Monday, January 30, 2012

All About Dense Wave Division Multiplexing (DWDM)


The Dense Wave Multiplexing DWDM channel or light wavelength matrix (please see chart below) has brought tremendous benefit to the metropolitan and long haul data transmission world.
Bandwidth hungry applications are requiring more information over the same transport infrastructure with the explosive growth of the internet.  With CWDM and DWDM Optics, the carrying capacity of the physical medium (fiber)  is increased because  each  DWDM/CWDM channel is transmitted at a different frequency.  Many engineers refer to this as the ‘rainbow’ of light, where each channels represents a color of light available within or over the medium (fiber).
DWDM also has the ability to amplify all the wavelengths at the same moment, without first having to convert them to electrical signals, as well as the ability to carry signals of different speeds and types simultaneously over the medium (fiber).  This is called protocol and bit rate independence.
DWDM is a big winner in the Metropolitan backbone.  It is fast and flexible in the provisioning of protocol- and bit rate-transparent, data centric, protected services, and has the ability to offer new and higher speed services at less cost.
The key requirements for DWDM systems in the Metropolitan area include:  Multi-protocol support, cost effectiveness, reliability and availability, openness (interfaces, network management, standard fiber types, electromagnetic compatibility, ease of installation and management, size and power consumption, and scalability.
Overall, the technical advantages to DWDM (Bandwidth Aside) are: DYNAMIC PROVISIONING (Provides engineers the ability to provision in days, not months, because of its fast and simple connections), SCALABILITY (DWDM leverages the available dark fiber to  meet the demand for capacity on point to point links and existing SONET/SDH rings), and TRANSPARANCY (It can transparently support TDM and data formats such as Gigabit Ethernet, ATM, ESCON, and fiber channel wit open interfaces over a common physical layer.
DWDM enables a large savings on regenerators (RPTR) and amplifier infrastructure compared to the typical SONET/SDH optical networks, greatly reducing up front infrastructure cost barriers.   Besides the lowered infrastructure cost benefit, the DWDM systems have simplified the of network capacity by problem in many ways.

Dense Wavelength Division Multiplexing (DWDM)
ITU Grid: C-Band, 100 GHz Spacing
Channel
Frequency
Wavelength
http://www.fiberdyne.com/products/images/spacer.gif
Channel
Frequency
Wavelength
(#)
(GHz)
(nm)
(#)
(GHz)
(nm)
1
190100
1577.03
37
193700
1547.72
2
190200
1576.20
38
193800
1546.92
3
190300
1575.37
39
193900
1546.12
4
190400
1574.54
40
194000
1545.32
5
190500
1573.71
41
194100
1544.53
6
190600
1572.89
42
194200
1543.73
7
190700
1572.06
43
194300
1542.94
8
190800
1571.24
44
194400
1542.14
9
190900
1570.42
45
194500
1541.35
10
191000
1569.59
46
194600
1540.56
11
191100
1568.11
47
194700
1539.77
12
191200
1567.95
48
194800
1538.98
13
191300
1567.13
49
194900
1538.19
14
191400
1566.31
50
195000
1537.40
15
191500
1565.50
51
195100
1536.61
16
191600
1564.68
52
195200
1535.82
17
191700
1563.86
53
195300
1535.04
18
191800
1563.05
54
195400
1534.25
19
191900
1562.23
55
195500
1533.47
20
192000
1561.42
56
195600
1532.68
21
192100
1560.61
57
195700
1531.90
22
192200
1559.79
58
195800
1531.12
23
192300
1558.98
59
195900
1530.33
24
192400
1558.17
60
196000
1529.55
25
192500
1557.36
61
196100
1528.77
26
192600
1556.56
62
196200
1527.99
27
192700
1555.75
63
196300
1527.22
28
192800
1554.94
64
196400
1526.44
29
192900
1554.13
65
196500
1525.66
30
193000
1553.33
66
196600
1524.89
31
193100
1552.52
67
196700
1524.11
32
193200
1551.72
68
196800
1523.34
33
193300
1550.92
69
196900
1522.56
34
193400
1550.12
70
197000
1521.79
35
193500
1549.32
71
197100
1521.02
36
193600
1548.52
72
197200
1520.25
Note:
for 200GHz spacing use either odd or even numbered channels.

No comments:

Post a Comment