SoftBank and Sceye sign five-year deal for a stratospheric HAPS network for mobile coverage across Japan

SoftBank has signed a five-year agreement with US aerospace company Sceye to build a stratospheric network of High Altitude Platform Systems (HAPS) with the goal of providing nationwide mobile coverage in Japan, eeNews Europe reports. The agreement covers manufacturing, launch and operation of the platforms. eenewseurope.comeeNews Europeeenewseurope.comOpen source ↗

The planned fleet would operate between terrestrial infrastructure and orbiting satellites. Most of the initial fleet will provide mobile broadband, while selected platforms will support free-space optical communications, using laser links to transmit data through the atmosphere.

How the platforms work

Unlike satellites, HAPS operate within the Earth's atmosphere and are designed to remain over a particular region for extended periods. Sceye's platforms hold their altitude and position through successive day and night cycles. The SceyeCell system functions as an airborne cellular base station and transmits mobile signals directly to standard devices on the ground.

During a 30-day test mission in 2026, a Sceye platform flew from New Mexico to Japan and back. Over Japan, the companies demonstrated voice calls, text messaging, internet access and video streaming. The tests also covered indoor connectivity, emergency communications, remote drone control and edge computing aboard the platform. eenewseurope.comeeNews Europeeenewseurope.comOpen source ↗

The companies also demonstrated ground-based laser ranging of a HAPS, described as a step toward optical links between ground stations, stratospheric platforms and satellites.

Plans and open questions

Part of the fleet will form a free-space optical network in the stratosphere, where optical links could carry high-capacity data between airborne platforms and other network infrastructure instead of radio frequencies.

SoftBank intends to include HAPS in its Ubiquitous Network strategy, which aims to connect terrestrial, airborne and satellite infrastructure. Masayuki Kamimura, Senior Director of SoftBank's Ubiquitous Network Planning Division, said the agreement represents the commercialization of HAPS and the realization of the company's vision for Ubiquitous Transformation. eenewseurope.comeeNews Europeeenewseurope.comOpen source ↗

SoftBank previously invested in Sceye in its Series C round in 2025. Sceye is preparing to scale production of its platforms. Neither company has announced the fleet size needed for nationwide coverage, a deployment timetable or the financial terms of the agreement.

The companies name emergency communications, IoT connectivity, aerial services and distributed computing as possible applications of the network.