Demand for outdoor wireless Internet access hotspots, such as the ones offered by cafes, airports and municipalities, is skyrocketing as mobile smartphone and cloud computing become mainstream. It's rising so fast that, according to a market research study, the global market for this service will more than double over the next five years.

“Outdoor Wi-Fi is expected to grow from $15.41 billion in 2013 to $37.2 billion in 2018, at a CAGR (compounded annual growth rate) of 15.82 percent during this forecast period,” says a new study by Dallas-based global market researcher MarketsandMarkets.

The estimate includes all the products and services used to facilitate outdoor wireless hotspot connectivity, such as repeaters and relays that broaden the range of wireless access, and network planning, installation and support.

This growth will help boost business for companies like Transit Wireless, which is investing $200 million to build out New York City’s subway Wi-Fi network in deals worked out with the local transport authority and phone and data carriers T Mobile US Inc. (NYSE:TMUS), AT&T Inc. (NYSE:T) and Boingo Wireless Inc. (NASDAQ:WIFI).

Google Inc. (NASDAQ:GOOG) this week announced it was testing in New Zealand using solar-powered balloons floating 12 miles above the ground as a way to expand Wi-Fi hotspots globally.