Appendix "A1" - Message types - OTA bitmap
Introduction
An OTA bitmap is used for various SMS formats: Operator logo, CLI icon, Picture Message, and Downloadable Profile. In most phone the maximum size of the operator logo and the CLI icon is 72 x 14 pixels, while the maximum size of the picture message and the screen saver is 72 x 28 pixels. An OTA bitmap consists of a bitmap header and bitmap data. The size of the bitmap is specified in the header.
A typical OTA bitmap (72 x 14 pixels) header is: 00480E01
00 |
Infofield |
48 |
Width of the bitmap is 72 pixels |
0E |
Height of the bitmap is 14 pixels |
00 |
Number of colors or grey shades (only one color) |
The image data is located after the header information and is encoded as follows. Each semi-octet in the OTA bitmap presents 4 pixels in the original bitmap. Because one row takes 18 semi-octets, the whole 72 x 14 (operator logo and CLI icon) bitmap takes 18 x 14 = 252 semi-octets = 126 octets. With picture message and screen saver, the entire 72 x 28 size bitmap takes 18 x 28 = 504 semi-octets = 252 octets. For example, if the first four pixels of the image are 1010 (1 - black, 0 - white), the first semi-octet of the OTA bitmap data is hex A.
Example
Here is an example of a simple OTA bitmap (72 x 14 pixels). In the picture, there are two black lines and several black dots:
FFFFFFFFFFFFFFFFFF <- First line black000000000000000000 <- Second line white
FFFFFFFFFFFFFFFFFF
000000000000000000
10F000000000000000 <- Fourth pixel of this line is black and 9-12
000000000000000000 pixels are also black
000000000000000000
000000000000000000
000000000000000000
000000000000000000
000000000000000000
000000000000000000
000000000000000000
000000000000000001 <- Last pixel of this row/bitmap is black
More information
- A2 - Operator logo I
- A3 - Operator logo II
- A4 - Ringtone
- A5 - Wappush
- A6 - VCalendar
- Appendix "A7" - Message types - VCard
- A8 - Barcode
- B - Service providers
- C - SMSC numbers
- D - GSM Operators
- E - SMS alphabet
- Appendix "F" - GSM error codes
- G - Conn strings
- H - References
- I - MMSC information
- Frequently asked questions
- K - SMS Format