Cabletron Systems MicroMMAC 24T MICROMMAC- - Manual (Page 23)

REQUIREMENTS/SPECIFICATIONS
2-4
2.1.2 STP Cable Specifications
MicroMMACs 42T and 44T and TPIMs T1 and T4 support IBM Type 1,
2, 6, and 9 STP cabling as described below:
• IBM Type 1: Two STP lengths of 22 AWG solid wire for data. Used
for the longest cable runs within building walls of buildings.
• IBM Type 2: Similar to Type 1 data cable, but having four additional
UTP lengths of 22 AWG solid wire carried outside of the shield casing.
Typically used for voice communication and often used to wire cable
runs within the walls of buildings.
• IBM Type 6: Two STP lengths of 26 AWG stranded wire for data.
Used in patch panels or to connect devices to/from wall jacks.
Attenuation for Type 6 cable is 3/2 x Type 1 cable (66 m of Type 6
=100 meters of Type 1).
• IBM Type 9: Similar to Type 1, but uses 26 AWG solid wire.
Attenuation for Type 9 cable is 3/2 x Type 1 cable (66 m of Type 9
= 100 meters of Type 1).
Attenuation and Impedance
The attenuation values shown in Table 2-3 include the attenuation of the
cables, connectors, patch panels, and reflection losses due to impedance
mismatches in the segment
.
Maximum Lobe Lengths
The lobe length is the physical length of the cable connecting a station to
its TCU port at the MicroMMAC-T. Table 2-4 lists the maximum lobe
Table 2-3. STP Cable Specifications
Types Frequency Impedance Attenuation
1 & 2 4 MHz
16 MHz
150
Ω
+ 15%
150
Ω
+ 15%
<22 dB/km (6.7 db/1000 ft.)
<45 dB/km (13.7 db/1000 ft.)
6 & 9 4 MHz
16 MHz
150
Ω
+ 15%
150
Ω
+ 15%
<33 dB/km (10 db/1000 ft.)
<66 dB/km (20 db/1000 ft.)