4 Messages functional definitions and contents
3GPP48.071Layer 3 specificationLocation Services (LCS)Release 17Serving Mobile Location Centre - Base Station System (SMLC-BSS) interfaceTS
4.1 General
This sub-clause defines the structure of the messages of the SMLC-BSS layer 3 protocol defined in 3GPP TS 43.059.
Each definition includes:
a) a brief description of the message;
b) a table listing the information elements in the order of their appearance in the message.
For each IE the table indicates:
1) the name of the IE (which gives an idea of the semantics of the element), which is used in this and other specifications as a reference to the IE within the message;
2) the name of the type of the IE (which indicates the coding of the value part of the IE), and a reference to a description of the value part of the IE;
3) the presence requirement indication (M, C or O) for the IE, as defined in 3GPP TS 24.007;
4) the format of the IE (T, V, TV, LV, TLV) as defined in 3GPP TS 24.007;
5) the length of the IE (or permissible range of lengths), in octets, in the message. The value of the length gives the number of octets in the IE following the length and element identifier. Where the length is encoded using more than one octet, the high order bit is bit 8 of the first (lowest numbered octet) and the low order bit is bit 1 of the last (highest numbered octet). When a length has a range of M to N octets, the notation "M-N" is used. The symbol "n" represents the maximum of a range when indefinite.
c) sub-clauses specifying conditions for IEs with presence requirement C or O in the relevant message. Together with other conditions specified in 3GPP TS 43.059 this defines when the IE shall be included or not, what non‑presence of such IEs means, and (for IEs with presence requirement C) the static conditions for presence and/or non-presence of the IEs (see 3GPP TS 43.059).
4.2 Messages
The following Location Services related messages are exchanged between the SMLC and the BSS:
– TA Request;
– TA Response;
– Reject;
– Reset;
– Abort;
– TA Layer3;
– MS Position Command;
– MS Position Response;
– U-TDOA Request;
– U-TDOA Response.
On the Lb interface the messages are contained in the BSSLAP APDU IE which is encapsulated in the following messages as specified in 3GPP TS 49.031:
– BSSMAP-LE CONNECTION ORIENTED INFORMATION message (for all messages except the TA LAYER 3 message);
– BSSMAP-LE PERFORM LOCATION REQUEST message (for the TA LAYER 3 message)
– BSSMAP-LE PERFORM LOCATION INFORMATION message (for the TA LAYER 3 message).
4.2.1 TA Request
The TA Request is a message from the SMLC to the BSS, requesting BSS to return the timing advance (or access delay) of the MS.
Table 4.2.1.1: TA Request message content
|
Information element |
Type/Reference |
Presence |
Format |
Length |
|
Message Type |
Message Type IE / 5.1 |
M |
V |
1 |
4.2.2 TA Response
The TA Response is a message from the BSS to the SMLC. It is a response to TA Request message and contains the following information elements.
Table 4.2.2.1: TA Response message content
|
Information element |
Type/Reference |
Presence |
Format |
Length |
|
Message Type |
Message Type IE / 5.1 |
M |
V |
1 |
|
Serving Cell Identity |
Cell Identity IE / 5.4 |
M |
TV |
3 |
|
Timing Advance |
Timing Advance IE / 5.2 |
M |
TV |
2 |
|
Measurement Report |
Measurement Report IE / 5.12 |
O |
TLV |
18 |
|
Enhanced Measurement Report |
Enhanced Measurement Report IE / 5.18 |
O |
TLV |
4-n |
|
Measured Cell Identity List |
Cell Identity List IE / 5.17 |
O |
TLV |
6-n |
|
Concurrent Method Flag |
Concurrent Positioning Flag IE / 5.34 |
O (note 1) |
TV |
2 |
|
NOTE 1: This IE is only included when the BSC allows a concurrent invocation of a first and second positioning procedure |
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4.2.3 (void)
4.2.4 (void)
4.2.5 Reject
The Reject is a message from the BSS to the SMLC. It is a possible response to TA Request, MS Position Command or U-TDOA Request and contains the following information elements.
Table 4.2.5.1: Reject message content
|
Information element |
Type/Reference |
Presence |
Format |
Length |
|
Message Type |
Message Type IE / 5.1 |
M |
V |
1 |
|
Cause |
Cause IE / 5.14 |
M |
TV |
2 |
The following are the expected cause values for Reject message:
– congestion;
– channel Mode not supported;
– positioning procedure not supported;
– failure for other radio related events;
– incorrect serving cell identity;
– BSSAP-LE Segmentation error;
– Concurrent Positioning not enabled.
4.2.6 Reset
The Reset is a message from the BSS to the SMLC. It is sent when the Response message contents for a positioning request are invalidated (e.g. due to handover) before the positioning procedure was completed.
Table 4.2.6.1: Reset message content
|
Information element |
Type/Reference |
Presence |
Format |
Length |
|
Message Type |
Message Type IE / 5.1 |
M |
V |
1 |
|
Cell ID |
Cell Identity IE / 5.4 |
M |
TV |
3 |
|
Timing Advance |
Timing Advance IE / 5.2 |
M |
TV |
2 |
|
Channel description |
Channel Description IE / 5.8 |
M |
TV |
4 |
|
Cause |
Cause IE / 5.1 |
M |
TV |
2 |
|
Measurement Report |
Measurement Report IE / 5.12 |
O |
TLV |
18 |
|
Enhanced Measurement Report |
Enhanced Measurement Report IE / 5.18 |
O |
TLV |
4-n |
|
Measured Cell Identity List |
Cell Identity List IE / 5.17 |
O |
TLV |
6-n |
|
LAC |
Location Area Code IE / 5.19 |
O |
TV |
3 |
|
Frequency List |
Frequency List IE 5.20 |
C (note 1) |
TLV |
3-n |
|
Channel Mode |
Channel Mode IE 5.26 |
C (notes 2 & 4) |
TV |
2 |
|
MultiRate Configuration |
MultiRate Configuration 5.27 |
C (notes 3 & 4) |
TLV |
4-n |
|
Packet Channel Description |
Packet Channel Description IE 5.29 |
C (note 5) |
TV |
4 |
|
TLLI |
TLLI IE 5.30 |
C (note 5) |
TV |
5 |
|
TFI |
TFI 5.31 |
C (note 5) |
TV |
2 |
|
TBF Starting Time |
Starting Time IE 5.32 |
C (note 5) |
TV |
3 |
|
Encryption Key (Kc) |
Encryption Key IE 5.24 |
C (note 6) |
TV |
9 |
|
Cipher Mode Setting |
Cipher Mode Setting IE 5.25 |
C (note 4) |
TV |
2 |
|
Long Encryption Key (Kc128) |
Long Encryption Key IE 5.33 |
C(note 7) |
TV |
17 |
|
NOTE 1: The Frequency List IE is included only for U-TDOA when frequency hopping is used. NOTE 2: The Channel Mode IE is included only for U-TDOA using FR or AMR (not included for EFR). NOTE 3: The MultiRate Configuration IE is included only for U-TDOA using AMR. NOTE 4: This IE can only be present for CS U-TDOA location method NOTE 5: This IE can only be present for PS U-TDOA location method NOTE 6: This IE can only be present for CS U-TDOA location method and if the Ciphering Mode Setting IE indicates A5/1 or A5/3. NOTE 7: This IE can only be present for CS U-TDOA location method and if the Ciphering Mode Setting IE indicates A5/4. |
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The following are the expected cause values for Reset message:
– intra-BSS handover;
– failure for other radio related events;
– supervision Timer Expired;
– incorrect serving cell identity.
4.2.7 Abort
The Abort is a message from the BSS to the SMLC. Upon receiving this signal, the SMLC shall abort ongoing positioning procedure.
Table 4.2.7.1: Abort message content
|
Information element |
Type/Reference |
Presence |
Format |
Length |
|
Message Type |
Message Type IE / 5.1 |
M |
V |
1 |
|
Cause |
Cause IE / 5.14 |
M |
TV |
2 |
The following are the expected cause values for Abort message:
– failure for other radio related events;
– supervision Timer Expired;
– inter BSS handover;
– loss of signalling connection to MS.
4.2.8 TA Layer3
The TA Layer3 is an optional encapsulated message from the BSS to the SMLC that adds the following information in Complete layer 3 Information as described in 3GPP TS 48.008.
Table 4.2.8.1: TA Layer3 message content
|
Information element |
Type/Reference |
Presence |
Format |
Length |
|
Message Type |
Message Type IE / 5.1 |
M |
V |
1 |
|
Timing Advance |
Timing Advance IE / 5.2 |
M |
TV |
2 |
|
Measurement Report |
Measurement Report IE / 5.12 |
O |
TLV |
18 |
|
Enhanced Measurement Report |
Enhanced Measurement Report IE / 5.18 |
O |
TLV |
4-n |
|
Measured Cell Identity List |
Cell Identity List IE / 5.17 |
O |
TLV |
6-n |
4.2.9 MS Position Command
The BSSLAP MS Position Command is a message from the SMLC to BSS that contains the following information elements.
Table 4.2.9.1: MS Position Command message content
|
Information element |
Type/Reference |
Presence |
Format |
Length |
|
Message Type |
Message Type IE / 5.1 |
M |
V |
1 |
|
flag |
RRLP flag IE / 5.15 |
M |
TV |
2 |
|
RRLP Info |
RRLP IE / 5.16 |
M |
TLV |
3-n |
4.2.10 MS Position Response
The BSSLAP MS Position Response is a message from the BSS to the SMLC that contains the following information elements.
Table 4.2.10.1: MS Position Response message content
|
Information element |
Type/Reference |
Presence |
Format |
Length |
|
Message Type |
Message Type IE / 5.1 |
M |
V |
1 |
|
flag |
RRLP flag IE / 5.15 |
M |
TV |
2 |
|
RRLP Info |
RRLP IE / 5.16 |
M |
TLV |
3-n |
|
Timing Advance |
Timing Advance IE / 5.2 |
O |
TV |
2 |
|
Measurement Report |
Measurement Report IE / 5.12 |
O |
TLV |
18 |
|
Enhanced Measurement Report |
Enhanced Measurement Report IE / 5.18 |
O |
TLV |
4-n |
|
Measured Cell Identity List |
Cell Identity List IE / 5.17 |
O |
TLV |
6-n |
|
Concurrent Method Flag |
Concurrent Positioning Flag IE / 5.34 |
O (note 1) |
TV |
2 |
|
NOTE 1: This IE is only included when the BSC allows a concurrent invocation of a first and second positioning procedure |
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4.2.11 U-TDOA Request
The U-TDOA Request is a message from the SMLC to the BSS. It contains the following information elements.
Table 4.2.11.1: U-TDOA Request message content
|
Information element |
Type/Reference |
Presence |
Format |
Length |
|
Message Type |
Message Type IE 5.1 |
M |
V |
1 |
|
Delta Timer |
Delta Timer IE 5.22 |
O (note 1) |
TV |
2 |
|
Polling Repetition |
Polling Repitition IE 5.28 (note) |
C (note 2) |
TV |
2 |
|
NOTE 1: This IE can only be present for CS U-TDOA location method |
||||
|
NOTE 2: This IE is only present for PS U-TDOA location method |
||||
4.2.12 U-TDOA Response
The U-TDOA Response is a message from the BSS to the SMLC. It is a response to the U-TDOA Request message. It contains the following information elements.
Table 4.2.12.1: U-TDOA Response message content
|
Information element |
Type/Reference |
Presence |
Format |
Length |
|
Message Type |
Message Type IE 5.1 |
M |
V |
1 |
|
Channel Description |
Channel Description IE 5.8 |
M |
TV |
4 |
|
Serving Cell Identifier |
Cell Identifier IE 5.23 |
M |
TLV |
4-n |
|
Frequency List |
Frequency List IE 5.20 |
C (note 3) |
TLV |
3-n |
|
Timing Advance |
Timing Advance IE 5.2 |
O |
TV |
2 |
|
MS Power |
MS Power IE 5.21 |
O |
TV |
2 |
|
Measurement Report |
Measurement Report IE 5.12 |
O |
TLV |
18 |
|
Encryption Key (Kc) |
Encryption Key IE 5.24 |
C (note 7) |
TV |
9 |
|
Cipher Mode Setting |
Cipher Mode Setting IE 5.25 |
C (note 4) |
TV |
2 |
|
Channel Mode |
Channel Mode IE 5.26 |
C (notes 1 & 4) |
TV |
2 |
|
MultiRate Configuration |
MultiRate Configuration IE 5.27 |
C (notes 1 & 4) |
TLV |
4-n |
|
Measured Cell Identity List |
Cell Identity List IE / 5.17 |
O |
TLV |
6-n |
|
Packet Channel Description |
Packet Channel Description IE 5.29 |
C (note 5) |
TV |
4 |
|
TLLI |
TLLI IE 5.30 |
C (note 5) |
TV |
5 |
|
TFI |
TFI IE 5.31 |
C (note 5) |
TV |
2 |
|
TBF Starting Time |
Starting Time IE 5.32 |
C (note 5) |
TV |
3 |
|
Power-Up Starting Time |
Starting Time IE 5.32 |
O (note 6) |
TV |
3 |
|
Long Encryption Key (Kc128) |
Long Encryption Key IE 5.33 |
C (note 8) |
TV |
17 |
|
Concurrent Method Flag |
Concurrent Positioning Flag IE / 5.34 |
O (note 9) |
TV |
2 |
|
NOTE 1: The Channel Mode IE is included only for U-TDOA using FR or AMR (not included for EFR). NOTE 2: The MultiRate Configuration IE is included only for U-TDOA using AMR. NOTE 3: The Frequency List IE is included only when frequency hopping is used. NOTE 4: This IE can only be present for CS U-TDOA location method. NOTE 5: This IE can only be present for PS U-TDOA location method . NOTE 6: The Power-Up Starting Time IE is included if the Power-Up procedure is supported for U-TDOA location method. It represents the starting time of the power-up and DTX suspension. NOTE 7: This IE can only be present for CS U-TDOA location method and if the Ciphering Mode Setting IE indicates A5/1 or A5/3. NOTE 8: This IE can only be present for CS U-TDOA location method and if the Ciphering Mode Setting IE indicates A5/4. NOTE 9: This IE is only included when the BSC allows a concurrent invocation of a first and second positioning procedure |
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