Mobile phone carrier SoftBank Corp. and Google LLC parent Alphabet Inc. said Thursday they will jointly set up airborne mobile phone base stations, using balloons and aircraft in the stratosphere, to cover wider areas for next-generation 5G wireless services.

SoftBank's year-old HAPSMobile and Alphabet's Loon, which spun out last July from the research incubator of the Google parent, have been trying separately to fly networking equipment at high altitudes to provide high-speed internet in spots where ground-based towers are unreachable.

Loon carries the gear with a large balloon, while HAPSMobile uses a large drone.