Dear 802.3cg,
In industrial building Profibus type cable is deployed but some
other types of cable are present in those structures.
Today, in most of them we also find single twisted pair cables
(screened or unscreened) cabling for telecommunication purposes
particularly for TDM (Time Division Multiplexing) telephonic
systems.
The typical application is to transport Voice and Signalling
messages between devices.
This cabling system is provided at a low cost and lot of cabling installers are well aware of its specifications.
Having Ethernet over the existing wiring system in the buildings
will provide a solution to migrate traditional TDM equipments
towards the IP world. While keeping the current cabling the
solution becomes cost effective : it requires only changing
devices (i.e. VoIP phone sets instead of TDM ones). The solution
needs only minor investments (put in place some Ethernet switches)
but no civil engineering is required to deploy specific Ethernet
cables (e.g. Category 5 or Category 6). De facto, this optimizes
the overall cost of the IP infrastructure.
The single twisted pair cable is similar to AWG 22, corresponding roughly to Æ 0,6 mm copper or AWG 24 corresponding roughly to Æ 0,5 mm copper.
The cable characteristics are :
-80-135 Ohms at 700 kHz with a 25dB max attenuation between 340
and 680 kHz.
-types : SYT0.5 & SYT0.6 or 278 or ITT 26626 BBEB DEBE or
TsR-R depending on the country with a range between 800m and 1200m
The decreasing loss with a constant of 15dB per decade of
frequency and a 44dB loss at 700 kHz (90% level of confidence).
An artificial line equivalent to 900m of LY0.5 cable (Æ 0,5 mm
copper) could be as follow:
We are wondering if the 802.3cg group could have some interests for consideration in standardization of Ethernet (10Mb/s ?) on this type of cable.
Feel free to comment and thank you for your feedback.
Regards,
P. Mourot