Wi-Fi Problem

> [...] The router is in one downstairs room, [...]

   With my weak psychic powers, "the router" is not a very useful
description of anything.

> [...] I couldn't find a Wi-Fi unit with an ethernet input, [...]

   Where did you look for what?  Practically any wireless router can be
configured as a wireless access point, which seems to be what you want.
There also exist purpose-built WAPs.

> 1. Use the Cat5e cable and plug it into a Wi-Fi broadcast unit (they
> surely must exist?), [...]

   Wireless access point.

> [...] and then put a USB Network adapter into the Sky box.

   I know nothing about your (unspecified) "the Sky box", but, before I
tried that, I would look for documentation which says that you can use
any kind of "USB Network adapter" (wireless?) with it.

> 2. Use the Cat5e cable and plug it into a W-Fi broadcast unit that has
> an ethernet pass-through or an ethernet output. Do they exist?

   Wireless access point.

> 3. Interrupt the DSL router feed with a modem, have one output going
> to the existing router, and then add a second router in the dead zone.

   You lost me. How does this (unspecified) "the DSL router" compare
with your (unspecified) "the router" or your (unspecified) "the existing
router"?

   It sounds as if you might want to connect two routers to one modem,
which wouldn't work.

   "solution" 2 sounds plausible.  All you'd need would be a wireless
access point (or a wireless router which is configured as a WAP).

   Being conservative, I'd try to find some cheap/used router in a local
thrift/junk store or friend's junk pile, configure it as a WAP, and run
the experiment.  Then, if the proof-of-concept works, but better
performance is needed, look for something better to use as a WAP.

   General info: Terms like "input" and "output" don't really apply to
this kind of networking; all the paths and ports are bidirectional.

   For practically any reasonably recent Netgear Rxxxx model, visit
http://netgear.com/support , put in the model number, and look for
Documentation.  Get the User Manual (at least).  Read.  Look for a topic
like "Use the Router as a WiFi Access Point Only" or simply "access
point".  For other makers' stuff, check the appropriate docs.  There
also exist general guides for router-as-WAP, such as:

      https://community.netgear.com/t5/x/x/m-p/1463500

That's written for a Netgear C6300-as-WAP, but the steps are about the
same for any other router (any make/model) which lacks a one-step WAP
option.  If the router which you're reconfiguring has a WAN/Internet
Ethernet port (unlike a Cxxxx), then leave it unconnected.

---

MagicFriend wrote:

Now, Sky have been out because this dead zone has some of their equipment. They have run a Cat5e cable directly from the router to their TV box in the dead zone. I was about to run some Cat6a cable alongside it, but firstly I couldn't find a Wi-Fi unit with an ethernet input, and secondly I thought that I would speak to you guys first and ask for help.

 

You should not need to run an Ethernet cable alongside Sky's Cat5e cable if it is simply an Ethernet cable feeding from a router into an Ethernet port on the TV box. You can just interrupt the existing cable, insert a cheap switch and plug the TV into that. You can then plug an wireless extender into another outlet port on the switch and use it in wireless access point (AP) mode.

These are dead cheap:

Gigabit Unmanaged Switch Series - GS105 | NETGEAR

Less then £20 in the UK. Other brands could be even cheaper.

Just about any "wifi extender" – what you call a "Wi-Fi broadcast unit" – should plug into that and provide wifi in what sounds like a small area. Again, you can pick up a Netgear device for <£30, possibly even less for other brands and no-name knock offs.

I am surprised that you could not find "a Wi-Fi unit with an ethernet input". Amazon lists them by the shelf load. (Buy from your preferred seller.) Search for "WiFi Repeater" and pick something that claims to work in AP mode. Most do.