The quick answer is: Tether your mobile phone (turn on the hotspot on your phone and use it as wifi) if you struggle with the signal as we often do then put your mobile phone near a window or skylight (keeping in mind the sun's strength).

But there may be a few things to consider…

This is a question I am often asked as full-time van lifer living in my campervan. I am an English bloke and I mostly travel in my campervan around Europe.

Back when I started in 2016 the answer to an internet connection was simple. The Three network offered free European data roaming. Now post Brexit things are a little different. 

I do use free public wifi when I can and download local maps from Google before embarking on a walking tour of a European city. Sometimes I will buy data roaming at 5 euros a day (usually when I am lost and hangry). 

If I am travelling in another country for more than 2 weeks then I buy a local sim with 4g signal and limited data, we can usually get one for under 20 euros a month on a pay as you go basis. I go for this as I find the unlimited data package too expensive for my budget. I have never had any problems using the phone as a hotspot with these sims.

One of the biggest benefits for me was that the internet was not tethered to a mobile phone, it really gave me my own campervan wifi, so I could connect multiple devices. (Very useful when you're working on a laptop and need the tablet. The mifi also allowed me to stay in semi remote spots, the coverage was good, it was portable, functioned easily and gave me 4g speed.

Those are the 2 options that I have used but there are many others. Here are some other options. They all have pros and cons and fit different budgets.

Starlink

Starlink is a satellite internet operated by SpaceX, providing satellite internet access coverage to 47 countries. (It also aims for a global mobile phone service after 2023).

At the time of writing it is 135 USD a month with a one time cost of 599 USD for portable hardware or 2,500 USD for in-motion hardware, satellite dish etc...

Pros: Almost world coverage. Your own motorhome wifi. Can connect multiple devices.

Cons: Expensive upfront costs, monthly rental and a satellite dish on the roof of your RV or campervan (some people don’t like the aesthetics of this).

https://www.starlink.com/rv

Tiekom (Spain). 

Tiekom is a telecom company for expats living in Spain. They offer an E-sim with unlimited internet in more than 140 countries. You rent (by the day) a worldwide router.

Pros: Connect up to 5 devices, pocket sized, worldwide coverage.

Cons: Ambiguous pricing.

https://tiekom.com/mobile/international/

Hippocket (France). 

Hippocket is a French network provider offering international coverage and data in France. It has mobile hotspot rental starting at 3.90 euros per day.

Pros: Clear pricing.

Cons: Roaming charges and no unlimited data outside France. 

https://hippocketwifi.com/en/

 Quick word reference.

Wifi -Wireless internet.

Mifi-Portable device acting as wireless internet.

Router-An electronic device that connects other devices to a network so they can talk to each other, usually connected to the internet as well.

Devices-Smart appliances that can connect to the internet.

Antenna-aternal mast that sends and  receives signals.

Network provider-Normally telephone companies that sell calls and internet, Data. 

Data roaming-Internet from your provider outside of the original country.

Signal strength-The strength of your connection to the device giving  you the internet.

Remote worker-A person that works away from company premises.

Overlander-A vehicle that has four wheel drive capability.

Campervan-A van made for living in.

Huawei-Manufacture of electronic devices.

Hot spot-A broadcast signal offering connection to the internet.

Tether-Connection to a device.

Conclusion

When I am in the UK I find my mobile network provider fits the bill perfectly. I also use public wifi when I am visiting a city or town.

I found the Huawei E5577 mifi very efficient whilst travelling around Europe. The wifi signal was good and it gave me our very own campervan wifi.

If you are living and travelling in the USA  then I would recommend a mobile cell service provider of your choice, free wifi, public wifi or Google Fi. https://fi.google.com/about/plans/

If you are planning to traverse continents in an overlander, RV, or campervan,  then Starlink for wifi signal strength and peace of mind seems a viable investment, especially if it is long term, you will have a satellite dish on your RV and unlimited data. https://www.starlink.com/rv

FAQ`s

How much is mifi? Around 74 USD, 64 Euros, 68 GBP

Where can I buy mifi?  Amazon https://www.amazon.com/E5577-320-Hotspot-Festival-Portable-Globally/dp/B08KSQS7P8?th=1 

Is mifi secure?  Yes, you can set up a password.

Do I need a code for the mifi?  Not if it is unlocked.

Is the mifi water and shockproof?  No, it is plastic

How many devices can I connect to the mifi?   16 devices

How much data does the mifi use?  Check with the network provider.

Is the mifi easy to set up?   Yes, instructions are included and there are you tube tutorials available.