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→Codec 16 Nebaigta
AVL data or events can be sent encapsulated in binary SMS. TP-DCS field of these SMS should indicate that message contains 8-bit data (for example: TP-DCS can be 0x04).
AVL data or events can be sent encapsulated in binary SMS. TP-DCS field of these SMS should indicate that message contains 8-bit data (for example: TP-DCS can be 0x04).
{| class="wikitable"
|-
! colspan="3" align="center" style="background: black; color: white;"|SM data (TP-UD)
|-
| AVL data array ||IMEI: 8 bytes
|}
AVL data array – array of encoded AVL data
IMEI – IMEI of sending module encoded as a big endian 8-byte long number.
*'''24 position SMS data protocol'''
24-hour SMS is usually sent once every day and contains GPS data of last 24 hours. TP-DCS field of this SMS should indicate that message contains 8-bit data (i.e. TP-DCS can be 0x04).
Note, that 24 position data protocol is used only with subscribed SMS. Event SMS use standard AVL data protocol.
'''Encoding'''
To be able to compress 24 GPS data entries into one SMS (140 octets), the data is encoded extensively using bit fields. Data packet can be interpreted as a bit stream, where all bits are numbered as follows:
{| class="wikitable"
|-
!style="background: black; color: white;"| Byte 1 !!style="background: black; color: white;"| Byte 2 !!style="background: black; color: white;"| Byte 3 !!style="background: black; color: white;"| Bytes 4-…
|-
| Bits 0-7 || Bits 8-15 || Bits 16-24 || Bits 25-…
|}
Bits in a byte are numbered starting from least significant bit. A field of 25 bits would consist of bits 0 to 24 where 0 is the least significant bit and bit 24 – most significant bit.
'''Structure'''
{| class="wikitable "
|-
! colspan="4" align="center" style="background: black; color: white;"|SMS Data Structure
|-
| || 8 || Codec ID || Codec ID = 4
|-
| || 35 || Timestamp || Time corresponding to the first (oldest) GPS data element,
represented in seconds elapsed from 2000.01.01 00:00 EET.
|-
| || 5 || ElementCount || Number of GPS data elements
|}
{| class="wikitable "
|-
! colspan="4" align="center" style="background: black; color: white;"|SMS Data Structure
|-
|ElementCount * || || GPSDataElement || GPS data elements.
|-
| || || Byte-aling padding || Padding bits to align to 8-bits boundary
represented in seconds elapsed from 2000.01.01 00:00 EET.
|-
| || 64 || IMEI || IMEI of sending device as 8-byte long integer
|}
The time of only the first GPS data element is specified in Timestamp field. Time corresponding to each further element can be computed as elementTime = Timestamp + (1 hour * elementNumber).
{| class="wikitable "
|-
! colspan="5" align="center" style="background: black; color: white;"|GPSDataElement
|-
| || || Size (bits) || Field || Description
|-
| || || 1 || ValidElement || ValidElement=1 – there is a valid GpdDataElement following,
ValidElement=0 – no element at this position
|-
| rowspan="8"| ValidElement == 1
|-
| || 1 || DifferentialCoords || Format of following data.
|-
| rowspan="3"| DifferentialCoords == 1
|-
| 14 || LongitudeDiff || Difference from previous element‘s longitude.
LongitudeDiff = prevLongitude – Longitude + 213 – 1
|-
| 14 || LatitudeDiff || Difference from previous element‘s latitude
LatitudeDiff = prevLatitude – Latitude + 213 – 1
|-
| rowspan="3"| DifferentialCoords == 0
|-
| 21 || Longitude || Longitude= {(LongDegMult + 18 * 108) * (221 –
1)} over {36*108}
|-
| 20 || Latitude || Latitude=(LatDegMult + 9*108) * (220 – 1) over
{18*108}
|-
| || || 8 || Speed || Speed in km/h
|}
Longitude - longitude field value of GPSDataElement
Latitude - latitude field value of GPSDataElement
LongDegMult - longitude in degrees multiplied by 107 (integer part)
LatDegMult latitude in degrees multiplied by 107 (integer part)
prevLongitude longitude field value of previous GPSDataElemen
prevLatitude latitude field value of previous GPSDataElement
*'''Decoding GPS position'''
When decoding GPS data with DifferentialCoords=1, Latitude and Longitude values can be computed as follows: Longitude=prevLongitude – LongitudeDiff + 213 – 1, Latitude=prevLatitude – LatitudeDiff + 213 – 1.
If there were no previous non-differential positions, differential coordinates should be computed assuming prevLongitude=prevLatitude=0.
When Longitude and Latitude values are known, longitude and latitude representation in degrees can be computed as follows:
[[Image:f11.png|f11.png]]
*'''SMS Events'''
When Configured to generate SMS event user will get this SMS upon event
<Year/Month/Day> <Hour:Minute:Second> P:<profile_nr> <SMS Text> Val:<Event Value> Lon:<longitude> Lat:<latitude> Q:<HDOP>
Example:
2016./04/11 12:00:00 P:3 Digital Input 1 Val:1 Lon:51.12258 Lat: 25.7461 Q:0.6
{| class="wikitable"
|-
| No information available || 0 || Iceland || 1C
|-
| Austria || 1 || Kazakhstan || 1D
|-
| Albania || 2 || Luxembourg || 1E
|-
| Andorra || 3 || Lithuania || 1F
|-
| Armenia || 4 || Latvia || 20
|-
| Azerbaijan || 5 || Malta || 21
|-
| Belgium || 6 || Monaco || 22
|-
| Bulgaria || 7 || Republic of Moldova || 23
|-
| Bosnia and Herzegovina || 8 || Macedonia || 24
|-
| Belarus || 9 || Norway || 25
|-
| Switzerland || 0A || Netherlands || 26
|-
| Cyprus || 0B || Portugal || 27
|-
| Czech Republic || 0C || Poland || 28
|-
| Germany || 0D || Romania || 29
|-
| Denmark || 0E || San Marino || 2A
|-
| Spain || 0F || Russian Federation || 2B
|-
| Estonia || 10 || Sweden || 2C
|-
| France || 11 || Slovakia || 2D
|-
| Finland || 12 || Slovenia || 2E
|-
| Liechtenstein || 13 || Turkmenistan || 2F
|-
| Faeroe Islands|| 14 || Turkey || 30
|-
| United Kingdom || 15 || Ukraine || 31
|-
| Georgia || 16 || Vatican City || 32
|-
| Greece || 17 || Yugoslavia || 33
|-
| Hungary || 18 || RFU || 34..FC
|-
| Croatia || 19 || European Community || FD
|-
| Italy || 1A || Example || FE
|-
| Ireland || 1B || Rest of the world || FF
|}
