Japan operator certification: DoCoMo, KDDI, SoftBank bands

Author Hugues Orgitello Last updated 12 July 2026 ~14 min read

Guide · Japanese cellular operators

Certifying a cellular device for Japan takes two layers: GITEKI radio certification under MIC (Ministry of Internal Affairs and Communications, Soumusho), issued by an RCB such as TELEC, then a separate network acceptance from each target operator, NTT DoCoMo, KDDI au, SoftBank or Rakuten Mobile, covering bands, IMS profiles and eUICC. NTT DoCoMo (NTTドコモ), KDDI under the commercial brand au, SoftBank (ソフトバンク) and Rakuten Mobile (楽天モバイル) each run their own acceptance programme for modules and end devices, with their own bands, protocol profiles, eUICC rules and partner laboratories. A GITEKI-only module will not attach to a commercial network unless the target operator has validated the device. This page describes the regulator-versus-operator split, the scope of each operator, Japan-specific cellular bands, eUICC mechanics, and the recurring pitfalls for non-Japanese manufacturers.

TL;DR:

• GITEKI (MIC, via TELEC or another RCB) is mandatory but not sufficient: without operator acceptance the device cannot attach, even with a valid SIM inserted.
• Japanese 800 MHz means Band 18 (KDDI) and Band 19 (NTT DoCoMo), not US Band 5 or EU Band 20; n79 4.5 GHz is deployed by NTT DoCoMo only.
• No 2G/3G fallback remains in Japan: KDDI closed 3G in March 2022, SoftBank in April 2024, NTT DoCoMo ended FOMA in March 2026.
• Select modules already pre-certified with the target operators: each of the four runs its own programme, and one acceptance never covers the others.

Regulator and operator: two layers not to be conflated

In Japan, the split between the regulatory authority and the commercial operators is sharp and shapes the entire schedule of a cellular programme.

MIC (Ministry of Internal Affairs and Communications, Soumusho) is the regulatory authority. It issues the Radio Law (電波法, Denpa-hou), the band plans, the technical limits and the ministerial ordinances. It accredits Registered Certification Bodies (RCB), led by TELEC (Telecom Engineering Center), to assess radio certification dossiers. The visible mark on the product, GITEKI (technical conformity), is the regulatory marking. That regime is detailed in the TELEC / GITEKI in Japan guide.

Cellular operators are commercial entities licensed by MIC to use spectrum. They acquire spectrum usage rights, deploy their access network (RAN), their core, their IMS, their backbone, and sell services. MIC does not prescribe a terminal acceptance procedure: each operator defines its own programme, in line with its commercial and technical priorities.

The practical stack for a cellular module targeted at Japan is the following:

1. GITEKI via TELEC or another radio RCB: compliance with MIC ordinances on the bands used, output power, emission masks, emission classes. Without GITEKI, the module is unlawful to sell or use in Japan.
2. Operator acceptance: validation by the target operator (one, two, three or all four) that the module behaves correctly on its network. Without operator acceptance, the module cannot register or open data/voice sessions on that operator's network, even with valid GITEKI.
3. eUICC profile and RSP: download of the operator profile through SM-DP+ (Subscription Manager - Data Preparation Plus) per GSMA GSMA SGP.22 for consumer or GSMA SGP.32 for IoT, conditional on prior device acceptance.

See the glossary for definitions of RCB, IMS, NSA, SA, eUICC, SM-DP+.

The four Japanese cellular operators

The Japanese cellular market has consolidated around three large incumbents and one disruptor that arrived in 2020. Each has its own history, band footprint, IoT platform and acceptance logic.

Operator	Commercial brand	Type	Main IoT platform	Specificity
NTT DoCoMo (NTTドコモ)	DoCoMo	Incumbent (NTT group)	docomo IoT (LTE-M, Cat-1, 5G)	Historically the largest subscriber base, interoperability testing (IOT) for modules
KDDI	au	Incumbent	KDDI IoT, KDDI IoT Connect Air	CDMA heritage, LTE/5G transition, mature industrial IoT
SoftBank	SoftBank (ソフトバンク)	Incumbent (former Vodafone Japan)	SoftBank IoT, Wireless City Planning	Vodafone heritage, WCP for lower bands
Rakuten Mobile	Rakuten Mobile (楽天モバイル)	Challenger (since 2020)	Rakuten Communications Platform	Fully virtualised Open RAN, announced 5G SA-native

The first three (NTT DoCoMo, KDDI, SoftBank) are long-standing incumbents with 2G then 3G heritage, large subscriber bases on the low bands (800 MHz, 900 MHz, 1.5 GHz, 1.7 GHz, 2 GHz) and 4G/5G rollouts in mid-band and sub-6. Their acceptance programmes are as old as their networks: well-run, with many pre-certified modules available off the shelf. Their 3G legacy is now entirely gone: KDDI closed its CDMA 1X WIN 3G network on March 31, 2022, SoftBank closed its 3G network on April 15, 2024, and NTT DoCoMo ended FOMA (3G W-CDMA) on March 31, 2026. No 2G or 3G fallback exists any longer in Japan for an IoT product.

Rakuten Mobile is a greenfield operator commercially launched in 2020. It built its access network as a fully virtualised Open RAN, with no 2G or 3G legacy, opting for a cloud-native architecture. Its acceptance logic is more recent and reflects that architecture: compatibility tests are oriented more toward pure 4G LTE and 5G NR SA profiles, without the legacy fallback layers of the incumbents.

NTT DoCoMo: interoperability testing (IOT)

NTT DoCoMo gates access to its network on modules and terminals that have completed its interoperability testing, abbreviated IOT (Inter-Operability Testing): protocol testing, performance testing, antenna performance and field testing, with the exact list depending on the device type and its specifications. A product that integrates an already IOT-completed module benefits from a significantly shortened test programme compared with integrating a bare chipset, and the application must be filed roughly two months before the desired start date. Module vendors (Telit, Sierra Wireless, Fibocom, Nordic and others) publicly announce completion of this testing. On the service side, docomo sells IoT plans on LTE Cat-M, Cat-1 and 5G NR; its NB-IoT service was shut down in March 2020, less than a year after launch.

KDDI (au): KDDI IoT and KDDI IoT Connect Air

KDDI markets its consumer mobile services under the au brand and its enterprise services under KDDI. Its IoT offer is built around the KDDI IoT services and the KDDI IoT Connect Air connectivity offer. As an heir to a 3G CDMA2000 network (CDMA 1X WIN) closed on March 31, 2022, KDDI retains a strong focus on low bands (Band 18 at 800 MHz, Band 26 encompassing). KDDI acceptance covers the deployed bands (Band 1, 3, 11, 18/26, 28, 41 LTE; n28, n77, n78, n257 NR), IMS profiles (VoLTE, VoNR), eUICC and inter-band handover.

SoftBank: SoftBank IoT and Wireless City Planning

SoftBank emerged from the Vodafone Japan acquisition in 2006. For the 2.5 GHz TDD band (Band 41), it operates through the Wireless City Planning (WCP) subsidiary, which holds the AXGP licence. Its SoftBank IoT offer covers Cat-M, NB-IoT, LTE-A and 5G NR segments. SoftBank acceptance reviews compatibility with the group's bands (Band 1, 3, 8, 11, 28, 41 LTE; n3, n28, n77, n257 NR), IMS profiles and eUICC rules.

Rakuten Mobile: Open RAN and 5G SA-native

Rakuten Mobile entered commercial operation in 2020 as the fourth national operator, with a distinctive architecture: a fully virtualised RAN in Open RAN, without a dominant traditional vendor, and an announced 5G NR SA-native orientation. Rakuten acceptance therefore tests specific behaviours (handover resilience in vRAN, performance on pure 5G SA), but does not cover the non-existent 2G/3G legacy. A module optimised for 5G SA on Rakuten must also demonstrate its 4G LTE behaviour if incumbents are targeted.

Layered architecture

Compliance stack for a cellular module in Japan:

+-----------------------------------------------+
|  Commercial layer: operator contract,          |
|  SIM or eUICC profile, tariff plan             |
+-----------------------------------------------+
|  Operator acceptance (per target operator):    |
|  - NTT DoCoMo: interop testing (IOT)           |
|  - KDDI au:    KDDI IoT, IoT Connect Air       |
|  - SoftBank:   SoftBank IoT, WCP (AXGP 2.5G)   |
|  - Rakuten:    Rakuten Mobile vRAN, 5G SA      |
|  Deployed bands, IMS, handover, eUICC          |
+-----------------------------------------------+
|  eUICC profile and RSP (GSMA SGP.22 / SGP.32): |
|  operator SM-DP+, profile downloadable         |
|  conditional on device acceptance              |
+-----------------------------------------------+
|  GITEKI radio (TELEC or another radio RCB):    |
|  compliance with MIC ordinances, band plan,    |
|  output power, emission masks                  |
+-----------------------------------------------+
|  Regulatory frame: MIC (Soumusho), Denpa-hou,  |
|  Frequency Allocation Plan                     |
+-----------------------------------------------+

A failure at any layer blocks the layers above. A module without GITEKI cannot be sold, so no operator acceptance starts. A GITEKI module without NTT DoCoMo acceptance fails to attach to the NTT DoCoMo network, even with a NTT DoCoMo SIM inserted.

Which cellular bands does Japan use?

The Japanese cellular frequency plan published by MIC allocates specific bands to operators and shows several important deviations from the North-American (FCC) and European (CEPT) plans. The table below summarises the main bands deployed as of 2026.

3GPP band	Frequency (DL)	Main operators	Use and specificity
Band 1 LTE	2110-2170 MHz	NTT DoCoMo, KDDI, SoftBank	Global band, little JP specificity
Band 3 LTE	1805-1880 MHz	NTT DoCoMo, KDDI, SoftBank, Rakuten	Global band, Rakuten's main 4G band
Band 8 LTE	925-960 MHz	SoftBank	900 MHz platinum band, low-band coverage
Band 11 LTE	1475.9-1495.9 MHz	KDDI, SoftBank	Japan-specific band, 1.5 GHz
Band 18 LTE	860-875 MHz	KDDI au	Japanese 800 MHz KDDI, distinct from US Band 5 and EU Band 20
Band 19 LTE	875-890 MHz	NTT DoCoMo	Japanese 800 MHz NTT DoCoMo, distinct from Band 18
Band 21 LTE	1495.9-1510.9 MHz	NTT DoCoMo	NTT DoCoMo 1.5 GHz Japan
Band 26 LTE	859-894 MHz	KDDI au	Encompassing Band 18, extended 3GPP nomenclature
Band 28 LTE	758-803 MHz	NTT DoCoMo, KDDI, SoftBank, Rakuten	700 MHz APT, Rakuten since June 2024
Band 41 LTE	2496-2690 MHz	KDDI (UQ WiMAX 2+), SoftBank (AXGP via WCP)	2.5 GHz TDD
Band 42 LTE	3400-3600 MHz	NTT DoCoMo, KDDI, SoftBank	3.5 GHz TDD, being refarmed to 5G
n28 NR	758-803 MHz	NTT DoCoMo, KDDI, SoftBank	700 MHz 5G low-band coverage
n77 NR	3300-4200 MHz	KDDI, SoftBank, Rakuten	5G sub-6 GHz, shared with n78
n78 NR	3300-3800 MHz	NTT DoCoMo, KDDI	5G mid-band 3.5 GHz, global band
n79 NR	4400-5000 MHz	NTT DoCoMo	5G 4.5 GHz, docomo only, rare in global modules
n257 NR	26.5-29.5 GHz	NTT DoCoMo, KDDI, SoftBank, Rakuten	mmWave 28 GHz, niche rollout

Band 18 / Band 19: two 800 MHz bands not to be confused

Band 18 (KDDI au) and Band 19 (NTT DoCoMo) are two distinct Japanese 800 MHz bands which do not coincide with US Band 5 (824-849 MHz UL / 869-894 MHz DL) nor with EU Band 20 (832-862 MHz UL / 791-821 MHz DL). A cellular module designed for the US or EU market on the 800 MHz band is not, without explicit support, compatible with Japanese 800 MHz. This is one of the most frequent causes of poor low-band coverage on Japanese networks. Band 26, defined in 3GPP as encompassing Band 18, is what KDDI typically signals in module firmware for 800 MHz JP coverage.

n79 4.5 GHz, an NTT DoCoMo specificity

The n79 band (4400-5000 MHz, operated around 4.5 GHz in Japan) is deployed only by NTT DoCoMo among Japanese operators. In mainland China it is allocated to China Mobile (4.8-4.9 GHz) with localised capacity deployments. n79 support remains rare in global cellular modules: a 5G product targeting NTT DoCoMo's full mid-band coverage must explicitly verify that the selected module supports n79.

mmWave n257, niche rollout

The n257 band (28 GHz) is allocated to all four Japanese operators, but rollout remains limited to very high-density areas (major railway stations, events). Designing an IoT product that assumes mmWave is available everywhere in Japan is a hypothesis not to make in 2026: mmWave coverage is marginal compared to sub-6 GHz.

eUICC and RSP in Japan

eUICC (embedded UICC) and RSP (Remote SIM Provisioning) are supported by all four Japanese operators, with their own SM-DP+, activation rules and profiles. Applicable specifications:

• GSMA SGP.22 for consumer eUICC (smartphones, watches): pull model, QR code or activation code, per-operator SM-DP+.
• GSMA SGP.32 for IoT eUICC (cellular modules without user interface): push model orchestrated by an IoT Profile Assistant (IPA).

Device acceptance is generally a prerequisite for an operator profile to be downloadable: until the module identifiers (EID, IMEI, attached certifications) are recognised, the SM-DP+ refuses the download. For a multi-operator IoT product, each target operator must have accepted the device and profiles must be downloadable through eUICC. A physical multi-IMSI SIM is the historical alternative, increasingly displaced by eUICC.

Module-level pre-acceptance

Most cellular modules sold for the Japanese market (Cat-M / Cat-1 / Cat-4 / Cat-6 / 5G NR modules from major Asian and European vendors) are pre-certified with one or more Japanese operators. The module datasheet explicitly declares supported operators, with phrasing such as:

• "Pre-certified NTT DoCoMo" (interoperability testing IOT completed),
• "Pre-certified KDDI au",
• "Pre-certified SoftBank",
• "Pre-certified Rakuten Mobile".

A non pre-certified module can technically undergo operator acceptance through the integrating manufacturer, but cost and lead time are prohibitive outside volumes that justify the investment. The practical rule is to select the module against the operator footprint targeted by the final product and to prefer modules already pre-certified with the relevant operators.

See PTCRB for the analogue logic on the North-American side, where PTCRB Type Approval plays a similar cross-operator pre-validation role, complemented by individual AT&T, Verizon and T-Mobile acceptance.

JATE and terminal equipment approval

JATE (Japan Approvals Institute for Telecommunications Equipment) is the historical approval body for terminal equipment under the Telecommunications Business Act (電気通信事業法), the sister law of the Radio Law covered by GITEKI. This terminal approval (T mark) applies to any equipment connected to a public telecommunications network: wireline interfaces (PSTN, DSL, leased lines, certain VoIP gateways) but also cellular terminals and modules that attach to an operator's network. A cellular module targeted at Japan therefore generally carries two regulatory references, the Radio Law certification (GITEKI, R mark) and the terminal equipment approval (T mark), often assessed in the same campaign. The operator acceptance described in this page remains a separate process from these two layers.

Terminal equipment approval naturally also covers hybrid products, for example:

• a gateway combining a 4G/5G cellular modem and a DSL port,
• a payment terminal with cellular fallback and a PSTN line,
• an industrial device with both wireline and cellular backhaul.

For such products, the wireline interface compliance adds to the cellular interface compliance, in parallel with radio compliance. See TELEC / GITEKI in Japan for the detailed scope of Japanese radio RCBs.

A typical operator acceptance programme

Typical sequence for a manufacturer approaching Japan with a cellular module or product:

1. Commercial scoping: identify the target operator(s) based on the final product's market.
2. Module selection: prefer a module already pre-certified with the target operators. Explicitly verify support for critical bands (Band 18, 19, 28, n28, n78, n79 depending on targeted operators).
3. GITEKI via TELEC or another radio RCB: run the MIC radio certification, per the regime detailed in TELEC / GITEKI in Japan. Without GITEKI, no operator acceptance can start.
4. Operator engagement(s): open the acceptance file with each target operator (technical characteristics, GITEKI number, test reports, embedded module certifications, PTCRB where relevant).
5. Operator test campaign: each operator runs its own tests (or via partner lab) on radio behaviour, network attach, inter-band handover, IMS (VoLTE, VoNR), eUICC handling and integration with operator-specific services.
6. Question handling and issuance: iterative cycles, then device added to the list of compatible terminals. For NTT DoCoMo, this corresponds to completion of interoperability testing (IOT).
7. eUICC provisioning: operator profiles become downloadable through the SM-DP+ for accepted devices; commercial logistics (EID, activation, supervision) kicks in.
8. Maintenance: any hardware change (module, RF chain, antenna) or major modem firmware change can trigger partial or full re-acceptance.

For the global multi-market schedule, see the certification timeline.

See also

• Telstra, Optus, TPG: cellular IoT acceptance in Australia
• HAC: Hearing Aid Compatibility (FCC 20.19, C63.19)
• China Mobile, Telecom, Unicom: cellular IoT acceptance
• AT&T Network Ready: carrier homologation, cellular IoT
• Verizon Open Development: carrier homologation after PTCRB

Working on operator acceptance in Japan (NTT DoCoMo, KDDI au, SoftBank, Rakuten Mobile) for a cellular product for a real product? AESTECHNO can audit your design and certification plan. Get in touch →

Frequent pitfalls for non-Japanese manufacturers

Assuming GITEKI is enough to attach to the network

The most frequent scoping error. GITEKI attests radio compliance with MIC, which authorises sale and use of the device. It does not mean operators will accept network attach. A GITEKI-only device without NTT DoCoMo acceptance fails authentication on the NTT DoCoMo network, even with a NTT DoCoMo SIM inserted.

Forgetting bands 18, 19 and 26 for Japanese 800 MHz

A module designed for the US or EU market on 800 MHz typically covers Band 5 (US) or Band 20 (EU), neither used in Japan. Japanese 800 MHz uses Band 18 (KDDI au) and Band 19 (NTT DoCoMo), with Band 26 as the 3GPP encompassing definition for KDDI. Without explicit support, low-band coverage in Japan is non-existent: a recurring cause of Japanese IoT products limited to mid-band, with disappointing indoor performance.

Confusing Band 18 and Band 19

Band 18 is KDDI, Band 19 is NTT DoCoMo. The two are not interchangeable: UL and DL sub-bands differ. For a product targeting both KDDI and NTT DoCoMo in low band, the module must support Band 18 and Band 19, or Band 26 (encompassing 18) plus Band 19.

Assuming one operator's acceptance covers all four

NTT DoCoMo interoperability testing (IOT) is specific to its network. A module that has completed it is not pre-accepted by KDDI, SoftBank or Rakuten. Each operator runs its own programme, list and criteria. The module datasheet must declare each supported operator explicitly.

Universal 5G SA assumption for Rakuten or incumbents

Rakuten Mobile has announced a 5G SA-native architecture, but SA coverage is not universal across Japan as of 2026. NTT DoCoMo, KDDI and SoftBank operate NSA and migrate to SA progressively by area and band. A product depending on SA everywhere is a hypothesis to verify per operator, band and region. Robust 4G LTE fallback remains essential.

eUICC and acceptance mismatch

eUICC does not bypass operator acceptance. On a device not accepted by an operator, the SM-DP+ refuses to download that operator's profile. Subscribing a device on several operators means acceptance from each and coordination with their respective SM-DP+.

Neglecting operator-specific IMS profiles (VoLTE, VoNR)

Japanese IMS profiles may differ from US or EU profiles on voice codecs and emergency services (110, 119, 118). A device without the target IMS profile may be accepted data-only, with no VoLTE and no emergency calls, which excludes some use cases.

Confusing operator acceptance with PTCRB

PTCRB is North-American. It enables cross-operator test reuse among US operators but has no direct equivalent in Japan: each operator runs its acceptance independently. See PTCRB for the North-American regime.

Underestimating the overall schedule

A multi-operator programme in Japan must be planned over several months, in parallel where possible but with re-test dependencies if a shared band reveals an issue.

Further reading

• TELEC / GITEKI in Japan: the upstream radio certification, MIC and RCBs
• PTCRB: North-American cellular pillar, partial analogue
• Certification timeline
• Glossary: GITEKI, MIC, TELEC, eUICC, SM-DP+, IMS, NSA, SA, vRAN

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Sources & references

1. NTT DoCoMo: interoperability testing (IOT) for modules and devices , NTT DoCoMo www.nttdocomo.co.jp/biz/support/iot/
2. NTT DoCoMo: supported frequency bands per device (band.pdf) , NTT DoCoMo www.docomo.ne.jp/binary/pdf/support/product/band.pdf
3. KDDI IoT: enterprise IoT services , KDDI biz.kddi.com/service/iot/
4. KDDI: end of CDMA 1X WIN 3G service on March 31, 2022 , KDDI news.kddi.com/kddi/corporate/english/newsrelease/2021/11/29/5581.html
5. SoftBank IoT: enterprise IoT solutions , SoftBank www.softbank.jp/biz/services/iot/
6. SoftBank: discontinuation of 3G service on April 15, 2024 , SoftBank www.softbank.jp/en/corp/news/press/sbkk/2024/20240313_01/
7. Rakuten Mobile network: technical overview , Rakuten Mobile network.mobile.rakuten.co.jp/
8. MIC (English): Ministry of Internal Affairs and Communications , MIC / Soumusho www.soumu.go.jp/english/
9. GSMA SGP.22 and SGP.32: Remote SIM Provisioning specifications , GSMA www.gsma.com/solutions-and-impact/technologies/esim/esim-specification/