields

spare_3 (3 bits)

This field shall be ignored.

OI (1 bit)

0

The MS is not the originator of the call

1

The MS is the originator of the call

9.4.5 Spare Half Octet

This element is used in the description of messages in clause 8 when an odd number of half octet type 1 information elements are used . This element consists of 4 bits set to zero and is placed in bits 5 to 8 of the octet unless otherwise specified. It is a type 1 information element.

9.4.6 State attributes

The state attributes information element contains information about parameter values of the MS. It is a type 1 information element.

The value part is coded as shown below:

<state attributes> ::= DA UA COMM OI

Attributes

The IE defines values of parameters D‑ATT, U‑ATT, ORIG, and COMM..

Field contents

The fields of the information element are coded as shown in table 9.7.

Table 9.7: state attributes information element fields

DA (1 bit)

0

User connection in the downlink not attached (D‑ATT = F)

1

User connection in the downlink attached (D‑ATT = T)

UA (1 bit)

0

User connection in the uplink not attached (U‑ATT = F)

1

User connection in the uplink attached (U‑ATT = T)

COMM (1 bit)

0

COMM = F

1

COMM = T

OI (1 bit)

0

The MS is not the originator of the call (ORIG = F)

1

The MS is the originator of the call (ORIG = T)

Annex A (Informative):
Change Request History

SMG#

CR #

TDoc

SPEC

PHASE

VERS

NEW_VERS

SUBJECT

S20

648/96

04.69

2+

2.0.0

5.0.0

GSM 04.69 on VBS

s27

98-0678

04.69

R96

5.0.1

5.1.0

GSM 04.69 Corrections.

s27

98-0678

04.69

R96

5.0.1

5.1.0

Get Status Procedure

s27

98-0678

04.69

R96

5.0.1

5.1.0

Set Status Procedure

s29

A008

04.69

R97

6.0.0

6.1.0

Broadcast call control states, state attibutes

s29

A009

04.69

R97

6.0.0

6.1.0

Broadcast call control states, call state IE

s29

A010

04.69

R97

6.0.0

6.1.0

Broadcast call control states, IE state attibutes

s29

A011

04.69

R97

6.0.0

6.1.0

Coding of Call Reference IE

s29

04.69

R97

6.1.0

7.0.0

Version update for GSM R98

CN#5

A014

N1-99753

04.69

R98

7.0.0

7.1.0

Correction of Reject Cause in Termination Reject message

CN#5

A017

N1-99805

04.69

R98

7.0.0

7.1.0

Message name correction

S31

04.69

R99

7.1.0

8.0.0

Version upgrade to release 1999

04.69

8.0.0

8.0.1

Version update to 8.0.1 for Publication