10.5.3 Mobility management information elements.

24.0083GPPCore network protocolsMobile radio interface Layer 3 specificationRelease 18Stage 3TS

10.5.3.1 Authentication parameter RAND

The purpose of the Authentication Parameter RAND information element is to provide the mobile station with a non-predictable number to be used to calculate the authentication response signature SRES and the ciphering key Kc (for a GSM authentication challenge), or the response RES and both the ciphering key CK and integrity key IK (for a UMTS authentication challenge).

The Authentication Parameter RAND information element is coded as shown in figure 10.5.75/3GPP TS 24.008 and table 10.5.89/3GPP TS 24.008.

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

8

7

6

5

4

3

2

1

Authentication parameter RAND IEI

octet 1

RAND value

octet 2

octet 17

Figure 10.5.75/3GPP TS 24.008 Authentication Parameter RAND information element

Table 10.5.89/3GPP TS 24.008: Authentication Parameter RAND information element

RAND value (octet 2, 3,… and 17)

The RAND 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.
10.5.3.1.1 Authentication Parameter AUTN (UMTS and EPS authentication challenge)

The purpose of the Authentication Parameter AUTN information element is to provide the MS with a means of authenticating the network.

The Authentication Parameter AUTN information element is coded as shown in figure 10.5.75.1/3GPP TS 24.008 and table 10.5.89.1/3GPP TS 24.008.

The Authentication Parameter AUTN is a type 4 information element with a length of 18 octets.

8

7

6

5

4

3

2

1

Authentication Parameter AUTN IEI

octet 1

Length of AUTN contents

octet 2

octet 3

AUTN

octet 18

Figure 10.5.75.1/3GPP TS 24.008 Authentication Parameter AUTN information element (UMTS and EPS authentication challenge)

Table 10.5.89.1/3GPP TS 24.008 Authentication Parameter AUTN information element (UMTS and EPS authentication challenge)

AUTN value (octets 3 to 18)

The AUTN consists of (SQN xor AK)||AMF||MAC

=48+16+64 bits

(see 3GPP TS 33.102 [5a])

Bit 8 of octet 9 is the "separation bit" of the AMF field (see 3GPP TS 33.401 [123]).

10.5.3.2 Authentication Response parameter

The purpose of the authentication response parameter information element is to provide the network with the authentication response calculated in the SIM/USIM.

The Authentication Parameter SRES information element is coded as shown in figure 10.5.76/3GPP TS 24.008 and tables 10.5.90 a & b /3GPP TS 24.008.

The Authentication Response Parameter is a type 3 information element with 5 octets length. In a GSM authentication challenge, the response calculated in the SIM/USIM (SRES) is 4 bytes in length, and is placed in the Authentication Response Parameter information element.

In a UMTS authentication challenge, the response calculated in the USIM (RES) may be up to 16 octets in length. The 4 most significant octets shall be included in the Authentication Response Parameter information element. The remaining part of the RES shall be included in the Authentication Response Parameter (extension) IE (see subclause 10.5.3.2.1)

8

7

6

5

4

3

2

1

Authentication Response parameter IEI

octet 1

SRES value or most significant

4 octets of RES

:

octet 2

:

octet 5

Figure 10.5.76/3GPP TS 24.008 Authentication Response Parameter information element

Table 10.5.90a/3GPP TS 24.008: Authentication Response Parameter information element
(SRES) (GSM authentication challenge only)

SRES value (octet 2, 3, 4 and 5)

The SRES value consists of 32 bits. Bit 8 of octet 2 is the most significant bit while bit 1 of octet 5 is the least significant bit.

Table 10.5.90b/3GPP TS 24.008: Authentication Response Parameter information element (RES) (UMTS authentication challenge only)

RES value (octet 2, 3, 4 and 5)

This contains the most significant 4 octets of RES

If RES>4 octets, the remaining octets of RES shall appear in the Authentication Response Parameter (extension) IE (see subclause 10.5.3.2.1)
10.5.3.2.1 Authentication Response Parameter (extension) (UMTS authentication challenge only)

This IE is included if the authentication response parameter RES is longer than 4 octets (UMTS only) and therefore does not fit in the Authentication Response Parameter field (see 10.5.3.2).

The Authentication Response parameter (extension) IE is coded as shown in figure 10.5.76.1/3GPP TS 24.008 and table 10.5.90.1/3GPP TS 24.008.

The Authentication Response parameter (extension) IE is a type 4 information element with a minimum length of 3 octets and a maximum length of 14 octets.

8

7

6

5

4

3

2

1

Authentication Response (extension) IEI

octet 1

Length of Authentication Response contents

octet 2

RES (all but 4 most significant octets)

:

octet 3

:

octet 14

Figure 10.5.76.1/3GPP TS 24.008 Authentication Response Parameter (extension) information element (UMTS authentication challenge only)

Table 10.5.90.1/3GPP TS 24.008: Authentication Response Parameter (extension) information element (RES)

RES (extension) value (octet 3 to 14)

This contains all but the 4 most significant octets of RES
10.5.3.2.2 Authentication Failure parameter (UMTS and EPS authentication challenge)

The purpose of the Authentication Failure parameter information element is to provide the network with the necessary information to begin a re-authentication procedure (see 3GPP TS 33.102 [5a]) in the case of a ‘Synch failure’, following a UMTS or EPS authentication challenge.

The Authentication Failure parameter IE is coded as shown in figure 10.5.76.2/3GPP TS 24.008 and table 10.5.90.2/3GPP TS 24.008.

The Authentication Failure parameter IE is a type 4 information element with a length of 16 octets.

8

7

6

5

4

3

2

1

Authentication Failure parameter IEI

octet 1

Length ofAuthentication Failure parameter contents

octet 2

Authentication Failure parameter

:

octet 3

:

octet 16

Figure 10.5.76.2/3GPP TS 24.008 Authentication Failure parameter information element (UMTS and EPS authentication challenge)

Table 10.5.90.2/3GPP TS 24.008: Authentication Failure parameter information element

Authentication Failure parameter value (octet 3 to 16)

This contains AUTS (see 3GPP TS 33.102 [5a])

10.5.3.3 CM service type

The purpose of the CM Service Type information element is to specify which service is requested from the network.

The CM Service Type information element is coded as shown in figure 10.5.77/3GPP TS 24.008 and table 10.5.91/3GPP TS 24.008.

The CM Service Type is a type 1 information element.

8

7

6

5

4

3

2

1

CM service type IEI

service type

octet 1

Figure 10.5.77/3GPP TS 24.008 CM Service Type information element

Table 10.5.91/3GPP TS 24.008: CM Service Type information element

Service type (octet 1)

Bits

4

3

2

1

0

0

0

1

Mobile originating call establishment or packet mode connection establishment

0

0

1

0

Emergency call establishment

0

1

0

0

Short message service

1

0

0

0

Supplementary service activation

1

0

0

1

Voice group call establishment

1

0

1

0

Voice broadcast call establishment

1

0

1

1

Location Services (NOTE)

All other values are reserved.

NOTE: this service type shall only be used by a type A LMU if the MM connection was requested for the transmission of LCS signalling messages specified in 3GPP TS 44.071 [23a].

10.5.3.4 Identity type

The purpose of the Identity Type information element is to specify which identity is requested.

The Identity Type information element is coded as shown in figure 10.5.78/3GPP TS 24.008 and table 10.5.92/3GPP TS 24.008.

The Identity Type is a type 1 information element.

8

7

6

5

4

3

2

1

Identity type IEI

0

spare

type of identity

octet 1

Figure 10.5.78/3GPP TS 24.008 Identity Type information element

Table 10.5.92/3GPP TS 24.008: Identity Type information element

Type of identity (octet 1)

Bits

3

2

1

0

0

1

IMSI

0

1

0

IMEI

0

1

1

IMEISV

1

0

0

TMSI

1

0

1

P-TMSI, RAI, P-TMSI signature

All other values are reserved.

10.5.3.5 Location updating type

The purpose of the Location Updating Type information element is to indicate whether a normal updating, a periodic updating or an IMSI attach is wanted. It may also indicate that a follow-on request has been received from the mobile station CM layer.

The Location Updating Type information element is coded as shown in figure 10.5.79/3GPP TS 24.008 and table 10.5.93/3GPP TS 24.008.

The Location Updating Type is a type 1 information element.

8

7

6

5

4

3

2

1

Location updating

type IEI

FOR

0

spare

LUT

octet 1

Figure 10.5.79/3GPP TS 24.008 Location Updating Type information element

Table 10.5.93/3GPP TS 24.008: Location Updating Type information element

LUT (octet 1)

Bits

2

1

0

0

Normal location updating

0

1

Periodic updating

1

0

IMSI attach

1

1

Reserved

FOR (octet 1)

The Follow-On Request bit (FOR) is coded as follows:

Bits

4

0

No follow-on request pending

1

Follow-on request pending

10.5.3.5a Network Name

The purpose of this information element is to pass a text string to the mobile station.

The Network Name information element is coded as shown in figure 10.5.80/3GPP TS 24.008 and table 10.5.94/3GPP TS 24.008.

If the coding scheme UCS2 is used and Chinese-Japanese-Korean-Vietnamese (CJKV) ideographs as defined in ISO/IEC 10646 [72] are received in the text string, the MS shall use the MCC of the PLMN from which it received the network name information element to determine the language for those CJKV ideographs as specified in table 10.5.93a/3GPP TS 24.008:

Table 10.5.93a/3GPP TS 24.008: MCC to CJKV ideograph language mapping table

MCC(s)

Country/Region

Language
(C, J, K, or V)

460, 461

Mainland China

Chinese-G

466

Taiwan

Chinese-T

454

HongKong

Chinese-T

455

Macao

Chinese-T

440, 441

Japan

J (Kanji)

450, 467

Korea

K (Hanja)

452

Vietnam

V (Chunom)

NOTE: This is due to CJKV ideograph language ambiguity in UCS2, in the sense that the same hexadecimal code can be mapped to different character displays dependent on the used language. The coding of CJKV ideographs itself does not allow to discriminate the CJKV ideograph language.

The Network Name is a type 4 information element with a minimum length of 3 octets. No upper length limit is specified except for that given by the maximum number of octets in a L3 message (see 3GPP TS 44.006 [19]).

8

7

6

5

4

3

2

1

Network Name IEI

octet 1

Length of Network Name contents

octet 2

ext

1

coding scheme

Add

CI

Number of spare

bits in last octet

octet 3

octet 4

Text String

octet n

Figure 10.5.80/3GPP TS 24.008 Network Name information element

Table 10.5.94/3GPP TS 24.008 Network Name information element

Number of spare bits in last octet (octet 3, bits 1 to 3)

2

1

0

0

1

bit 8 is spare and set to "0" in octet n

0

1

0

bits 7 and 8 are spare and set to "0" in octet n

0

1

1

bits 6 to 8(inclusive) are spare and set to "0" in octet n

1

0

0

bits 5 to 8(inclusive) are spare and set to "0" in octet n

1

0

1

bits 4 to 8(inclusive) are spare and set to "0" in octet n

1

1

0

bits 3 to 8(inclusive) are spare and set to "0" in octet n

1

1

1

bits 2 to 8(inclusive) are spare and set to "0" in octet n

0

0

0

this field carries no information about the number of spare bits in octet n

Add CI (octet 3, bit 4)

0

The MS should not add the letters for the Country’s Initials to the text string

1

The MS should add the letters for the Country’s Initials and a separator

(e.g. a space) to the text string

Coding Scheme (octet 3, bits 5-7)

0

0

0

Cell Broadcast data coding scheme, GSM default alphabet, language unspecified, defined in 3GPP TS 23.038 [8b]

0

0

1

UCS2 (16 bit) [72]

0

1

0

to

reserved

1

1

1

If Coding Scheme = "000" and the <CR> as specified in 3GPP TS 23.038 [8b] is intended to be added to the octet boundary by the network, the Number of spare bits in last octet is set to "111".

If Coding Scheme is not equal to "000", all values of number of spare bits in last octet received by the mobile station shall be interpreted as "this field carries no information about the number of spare bits in octet n".

Text String (octet 4 to octet n, inclusive)

Encoded according to the Coding Scheme defined by octet 3, bits 5-7

10.5.3.6 Reject cause

The purpose of the Reject Cause information element is to indicate the reason why a request from the mobile station is rejected by the network.

The Reject Cause information element is coded as shown in figure 10.5.81/3GPP TS 24.008 and table 10.5.95/3GPP TS 24.008.

The Reject Cause is a type 3 information element with 2 octets length.

8

7

6

5

4

3

2

1

Reject cause IEI

octet 1

reject cause value

octet 2

Figure 10.5.81/3GPP TS 24.008 Reject Cause information element

Table 10.5.95/3GPP TS 24.008: Reject Cause information element

Reject cause value (octet 2)

Bits

8

7

6

5

4

3

2

1

0

0

0

0

0

0

1

0

IMSI unknown in HLR

0

0

0

0

0

0

1

1

Illegal MS

0

0

0

0

0

1

0

0

IMSI unknown in VLR

0

0

0

0

0

1

0

1

IMEI not accepted

0

0

0

0

0

1

1

0

Illegal ME

0

0

0

0

1

0

1

1

PLMN not allowed

0

0

0

0

1

1

0

0

Location Area not allowed

0

0

0

0

1

1

0

1

Roaming not allowed in this location area

0

0

0

0

1

1

1

1

No Suitable Cells In Location Area

0

0

0

1

0

0

0

1

Network failure

0

0

0

1

0

1

0

0

MAC failure

0

0

0

1

0

1

0

1

Synch failure

0

0

0

1

0

1

1

0

Congestion

0

0

0

1

0

1

1

1

GSM authentication unacceptable

0

0

0

1

1

0

0

1

Not authorized for this CSG

0

0

1

0

0

0

0

0

Service option not supported

0

0

1

0

0

0

0

1

Requested service option not subscribed

0

0

1

0

0

0

1

0

Service option temporarily out of order

0

0

1

0

0

1

1

0

Call cannot be identified

0

0

1

1

0

0

0

0

}

to

} retry upon entry into a new cell

0

0

1

1

1

1

1

1

}

0

1

0

1

1

1

1

1

Semantically incorrect message

0

1

1

0

0

0

0

0

Invalid mandatory information

0

1

1

0

0

0

0

1

Message type non-existent or not implemented

0

1

1

0

0

0

1

0

Message type not compatible with the protocol state

0

1

1

0

0

0

1

1

Information element non-existent or not implemented

0

1

1

0

0

1

0

0

Conditional IE error

0

1

1

0

0

1

0

1

Message not compatible with the protocol state

0

1

1

0

1

1

1

1

Protocol error, unspecified

Any other value received by the mobile station shall be treated as 0010 0010, ‘Service option temporarily out of order’. Any other value received by the network shall be treated as 0110 1111, ‘Protocol error, unspecified’.

NOTE: The listed reject cause values are defined in Annex G.

10.5.3.7 Follow-on Proceed

The purpose of the Follow-on Proceed information element is to indicate that an MM connection may be established on an existing RR connection.

The Follow-on Proceed information element is coded as shown in figure 10.5.82/3GPP TS 24.008.

The Follow-on Proceed is a type 2 information element.

8

7

6

5

4

3

2

1

Follow-on Proceed IEI

octet 1

Figure 10.5.82/3GPP TS 24.008 Follow-on Proceed information element

10.5.3.8 Time Zone

The purpose of this information element is to encode the offset between universal time and local timein steps of 15 minutes.

The Time Zone information element is coded as shown in figure 10.5.83/3GPP TS 24.008 and table 10.5.96/3GPP TS 24.008.

The Time Zone is a type 3 information element with a length of 2 octets.

8

7

6

5

4

3

2

1

Time Zone IEI

octet 1

Time Zone

octet 2

Figure 10.5.83/3GPP TS 24.008 Time Zone information element

Table 10.5.96/3GPP TS 24.008 Time Zone information element

Time Zone (octet 2, bits 1-8)

This field uses the same format as the Timezone field used in the TP-Service-Centre-Time-Stamp, which is defined in 3GPP TS 23.040 [90], and its value shall be set as defined in 3GPP TS 22.042 [89]

10.5.3.9 Time Zone and Time

The purpose of the timezone part of this information element is to encode the offset between universal time and local time in steps of 15 minutes.

The purpose of the time part of this information element is to encode the universal time at which this information element may have been sent by the network.

The Time Zone and Time information element is coded as shown in figure 10.5.84/3GPP TS 24.008 and table 10.5.97/3GPP TS 24.008.

The Time Zone and Time is a type 3 information element with a length of 8 octets.

8

7

6

5

4

3

2

1

Time Zone and Time IEI

octet 1

Year

octet 2

Month

octet 3

Day

octet 4

Hour

octet 5

Minute

octet 6

Second

octet 7

Time zone

octet 8

Figure 10.5.84/3GPP TS 24.008 Time Zone and Time information element

Table 10.5.97/3GPP TS 24.008 Timezone and Time information element

Year (octet 2, bits 1-8)

This field uses the same format as the Year field used in the TP-Service-Centre-Time-Stamp, which is defined in 3GPP TS 23.040 [90], and its value shall be set as defined in 3GPP TS 22.042 [89]

Month (octet 3, bits 1-8)

This field uses the same format as the Month field used in the TP-Service-Centre-Time-Stamp, which is defined in 3GPP TS 23.040 [90], and its value shall be set as defined in 3GPP TS 22.042 [89].

Day (octet 4, bits 1-8)

This field uses the same format as the Day field used in the TP-Service-Centre-Time-Stamp, which is defined in 3GPP TS 23.040 [90], and its value shall be set as defined in 3GPP TS 22.042 [89].

Hour (octet 5, bits 1-8)

This field uses the same format as the Hour field used in the TP-Service-Centre-Time-Stamp, which is defined in 3GPP TS 23.040 [90], and its value shall be set as defined in 3GPP TS 22.042 [89].

Minute (octet 6, bits 1-8)

This field uses the same format as the Minute field used in the TP-Service-Centre-Time-Stamp, which is defined in 3GPP TS 23.040 [90], and its value shall be set as defined in 3GPP TS 22.042 [89].

Second (octet 7, bits 1-8)

This field uses the same format as the Second field used in the TP-Service-Centre-Time-Stamp, which is defined in 3GPP TS 23.040 [90], and its value shall be set as defined in 3GPP TS 22.042 [89].

Time Zone (octet 8, bits 1-8)

This field uses the same format as the Time Zone field used in the TP-Service-Centre-Time-Stamp, which is defined in 3GPP TS 23.040 [90], and its value shall be set as defined in 3GPP TS 22.042 [89].

NOTE: Due to ambiguities in earlier versions of the protocol specifications, some mobile stations may interpret the received NITZ time as local time. This may result in incorrect time settings in the mobile.

10.5.3.10 CTS permission

The purpose of the CTS permission information element is to indicate that the mobile station is allowed to use GSM-Cordless Telephony System in the Location Area. The CTS permission information element is coded as shown in figure 10.5.84a/3GPP TS 24.008.

The CTS permission is a type 2 information element.

8

7

6

5

4

3

2

1

CTS Permission IEI

octet 1

Figure 10.5.84a/3GPP TS 24.008 CTS permission information element

10.5.3.11 LSA Identifier

This element uniquely identifies a LSA.

The LSA Identifier information element is coded as shown in figure 10.68c/3GPP TS 24.008.

The LSA Identifier is a type 4 information element with a length of 2 or 5 octets.

8

7

6

5

4

3

2

1

LSA Identifier IEI

octet 1

Length of LSA Identifier contents

octet 2

LSA ID

octet 3

LSA ID cont.

octet 4

LSA ID cont.

octet 5

Figure 10.68c/3GPP TS 24.008 LSA Identifier information element

If the Length = 0, then no LSA ID is included. This is used to indicate that the MS has moved to an area where there is no LSA available for that MS.

Octets 3-5 are coded as specified in 3GPP TS 23.003 [10], ‘Identification of Localised Service Area’. Bit 8 of octet 3 is the most significant bit.

10.5.3.12 Daylight Saving Time

The purpose of this information element is to encode the Daylight Saving Time in steps of 1 hour.

The Daylight Saving Time information element is coded as shown in figure 10.5.84b/3GPP TS 24.008 and table 10.5.97a/3GPP TS 24.008.

The Daylight Saving Time is a type 4 information element with a length of 3 octets.

8

7

6

5

4

3

2

1

Daylight Saving Time IEI

octet 1

Length of Daylight Saving Time contents

octet 2

spare

value

0

0

0

0

0

0

octet 3

Figure 10.5.84b/3GPP TS 24.008 Daylight Saving Time information element

Table 10.5.97a/3GPP TS 24.008: Daylight Saving Time information element

Daylight Saving Time value (octet 3)

Bits

2

1

0

0

No adjustment for Daylight Saving Time

0

1

+1 hour adjustment for Daylight Saving Time

1

0

+2 hours adjustment for Daylight Saving Time

1

1

Reserved

10.5.3.13 Emergency Number List

The purpose of this information element is to encode emergency number(s) for use within the country where the IE is received.

The Emergency Number List information element is coded as shown in figure 10.5.84c/3GPP TS 24.008.

The Emergency Number List IE is a type 4 information element with a minimum length of 5 octets and a maximum length of 50 octets.

8

7

6

5

4

3

2

1

Emergency Number List IEI

octet 1

Length of Emergency Number List IE contents

octet 2

Length of 1st Emergency Number information (Note 1)

octet 3

Spare

Emergency Service Category Value

octet 4

0

0

0

Number digit 2

Number digit 1

octet 5

(Note 2)

Number digit 4

Number digit 3

octet 6*

:

:

:

(Note 3)

octet j-1*

Length of 2nd Emergency Number information (Note 1)

octet j*

Spare

Emergency Service Category Value

octet j+1*

0

0

0

Number digit 2

Number digit 1

octet j+2*

(Note 2)

Number digit 4

Number digit 3

octet j+3*

:

:

:

(Note 3)

:

octet j+k*

.

.

.

.

.

.

Length of xth Emergency Number information (Note 1)

octet n*

Spare

Emergency Service Category Value

octet n+1*

0

0

0

Number digit 2

Number digit 1

octet n+2*

(Note 2)

Number digit 4

Number digit 3

octet n+3*

:

:

:

(Note 3)

:

octet n+m*

NOTE 1: The length contains the number of octets used to encode the Emergency Service Category Value and the Number digits.

NOTE 2: The number digit(s) in octet 5 precedes the digit(s) in octet 6 etc. The number digit, which would be entered first, is located in octet 5, bits 1 to 4. The contents of the number digits are coded as shown in table 10.5.118/3GPP TS 24.008.

NOTE 3: If the emergeny number contains an odd number of digits, bits 5 to 8 of the last octet of the respective emergency number shall be filled with an end mark coded as "1111".

Figure 10.5.84c/3GPP TS 24.008 Emergency Number List information element

Table 10.5.97aa/3GPP TS 24.008: Emergency Number List information element

Emergency Service Category Value (octet 4, j+1, n+1, etc.; bit 1 to 5)

Bits 1 to 5 are coded as bits 1 to 5 of octet 3 of the Service Category information element as specified in subclause 10.5.4.33.

10.5.3.14 Additional update parameters

The purpose of the Additional update parameters information element is to provide additional information during the location updating procedure and during MM connection establishment.

The Additional update parameters information element is coded as shown in figure 10.5.84d/3GPP TS 24.008 and table 10.5.97b/3GPP TS 24.008.

The Additional update parameters information element is a type 1 information element.

8

7

6

5

4

3

2

1

Additional update parameters

IEI

0

Spare

DR-VCC

CSMO

CSMT

octet 1

Figure 10.5.84d/3GPP TS 24.008: Additional update parameters information element

Table 10.5.97b/3GPP TS 24.008: Additional update parameters information element

Additional update parameters value (octet 1, bit 1 to 4)

CSMT (1 bit field)

Bit

1

0

No additional information.

1

CS fallback mobile terminating call

CSMO (1 bit field)

Bit

2

0 No additional information.

1 CS fallback mobile originating call

DRVCC call (1 bit field)

Bit

3

0 No additional information.

1 DRVCC call

Bit 4 of octet 1 is spare and shall be coded as zero.

10.5.3.15 Void

10.5.3.16 MM Timer

The purpose of the MM timer information element is to specify MM specific timer values, e.g. for the timer T3246.

The MM timer is a type 4 information element with 3 octets length.

The MM timer information element is coded as shown in figure 10.5.3.16-1/3GPP TS 24.008 and table 10.5.3.16-1/3GPP TS 24.008.

8

7

6

5

4

3

2

1

MM Timer IEI

octet 1

Length of MM Timer contents

octet 2

MM Timer value

octet 3

Figure 10.5.3.16-1/3GPP TS 24.008: MM Timer information element

Table 10.5.3.16-1/3GPP TS 24.008: MM Timer information element

Timer value (octet 3)

Bits 5 to 1 represent the binary coded timer value.

Bits 6 to 8 defines the timer value unit for the MM timer as follows:

Bits

8 7 6

0 0 0 value is incremented in multiples of 2 seconds

0 0 1 value is incremented in multiples of 1 minute

0 1 0 value is incremented in multiples of decihours

1 1 1 value indicates that the timer is deactivated.

Other values shall be interpreted as multiples of 1 minute in this version of the protocol.

The value indicated is contructed by multiplying the value in bits 5 to 1 with the timer value unit in bits 8 to 6, unless the timer value unit indicates the timer being deactivated.