Signal124

Binary data to GSM 7-bit transfer

Signal124 is a method focusing to transfer binary data in obsolete communication in the most effective way. Ideal for streaming short binary strings to the network. It is effective because 124 GSM accepted chars were used instead of other Base distributions.

The current algorithm has been written for the most usable way for obsolete communication. For minifying data is recommended to use a compressor before encoding.

Alphabet

Signal124 needs 124 characters to represent the encoded binary data in ASCII.

From the 128 GSM 03.38 characters, the following three ones have been omitted:

Char	Explanation	Verdict
LF	a Line Feed control	excluded
ESC	an Escape control	excluded

Strings with special meaning:

Char	Explanation	Verdict
SP	a Space character; indicate the use of the encoding	excluded
CR	a Carriage Return control; used as a delimiter between messages	excluded

The translation table is composed of following characters:

№	Symbol	№	Symbol	№	Symbol	№	Symbol	№	Symbol	№	Symbol	№	Symbol	№	Symbol
0	@	14	Δ	✕	SP	44	0	60	¡	76	P	92	¿	108	p
1	£	15	_	29	!	45	1	61	A	77	Q	93	a	109	q
2	$	16	Φ	30	"	46	2	62	B	78	R	94	b	110	r
3	¥	17	Γ	31	#	47	3	63	C	79	S	95	c	111	s
4	è	18	Λ	32	¤	48	4	64	D	80	T	96	d	112	t
5	é	19	Ω	33	%	49	5	65	E	81	U	97	e	113	u
6	ù	20	Π	34	&	50	6	66	F	82	V	98	f	114	v
7	ì	21	Ψ	35	'	51	7	67	G	83	W	99	g	115	w
8	ò	22	Σ	36	(	52	8	68	H	84	X	100	h	116	x
9	Ç	23	Θ	37	)	53	9	69	I	85	Y	101	i	117	y
✕	LF	24	Ξ	38	*	54	:	70	J	86	Z	102	j	118	z
10	Ø	✕	ESC	39	+	55	;	71	K	87	Ä	103	k	119	ä
11	ø	25	Æ	40	,	56	<	72	L	88	Ö	104	l	120	ö
✕	CR	26	æ	41	-	57	=	73	M	89	Ñ	105	m	121	ñ
12	Å	27	ß	42	.	58	>	74	N	90	Ü	106	n	122	ü
13	å	28	É	43	/	59	?	75	O	91	§	107	o	123	à

Example of transaction

Encoded:

 tØàù;Θf£&0ì8E(Å
J#c+§ΦèCØå
CΩÄ+'6¿£/ù

• a Space character indicates the encoding is used (optional)
• a Carriage return is a delimiter for next data

Decoded:

space - encoding signal124

Hell-o World
John Doe
signal01

Distributions

• Go
• PHP

Project

Please, feel free to contribute to this project to improve it and integrate it into use cases.

You can raise issue or send pull request.

Compression

Consider using lossless compression before transferring and streaming your data. Probably you want to achieve a compromise between fast encoding and data size.

Examples of lossless compression libraries:

• Brotli - allows a denser packing than gzip and deflate
• LZ4 - compression and decompression speed
• Snappy - aims for very high speeds and reasonable compression

License

CORE License