At 07:56 p.m. 17/07/2009, you wrote:
Were doing a lot of in
building Multi-Dwelling installations, most
are based on Ethernet, but some buildings it is
not cost effective to deploy UTP and the copper
is already in place, so DSLAMs become the best option.
Good luck. At my previous job we gave up on
apartments. Where we had our own UTP it was
madness. Contractors for the incumbent stole
pairs or even sheaths with wild disregard of
ownership. The clients have a reluctance to pay and frequently do a runner.
Make sure you have a fella called "Big Ted" who
is a cross between King Kong and Wurzel Gumidge,
wears a tool belt with bloody big side cutters
and picks his teeth with a screwdriver. He visits
clients frequently and in his limited vocabulary
says, "you gonna pay ?". They do.
In between client visits, Big Ted "educates"
installation contractors on "the rules" about
using other folks cables and gives them "First
Aid" lessons. Based on my experience with
electricity in apartments, and a guy called Ted
Grace. He taught me how to be a linesman.
If anyone has any other ideas (apart from
Powerline Communications just not interested).
Well I have powerline that has been working
fine since 1977, but it only signals at 1bps and
does require a 10KW amplifier injecting at 33KV.
Its called ripple control. Turns the street
lights on pretty reliably in Wellington. The amp
sounds like a locomotive when its running and does rather dim the lights.
I use Planet and MicroNet gear in our OB stuff.
Its VDSL 1.0 and gives us 20Mbps symmetric for
1KM. We tend to use it point to point and not
with big DSLAMs. It works on audio way-lines in
stadiums, museums etc, wet string in old
buildings and is pretty useful. Its also good in
newer buildings where you have over 25 floor to
traverse (allow 4 m per floor). We dropped a
cable down 25+ floors the other day with a total run of 250m. No issues at all.
Both Planet and Micronet make multi-way switches
with it, but we don't have that need yet. It just
works and has been great for us.
We do have some modern powerline stuff and it
does work in high rise buildings, but you need to
understand how higher (than 50Hz) propagates on
the mains network. Its great in corporates where
you aren't allowed to run any cables thru the
office, but you need to avoid any coils such as
found in meters, CTs, etc. so would be crap in a
multi-dwelling building. Ripple and DC inject
work a treat tho, and reverse signalling at 100
to 300KHz is also very good. Lower freqs go thru
transformers fine. LEB used to read meters that way.