Position Based Services –
Technical Solution, v.2.2
Digest version for technological partners
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SMS flow during position determination
Interface SMS description
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4
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SMS No.1 – Position determination request
SMS No.4 – Position information, Coordinates variant
SMS No.4 – Position information, Text variant
Position Based Services
SMS flow during position determination
One position determination will consist of a total of 4 SMSs:
PBS
Positioning
Server
PBS
Switcher
Server
1
4
3
2
Dispatcher
ME
Interface SMS description
SMS messages used for requesting and obtaining position information have two options: binary SMS or text SMS.
The basic structure of binary messages is divided into two main parts: header and body. The header contains information about
the type and length of the message, the body consists of several blocks with actual parameters or variables. All blocks have the
same following structure:
Block tag
Block length
Block value
1 byte
1 byte
variable length
represents block type, uses reserved numbers, e.g. (01, 02, …)
contains block value length
contains actual value
Text messages contain text expressed values which are separated by white spaces.
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Position Based Services
SMS No.1 – Position determination request
From:
Dispatcher
To:
PBS Switch server
Total length: 16+M1+M2+P+F+T bytes (8 bit coding)
Structure:
Position (bytes)
1
2
3
4
5
5+M1
6+M1
7+M1
7+M1+M2
8+M1+M2
9+M1+M2
9+M1+M2+P
10+M1+M2+P
11+M1+M2+P
12+M1+M2+P
13+M1+M2+P
14+M1+M2+P
15+M1+M2+P
16+M1+M2+P
17+M1+M2+P
17+M1+M2+P+F
18+M1+M2+P+F
19+M1+M2+P+F
Description
Transaction type (Reserved to: 01)
Message length
Tracked SIM card MSISDN tag (Reserved to: 01)
Tracked SIM card MSISDN length
Tracked SIM card MSISDN
Dispatcher MSISDN tag (Reserved to: 02)
Dispatcher MSISDN length
Dispatcher MSISDN
Password tag (Reserved to: 03)
Password length
Password
Position determination method tag (Reserved to: 04)
Position determination method length
Position determination method
Answer type tag (Reserved to: 05)
Answer type length
Answer type
Flags tag (Reserved to: 06)
Flags length
Flags
Prompt text tag (Reserved to: 07)
Prompt text length
Prompt Text
Length (bytes)
1
1
1
1
M1
1
1
M2
1
1
P
1
1
1
1
1
1
1
1
F
1
1
T
where:
Message length
MSISDN
8
7
6
X
Type of number
Number digit 2
Number digit 4
…
…
Total length of the SMS request (counted from Byte 3).
MSISDN in blocks 01 and 02 use the same format like in fig. 8.5/GSM 04.11 (available at
www.etsi.org) from octet 3:
5
4
3
2
Numbering plan identification
Number digit 1
Number digit 3
…
…
1
bits
Byte 1
Byte 2
Byte 3
…
Byte n
Position determination method Block 04 value defines the method, how the position should be determined. There is only one
option: M = position determination based on Network Measurement Results
Answer type
3
Determines how the position of tracked SIM will be expressed back to dispatcher. Options are:
N = position expressed in coordinates, T = position expressed in text
Position Based Services
Flags
Flags in block 06 are octets of flags F1 to FF. LSB of FF is flag FL0, USB of F1 is the highest flag FLX (X=7, 15,…)
Functions of following flags are defined at present:
FL0: If equal to 1 (Yes) then ME will output beep after receiving SMS (SIM toolkit proactive
command ‘Play Tone’ – according to ETSI 11.14)
FL1: If equal to 1 (Yes) then ME will prompt user with Prompt text in block 07.
Then a menu selection will be offered with options: "Yes" and "Cancel".
Additional functions can be added if necessary. If FL0 to FL1 is missing in SMS, SIM card will interpret this fact as:
FL0=1, FL1=1 and default text defined on SIM card will be used for prompt.
Prompt text Text of the confirmation prompt on users ME display, e.g. ‘Send your position?’
SMS No.4 – Position information, Coordinates variant
From:
PBS Switch server (short code: 5727)
To:
Dispatcher (MSISDN from block 02 in SMS No.1)
Total length: 41+M1 chars (8 bit coding)
Structure:
Position (bytes)
1
2
3
4
5
5+M1
6+M1
7+M1
14+M1
15+M1
16+M1
24+M1
25+M1
26+M1
27+M1
28+M1
29+M1
Description
Transaction type (Reserved to: 04)
Message length
Tracked SIM card MSISDN (Reserved to: 01)
Tracked SIM card MSISDN length
Tracked SIM card MSISDN
Latitude tag (Reserved to: 0B)
Latitude length
Latitude
Longitude tag (Reserved to: 0C)
Longitude length
Longitude
Precision tag (Reserved to: 0D)
Precision length
Precision
Time Stamp tag (Reserved to: 0E)
Time Stamp length
Time Stamp
Length (bytes)
1
1
1
1
M1
1
1
7
1
1
8
1
1
1
1
1
14
where:
MSISDN
MSISDN in block 01 uses the same format like in fig. 8.5/GSM 04.11 (available at www.etsi.org) from octet 3:
8
7
6
X
Type of number
Number digit 2
Number digit 4
…
…
Latitude
4
5
4
3
2
Numbering plan identification
Number digit 1
Number digit 3
…
…
1
bits
Byte 1
Byte 2
Byte 3
…
Byte n
Is expressed as "HDDMMSS". H is Earth’s hemisphere (N or S, 1 char), DD are degrees (00 to 90, 2 chars), MM are
minutes (00 to 59, 2 chars) and SS are seconds (00 to 59, 2 chars) of co-ordinates.
Position Based Services
Longitude
Is expressed "HDDDMMSS": H is Earth’s hemisphere (E or W, 1 char), DDD are degrees (000 to 180, 3 chars), MM
are minutes (00 to 59, 2 chars) and SS are seconds (00 to 59, 2 chars) of co-ordinates.
Precision
Precision is expressed by one character in logarithmic scale:
0
>50 km
1
50 km to 20 km
2
20 km to 10 km
3
10 km to 5 km
4
5 km to 2 km
5
2 km to 1km
6
1 km to 500 m
7
500m to 200 m
8
200 m to 100 m
9
less than 100 m
Time Stamp Timestamp represents time when SMS No.3 was sent by tracked ME in following format
YYMMDDHHNNSSTT, where:
YY is year (00 to 99, 2 chars., 00 stands for 2000, 98 stands for 2098, 99 stands for 1999)
MM is month (01 to 12,2 chars)
DD is day (01 to 31, 2 chars)
HH is hour (00 to 23, 2 chars)
NN is minute (00 to 59, 2 chars)
SS is second (00 to 59, 2 chars)
TT is Time Zone (according to GSM 03.04, v.5.3.0, chapter 9.2.3.11 TP-SCTS)
SMS No.4 – Position information, Text variant
From:
PBS Switch server (short code: 5727)
To:
Dispatcher (MSISDN from block 02 in SMS No.1)
Total length: varies (7 bit coding)
Structure:
• telephone number of the tracked SIM card (some handsets may interpret this number by the name under which it is saved in
SIM phone book (EFADN) or in the handset directory)
• verbal description of the position
• approximate distance of the center of the above described place from the spot defined by coordinates (it is displayed only if it is
higher than 5km)
• X coordinate (expressed as HDD*MM’SS" where H is Earth’s hemisphere ("E" or "W"), DD are degrees (00 to 90), MM are
minutes (00 to 59) and SS are seconds (00 to 59))
• Y coordinate (expressed as HDD*MM’SS" where H is Earth’s hemisphere ("N" or "S"), DD are degrees (00 to 90), MM are
minutes (00 to 59) and SS are seconds (00 to 59))
• precision of the localisation
• time of the localisation
• date of the localisation
Example:
+420603012345 Kraj: Jihočeský, Okres: Jindřichův Hradec, Název: Nová Ves nad Lužnicí. Vzdálenost asi 5,4 km.
E14*52'1"@N48*50'24" + -200m 15:23:01 18.09.01
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