Below 1 GHz lies the quiet workhorse spectrum of the connected world. Sub-GHz radio — and the 433 MHz band in particular — carries an enormous share of the world’s short-range wireless traffic: car key fobs, gate and garage door openers, wireless doorbells, weather stations, tyre pressure monitoring systems, industrial remote controls, alarm sensors, smart meters, and a fast-growing population of LPWAN IoT nodes. Sub-GHz signals travel further and penetrate walls better than 2.4 GHz, at very low power — which is precisely why regulators keep these bands on a tight technical leash.

In India, the sub-GHz short range device (SRD) landscape is defined by a cluster of gazette notifications issued by the WPC Wing of the Department of Telecommunications: GSR 680 (E) and GSR 698 (E) for the 433 MHz band, GSR 1047 (E) — the omnibus short range device notification of 18.10.2018 — for a wide set of bands from 169 MHz to 61 GHz, and GSR 564 (E) for 865–867 MHz, which doubles as India’s main licence-exempt LPWAN band. Every device using these bands requires WPC Equipment Type Approval (ETA) before import or sale, obtainable through self-declaration because the bands are de-licensed. This guide explains each notification, the duty-cycle and power conditions that trip up product teams, and the full ETA process for sub-GHz devices.

The 433 MHz Band: Two Notifications, Read Together

GSR 680 (E) dated 12.09.2012 — 433–434 MHz Indoor Devices

GSR 680 (E) de-licensed 433–434 MHz for low power devices or equipment for indoor applications, with conditions of 10 mW maximum power and channel bandwidth within 10 kHz, using built-in antennas. This notification covers the classic indoor use cases: wireless sensors, remote switches, and home automation nodes.

GSR 698 (E) dated 16.09.2015 — 433–434.79 MHz Including RFID

GSR 698 (E) extended the de-licensed range to 433–434.79 MHz for very low power radio frequency devices including Radio Frequency Identification Devices, at 10 mW e.r.p with maximum channel bandwidth of 10 kHz and a duty-cycle limit of 10%. The wider band edge and explicit RFID coverage make this the primary basis for active tags, key fobs, and telemetry devices in the 433 MHz ISM range.

The practical conditions for any 433 MHz product entering India are therefore: stay inside 433–434.79 MHz, keep radiated power at or below 10 mW e.r.p, respect the narrow 10 kHz channel bandwidth condition, and keep transmit duty cycle at or below 10%.

GSR 1047 (E): India’s Omnibus Short Range Device Notification

GSR 1047 (E) dated 18.10.2018 is the broadest SRD notification in the Indian framework, de-licensing multiple bands for low power and very low power short range devices across nine device families: inductive devices, active medical implants, high duty cycle / continuous transmission devices, assistive listening devices, Personal Mobile Radio (PMR 446), radio determination devices, RFID, transport and traffic telematics devices, and non-specific short range devices.

Key sub-GHz entries include:

The duty-cycle figures deserve emphasis: the 169 MHz sub-bands range from 1% down to an extraordinarily strict 0.001%. A firmware beaconing schedule that would be legal in Europe may violate the Indian conditions — duty cycle is a design parameter, not a paperwork afterthought.

PMR 446: India’s Licence-Exempt Walkie-Talkie Band

Consumer walkie-talkies are a recurring compliance flashpoint. Under GSR 1047 (E), licence-exempt PMR operation is confined to 446–446.2 MHz at up to 500 mW e.r.p with 6.25/12.5 kHz channel spacing. Imported radios covering wider ranges (e.g., 400–470 MHz handhelds) are not compliant, are regularly seized at customs, and have triggered marketplace delistings. Only radios locked to the notified PMR band parameters can obtain ETA through self-declaration.

865–867 MHz: India’s LPWAN Home

India’s licence-exempt sub-GHz IoT deployments — LoRaWAN above all — operate in 865–867 MHz under GSR 564 (E) dated 30.07.2008, sharing the band with UHF RFID. The conditions (1 W transmitter power, 4 W e.r.p, 200 kHz carrier bandwidth) accommodate LoRa gateways and nodes using the IN865 channel plan. Manufacturers of LoRa modules, gateways, trackers, and smart city sensors must ensure regional firmware uses the Indian channel plan, and each shipped model requires its own ETA.

Step-by-Step: WPC ETA Self-Declaration for Sub-GHz Devices

1. Fix the India RF profile. Confirm operating frequencies, power, bandwidth, and duty cycle against the exact notification that covers your band. Where hardware supports multiple regions, lock the India SKU in firmware.
2. Accredited RF testing. Obtain test reports evidencing frequency range, radiated power (e.r.p), occupied bandwidth, and duty-cycle behaviour. EN 300 220 is the commonly referenced standard family for sub-GHz SRDs.
3. Register on Saral Sanchar (saralsanchar.gov.in). Foreign manufacturers file through an Authorised Indian Representative (AIR) or Indian importer.
4. Submit the ETA-SD application with model and RF module details, band/power declarations, test reports, and datasheets.
5. Pay ₹10,000 government fee per application/model online.
6. Download the ETA certificate generated on self-declaration basis.
7. Import with undertaking. Present the ETA and customs undertaking confirming operation in de-licensed bands.

Documents Required

• Saral Sanchar ETA-SD online application
• RF test report from an accredited laboratory (frequency, e.r.p, bandwidth, duty cycle)
• Device and RF module datasheets
• Declaration of India-specific channel plan and power configuration
• Applicant incorporation documents and IEC
• AIR authorisation letter for foreign manufacturers
• Customs undertaking accompanying the ETA at import

Common Causes of Rejection and Customs Trouble

• Out-of-band operation. Devices transmitting at 433.92 MHz but with modulation spilling beyond 434.79 MHz, or “433 MHz” products actually shipping 315 MHz variants (a US band, not de-licensed in India).
• Duty-cycle violations. Beacon intervals and retry logic that exceed the notified duty-cycle limits, particularly in the 169 MHz and 433 MHz bands.
• Bandwidth non-conformity. The 10 kHz channel bandwidth condition at 433 MHz is incompatible with some wideband modulation schemes — verify before committing hardware.
• Wide-band walkie-talkies. Radios tunable outside 446–446.2 MHz cannot be approved via self-declaration and face seizure.
• External high-gain antennas. e.r.p limits include antenna gain; swapping antennas post-approval can silently break compliance.
• Unlocked multi-region firmware. If the device can be user-configured to non-Indian bands, expect scrutiny — India-locked firmware is the safe route.

Design Notes: Engineering Within the Indian Sub-GHz Rules

Duty cycle is a system property. The notified duty-cycle limits apply to how the device actually behaves on air, which is a function of firmware: packet length, retry counts, acknowledgement schemes, and beacon intervals. A sensor that transmits a 50 ms frame every 10 seconds runs at 0.5% duty cycle — comfortably inside the 10% limit at 433 MHz but far above the 0.001% limit in the 169.4875–169.5875 MHz sub-band. Engineering teams should compute worst-case duty cycle (including retries under poor link conditions) and document it, because that calculation is exactly what a reviewer or auditor will ask for.

Bandwidth discipline at 433 MHz. The 10 kHz channel bandwidth condition rules out several popular wideband modulation profiles in this band. Narrowband FSK/OOK links fit naturally; anything wider needs careful verification of occupied bandwidth at the notified measurement points. Where a protocol cannot fit 10 kHz, the practical answer is usually to move the design to 865–867 MHz, where the 200 kHz carrier bandwidth accommodates LoRa and similar schemes.

e.r.p includes the antenna. All sub-GHz limits are radiated (e.r.p), so the same transmitter module can be compliant with an integral PCB antenna and non-compliant with a customer-fitted whip. Products designed for field-replaceable antennas should specify the maximum permissible gain in the manual and the compliance file — and ideally use connectors that discourage arbitrary substitution.

Multi-region platforms. Silicon vendors ship sub-GHz SoCs covering 315/433/868/915 MHz in one part. The India compliance question is not what the chip can do but what the shipped product does: region-locked firmware, an India SKU in the production system, and test reports on that configuration. Products that expose band selection to end users invite scrutiny that region-locked products avoid.

Timeline, Cost, and Enforcement Realities

A sub-GHz sensor or remote with a settled India configuration moves through the process quickly: about a week for documentation and band mapping, one to two weeks for accredited testing (duty-cycle characterisation adds some time versus simple power measurements), and days for the Saral Sanchar ETA-SD filing at the ₹10,000 government fee per model. Product families sharing one radio platform amortise test evidence across SKUs.

Enforcement in this segment concentrates at two choke points. The first is customs, where consignments of remotes, sensors, and walkie-talkies are checked for ETA — wide-band handheld radios are among the most frequently seized wireless products in India. The second is marketplaces, which have delisted large numbers of non-compliant walkie-talkie and remote-control listings. For legitimate brands this enforcement is good news: the compliant path through ETA-SD is inexpensive and fast, and it clears the field of grey-market competition that cannot produce approval evidence.

Related Approvals for Sub-GHz Products

Most sub-GHz devices also require BIS CRS registration where the product category is notified, EPR e-waste registration with CPCB, and Legal Metrology (LMPC) compliance for packaged imports. Devices with cellular fallback (NB-IoT/LTE-M) bring TEC MTCTE into scope. Battery-powered nodes additionally engage EPR for battery waste.

Pre-Launch Compliance Checklist for Sub-GHz Products

Sub-GHz products punish assumptions, so verify the fundamentals before committing to tooling or shipment. Start with the band question: confirm the product family’s India variant transmits inside 433–434.79 MHz (or 865–867 MHz for LPWAN designs) and that no 315 MHz or 868/915 MHz stock can reach the Indian channel. Confirm the three notified conditions numerically — radiated power at or below 10 mW e.r.p including antenna gain, occupied bandwidth within the 10 kHz channel condition, and worst-case duty cycle at or below 10% with retries included. Write these three numbers into the engineering release documentation so they survive team changes.

Next, verify the evidence chain: the accredited test report should name the shipped model, state the Indian band edges, and include the duty-cycle characterisation — reports that omit duty cycle invite questions precisely where the Indian conditions are strictest. Confirm the applicant arrangement (importer or AIR), file the ETA-SD, and archive the certificate with the test report and firmware version as one immutable compliance pack per model.

For walkie-talkie and PMR products, apply a harder gate: physically verify that production units cannot tune outside 446–446.2 MHz, because tunable radios are seized regardless of paperwork. For LoRa deployments, confirm gateways and nodes both carry approval and that the IN865 channel plan is locked in the network server as well as the devices. And for products sold through marketplaces, keep the ETA PDF ready for listing verification — platforms ask for it with short deadlines, and a delisted festival-season listing is an expensive way to locate a filing cabinet.

Frequently Asked Questions

Is 433 MHz legal in India without a licence?

Yes — within 433–434.79 MHz at up to 10 mW e.r.p, 10 kHz channel bandwidth, and 10% duty cycle under GSR 698 (E). The device model still requires ETA.

Is 315 MHz allowed in India?

No de-licensing notification covers 315 MHz. Products must use their 433 MHz variants for India.

Which band should my LoRa product use?

865–867 MHz (IN865 plan) under GSR 564 (E), at up to 1 W transmitter power / 4 W e.r.p with 200 kHz carrier bandwidth.

Do simple key fobs and doorbells really need ETA?

Yes. Any transmitting device model requires ETA, however small. The self-declaration route keeps the burden modest — ₹10,000 fee and an RF test report.

Can walkie-talkies be sold freely in India?

Only PMR sets confined to 446–446.2 MHz at ≤500 mW with notified channel spacing qualify for licence-exempt use and ETA-SD. Anything wider requires licensing and is effectively blocked for consumer sale.

How long does ETA take for a sub-GHz sensor?

Days, once accredited test reports exist; two to four weeks end to end including lab time is a sensible plan.

What happens if my device transmits on both 433 MHz and 2.4 GHz?

Both radios are covered in one ETA application for the model — the 433 MHz link against GSR 698 (E) and the 2.4 GHz link against GSR 45 (E) — each supported by its own test evidence. Hybrid remotes and hubs with dual radios are common and file smoothly when both bands are declared.

Do I need to re-test if I change only the enclosure or branding?

Cosmetic changes that do not affect the antenna, RF layout, power, or firmware behaviour generally do not require new testing, but the model designation must remain traceable to the approved configuration. If the enclosure change moves or detunes the antenna, treat it as an RF change and reassess.

Why Choose PCN India Global

• Notification mapping — we identify exactly which GSR applies to your band, power, and application before testing
• Duty-cycle and bandwidth review — firmware behaviour assessed against the notified conditions, not just the datasheet
• Accredited lab coordination — sub-GHz test plans aligned to EN 300 220 methodology and Indian parameters
• End-to-end ETA-SD filing — Saral Sanchar registration through certificate download
• AIR services — Authorised Indian Representative support for overseas manufacturers
• Customs and marketplace support — undertakings, clearance queries, and listing-verification documentation

It is worth closing with the bigger picture. Sub-GHz wireless is becoming more important in India, not less: smart metering programmes, agricultural sensing, logistics tracking, and building automation are all expanding on the back of LPWAN economics, and the 865–867 MHz band is carrying an ever-larger share of the country’s machine-to-machine traffic. Regulators respond to growing bands with growing scrutiny, and the gap between compliant and non-compliant suppliers will keep widening — in customs outcomes, in marketplace access, and in enterprise procurement decisions. For manufacturers and importers, the strategic takeaway is simple: the Indian sub-GHz rules are stable, published, and inexpensive to satisfy through the self-declaration route, so there is no commercial logic in shipping grey. Lock the India configuration at design time, keep the evidence pack current, and the entire regulatory layer becomes a solved problem that never touches a launch date.

PCN India Global manages end-to-end WPC ETA approval for 433 MHz, 169 MHz, PMR 446, and 865–867 MHz devices — from band selection to certificate grant and import clearance. Contact us: WhatsApp +91 92895 87478 or email bdm@pcnindiaglobal.com.