Microwave routes — Wakasu
Original: Ryota / JJ1WTL — 517567284 · Original Japanese HTML
Published: 2025-08-10T15:00:00+09:00
English translation of the archived article text. The author’s first-person observations, uncertainty and later additions are preserved; this is not the research summary. Image contents are preserved as images, not silently incorporated into the translated prose.
Hello to HF digital fixed-station enthusiasts across Japan.
There is still unfinished work.
We need to find the receiving ends in Koto Ward of the microwave links from each experimental station.
I will tackle that.
These are the ones
●DATACOM SERVICES
Ermis
Reviewing the Sodegaura ends of the links
DATACOM SERVICES — JS2RA / JS2RB
At Kubota, Sodegaura City. 
The counterpart of this ↑ is somewhere in Koto Ward.
Ermis — under construction
At Shimoizumi, Sodegaura City. 
Same story.
Relative locations
The main participants. 
July 12
Most of you probably don't often have occasion to visit Ariake.
From Ariake, I look toward the Toyosu data centres and check for changes.
TEPCO Toyosu. Click to enlarge.
No long-bodied antennas, are there…
(The west-facing ones, on the left, are the known JOSADA TELECOM antennas opposite Mount Oyama.)
Shin-Toyosu Cube. Click to enlarge.
…No changes at the other known relay buildings nearby either:
No. 5 Inoue Building in front, and Marusada Ariake Building behind.
Kyowa Bussan Ariake Center.
Defeated.
July 21
The final day of the three-day holiday after KANHAM.
I expanded the search beyond the Toyosu area.
In the end, I walked from Telecom Center to Minamisuna.
Considering the Telecom Center Building
Apparently not. Click to enlarge.
Considering rented space on Koto Substation's towers
Photographed from the south. Apparently not. Click to enlarge.
Then north past the Shinsuna data-centre district toward Minamisuna.
No antennas found. Defeated.
August 3
Considering another data centre
I went to Toyosu on the Yurikamome and began the search.
A festival at Susaki Shrine.
Speaking of low latency: Colt, formerly KVH.
I investigated Colt's Shiohama data centre… but no luck.
No antennas.
Trying to survey everything from Tokyo Gate Bridge
Walk to Shin-Kiba, then a bus to Wakasu Seaside Park.
Activate Plan B: a long-distance survey from Tokyo Gate Bridge.
…But I cannot find them.
As below, each station is at least visible.
No. 5 Inoue Building, left, and Marusada Ariake Building, right.
Marusada Ariake Building and Kyowa Bussan Ariake Center;
TEPCO Toyosu in the background.
Kyowa Bussan Ariake Center and Shin-Toyosu Cube.
You might ask, ‘Where are TEPCO Toyosu's antennas?’ They can be seen.
From a slightly different photography position.
Retreat
No new site found. I would leave the rest to analysing the photographs at home.
Back to Shin-Kiba by bus.
?
What?!
August 9
Another outing. This time Wakasu is the only candidate.
Who would have thought it would be in Wakasu, so far from Toyosu?
Like discovering the Project V base in Side 7 [a Gundam reference].
Outbound
Choosing the subway to avoid traffic heading to ‘Mouse Land’.
Mita.
Changing to the Yurakucho Line at Hibiya.
For the first time I learn that it is close if you choose the right staircase.
Onto the bus at Shin-Kiba.
I got off at Wakasu-chuo. Koto Soko Kumiai-mae would be closer.
As I watch the bus leave… the target is visible beyond it.
This is it.
Enjoy the view
Here: Yamazaki Shoji's Wakasu office.
https://www.google.com/maps/@35.6255878,139.8328478,58m/data=!3m1!1e3
All photographs in this section can be clicked to enlarge.
Front
From the southwest. On the roof of the Yamazaki Shoji building, facing Sodegaura.
From the east-southeast, at the intersection beside the golf course.
At first glance it looks as though it is on Senju Warehouse's roof, but it is on Yamazaki Shoji's roof behind it.
Zoom.
Rear
The full view from the northwest.
From around the Wakasu-chuo bus stop.
Mast.
There is a northwest-facing E-band antenna…
A new mystery appears.
Zoom.
Even the position of the label closely resembles DATACOM SERVICES' Sodegaura station discussed above.
A little farther south… the mast.
Large antenna.
Small antenna.
The combination is the same as at the Sodegaura end too.
It seems reasonable to regard it as belonging to that company.
Where is the E-band antenna aimed?
One would naturally want a direct shot at Shin-Toyosu Cube.
Moving the investigation to Ariake.
Wakasu-chuo.
There are buses about every thirty minutes here, except Sundays.
Yurakucho Line from Shin-Kiba.
Change at Toyosu to the Yurikamome for Ariake-tennis-no-mori.
Huh?
Space-diversity antennas have been added in just this short interval. Marked ★.
Click to enlarge.
The ★ above is probably Ermis.
Apparently it connects directly from Sodegaura without a relay, with an Ichiro-class ‘laser beam’ throw.
So I reconsidered it as in the table below.
Taking everything together… difficult though it is… VY SRI if I have got it wrong.
| Mark | Operator | Counterpart |
|---|---|---|
| ★ | Ermis | Shimoizumi, Sodegaura City |
| Large | NuVo | Kyowa Bussan Ariake Center |
| Small, left | DATACOM SERVICES | Yamazaki Shoji, Wakasu |
| Tiny | … ? | |
| Small, right | GTT | No. 5 Inoue Building |
| Medium | JOSADA | Marusada Ariake Building |
Ermis—probably—has smaller antennas here than at the Sodegaura end?
An unexpected by-product of the investigation. Enlarged.
I walked home from Ariake.
Does the path actually clear?
●DATACOM SERVICES
Can Yamazaki Shoji in Wakasu connect directly to Shin-Toyosu Cube?
…With Kitabeppu-class pitching accuracy, it clears the two apartment towers.
The distances were calculated using ‘Distance and Azimuth Calculation’:
https://vldb.gsi.go.jp/sokuchi/surveycalc/surveycalc/bl2stf.html
That was the source.
Had this demand been apparent earlier—wanting to link data centres and cable landing stations by microwave—the land-use plan for Toyosu's redevelopment itself might have been different.
A pity…
Ermis
The bearing from Shin-Toyosu Cube is 138.3°.
The southeast is open, so this path also looks all right.
33.3km．
Updated overview
Click to enlarge.
Table
Map
E-band licensing
Each company has licences.
Except Ermis.
Sora uses E-band to connect into NuVo's Mother Farm station.
Reference URLs
Motegi Network Center: ‘Overseas telecommunications operators’
https://moginwc.sakura.ne.jp/uty_oversea.html
‘Microwave routes — Toyosu / Shinonome’ (June 4, 2023)
https://jj1wtl.seesaa.net/article/499593521.html (English translation)
At that time, on Shin-Toyosu Cube's roof:
(1) The ‘tiny’ antenna was not yet there.
(2) I had overlooked the ‘large’ antenna: it is near the centre of the roof and disappears from view when looking upward.