1Encode::GSM0338(3)    User Contributed Perl Documentation   Encode::GSM0338(3)
2
3
4

NAME

6       Encode::GSM0338 -- ETSI GSM 03.38 Encoding
7

SYNOPSIS

9         use Encode qw/encode decode/;
10         $gsm0338 = encode("gsm0338", $unicode); # loads Encode::GSM0338 implicitly
11         $unicode = decode("gsm0338", $gsm0338); # ditto
12

DESCRIPTION

14       GSM0338 is for GSM handsets. Though it shares alphanumerals with ASCII,
15       control character ranges and other parts are mapped very differently,
16       mainly to store Greek characters.  There are also escape sequences
17       (starting with 0x1B) to cover e.g. the Euro sign.
18
19       This was once handled by Encode::Bytes but because of all those unusual
20       specifications, Encode 2.20 has relocated the support to this module.
21
22       This module implements only GSM 7 bit Default Alphabet and GSM 7 bit
23       default alphabet extension table according to standard 3GPP TS 23.038
24       version 16. Therefore National Language Single Shift and National
25       Language Locking Shift are not implemented nor supported.
26
27   Septets
28       This modules operates with octets (like any other Encode module) and
29       not with packed septets (unlike other GSM standards). Therefore for
30       processing binary SMS or parts of GSM TPDU payload (3GPP TS 23.040) it
31       is needed to do conversion between octets and packed septets. For this
32       purpose perl's "pack" and "unpack" functions may be useful:
33
34         $bytes = substr(pack('(b*)*', unpack '(A7)*', unpack 'b*', $septets), 0, $num_of_septets);
35         $unicode = decode('GSM0338', $bytes);
36
37         $bytes = encode('GSM0338', $unicode);
38         $septets = pack 'b*', join '', map { substr $_, 0, 7 } unpack '(A8)*', unpack 'b*', $bytes;
39         $num_of_septets = length $bytes;
40
41       Please note that for correct decoding of packed septets it is required
42       to know number of septets packed in binary buffer as binary buffer is
43       always padded with zero bits and 7 zero bits represents character "@".
44       Number of septets is also stored in TPDU payload when dealing with 3GPP
45       TS 23.040.
46

BUGS

48       Encode::GSM0338 2.7 and older versions (part of Encode 3.06)
49       incorrectly handled zero bytes (character "@"). This was fixed in
50       Encode::GSM0338 version 2.8 (part of Encode 3.07).
51

SEE ALSO

53       3GPP TS 23.038 <https://www.3gpp.org/dynareport/23038.htm>
54
55       ETSI TS 123 038 V16.0.0 (2020-07)
56       <https://www.etsi.org/deliver/etsi_ts/123000_123099/123038/16.00.00_60/ts_123038v160000p.pdf>
57
58       Encode
59
60
61
62perl v5.34.0                      2021-10-10                Encode::GSM0338(3)
Impressum