Classifications for links and data cables
 pic_uninet.gif (1629 Byte)
Classifications for links
The Links are classified in different performance classes. These performance classes define the maximum usable bandwidth over the maximum usable length of the communication link on the basis of copper data cables.
Application classes Class A Class B Class C Class D Class E* Class F*
Maximum bandwith 100 kHz 1 MHz 16 MHz 100 MHz 200 MHz 600 MHz
cablekategorie
Cat. 3,
symmetrical cable		 2 km 200m 100m
Cat. 4,
symmetrical cable		 3 km 260 m 150 m      
Cat. 5,
symmetrical cable		 3 km 260 m 160 m 100 m
Cat. 6,
symmetrical cable		       100m    
Cat. 7,
symmetrical cable		 100 m
150 Ohm
symmetrical cable		 3 km 400 m 250 m 150 m    
*as of April 1998
Data cable categories

The international guidelines divide cables and connection hardware into categories. The American standards cover categories 1 to 5, the international standards cover 3,4 and 5 and the European standards cover 3 and 5 only. These current standards are still beeing worked out. Future issues of the standards will only specify categories 5, 6 and 7. The following table provides the applicable requirements of the various categories.
Cat. 3 4 5 6* 7*
Bandwidth [MHz] 16 20 100 200 600
Frequency
[MHz]
Attenuation NEXT
[dB/100m] [dB]
Attenuation NEXT
[dB/100m] [dB]
Attenuation NEXT
[dB/100m] [dB]
Attenuation NEXT
[dB/100m] [dB]
Attenuation NEXT
[dB/100m] [dB]
1
2.6 43
2.1 56
2.1 62
1.9 74.3
2 80
4
5.6 32
4.3 47
4.3 53
3.8 65.3
3.8 80
10
9.8 26
7.2 41
6.6 47
6.1 59.3
6 80
16
13.1 23
8.9 38
8.2 44
7.8 56.2
7.6 80
20
10.2 36
9.2 42
8.8 54.8
8.5 80
31.25
11.8 40
11.1 51.9
10.6 80
62.5
17.1 35
16.1 47.4
15 75.3
100
22.0 32
20.9 44.3
19 71.1
155
26.8 41.4
175        
25 67.3
200
30.9 39.8
300        
33 63.7
600
50 60
* not yet standardised; as of April 1998
Technical changes reserved
 
26.11.2002