As of 2017, more than
70 billion meters of Cat 5e
and Cat 6 cable has been
installed over the last 12 years.
October/November/December 2019 I 43
susceptibility of the affected systems in order to maintain
an acceptable level of interference. An acceptable level is
defined as an amount of steady-state or surge induced
longitudinal voltage or current that does not cause
a personnel or public safety hazard, damage to cable
or equipment, and/or circuit degradation or failure.”
While the document is intended more for communication
service providers (CSPs), the information is
applicable to LANs.
In 1991, IEEE standard 1137, Guide For The Implementation
of Inductive Coordination Mitigation Techniques and
Application, was published. In December 2018, it was also
updated along with its new title, Recommended Practice for
the Implementation of Inductive Coordination Mitigation
Techniques and Application.9 Its scope states that “This
recommended practice offers users assistance in controlling
or modifying the inductive environment and the
susceptibility of affected wire-line telecommunications
facilities in order to operate within the acceptable levels
of steady-state or surge-induced voltages of the environmental
interface (probe wire) defined by IEEE Std 776.”
IEEE 1137 discusses the application and operation of
an INT but not in a LAN environment.
It is important to note that the remaining standards
that are mentioned do not discuss the problems caused by
lower frequency induction and GPR; however, they are
helpful for the design and installation for the performance
and reliability of high-speed ICT wireline and
wireless networks that support IPTV and video streaming.
The TIA released Telecommunications Systems Bulletin
TSB-162-A on Telecommunications Cabling Guidelines for
Wireless Access Points10 about the time of the 2013 release
of IEEE 802.11ac11 for very high throughput Wi-Fi, com-
monly known as Wi-Fi 5. It basically recommends Cat
6A cabling to support WLANs, and it coincides with
information from ANSI/BICSI 008-2018, Wireless Local
Area Network Systems Design and Implementation
Best Practices.12
In January 2017, TIA issued TSB-5021, Guidelines for
the Use of Installed Category 5e and Category 6 Cabling to
Support 2.5GBASE-T and 5GBASE-T,13 that includes "visual
inspection procedures to predict the suitability and field
test guidelines to determine the suitability of such cabling
installations to support these applications, mitigation
techniques to improve cabling performance, and recommends
category 6A channels for new installations.”
In September 2018, ANSI/TIA-568-C.2 Revision D,
Balanced Twisted-Pair Telecommunications Cabling and
Components was published.14 Similar to ANSI/TIA-1005,
Telecommunications Infrastructure Standard for Industrial
Premises,15 these standards include two-mode conversion
parameters that indicate balance: transverse conversion
loss (TCL) and transverse conversion transfer loss (TCTL).
TCL is mode conversion measured within a pair at the
same end, and it is measured by injecting a differentialmode
signal into a twisted pair and then measuring the
common-mode signal returned on that same twisted pair.
The smaller the common-mode signal returned, the better
the balance.
TCTL is mode conversion within a pair measured
at the opposite end, and it is measured by injecting
a differential-mode signal into a twisted pair and then
measuring the common-mode signal at the other end
of the link on that same twisted pair. Since the amount
of common-mode signal is length dependent, equalization
must be applied to take insertion loss into
account. Therefore, the more meaningful measure-
ment is equal level TCTL (ELTCTL). Similar to TCL,
the smaller the common-mode signal at the far end,
the better the balance. This sounds very similar to the
earlier discussion of how the CSP industry has traditionally
determined the longitudinal balance of its
twisted pairs!
Lastly, another standard worth mentioning is BICSI
G1-17, ICT Outside Plant Construction and Installation:
General Practices16 that provides valuable information
on cable sheath bonding and grounding for LAN cables
between buildings.