Siemens MC55 manual 2 UCS2 and GSM data coding and conversion for SMS text mode, Cscs, Gsm

MC55 AT Command Set

1.5 Supported character sets

s

mobile

In the event that an MS receives a code where a symbol is not represented in figure Extension character table of GSM 03.38 alphabet the MS shall display the character shown in the main default 7 bit alphabet table (see figure Main character table of GSM 03.38 alphabet).

1.5.2UCS2 and GSM data coding and conversion for SMS text mode

This chapter provides basic information on how to handle input and output character conversion for SMS text mode and Remote-SAT if internal (ME) and external (TE) character representation differ, i.e. if the Data Coding Scheme and the TE character use different coding.

1.5.2.1 Implementing output of SIM data to the TE (direction ME to TE)

dcs	7-Bit	8-Bit	16-Bit
CSCS	(GSM default)		(UCS2)
GSM	Case 1	Case 2	Case 3
	GSM (1:1)	IRA (1:1)	IRA (2:2)
UCS2	Case 4	Case 5	Case 6
	GSM to UCS2 (1:2)	GSM to UCS2 (1:2)	IRA (2:2)

Case 1

Every byte will be sent as GSM character (or ASCII with Hyperterminal).

Example: 0x41,0x21 ￿ "AB" (because of conversion from 7-bit to 8-bit)

Case 2

Every byte will be sent as IRA. No conversion.

Example: 0x41,0x42 ￿ "4142"

Case 3

Every byte will be sent as IRA. No conversion to GSM to avoid data loss.

Example: 0x00,0x41 ￿ "0041"

Problems:

•0x41,0x42 ￿ "4142" (invalid GSM character, but ignored with respect to GSM 07.05)

•0x41 ￿ Error (there are two bytes needed)

Case 4

Every byte will be converted from GSM to UCS2.

Example: 0x41,0x42 ￿ "00410042"

Case 5

Every byte will be converted from GSM to UCS2.

Example: 0x41,0x42 ￿ "00410042"

Case 6

Example: 0x41,0x42 ￿ "4142" Problems:

• 0x41 ￿ Error (there are two bytes needed)

MC55_ATC_V01.05	Page 23 of 469	2/10/04
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