B.2.1 Rule A2 : Exponent notation

04.073GPPMobile Radio Interface Signalling Layer 3 - General AspectsTS

An arithmetic expression used as exponent after a delimited string description is used to indicate repetitions.

A numerical expression between parentheses indicates a fixed number of repetitions.

<octet> ::= {0 | 1}(8) ;

is equivalent to

<octet> ::= {0 | 1} {0 | 1} {0 | 1} {0 | 1} {0 | 1} {0 | 1} {0 | 1} {0 | 1} ;

This could also be written :

<octet> ::= bit(8) ;

When the exponent is negative or equal to 0, the exponentiated construction is equivalent to the null string.
An example of a common construction is the following :

<name : bit(5)>

Simple arithmetic, using numbers, terms "+", "-", "*" and "/", and parentheses are allowed in expressions..

Example :

<octet string(40)> ::= <octet>(8*(4+1)) ;

A star used alone between parentheses, or a double star, indicates a finite, possibly null, but indeterminate, number of repetitions. (The star used as an exponent can be understood also as meaning the union of all the sets obtained by replacing the star by zero or some positive integer.)

<all bit strings> ::= {0 |1}(*) ;

<all bit strings> ::= {0 |1}** ;

This allows a shorter notation of recursive constructions such as:

<all bit strings> ::= {0|1} <all bit strings> | null;

A shorter notation is allowed when the expression has a single term, consisting of a star followed by the term:

<octet> ::= {0 | 1}*8 ;

<octet string(40)> ::= <octet>*(8*(4+1)) ;

<all bit strings> ::= bit**;

Application note :

The indefinite exponent is usually combined with some mean to indicate to the decoder the end of the repetition. Different techniques exist, such as indicating in a previous field the number of repetitions. Another technique is one-bit tagging, an example of which follows : {1 <item>}** 0

Annex C (informative):
GPRS‑Services sequence diagram

Instead of providing a complete set of all scenarios, the intention of this section is to provide some typical examples. It shall be noted, that within the figures only those parameters of the PDUs and the service primitives are shown, which are needed for a general understanding of the examples. Furthermore during the examples below (except C.17) no cell re-selection takes place.

NOTE: The standalone PDP context modification procedure should use graceful disconnection of the LLC link

Annex D (informative):
Change Request History

 SMG# CR rev phase VERS new_vers SUBJECT 25 A015 1 R97 5.3.0 6.0.0 Page response parameter introduction between GMM-LLC-GRR 26 A014 1 R97 6.0.0 6.1.0 Primitives MMXX_PROMPT_IND, MMXX_PROMPT_REJ added 27 A019 R97 6.1.0 6.2.0 SNSM Primitives 27 R97 6.2.0 6.2.1 Correction of CR implementation 28 A017 R97 6.2.1 6.3.0 Introduction of Service primitives for the GMMSMS-SAP 28 A020 R97 6.2.1 6.3.0 Enhancement to CSN.1 Definition in 04.07 Annex B 28 A021 1 R97 6.2.1 6.3.0 Inter-SGSN RA update 28 A022 1 R98 6.2.1 7.0.0 Addition of CTS features 29 A034 R98 7.0.0 7.1.0 LCS Synchronisation requirements ( was approved as A020) 29 A025 R98 7.0.0 7.1.0 Inconsistency in definition of comprehension required IEs 29 A030 R98 7.0.0 7.1.0 Inter-SGSN RA update 30 A032 2 R98 7.1.0 7.2.0 Addition of LL-STATUS-IND CN#6 A035 R98 7.2.0 7.3.0 Modifications for LCS enhancements