Draft Category 6 cable requirements

 

As a support to manufacturers who want to develop cables for the coming Category 6 standard, European Cabling group has made this set of specifications, which we consider to be very close to the coming standards. This current specification is based on ISO/IEC JTC 1/SC 25/WG3 N552, dated 1999-03-02. Our goal is that our specifications are equal to the first draft standard.

If you have to modify your test set-up when measuring cables above 100 MHz, please see DELTA's Technical Note No. 2 of March 1996, which describes test of data cables for extended frequency ranges. The note can be found on our website - Technical notes and reports.

Specifications for 250 MHz horizontal cables.

Table 6.1 Attenuation and crosstalk

Frequency
[MHz]
Attenuation
[dB/100m]
Pair-pair NEXT
[dB]
Power sum NEXT
[dB]
1
2
3
4
8
10
16
20
25
31.25
62.5
100
125
155.52
175
200
250
2.0
2.7
3.3
3.8
5.4
6.0
7.6
8.5
9.6
10.7
15.5
19.9
22.5
25.4
27.1
29.2
33.0
74.3
69.8
67.1
65.3
60.8
59.3
56.2
54.8
53.3
51.9
47.4
44.3
42.8
41.4
40.7
39.8
38.3
72.3
67.8
65.1
63.3
58.8
57.3
54.2
52.8
51.3
49.9
45.4
42.3
40.8
39.4
38.7
37.8
36.3

 

Table 6.2 Characteristic impedance

Frequency
[MHz]
Characteristic impedance
[ohm]
1-100
100 ±15
100-200
100±(15+0.05(f-100)), f: frequency in MHz

 

The same tolerances apply for 120 ohm cables.

 

Table 6.3 ELFEXT, LCL and return loss


Frequency
MHz
ELFEXT (pp)
[dB]
ELFEXT (ps)
[dB]
LCL
[dB]
Return Loss
[dB)
1.0
2.0
3.0
4.0
8.0
10.0
16.0
20.0
25.0
31.3
62.5
100.0
125.0
155.5
175.0
200.0
250.0
67.8
61.7
58.2
55.7
49.7
47.8
43.7
41.7
39.8
37.9
31.8
27.8
25.8
23.9
22.9
21.7
19.8
64.8
58.7
55.2
52.7
46.7
44.8
40.7
38.7
36.8
34.9
28.8
24.8
22.8
20.9
19.9
18.7
16.8
48.0
45.0
43.2
42.0
39.0
38.0
36.0
35.0
34.0
33.1
30.0
28.0
27.0
26.1
25.6
25.0
24.0





use impedance

 

Table 6.4 Balance, screening, coupling attenuation, skew, and DC loop.

Electrical characteristic
Cable type
Frequency
[MHz]
Requirement
Transfer impedance
Screened
10
<71 mohm/m
Coupling attenuation
Unscreened
30 - 200
>45 dB
Coupling attenuation
Screened
30 -200
>60 dB
Skew
All
100
<40 nS/100 m
DC loop resistance
All
DC
<40 ohm

 

All other characteristics according to Category 5 requirements in ISO/IEC 11801:95.

Rationale for the requirements for horizontal cables according to 250 MHz specification:

Table 6.1 Values according to ISO/IEC JTC 1//SC 25/WG3 N535.
Table 6.2 Tolerances as for Category 5, but with a little relaxation from 100 - 200 MHz
Table 6.3 Values according to ISO/IEC JTC 1//SC 25/WG3 N535, LCL from Tokyo 39.
Table 6.4 Transfer impedance requirement extended to 30 MHz. Coupling attenuation requirements based on initial experience at DELTA. Skew derived from channel requirements in draft addendum 2 to ISO/IEC 11801.