We were in campsite last night and a guy had this device that would pick up a WiFi signal and then we could use a laptop. It was a unit he purchased and then paid a monthly fee.
What are these units called?
Thanks!

Your laptop can pick up a WiFi signal. The issue is having a wifi signal to pick up!

What he had was a "mobile hotspot" device.

The Best Mobile Hotspots on Every Carrier | PCMag.com

It's basically a smart-phone with "tethering" (you need to buy a cell-network data plan to use either).

laptop <-wifi-> device <-cell network-> internet.

"Device" above can either be a smart phone or the mobile hotspot device.

It's basically a bridge between wifi and the cell-network.

I use my iPhone to do this.

Verizon makes a unit called The Jetpack. Other carriers have their own devices.

Depending on your phone and carrier, you can set it up on your phone, or tether to your phone.

My iPhone with Verizon service does it.

My Verizon iPad does it.

I have a Netgear Zing with Sprint branding. I'm lucky that I get a strong signal here.

I have a Nexus 4 on T-Mobile and I do this for free with some software on the phone and my laptop. I use it all the time since I have unlimited data and it works great in remote locations that still get cell service.

As an aside, some laptops also have an HSDPA/Wireless WAN antenna built in that can do the same thing without an intermediary device.

You can probably set your phone up as a mobile hotspot (sometimes called tethering). no need to purchase an additional device and pay an additional monthly fee. This all assumes you have a smart phone with a data plan of course.

I can do it on all my Android phones, using Ting as a carrier. FWIW if you have Sprint coverage and aren't a very heavy data user, I highly recommend Ting. It's saving our family about $100/month.

I believe "mifi" is the generic term.

My Verizon iPad does it.