Results 1. Emergence

Following are the types of cabling, Category 1 though Category 7, often referred to as Cat 1 through Cat 7. The standard TIA/EIA 568A no longer recognizes Cat 1, 2, or 4. As of July 2000, the FCC man-dated the use of cable no less than Cat 3 for home wiring. The naming convention specified by ISO/

IEC 11801 is shown in Figure 6.3.

Table 6.16 gives the equivalent TIA and ISO classifications for structured cabling.

Category 1. Meets the minimum requirements for analog voice or plain old telephone service (POTS). This category is not part of the EIA/TIA 568 standard.

Category 2. Defined as the IBM Type 3 cabling system. IBM Type 3 components were designed as a higher grade 100  UTP system capable of operating 1 Mb/s Token Ring, 5250, and 3270 applica-tions over shortened distances. This category is not part of the EIA/TIA 568 standard.

Category 3. Characterized to 16 MHz and supports applications up to 10 Mbps. Cat 3 conductors are 24 AWG. Applications range from voice to 10Base-T.

Category 4. Characterized to 20 MHz and supports applications up to 16 Mb/s. Cat 4 conductors are 24 AWG. Applications range from voice to 16 Mbps Token Ring. This category is no longer part of the EIA/TIA 568 standard.

XX/XXX

TP = twisted pair U = unshielded F = foil shielded F = foil shielded S = braid shielded SF = braid and foil shielded Balanced element

Element shield Overall shielding

fIGure 6.3

ISO/IEC 11801 cable naming convention.

TIA and ISO Equivalent Classifications Frequency

bandwidth TIA ISO

Components Cabling Components Cabling

1–100 MHz Cat 5e Cat 5e Cat 5e Class D

1–250 MHz Cat 6 Cat 6 Cat 6 Class E

1–500 MHz Cat 6a Cat 6a Cat 6a Class EA

1–600 MHz n/s n/s Cat 7 Class F

1–1000 MHz n/s n/s Cat 7A Class F_A

Table 6.16 Table 6.16

167 Category 5. Characterized to 100 MHz and supports applications up to 100 Mbps. Cat 5

conduc-tors are 24 AWG. Applications range from voice to 100 Base-T. This category is no longer part of the EIA/TIA 568 standard.

Category 5e. Characterized to 100 MHz and supports applications up to 1000 Mbps/1 Gbps. Cat 5e conductors are 24 AWG. Applications range from voice to 1000Base-T. Cat 5e is specified under the TIA standard ANSI/TIA/EIA-568-B.2. Class D is specified under ISO standard ISO/IEC 11801, 2nd Ed.

Category 6. Characterized to 250 MHz, in some versions bandwidth is extended to 600 MHz, and supports 1000 Mbps/1 Gbps and future applications and is backward compatible with Cat 5 cabling systems. Cat 6 conductors are 23 AWG. This gives improvements in power handling, insertion loss, and high-frequency attenuation. Figure 6.4 shows the improvements of Cat 6 over Cat 5e. Cat 6 is specified under the TIA standard ANSI/TIA/EIA-568-B.2-1. Class E is specified under ISO standard ISO/IEC 11801, 2nd Ed. Cat 6 is available most commonly in the United States as UTP.

Category 6 F/UTP. Cat 6 F/UTP (foiled unshielded twisted pair) or ScTP (screened twisted pair) consists of four twisted pairs enclosed in a foil shield with a conductive material on one side. A drain wire runs adjacent to the conductive side of the shield, Figure 6.5. When appropriately con-nected, the shield reduces ANEXT, RFI, and EMI. Cat 6 FTP can only be designed to 250 MHz per TIA/EIA 568B.2-1.

Category 6a. Cat 6a (Augmented Category 6) is characterized to 500 MHz, and in special versions to 625 MHz, has lower insertion loss, and has more immunity to noise. Cat 6a is often larger than the other cables. 10GBase-T transmission uses digital signal processing (DSP) to cancel out some of the internal noise created by NEXT and FEXT between pairs. Cat 6a is specified under the TIA stand-ard ANSI/TIA/EIA 568-B.2-10. Class EA is specified under ISO standstand-ard ISO/IEC 11801, 2nd Ed.

Amendment 1. Cat 6a is available as UTP or FTP.

Category 7 S/STP. Cat 7 S/STP (foil shielded twisted pair) cable is sometimes called PiMF (pairs in metal foil). Shielded-twisted pair 10GBase-T cable dramatically reduces alien crosstalk. Shielding reduces electromagnetic interference (EMI) and radio-frequency interference (RFI). This is particu-larly important as the airways are getting more congested. The shield reduces signal leakage and makes it harder to tap by an outside source. Shield termination at 14.16 Class F will be specified under ISO standard ISO/IEC 11801, 2nd Ed. Class FA will be specified under ISO standard ISO/IEC 11801, 2nd Ed. Amendment 1.

Bandwidth Loss NEXT

2.5 2.0 1.5 1.0 0.5 0.0

Normalized value

Cat 5 Cat 6

fIGure 6.4

Normalized comparison of Cat 5e and Cat 6.

Drain wire

Cable jacket

Foil shield

Source: BICSI

fIGure 6.5 Cat 6 F/UTP.

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Comparisons

Table 6.17 compares network data rates for Cat 3 through Cat 6a and Table 6.18 compares various characteristics of Cat 5e, 6, and 6a. Figure 6.6 compares the media distance-bandwidth product of Cat 5e and Cat 6a with 802.11 (a, b, g, n) wireless media, often called Wi-Fi.

New cable designs can affect size and pathway load so consult the manufacturer. Note that cable density is continually changing with newer, smaller cable designs. Numbers in Table 6.18 should be considered worst case. Designers and installers of larger systems should get specific dimensional infor-mation from the manufacturer.

Network Data Rates, Supporting Cable Types, and Distance

Minimum Performance Token Ring Ethernet Maximum Distance

Cat 3 4 Mb/s 10 Mbps 100 m/328 ft

Cat 4 16 Mb/s – 100 m/328 ft

Cat 5 – 100 Mbps 100 m/328 ft

Cat 5e 1000 Mbps 100 m/328 ft

Cat 6 – 10 Gbps 55 m/180 ft

Cat 6a 10 Gbps 100 m/328 ft

Table 6.17 Table 6.17

Characteristics of Cat 5e, Cat 6, and Cat 6a

Cabling Type Cat 5e Cat 6 Cat 6a

Relative Price (%) 100 135–150 165–180

Available Bandwidth 100 MHz 250 MHz 500 MHz

Data Rate Capability 1.2 Gbps 2.4 Gbps 10 Gbps

Noise Reduction 1.0 0.5 0.3

Broadband Video Channels 6 MHz/channel 17 42 83

Broadband Video Channels rebroadcast

existing channels 6 28 60

No. of Cables in Pathway 24 inches  4 inches 1400 1000 700 Table 6.18

Table 6.18

100,000 10,000 1000 100 10 1

Mbits/s

Cat 6

Transmission media

Cat 5e 802.11b 802.11n

802.11g fIGure 6.6

Comparison of media distance to bandwidth.

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Figure 6.7 shows various problems that can be found in UTP cabling. Figure 6.8 gives the maximum distances for UTP cabling as specified by ANSI/TIA.

Four (4) pair 100   15% UTP Cat 5e cabling is the recommended minimum requirement for resi-dential and light commercial installations because it provides excellent flexibility. Pair counts are four pair for desktop and 25 pair for backbone cabling. The maximum length of cable is 295 ft (90 m) with another 33 ft (10 m) for patch cords.

Unshielded twisted pairs (UTP) and shielded twisted pairs (STP) are used for structured cabling.

Unshielded twisted pairs (UTP) are the most common today. These cables look like the POTS cable, however their construction makes them usable in noisy areas and at high frequencies because of the short even twisting of the two wires in each pair. The twist must be even and tight so complete noise cancellation occurs along the entire length of the cable. To best keep the twist tight and even, better cable has the two wires bonded together so they will not separate when bent or flexed. Patch cable is flexible so twist and impedance are not as well controlled. The color codes for the pairs are given in Table 6.19.

Cable diameter varies for the different types of cable. TIA recommends that two Cat 6 cables but only one Cat 6a cable can be put in a ¾ inch (21 mm) conduit at 40% fill. The diameter and the stiff-ness of the cables determine their bend radius and therefore the bend radius of conduits and trays, Table 6.20.

Figure 6.9 shows the construction of UTP and screened UTP cable.

Reversed pair

500 m/1650 ft 300 m/1000 ft area

Jumper/patch cords:

Maximum distances between areas for UTP cable.

Color Code for UTP Cable

Pair No. 1st Conductor Base/Band 2nd Conductor

1 White/Blue Blue

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