Connectivity Technology Blog

We have looked at transparent antennas for a while now with my first post on the topic back in 2019. Since then this technology has matured immensely as I detailed in a blog post last year. Transparent antennas are no longer just experimental concepts but have reached the stage of commercial deployment, often combined with infrastructure sharing models to maximise efficiency and coverage. In Japan, infrastructure sharing has taken on special significance. The high cost of network deployment, limited availability of installation sites and the density of urban environments make it challenging for operators to expand coverage on their own. Shared infrastructure helps reduce duplication, control costs and speed up the roll-out of services. For readers unfamiliar with JTOWER , it is a Japanese company specialising in shared telecommunications infrastructure. JTOWER develops and manages towers and in-building solutions across Japan, with the goal of improving connectivity while reducing the...

At MWC 2025, NTT Docomo highlighted its latest initiatives under the NTT Group's "NTT C89" space-business strategy, such as mobile-connectivity services using unmanned vehicles, or high-altitude platform stations (HAPS), that fly in the stratosphere for days or months, using relays to provide mobile connectivity in mountainous and remote areas, including at sea and in the sky. A presentation on NTT C89 Aerospace Business Strategy is available here while a presentation on NTT DOCOMO's Non-Terrestrial Network (NTN) for Extreme Coverage Extension is available here . Stratospheric connectivity, enabled by High Altitude Platform Stations (HAPS), is emerging as a key solution for extending mobile coverage to remote and underserved areas. However, ensuring that these airborne platforms can provide stable, high-quality connectivity requires extensive testing and refinement. At MWC 2025, NTT Docomo showcased its progress in this domain, highlighting multiple real-world trials...

Recently I blogged about Disaster Roaming in 3GPP Release-17. While this will take time to be implemented worldwide, it is already available in Japan, maybe not in the 3GPP standardised way. Similarly, back in 2011, I blogged about Earthquake and Tsunami Warning service (ETWS) from NTT Docomo's Journal, it was two days before the  2011 Tōhoku earthquake and tsunami hit. Japan is no stranger to earthquakes, typhoons, and other natural disasters, which can have a devastating effect on infrastructure. To ensure that the mobile networks keep functioning, operators work extremely hard to ensure people remain connected one way or another. NTT Docomo has released a video detailing the countermeasures to keep everyone connected in case of emergencies. The following detail is provided with the video: DOCOMO's network is no exception, and our services could get cut off by a base station power outage, disconnected fiber-optic cable, or other malfunctions. DOCOMO established the three p...

NTT Docomo and Airbus have demonstrated the ability to use Airbus's solar-powered Zephyr High Altitude Platform Station (HAPS) to deliver future wireless broadband connectivity. The trial took place in the United States in August, when the Zephyr S aircraft undertook approx. 18-day stratospheric flights to test various capabilities. We have covered many of the topics here, see related blog posts link at the bottom. A press release said: Carrying an onboard radio transmitter, the Zephyr S provided an agile datalink during a stratospheric flight to simulate future direct-to-device connectivity. Test data was captured at different altitudes and at different times of day and night, focusing on assessing how connectivity is affected in the stratosphere by factors including weather conditions, different elevation angles and aircraft flight patterns. Tests included various bandwidths to simulate direct-to-device service from the HAPS to end users using low, nominal and high throughput. T...

GSMA together with some mobile network operators recently published a white paper to promote the use of High Altitude Platform Systems (HAPS) technology to meet the need for broadband connectivity worldwide. We have covered HAPS multiple times in our blog posts. They are unmanned aircrafts that fly typically at altitudes of around 20km.  The description of the paper says: Operating in the stratosphere, unmanned high-altitude platforms (HAPS) could bring connectivity to areas that are either not covered, or are only partially covered, by terrestrial cellular networks. This whitepaper highlights the potential of HAPS to meet the need for more broadband connectivity worldwide. HAPS are very versatile: they can be adjusted to prioritise coverage or capacity depending on the use case. Moreover, an aircraft can be deployed to cover a location at short notice. As HAPS can employ LTE and 5G, there are no special requirements on the user equipment: a normal smartphone can be used. As a res...

We wrote about  Futuristic Glass Antenna by NTT Docomo and AGC back in 2019. It's good to see the partnership continue with this new announcement about use of metasurface lens to enhance radio signal reception indoors.  Metamaterials is one of the focus areas of 6G as highlighted here . Samsung's 6G Vision whitepaper explains it as follows: A metamaterial is usually constructed by arranging multiple tunable elements (PIN diodes, varactor diodes, etc.) in repeating patterns, at scales that are smaller than the wavelengths. Its precise shape, geometry, size, orientation, and arrangement enable smart properties capable of manipulating electromagnetic waves, e.g., blocking, absorbing, enhancing, or bending waves, to achieve benefits that go beyond what is possible with conventional materials. In addition, each element constituting a metamaterial can be controlled independently to achieve desirable characteristics of the electromagnetic waves such as the direction of propagati...

Back in March this year, NTT Docomo announced that they are switching off their NB-IoT network due to not enough demand but will continue to support LTE-M and Cat 1 . Good spot. An odd reason to give "in order to concentrate management resources". You wouldn't think it would take much resource. — Tom Rebbeck (@tomrebbeck) March 30, 2020 This news have started a lot of discussions, as you would expect, about the future of NB-IoT. From the standards point of view, IoT is going ahead full steam with both LTE-M and NB-IoT having been enhanced for 5G in Release-16 to support massive Machine Type Communications (mMTC). This slide from Qualcomm illustrates it well A recent article from Mobile World Live had a heading, " China Mobile migrates IoT connections off 2G ". While reading the article, you would get a feeling that China Mobile will stop supporting the 2G IoT (more like M2M ) devices. But again this might not be that straightforward as I explain i...

For nearly a year, NTT Docomo has been working with the glass manufacturer AGC to create a new transparent antenna that can work with a base station to become an antenna. We know that as we move towards higher frequency, the penetration of radio waves in building is affected. While this is not obvious in C band, it is very visible in case of mmWaves. In a recent publication titled " An Unobtrusive Antenna ", Osamu Sawaji interviewed NTT Docomo and AGC engineers about this development To solve these problems, NTT DOCOMO entered into joint development with major glass manufacturer AGC, presenting a new glass antenna in November 2018. The antenna is 85 cm wide, 21.2 cm high and 6.6 mm thick, and on first glance appears to be normal transparent glass. However, the antenna becomes a base station when connected to cables and a wireless transceiver in the ceiling and attached to indoor window glass. The antenna makes use of the laminated glass manufacturing technique used ...