No 4G signal inside?

So, you have a weak 4G signal outside your property and no signal indoors?

What are your options? First, have you considered changing your mobile provider? that may be the simplest solution.
Otherwise, there are two methods of improving connectivity around the house.

Option 1) Boost 4G phone coverage inside

For this you will need a 4G mobile signal booster (£200 => an-awful-lot-more). There are many on the market and the only things to ensure are:

  1. The booster is compatible with your mobile provider's transmission frequency (vital). Versions have either single frequency receptors or cover multiple frequencies, the more, the higher the cost. A multi-frequency device is handy for visitors who may use a different provider than you.
  2. The external antenna is suitable for your location, chosen carefully between omnidirectional, multi-directional or directional.
  3. The internal antenna & booster combination is powerful enough to cover the area inside your house you wish to get reception.
  4. OFCOM have strict rules on the use of boosters - see here. Legal boosters must be designed to improve mobile phone coverage indoors only.
Broadband via this setup:

For broadband through this connection you need to purchase any LTE SIM modem, ranging from £20 to £(many hundreds). Unlike Option 2, any cheap modem will do. This can be placed anywhere within the umbrella of your in-house 4G mobile signal. You then feed your 4G broadband around the house, or outside the house, just like land-line broadband, via WiFi or Ethernet or a combination.
You can even consider a cheap portable LTE modem that many find useful when travelling.

Option 2) Get 4G broadband inside (not mobile signal)

For this you will need a 4G broadband router (MiFi or LTE SIM modem) but beware, cheap ones may not allow you to attach an outdoor aerial. There's quite a choice from both mobile providers and big names in routers; Netgear, D-Link, TP-link etc.. Be wary of one from a mobile provider as this will (probable) lock you forever into their network. Independents usually offer more functions & flexibility but may be more complicated to set up. Things to consider :

  1. The modem is compatible with the frequency/frequencies your mobile provider transmits on from their neartest cell tower(s) (vital).
  2. You choose a model that allows for connection to an external antenna.
  3. The external antenna is suitable for your location, chosen carefully between omnidirectional, multi-directional or directional.

You then feed your 4G broadband around the house just like land-line broadband via WiFi, Ethernet or a combination.

Making phone calls via this setup:

4G phone calls will have to be via WiFi and, very important, your phone must be compatible with WiFiCalling (not all phones or phone packages are). Unfortunately, there's the added inconvenience that guests must also have a compatible phone/package and you will have to log into your WiFi using your password.
For this reason alone, I much prefer, and recommend, Option 1.

Lightning protection (from £15 upwards)

Any external aerial on Coll needs lightning protection.
Bad winters on Coll (remember 2014) can bring extensive lightning storms, a master at seeking the easiest route to earth, usually through your expensive booster/modem: IT WILL FRY.
The lightning arrester is fitted in the cable between the outside antenna and booster/modem and must be connected to a good quality earth, either through your electricity supply or a substantial copper rod in the soil outside, preferably damp soil.
Believe me on this one, I learnt the expensive way!

Lightning arrestor for 4G