KDDI's Power Backup Solutions

Over the last few years you might have read multiple blog posts on our blogs (see related posts below) about how KDDI is preparing for disasters by having all kinds of backup solutions. In the last six months they have taken this even further by taking about their bendable solar cells and lighter backup batteries.

In some situations the base stations have to be installed at locations where it is not possible to deploy solar cells for power. In these locations, KDDI is working with partners to use next generation "perovskite" solar cells which are thin, light and flexible so it can be wrapped around the poles and generate a reasonable power all day long. 

Here is a video (no subtitles, but none needed):

You can learn more about this here.

Another innovation being tested by KDDI is the use of zinc secondary batteries to strengthen power outage countermeasures during disasters. While backup power supply equipment is effective as a countermeasure against long-term power outages during disasters, the problem is that it cannot be installed or expanded due to the load capacity of the building. 

Quoting from the Google translated article:

Zinc secondary batteries are approximately 50% lighter than the lead-acid batteries used in many base stations, allowing for more space to be installed, while having twice the capacity for the same size, extending base station operating time. This can be extended up to 72 hours. 

At base stations, there is an urgent need to install or expand large-capacity backup power supply equipment as a countermeasure against long-term power outages such as during disasters. Zinc secondary batteries are lightweight, allowing more space for installation, and are the same size as lead-acid batteries, allowing base stations to operate for long periods of time, so they are expected to contribute to maintaining communications during disasters. In addition, since it does not contain harmful lead and there is no risk of heat generation, installation work can be simplified, and it is expected to contribute to the acceleration of the expansion of 5G areas.

In this demonstration, we plan to operate a base station that uses zinc secondary batteries as backup power supply equipment in a real environment for one year, confirming its operation through seasonal changes in temperature and humidity, and conducting power outage tests.

Looking forward to hearing about the results of both these initiatives.

Related Posts: 

• Connectivity Technology Blog: KDDI Prepares for Disasters with Vehicle-Mounted Base Stations Backhauled via Starlink
• Telecoms Infrastructure Blog: KDDI's Underground 5G Base Stations
• Telecoms Infrastructure Blog: KDDI Plans to Improve Rural Connectivity in Japan using SpaceX's Starlink
• Telecoms Infrastructure Blog: KDDI to test 5G with base stations built in Street Lights
• Free 6G Training: KDDI's Seven B5G/6G Technologies Contributing to Society 5.0 Implementation
• Operator Watch Blog: KDDI Launched their Metaverse and Web3 Service called αU (Alpha–U)
• Operator Watch Blog: KDDI Japan's IoT march continues with over 10 Million Connections 

KDDI's Underground 5G Base Stations

Some five years back I talked about NTT Docomo's underground LTE base stations, now it's KDDI's turn for an underground 5G base station. Last week the Japanese operator KDDI announced to the world that they are testing an underground base station in a handhole (just big enough for the hand to go in as opposed to manhole where a person can go in). 

The press release (translated by Google from Japanese) said:

In December 2022, KDDI became the first domestic telecommunications carrier to begin operation of an embedded 5G base station (hereafter referred to as this base station) in Otemachi, Chiyoda-ku, Tokyo (on the premises of the KDDI Otemachi Building).

In the future, we aim to accelerate the expansion of areas that require consideration of scenery, such as Bikan districts, by utilizing this base station

Background

Conventional tower-mounted base stations and building roof-mounted base stations have exposed base station antennas, which can affect the scenery. It was. As one solution to this problem, the introduction of buried base stations, in which the base station equipment is installed underground (below the ground surface), is expected. In July 2021, the Ministry of Internal Affairs and Communications' new system of radio wave protection guidelines for embedded base stations came into effect.

About this base station

Since 2018, KDDI has been considering the start of commercial operation of embedded base stations. In December 2022, we succeeded in emitting radio waves from this base station, and verified radio wave propagation characteristics until February 2023, confirming that a communication area with a radius of about 50m can be secured.

By storing the devices necessary for radio wave radiation, such as wireless devices and antennas, in a housing buried underground (below the ground surface), it is possible to install the device in consideration of the landscape. In addition, by radiating radio waves upward, it will be an area along the ground.

It adopts a highly waterproof metal housing and is designed to withstand water intrusion. Also, since the antenna is underground, it is less susceptible to strong winds.

KDDI will continue to develop new concept base stations that are not bound by existing base station installation forms, and will continue to expand service areas, improve quality, and create an environment that is easier for customers to use.

n78(3.7G)離れても掴むから別みたい
もしかしてn77(4.0G)マンホールから吹いてる?
なお、このマンホール基地局を作るのにKDDIは周りに木もたてたようなので
ガーデニング基地局という名称になりましたｗ pic.twitter.com/TonrSLJ08M

— 電波やくざ@告白実行委員会😌💕 (@denpa893) March 11, 2023

Nice to see mobile enthusiasts already testing the base station out. We will have to wait to see how the PoC goes and if we will see more of these deployed commercially. 

Related Posts: 

• Telecoms Infrastructure Blog: NTT Docomo's Underground LTE Small Cells with possibility to deploy 5G in future
• Telecoms Infrastructure Blog: Underground Small Cells
• Telecoms Infrastructure Blog: Small Cells & Wi-Fi in the pavements & roads
• Telecoms Infrastructure Blog: KDDI Plans to Improve Rural Connectivity in Japan using SpaceX's Starlink
• Telecoms Infrastructure Blog: KDDI to test 5G with base stations built in Street Lights
• Free 6G Training: KDDI's Seven B5G/6G Technologies Contributing to Society 5.0 Implementation
• Operator Watch Blog: KDDI Japan's IoT march continues with over 10 Million Connections
• Operator Watch Blog: Japan allocates 5G Spectrum in 3.7GHz, 4.5GHz and 28GHz bands 

KDDI Plans to Improve Rural Connectivity in Japan using SpaceX's Starlink

Back in December 2022, KDDI announced that the first mobile tower in Japan to use Starlink has started commercial operation in Hatsushima, a remote island in Sagami Bay. The press release said:

Starting with this location, KDDI will expand its coverage to 1,200 remote towers in order to pursue its vision to bring an urban mobile experience to its rural customers.

「この地球上から、つながらない場所をなくす。」

日本には、山や離島など電波の届かない地域がまだまだあります。
KDDIはエリアを広げ、さらに宇宙ともつながっていくことで、
もっとすみずみまで電波を届けていきます📶

～衛星ブロードバンド Starlink～ pic.twitter.com/2epZYNnbEn

— KDDI公式 (@official_kddi) December 1, 2022

Developed by SpaceX, Starlink provides high-speed, low-latency satellite broadband internet around the world. With satellites positioned in low-Earth orbit at an altitude of 550 km, over 65 times closer than conventional geostationary satellites, Starlink achieves significantly lower latency and higher transmission speeds for its end users. Using Starlink to backhaul service from these remote stations complements KDDI's urban towers that utilize fiber for backhaul.

【速報】
日本に数拠点ある
SpaceX社のStarlinkの地球局ゲートウェイアンテナを見てきた
思った以上にデカい
既に稼働してる模様で衛星へのアップリンク漏れ電波も観測できた pic.twitter.com/mT2mWg8yNq

— 電波やくざ (@denpa893) November 20, 2022

KDDI has been conducting technical demonstrations of Starlink including for use in mobile backhaul since 2021. In order to ensure sufficient quality for cellular service with voice and data, Starlink has met the company's network technical guidelines in latency, jitters and uplink/downlink bandwidths. KDDI has completed its evaluation of Starlink and confirmed the conformance in customer experience that could be comparable to that of optical fiber.

KDDI will also offer Starlink Business to enterprise and civil government customers this year. With Japan having more than 16,000 mountains and 6,000 islands, with Starlink KDDI is now able to bring a new dimension of connectivity to Japanese society.

The video of the launch ceremony is embedded below:

In addition to the image from KDDI press release, additional images from Twitter here and here.

Related Posts:

• The 3G4G Blog: How Many People are Still Unconnected in 2023 and Why?
• Connectivity Technology Blog: Why Starlink is Already a Gamechanger
• Free 6G Training: KDDI's Seven B5G/6G Technologies Contributing to Society 5.0 Implementation
• Operator Watch Blog: KDDI Japan's IoT march continues with over 10 Million Connections
• Telecoms Infrastructure Blog: KDDI to test 5G with base stations built in Street Lights
• Telecoms Infrastructure Blog: Drones, UAVs, LTE & 5G
• Connectivity Technology Blog: Laser Inter-Satellite Links (LISLs) in a Starlink Constellation 

Drones, UAVs, LTE & 5G

Its been nearly couple of years since I was involved with EE/BT for their Airmasts project. Details here with some good links in that post too. Since then many other operators have been involved with something or other to do with drones, blimps, balloons, etc.

Here are a few recent ones that I found interesting

KT has unveiled its 5G emergency network service called Skyship that uses airship drones to search for survivors in the aftermath of disasters.

KT collaborated with local drone maker Metismake to design the helium gas-based airship, which has an attached pod with propellant, network module, high-resolution camera, and a trunk that can deploy smaller drones to the ground.

It was designed in NACA airfoil and can maintain stable flight in 13 metre-per-second winds. It has a maximum speed of 80 kilometers per hour and can fly up to six hours.

More details on ZDNet here.

KDDI announced today that it has successfully completed a live 4K video transmission test using a drone that leverages 5G technology. The test was carried out in an effort to realize consumer services that can benefit hugely from drones, such as public safety and surveillance, agriculture monitoring and disaster response. The test, the first of its kind to have taken place in Japan, was carried out in cooperation with Nakao Research Laboratory of the University of Tokyo, TripodWorks and Prodrone. 

The test area was set up in the university's Kashiwa campus using Samsung Electronics' 5G end-to-end solutions including 5G AU, 5G core and 5G tablet, and for video streaming 28GHz frequency were used. Using a 5G supporting device, the video shot in the air using the 4K camera mounted on the drone was uploaded in real time.

More details on Netmanias here.

Looking at Drone communications over LTE / 5G, Sequans communications have recently published a white paper looking at how LTE would be a communication technology of choice for drone communications over long distances. There are some issues to resolve including how to get reliable signal in the drones as they fly above the typical coverage zone of an LTE antenna.

Details here: http://lteanddrones.com/


Ericsson had done some similar study and published a whitepaper on this topic last year. Details available here but the video below is worth a watch too.

Small Cells World Summit 2017 Summary

I realised that I never got round to writing a summary post for Small Cells World Summit 2017. In fact I was waiting for summaries for various publications before writing a post but there was much less coverage this year.

Having said that, there were reasonable number of operators and most major vendors present. Small cells have sort of gone mainstream from their niche as many operators are now talking of small cells for 5G (mainly higher frequencies).

Anyway, here are some links with what I found interesting that you can explore further.

Here are some things ThinkSmallCell reported. Full report here:

SCWS, now in its 9th year, remains a regular feature of the small cell calendar. Now a two day conference, attendance was lower than some years ago but stable with noticeably more system integrators/installers actively participating. There was a little more focus on business enablers rather than technology this year, addressing deployment issues and neutral host opportunities for enterprise, urban and rural sectors.
...
The scope of SCWS is intended to embrace all of Small Cells, DAS and (Public Access) Wi-Fi. We saw one or two more DAS vendors participate but there was relatively little public Wi-Fi content. Perhaps that reflects the limited interest for that in Europe, as we saw at the recent Wireless Broadband Congress. The program included a few keynote speakers from operators (EE, O2, ATT, KDDI, Softbank) and some industry verticals (AEG, which operates the O2 dome and other stadiums; Grange Hotels etc.)       

Many mature small cell products are available today for both 3G and LTE. Form factors continue to shrink, software is becoming further automated and refined. The backhaul conference stream has been dropped with CCS now the most prominent independent small cell backhaul vendor.
...
The event provides an excellent opportunity to meet and reconnect with industry players, both old and new. The emphasis and participation has evolved over the years, but it remains a key focal point to assess the current state of play for the industry.

Here are some things The Mobile Network reported. Full report here:

The day before the Summit started Nokia assembled a few journalists in a meeting room and gave them a portfolio update. Of note in this was the revelation that the company will be shipping tens of thousands, in fact more than 50 thousand, of its Mini Macro cell sites to Sprint. This is on top of another wide scale roll out of the boxes – which are 2x20W sites in a 5 litre box – in China and Japan where the vendor expects to ship another 40,000. There are 3,000 headed to Brazil, as well, to be deployed as an underlay under Ericsson macro cells.
...
One notable aspect of the event was the amount of talk about using small cells in rural, in dense indoor and in other hard to reach areas. Mansoor Hanif spoke of some of the work BT is looking at to enable it to spread coverage to hard to reach areas. There is a real range of work, best summed up in this picture.

Of note is its work with TIP, where it hopes to be able to plug in open base stations as part of its Kuha community-run small cells programme – as per its project on the island of Harris supported by Nokia at the moment. With Lime Microsystems it is delivering a software defined radio base to Open Source, and hopes to attract developers to build applications on top of the Lime SDR platform. Hanif wants to move the cycle for introducing a new feature into a network from months to weeks – but he added that he doesn’t think any operator has the skills to manage that internally – hence the move to Open Source.
...
KDDI’s Fumio Watanabe presented some findings from the operators trials of mobile mmWave systems. The operator’s field trial use 40GHz and 60GHz bands, with a user moving between different bands and being “handed over” between access points. This sort of mobility requires dual interband connectivity and multi-site CoMP to handle the mobility between different sites and bands as a user goes out of line of site of an access point.

It may also require some architecture shifts Watanabe said, including the likes of ICN and MEC.
...
Backhaul provider CCS has a couple of things going on. First, it is involved as the backhaul provider to Telefonica O2’s deployment of outdoor WiFi and cellular small cells in the City of London. Steve Greaves, CEO, said that the company will support 450 small cells and 150 WiFi access points by siting its backhaul nodes at 30 Virgin media fibre points – with each backhaul node supporting 3-5 WiFi access points. The backhaul nodes are providing 1.2Gbps capacities at 24/26/28 GHz bands.

Greaves is also enthused by an upcoming product launch from CCS, as the company enters the 60GHz band with a 10Gbps product. Greaves says that CCS will go beyond products from the likes of Siklu, by modifying the basic WiGig chip that providers currently use, to add tighter carrier grade SynchE 1588, and greater interference control. The product will not be available until early 2018, he added.

Another interesting aspect of the City of London deployment – the concession model between the City of London and Telefonica – means that Telefonica must host other operators’ small cells within the deployment if asked. But these may not be on the same pole as Telefonica’s small cells, given there is a limit of two boxes per pole. From a backhaul perspective – that obviously introduces more complexity – as Telefonica must introduce a V-LAN for each operator, with different QoS.

Virgin Media Business, by the way, has 100,000 cabinets in London alone, and wants to use them to act as potential hosts for small cells, by adding a small pole to the cabinet, said its adviser Paul Coffey. The company is also looking at enabling neutral host model using its street infrastructure. Its wholesale business supplying backhaul to the UK’s operators already runs to £150 million per year, Coffey said.

Related Posts:

• Nokia Kuha: Community-run Small Cells
• Small Cell Forum Awards 2017 Winners
• Telecoms Infrastructure Blog: Flying Small Cells are here...
• Drone cells are becoming a reality 

KDDI to test 5G with base stations built in Street Lights

Street lamp incorporating the base station function in consideration of the landscape - by the Japan External Trade Organization (JETRO)

My earlier posts with street lighting and lampposts were mainly with Philips (see here and here) and one detailed one from EE (via Andy Sutton)

In fact the picture above reminded me of this tweet:

When is a telegraph pole not a telegraph pole? When it's a cell site. #industrialarchaeology #gsm #3G #mobilefuture pic.twitter.com/t1WzZ5crU5

— Andy Sutton (@960sutton) September 8, 2015

Anyway, the new article says (translated by Google translate from Japanese):

In experiments, we used a street lamp that incorporates the base station function inside the pillar so that the antenna and the radio are not noticeable. We set up one in the parking lot adjacent to the municipal wreckage field in Yeomachiro and investigate tourist reactions on the landscape and the reach of the radio waves. The period is one year from October this year. Since the 5G base station has not yet been downsized, experiments predict the radio range using the current 4G base station.

So from what I understand (news sites here and here):

• KDDI will be testing initially using 4G because 5G base stations are still quite big. It looks like a small cell but could be an RRH as well
• This experiment will start in October and last a year
• As it mentions relay, I am assuming in-band backhaul.
• As its on a sightseeing spot, they want to see how people react to this
• They will also examine the impacts of weather, terrain and look at maintenance issues as well.
• The intention is to roll it out commercially by 2020

KDDI Japan, Traffic Offloading Strategy

While going through some KDDI presentations, came across how they planned and perform Offloading. In fact, even before the deployment of LTE, they were aware that the network capacity would not be enough for the savvy Japanese mobile phone users. They had to start planning for how to offload the users as soon as possible. 

au Wi-Fi is their Wi-Fi offloading strategy where they make Wi-Fi hotspots available for the users. They even claim that with Wi-Fi on, the baattery life could be 1.5 times the normal 3G battery life.

UQ WiMAX is another KDDI company that allows users with compatible handsets to offload to WiMAX. KDDI have their own WiMAX branded services as well, see here.

Finally, with the LTE rollout they have different hierarchical cells available that the user could be moved to if one of the layers is congested.