SONET and SDH and PDH

SONET = Synchronous Optical NETwork : Bellcore proposal

SDH = Synchronous Digital Hierarchy : UIT/ITU/CCITT Recommendations G.707, G.708 and G.709

PDH = Plesiochronous Digital Hierarchy : UIT/ITU/CCITT Recommendations G.702, G.740 and G.750

PDH : Plesiochronous Digital Hierarchy
North American			European
Tx or DSx Digital Signal	Line rate	Capacity	Ex or CEPTx Digital Signal	Line rate	Capacity
DS0	64 kb/s	voice 4 kHz = 64 kb/s	CEPT 0	64 kb/s	1 x 64 kb/s
T1 or DS1	1,544 Mb/s	24 x DS0s	E1 or CEPT 1	2,048 Mb/s	30 x CEPT 0
T2 or DS2	6,312 Mb/s	4 x DS1s = 96 x DS0s	E2 or CEPT 2	8,448 Mb/s	120 x CEPT 0
T3 or DS3	44,736 Mb/s	7 x DS2s = 28 x DS1s	E3 or CEPT 3	34,368 Mb/s	480 x CEPT 0
	139,264 Mb/s	3 x DS3s = 21 x DS2s	E4 or CEPT 4	139,264 Mb/s	1 920 x CEPT 0
	274 Mb/s	6 x DS3s	CEPT 5	564,992 Mb/s	7 680 x CEPT 0

PCM = Pulse Code Modulation or MIC in French = Modulation par impulsion et Codage

CEPT-1 (E1) = 32 x 64 kbs channels, with 2 channels for Signalization

Virtual Tributary = VTs
Type	Transport for	Typically	VT rate
VT1.5	1 x DS1	1,544 Mb/s	1,728 Mb/s
VT2	1 x CEPT1	2,048 Mb/sb/s	2,048 Mb/s

SDH Virtual container size
Virtual container	Container capacity	PDH services supported
VC-11	1,7 Mb/s	1,544 Mb/s Noth American channel rate
VC-12	2,3 Mb/s	2,048 Mb/s European channel rate
VC-2	6,8 Mb/s	6,312 Mb/s channels (rarely used)
VC-3	50 Mb/s	34,368 Mb/s and 44,736 Mb/s channels
VC-4	150 Mb/s	139,268 Mb/s channels and other hight bit-rate services

SONET and SDH
SDH	SONET
CCITT Synchronous Transfert Mode (STM)	Optical Carrier Level (OC)	Electrical Signal Synchronous Transport Signal (STS)	Line rate (Mb/s)	Payload
	OC-1	STS-1	51,84 Mb/s	49,5 = 1 x DS3 or = 28 DS1 in form of VT1 or = 21 CEPT-1 in form of VT2
	OC-3	STS-3	155,52 Mb/s	3 x 49,5 Mb/s
STM-1	OC-3c	STS-3c	155,52 Mb/s	155 Mb/s : 672 x DS-0s
	OC-6	STS-6	311,04 Mb/s	...
	OC-9		466,56 Mb/s	...
STM-4	OC-12	STS-12	622,08 Mb/s	601,344 Mb/s : 8 064 x DS-0s
	OC-18		933,12 Mb/s	...
	OC-24	STS-24	1 244,16 Mb/s	...
	OC-36		1 866,24 Mb/s	...
STM-16	OC-48	STS-48	2 488,32 Mb/s	2 405,376 Mb/s : 32 256 x DS-0s
STM-64	OC-192	STS-192	9 953,28 Mb/s	...

STS-N = N x 51,84 Mb/s = N x STS-1

STM-N = N x 155,52 Mb/s = N x STM-1

Optical Wavelenght (ITU G.mcs)

Optic channel Wavelenght (nm)

23 1 558,98

25 1 557,36

27 1 555,75

29 1 554,13

31 1 552,52

33 1 550,92

35 1 549,32

37 1 547,72

43 1 542,94

45 1 541,35

47 1 539,77

49 1 538,19

51 1 536,61

55 1 533,47

57 1 531,90

Optical Wavelenght (ITU G.mcs)
Optic channel	Wavelenght (nm)
23	1 558,98
25	1 557,36
27	1 555,75
29	1 554,13
31	1 552,52
33	1 550,92
35	1 549,32
37	1 547,72
43	1 542,94
45	1 541,35
47	1 539,77
49	1 538,19
51	1 536,61
55	1 533,47
57	1 531,90