On Fri, 26 Jul 2013 14:41:02 -0700 (PDT),
wrote:

I have a customer who has an office with five rooms.
He would like me to install a video camera at the
front door and then be able to see who walks into
the office lobby on his computer. The individual
rooms' computers are not networked but he does
have WIFI. He says he thinks that there is a way
to put the video signal over the WIFI so that everyone
in the office with a computer who is logged on
to that WIFI will be able to see the camera signal
on their computer. Is there a way to do this?
Thanks, Lenny

The video is going to saturate the wi-fi to the point where the wi-fi
will be useless. Even one camera belching uncompressed video will do
that. The only way you're going to get it installed without
complaints is to run the necessary wires. You might be able to do it
using a dual band router, with the cameras on one band, and the users
on the other, but even that is problematic due to interference from
other offices. My worse wi-fi systems are in glass wall buildings,
looking out over the city or at other glass wall buildings, and seeing
hundreds of wi-fi routers.

If you want to do it cheaply, there are kits of cameras and camera
server available. I kinda like Swann:
http://www.swann.com/region/usa/entry/us
because they're commonly available and cheap. Not the best, not
great, just available and cheap. Since this is a repair newsgroup, I
suggest you buy a replacement fan for the camera server in advance. It
will blow in about 6 months, and continue to blow every 6 months.

For running wires, I use CAT5, not coax cable.
http://www.ebay.com/itm/220994815246
One pair for video, one pair for power, and 2 cameras per cable. About
150 ft maximum.

However, if you want to actually identify someone on the video, forget
about composite video cameras. They're too fuzzy and lack resolution.
For that, you'll need an IP camera. CAT5 wiring, with one camera per
cable.

If all the networked PC's need to view the video, you will find that
the composite video camera servers allow exactly one connection per
user. There are various ways to get the camera monitor image onto a
PC via the network, none of which are stock and all of which are
messy. I don't want to go there now.

Besides clarity, the other advantage of IP cameras is that network
users can login to the camera directly. There's usually an ugly and
buggy ActiveX control, that only works with Internet Exploder, for
logging into and controlling a camera from a PC. That will give you
the local viewing. Most IP cameras allow more than one user to login.
I don't recall if there's an upper limit. However, if you want one
person to view more than one camera at a time, or worse, control more
than one camera at a time, then you'll need an IP camera server and a
PC.
http://www.ispyconnect.com
http://www.zoneminder.com
With a camera server, anyone on the network that connects to the
camera server can see (and control) all the cameras.

Hint: Don't use wi-fi for devices that don't move.

Good luck.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558