In the past, airplanes (albeit a little cramped) allowed you to sit back and watch the latest movies or read a book. Now they are another entry point. Delta and United each have more than 1.5 million in-flight Wi-Fi sessions per month, the airline told CNN Business, and JetBlue says "millions of customers" use the service each year. Southwest declined to provide exact numbers, but said in-flight Wi-Fi is "popular."

Alaska Airlines, meanwhile, estimates that about 35 percent of its passengers use in-flight Wi-Fi services that cost an average of $8, including web browsing and streaming. Some airlines are provided free of charge for specific messages, and the Internet generally receives $50 in US dollars (airlines intend to move from $5 to $1 to a single flight, presented by the end of this year). It is expected that research institutions will increase $5 billion compared to the current market and expected that they will increase to $12 billion by 2030. In-flight Internet has been around for nearly two decades, when plane-maker Boeing announced a service called Connection in April 2000 and debuted on a Lufthansa flight from Munich to Los Angeles in 2004. Boeing discontinued the service in 2006. There was no" done' as expected. However, the advent of smartphones and the continued efforts of many satellite providers and airlines have helped the technology advance significantly over the past decade, although few still have comparable home and office networks.

How it works

There are two main types of joints in aircraft. The first, called air-to-ground, or ATG, relies on antennas attached to aircraft to receive signals from mobile phone base stations on the ground.

Intelsat, which began air-to-ground service with American Airlines in 2008, now operates a version of this technology on more than 1,000 aircraft in North America. The only major downside to this technology is that, like land-based cell phones, it relies on tower density and connectivity, so flying over rural areas, deserts, or large bodies of water can reduce connectivity. According to Andrew Zignani, director of research at ABI Research, a technology intelligence company specializing in wireless connectivity, the maximum speed of these systems is about 5 megabits per second (shared by hundreds of passengers). By comparison, the latest data from monitoring app Speed test shows average global download speeds for mobile and fixed broadband to be 30 megabits per second and 67 megabits per second respectively.

"The biggest challenges so far have been speed, limited availability, coverage gaps, outages and pricing," Zignani told CNN Business. This is why airlines and airlines are increasingly switching to satellite communications. Satellite communications are relatively less susceptible to interference because they can more efficiently cover the entire flight path in space and keep the signal active as it travels through the air.

This includes Intelsat, which has a network of more than 50 satellites serving airlines such as Alaska, American, Delta, United, Air Canada, British Airways and Cathay Pacific. "As regional aircraft are upgraded, we expect many aircraft to transition to satellite solutions," Jeff Sare, president of commercial aviation at Intelsat, told CNN Business.

Another major airline used by several airlines around the world, Viasat, uses its own satellite network to provide high-speed connectivity and is preparing to launch another constellation of satellites later this year. The company debuted with JetBlue in 2013 and currently serves more than a dozen airlines worldwide.

But even satellite communications are currently capable of about 100 megabits per second per aircraft, or about 15 megabits per second per passenger device, which is a far cry from ground-based Wi-Fi speeds. Many airlines use different types of Wi-Fi providers and technologies, depending on the type of aircraft and the routes they need to be deployed on.

New players are also joining the fray, such as Starlink, billionaire Elon Musk's SpaceX's satellite internet service. Earlier this year, SpaceX announced a partnership with Hawaiian Airlines to bring high-speed internet via the Starlink satellite network to low Earth orbit.

"Some of these solutions use a hybrid approach that combines the strengths of both technologies to provide optimal autonomy depending on a particular flight path," Zignani said. "I think we will see opportunities for each technology in the future, and our recent partnership shows that each technology has a role to play," he added.

Challenges and opportunities

There's still a gap between onboard Wi-Fi and the networks you use at home, at the office, at the coffee shop, or anywhere else on the planet. Most airline Wi-Fi connexions now support messaging and social networking features, and some offer live TV and video streaming capabilities, but it can be difficult to provide users with the same bandwidth and wireless connectivity.

"The biggest difference between in-flight Wi-Fi is the complexity of the mobility component," Don Buchman, Viasat's vice president and general manager of commercial aviation, told CNN Business. "Aircraft travel at high speeds, typically bank in flight, and frequently fly over large geographic areas that require consistent coverage for a high-quality in-flight communication experience."

In an Intelsat survey of airlines, service providers and equipment manufacturers last year, 65 percent of respondents said they expected an increase in the number of passengers waiting to check in. The two biggest obstacles to increasing onboard Wi-Fi adoption were high service costs and "poor internet connectivity".

Companies like Viasat, Intelsat and Starlink continue to expand these features, but more launches are coming.