8 General message format and information elements coding

04.573GPPGSM Cordless Telephony System (CTS), (Phase 1) CTS CTS supervising system Layer 3 SpecificationTS

The figures and text in this section describe the Information Elements contents.

8.1 Overview

See corresponding section in GSM 04.08.

8.2 Protocol Discriminator

The Protocol Discriminator (PD) and its use are defined in GSM 04.07 [20].

8.3 Skip indicator and transaction identifier

8.3.1 Skip indicator

Bits 5 to 8 of the first octet of every CTS Radio Resource management and CTS Mobility Management message contains the skip indicator. In order to differentiate GSM Radio Resource management and GSM Mobility Management messages from CTS Radio Resource management and CTS Mobility Management messages, the skip indicator used shall be 1111. A message received with skip indicator different from 1111 shall be ignored by the CTS Radio Resource management protocol entity and by the CTS Mobility Management protocol entity. A protocol entity sending a CTS Radio Resource management or a CTS Mobility Management message shall encode the skip indicator as 1111.

8.3.2 Transaction identifier

See GSM 04.08.

8.4 Message Type

The message type IE and its use are defined in GSM 04.07 [20]. Tables 8.1/GSM 04.xx define the value part of the message type IE used in the CTS Supervising management protocol.

Table 8.1/GSM 04.xx: Message types for CTS Supervising management

+——————————————————-+

 8 7 6 5 4 3 2 1 

 

 0 0 1 1 1 – – – CTS-FPInitialisation messages: 

 1 1 1 – CTS-SPM INITIALISATION REQUEST 

 0 0 1 – CTS-SPM INITIALISATION ACCEPT 

 0 1 0 – CTS-SPM INITIALISATION COMPLETE 

 1 0 0 – CTS-SPM INITIALISATION REJECT 

 

 0 0 1 1 0 – – – CTS-FP De-initialisation messages: 

 1 0 1 – CTS-SPM DE-INITIALISATION REQUEST 

 0 1 0 – CTS-SPM DE-INITIALISATION COMPLETE 

 0 0 1 – CTS-SPM DE-INITIALISATION REJECT 

 

 0 0 1 0 1 – – – Enrolment messages: 

 0 1 1 – CTS-SPM ENROLMENT REQUEST 

 1 0 0 – CTS-SPM ENROLMENT ACCEPT 

 0 0 0 – CTS-SPM ENROLMENT REJECT 

 

 0 0 0 0 1 – – – De-Enrolment messages: 

 1 0 1 – CTS-SPM DE-ENROLMENT INDICATION 

 1 1 0 – CTS-SPM DE-ENROLMENT REQUEST 

 0 1 1 – CTS-SPM DE-ENROLMENT COMPLETE 

 0 0 0 – CTS-SPM DE-ENROLMENT REJECT 

 

 0 0 1 0 0 – – – Operation data update messages: 

 0 0 1 – CTS-SPM OPERATION DATA REQUEST 

 0 1 0 – CTS-SPM OPERATION DATA DELIVER 

 1 0 0 – CTS-SPM OPERATION DATA ACCEPT 

 1 1 1 – CTS-SPM OPERATION DATA REJECT 

 

 0 0 0 1 1 – – – Information data request messages: 

 0 0 1 – CTS-SPM INFORMATION DATA REQUEST 

 0 1 0 – CTS-SPM INFORMATION DATA RESPONSE 

 

 0 0 0 1 0 – – – Authentication messages: 

 0 0 0 – CTS-SPM FP AUTHENTICATION REQUEST 

 0 1 0 – CTS-SPM FP AUTHENTICATION RESPONSE 

 1 1 1 – CTS-SPM FP AUTHENTICATION REJECT 

 1 0 0 – CTS-SPM MS AUTHENTICATION REQUEST 

 1 0 1 – CTS-SPM MS AUTHENTICATION RESPONSE 

 1 1 0 – CTS-SPM MS AUTHENTICATION REJECT 

 0 1 1 – CTS-SPM SN SIGNING MODE COMMAND 

 

+——————————————————-+

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

8.4.1 Supervising management information elements.

8.4.1.1 Authentication parameter RAND1

The purpose of the Authentication Parameter RAND1 information element is to provide the fixed part with a non-predictable number to be used to calculate the authentication response SRES.

The Authentication Parameter RAND1 information element is coded as shown in figure 10.x/GSM 04.xx and table 10.x/GSM 04.xx.

The Authentication Parameter RAND1 is a type 3 information element with 17 octets length.

8 7 6 5 4 3 2 1

+———————————————–+

 Authentication parameter RAND1 IEI  octet 1

+———————————————–

 

 RAND1 value  octet 2

:

:

  octet 17

 

+———————————————–+

Figure 10.x/GSM 04.xx Authentication Parameter RAND1 information element

Table 10.x/GSM 04.xx: Authentication Parameter RAND1 information element

+—————————————————–+

 RAND1 value (octet 2, 3,… and 17) 

 The RAND1 value consists of 128 bits. Bit 8 of octet

 2 is the most significant bit while bit 1 of octet 

 17 is the least significant bit. 

+—————————————————–+

8.4.1.2 Authentication parameter RAND2

The purpose of the Authentication Parameter RAND2 information element is to provide the service node with a non-predictable number to be used by the service node to calculate the data signature .

The Authentication Parameter RAND2 information element is coded as shown in figure 10.x/GSM 04.xx and table 10.x/GSM 04.xx.

The Authentication Parameter RAND2 is a type 3 information element with 17 octets length.

8 7 6 5 4 3 2 1

+———————————————–+

 Authentication parameter RAND2 IEI  octet 1

+———————————————–

 

 RAND2 value  octet 2

:

:

  octet 17

 

+———————————————–+

Figure 10.x/GSM 04.xx Authentication Parameter RAND2 information element

Table 10.x/GSM 04.xx: Authentication Parameter RAND2 information element

+—————————————————–+

 RAND2 value (octet 2, 3,… and 17) 

 The RAND2 value consists of 128 bits. Bit 8 of octet

 2 is the most significant bit while bit 1 of octet 

 17 is the least significant bit. 

+—————————————————–+

8.4.1.3 Authentication parameter SRES

The purpose of the authentication parameter SRES information element is to provide the service node with the authentication response signature calculated in the fixed part.

The Authentication Parameter SRES information element is coded as shown in figure 10.x/GSM 04.xx and table 10.x/GSM 04.xx.

The Authentication Parameter SRES is a type 3 information element with 17 octets length.

8 7 6 5 4 3 2 1

+———————————————–+

 Authentication parameter SRES IEI  octet 1

+———————————————–

 

 SRES value  octet 2

:

:

  octet 17

 

+———————————————–+

Figure 10.x/GSM 04.xx Authentication Parameter SRES information element

Table 10.x/GSM 04.xx: Authentication Parameter SRES information element

+—————————————————–+

 SRES value (octet 2, 3,… and 17) 

 The SRES value consists of 128 bits. Bit 8 of octet 

 2 is the most significant bit while bit 1 of octet 

 17 is the least significant bit. 

+—————————————————–+

8.4.1.4 Fixed part Identity

The purpose of the Fixed part Identity information element is to provide either the international fixed part subscriber identity, IFPSI, or the international fixed part equipment identity, IFPEI.

The IFPSI shall not exceed 15 digits, the IFPEI is composed of 16 digits (see GSM 03.03).

The Fixed part Identity information element is coded as shown in figure 10.x/GSM 04.xx and table 10.x/GSM 04.xx.

The Fixed part Identity is a type 4 information element with a minimum length of 3 octets and 11 octets length maximal.

8 7 6 5 4 3 2 1

+———————————————–+

  Fixed part Identity IEI  octet 1

+———————————————–

 

 Length of fixed part 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 10.5/GSM 04.xx Fixed part Identity information element

Table 10.8/GSM 04.xx: Fixed part Identity information element

+——————————————————–+

 Type of identity (octet 3) 

 Bits 

 3 2 1 

 0 0 1 IFPSI 

 0 1 0 IFPEI 

 

 All other values are reserved. 

 

 Odd/even indication (octet 3) 

 Bit 

 4 

 0 even number of identity digits and also when 

 1 odd number of identity digits 

 

 Identity digits (octet 3 etc) 

 For the IFPSI, IFPEI 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". 

+——————————————————–+

8.4.1.5 Mobile station Identity

The purpose of the Mobile station Identity information element is to provide to the service node the international mobile station subscriber identity, IMSI.

The IMSI shall not exceed 15 digits (see GSM 03.03).

The Mobile station Identity information element is coded as shown in figure 10.x/GSM 04.xx and table 10.x/GSM 04.xx.

The Mobile station Identity is a type 4 information element with a minimum length of 3 octets and 11 octets length maximal.

8 7 6 5 4 3 2 1

+———————————————–+

  Mobile station Identity IEI  octet 1

+———————————————–

 

 Length of fixed part 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 10.5/GSM 04.xx Mobile station Identity information element

Table 10.8/GSM 04.xx: Mobile station Identity information element

+——————————————————–+

 Type of identity (octet 3) 

 Bits 

 3 2 1 

 0 0 1 IMSI 

 

 

 All other values are reserved. 

 

 Odd/even indication (octet 3) 

 Bit 

 4 

 0 even number of identity digits and also when 

 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". 

+——————————————————–+

8.4.1.6 Fixed Part Classmark

The purpose of the Fixed part Classmark information element is to provide the service node with information concerning charactersitics of the fixed part. The contents might affect the manner in which the service node handles the operation of the fixed part.

The Fixed Part Classmark information element has 2 octets length.

The value part of a Fixed Part Classmark information element is coded as shown in figure 10.5.1.7/GSM 04.xx.

Table 10.5.1.7/GSM 04.xx: Fixed Part Classmark information element

8 7 6 5 4 3 2 1

+———————————————–+

  Fixed part Classmark IEI  octet 1

+—–┼—————————————–

 0  Band  0 0 0 0  octet 2

spare  spare 

+———————————————–+

Table 10.8/GSM 04.xx: Fixed part Classmark information element

+——————————————————–+

 Band (octet 2) 

 Bits 

 7 6 5 

 0 0 0 GSM900 band supported 

 0 0 1 E-GSM band supported 

 0 1 0 DCS1800 band supported 

 0 1 1 GSM1900 band supported 

 

 All other values are reserved. 

+——————————————————–+

8.4.1.7 Radio frequency control Parameters

The purpose of the Radio Frequency control parameters information element is to provide the radio parameters to be applied on the fixed part.

8 7 6 5 4 3 2 1

+———————————————–+

  Radio Frequency Control parameters IEI  octet 1

+—–┼—————————————–

AFA   APPROACH octet 2

USE  SEL_RANGE  TYPE 

+———————————————–

  FWT_SIZE_WIN  octet 3

 MIN_NB_FREQ  (high) 

+———————————————–

FWT_SIZE  CTSBCH  octet 4

WIN (low) SWT_SIZE_WIN SEL MODE

+———————————————–

  0 0 0  octet 5

 INTERF_THRESHOLD  spare 

+———————————————–+

Figure 10.2/GSM 04.xx Radio Frequency Control Parameters information element

Table 10.8/GSM 04.xx: Radio Frequency Control Parameters information element

+——————————————————–+

 AFA_USE, use of AFA algorithm (octet 2) 

 Bit 

 8 

 0 AFA used 

 1 AFA not used 

 

 

 SEL_RANGE, carrier list selection upper bound (octet 2)

 Bits 

 7 6 5 4 3 

 0 0 0 0 0 range 0 

 0 0 0 0 1 range 1 

 . 

 . 

 1 1 1 1 1 range 31 

 

 

 APPROACH TYPE, type of approach used in slection range 

 (octet 2) 

 

 Bits 

 2 1 

 0 0 Basic Threshold (BASIC) 

 0 1 Sliding window technique (SWT) 

 1 0 Fixed window technique (FWT) 

 1 1 List extension check (EXT) 

 

 MIN_NB_FREQ, minimum number of frequency (octet 3) 

 

 Bits 

 8 7 6 5 4 

 0 0 0 0 0 no frequency 

 0 0 0 0 1 1 frequency 

 . 

 . 

 1 1 1 1 1 31 frequencies 

 

 FWT_SIZE_WIN, minimum size of the window for FWT 

 (octet 3 and octet 4) 

 

 Bits 

 3 2 1 8 7 

 

 0 0 0 0 0 size 0 

 0 0 0 0 0 size 1 

 . 

 . 

 1 1 1 1 1 size 31 

 

 SWT_SIZE_WIN, fixed size of the window for SWT 

 (octet 4) 

 

 Bits 

 6 5 4 3 2 

 0 0 0 0 0 size 

 0 0 0 0 0 size 1 

 . 

 . 

 1 1 1 1 1 size 31 

 

 CTSBCH_SEL_MODE, CTSBCH selection mode (octet 4) 

 

 Bit 

 1 

 0 best carrier of TFH list 

 1 random carrier of TFH list 

 

 INTERF_THRESHOLD, interference threshold (octet 5) 

 

 Bits 

 8 7 6 5 4 

 0 0 0 0 0 0dB (steps of 2dB) 

 0 0 0 0 0 2dB 

 . 

 . 

 1 1 1 1 1 62dB 

+——————————————————–+

8.4.1.8 Radio link control Parameters

The purpose of the Radio Link control Parameters information element is to provide the radio parameters to be applied on the fixed part.

8 7 6 5 4 3 2 1

+———————————————–+

  Radio Frequency Link parameters IEI  octet 1

+———————————————–

CTS_FP_MAX_TXPWR  CTS_MS_MAX_TXPWR octet 2

  (high) 

+———————————————– CTS_MAX_TXPWR  octet 3

 (low)  CTS-RXLEV_ACCESS_MIN 

+———————————————–

 CTS_CELL_RESELECT_OFFSET  0 0  octet 4

  spare 

+———————————————–+

  octet 5

CTS_RADIO_LINK_TIMEOUT 

+———————–+

Figure 10.2/GSM 04.xx Radio Link Control Parameters information element

Table 10.8/GSM 04.xx: Radio Link Control Parameters information element

+——————————————————–+

CTS_FP_MAX_TXPWR, maximum Fixed Part transmission power 

(octet 2) 

 Bits 

 8 7 6 5 4 

 0 0 0 0 0 level 0 

 0 0 0 0 1 level 1 

 . 

 . 

 1 1 1 1 1 level 31 

 

 

 CTS_MX_MAX_TXPWR, maximum Mobile Station transmission 

power(octet 2 and octet 3) 

 Bits 

 3 2 1 8 7 

 0 0 0 0 0 level 0 

 0 0 0 0 1 level 1 

 . 

 . 

 1 1 1 1 1 level 31 

 

 

 CTS_RXLEV_ACCESS_MIN, minimum received level at the MS 

 (octet 3)coded as defined in GSM05.08 

 Bits 

 6 5 4 3 2 1 

 0 0 0 0 0 0 level 0 

 0 0 0 0 0 1 level 1 

 . 

 . 

 1 1 1 1 1 1 level 63 

 

CTS_CELL_RESELECT_OFFSET_, reselection offest(octet 4) 

 Bits 

 8 7 6 5 4 3 

 0 0 0 0 0 0 O dB 

 0 0 0 0 0 1 1 dB 

 . 

 . 

 1 1 1 1 1 1 63 dB 

 

 CTS_RADIO_LINK_TIMEOUT, maximum value of the radio 

link counter(octet 5) 

 Bits 

 8 7 6 5 

 0 0 0 0 4 SACCH blocks (setps of 4 blocks) 

 0 0 0 1 8 SACCH blocks 

 . 

 . 

 1 1 1 1 64 SACCH blocks 

+——————————————————–+

8.4.1.9 Generic Frequency List

The purpose of the Generic Frequency List information element is to provide the generic frequency list to be used to derive the AFA list (see GSM04.56) to be used on the CTS interface.

Its coding is similar to the "GSM04.08 Cell Channel Description" information field coding.

8.4.1.10 Cell Identity List

The purpose of the Cell Identity List information element is to provide to the service node the list of the cell global identities surrounding the fixed part.

8 7 6 5 4 3 2 1

+———————————————–+

  Cell Identity List IEI  octet 1

+———————————————–

 

 Length of Cell Identity List contents  octet 2

+———————————————–

  

 MCC1 digit 2  MCC1 digit 1  octet 3

+———————–+———————–

  

 1 1 1 1  MCC1 digit3  octet 4

+———————–┼———————–

  

 MNC1 digit 2  MNC1 digit1  octet 5

+———————————————–

 

 LAC1  octet 6

+———————————————–

 

 LAC1 (continued)  octet 7

+———————————————–

 

 CI1 value  octet 8

+———————————————–

 

 CI1 value (continued)  octet 9

+———————————————–

  

 MCC2 digit 2  MCC2 digit 1  octet 10

+———————–+———————–

  

 1 1 1 1  MCC2 digit3  octet 11

+———————–┼———————–

  

 MNC2 digit 2  MNC2 digit1  octet 12

+———————————————–

 

 LAC2  octet 13

+———————————————–

 

 LAC2 (continued)  octet 14

+———————————————–

 

 CI2 value  octet 15

+———————————————–

 

 CI2 value (continued)  octet 16

+———————————————–

……..

  

 MCCn digit 2  MCCn digit 1  octet 7n-4

+———————–+———————–

  

 1 1 1 1  MCCn digit3  octet 7n-3

+———————–┼———————–

  

 MNCn digit 2  MNCn digit1  octet 7n-2

+———————————————–

 

 LACn  octet 7n-1

+———————————————–

 

 LACn (continued)  octet 7n

+———————————————–

 

 CIn value  octet 7n+1

+———————————————–

 

 CIn value (continued)  octet 7n+2

+———————————————–+

Figure 10.5/GSM 04.xx Cell Identity List information element

Table 10.8/GSM 04.xx: Cell Identity List information element

+——————————————————–+

 MCC, Mobile country code(octets 7n-4 and 7n-3) 

 MNC, Mobile Network code (octet 7n-2) 

 LAC, Location area code (octets 7n-1 and 7n) 

These fields are coded as the "Location Area 

Identification" Information element in GSM04.08 

 

CI, Cell Identity (octets 7n+1 and 7n+2) is coded as 

"Cell Identity" Information element in GSM04.08 

 

+——————————————————–+

8.4.1.11 Application time

The purpose of the Application time information element is to provide to the fixed part the time when the new control data sent by the service node should apply.

8 7 6 5 4 3 2 1

+———————————————–+

  Application time IEI  octet 1

+———————————————–

Application  

time  

information  Tapplic  octet 2

+————+———————————-+

Tapplic 

(continued)  octet 3

+————+

Figure 10.5/GSM 04.xx Application time information element

Table 10.8/GSM 04.xx: Application time information element

+——————————————————–+

 Application time information(octet 2) 

 

 Bits 

 8 7 

 0 0 apply immediately 

 0 1 apply at Tval expiry 

 1 0 apply at Tapplic 

 

 All other values are reserved. 

 

 Tapplic, application timer (octets 2 and 3) 

 Bits 

 8 7 6 5 4 3 2 1 

 0 0 0 0 0 0 0 0 Tapplic = 0day 

 0 0 0 0 0 0 0 1 Tapplic = 1day 

 ….. 

 1 1 1 1 1 1 1 1 Tapplic = 255days 

+——————————————————–+

8.4.1.12 Enrolment time

The purpose of the Enrolment time information element is to provide to the fixed part the duration associated to a mobile enrolment.

8 7 6 5 4 3 2 1

+———————————————–+

  Enrolment time IEI  octet 1

+———————————————–

 Tenrol  octet 2

+———————————————–+

Figure 10.5/GSM 04.xx Enrolment time information element

Table 10.8/GSM 04.xx: Enrolment time information element

+——————————————————–+

 Enrolment time information(octet 2) 

 

 

 Bits 

 8 7 6 5 4 3 2 1 

 0 0 0 0 0 0 0 0 Tenrol = 0day 

 0 0 0 0 0 0 0 1 Tenrol = 1day 

 ….. 

 1 1 1 1 1 1 1 1 Tenrol = 255days 

+——————————————————–+

8.4.1.13 Validity period

The purpose of the Validity period information element is to provide to the fixed part the validity period associated with parameters updated by the service node.

8 7 6 5 4 3 2 1

+———————————————–+

  Validity period IEI  octet 1

+———————————————–

 Tval  octet 2

+———————————————–+

Figure 10.5/GSM 04.xx Validity period information element

Table 10.8/GSM 04.xx: Validity period information element

+——————————————————–+

 Validity period information(octet 2) 

 

 

 Bits 

 8 7 6 5 4 3 2 1 

 0 0 0 0 0 0 0 0 Tval = 0day 

 0 0 0 0 0 0 0 1 Tval = 1day 

 ….. 

 1 1 1 1 1 1 1 1 Tval = 255days 

+——————————————————–+

8.4.1.14 Recall period

The purpose of the Recall period information element is to require the fixed part to contact the service node for control purposes.

8 7 6 5 4 3 2 1

+———————————————–+

  Recall period IEI  octet 1

+———————————————–

 Trecal  octet 2

+———————————————–+

Figure 10.5/GSM 04.xx Recall period information element

Table 10.8/GSM 04.xx: Recall period information element

+——————————————————–+

 Recall period information(octet 2) 

 

 

 Bits 

 8 7 6 5 4 3 2 1 

 0 0 0 0 0 0 0 0 Trecal = 0day 

 0 0 0 0 0 0 0 1 Trecal = 1day 

 ….. 

 1 1 1 1 1 1 1 1 Trecal = 255days 

+——————————————————–+