MIIT 2021 No. 129 Updates China’s Requirements for Multiple Types of Radio Services
On October 13, 2021, the Ministry of Industry and Information Technology of the People’s Republic of China (MIIT) issued MIIT 2021 No. 129, “Notice on Strengthening and Standardizing the Radio Management of 2400 MHz, 5100 MHz, and 5800 MHz bands.” This regulation came into effect on January 1, 2022, with a two-year transitional period.
Scope
MIIT 2021 No. 129 applies to equipment operating in the 2400-2483.5 MHz, 5150-5350 MHz, and 5725-5850 MHz frequency bands which are allocated for multiple types of radio services, including fixed, mobile, radio navigation, fixed-satellite, earth exploration-satellite, satellite radiolocation, or space research applications. The 2400-2483.5 MHz and 5725-5850 MHz bands are also designated for industrial, scientific, and medical (ISM) applications that emit electromagnetic energy, which is subject to a different regulation. Radio stations or equipment do not have exclusive access to or use of the 2400-2483.5 MHz, 5150-5350 MHz, and 5725-5850 MHz frequency bands.
The 2400-2483.5 MHz frequency band can be used for radio communications systems utilizing wideband radio access (including wireless local area network (LAN)), Bluetooth transceivers, and point-to-point transmission. The 5150-5350 MHz frequency band can be used for radio communications systems utilizing wideband radio access (including wireless LAN), but is restricted to indoor use only (except devices installed in vehicles). The 5725-5850 MHz frequency band can be used for radio communication systems utilizing wideband radio access (including wireless LAN), point-to-point transmission, and electronic toll collections (ETC).
Technical Requirements
General Technical Requirements
The general technical requirements under MIIT 2021 No. 129 are summarized in Table 1. Antenna assembly gain and beamforming gain are taken into account for equipment employing multiple antennas, when performing equivalent isotropically radiated power (EIRP, Pe.i.r.p.) and power spectrum density (PSDe.i.r.p.) measurements.
| Parameter | Limits / Specifications | ||
| Frequency Band (MHz) | 2400-2483.5 | 5150 – 5350 | 5725 – 5850 |
| EIRP Power, Pe.i.r.p | Antenna Assembly Gain < 10 dBi:
≤ 20 dBm ≤ 27 dBm |
≤ 23 dBm | ≤ 33 dBm |
| EIRP Power Spectral Density, PSDe.i.r.p | DSSS or other Equipment: Antenna Assembly Gain < 10 dBi: ≤ 10 dBm/MHz Antenna Assembly Gain ≥ 10 dBi: ≤ 17 dBm/MHz FHSS Equipment: ≤ 20 dBm/100kHz |
≤ 10 dBm/MHz | ≤ 19 dBm/MHz |
| Frequency Tolerance | ≤ 20 x 10 -6 | ≤ 20 x 10 -6 | ≤ 20 x 10 -6 |
| Out of Band Transmit Power | ≤ -80 dBm/Hz | ≤ -80 dBm/Hz | ≤ -80 dBm/Hz |
| Spurious Emissions 1 | 30 MHz – 1 GHz: -36 dBm2 1 – 12.75 GHz: -30 dBm3 |
30 MHz – 1 GHz: -36 dBm2 1 – 26 GHz: -30 dBm3 |
30 MHz – 1 GHz: -36 dBm2 1 – 26 GHz: -30 dBm3 |
| Spurious Emissions 1 – Special Bands | 48.5 – 72.5 MHz: -54 dBm2 76 – 118 MHz: -54 dBm2 167 – 223 MHz: -54 dBm2 470 – 702 MHz: -54 dBm2 2300 – 2380 MHz: -40 dBm3 2380 – 2390 MHz: -40 dBm2 2390 – 2400 MHz: -30 dBm2 2400 – 2483.5 MHz *: -33 dBm2 2483.5 – 2500 MHz: -40 dBm3 5150 – 5350 MHz: -40 dBm3 5725 – 5850 MHz: -40 dBm3 |
48.5 – 72.5 MHz: -54 dBm2 76 – 118 MHz: -54 dBm2 167 – 223 MHz: -54 dBm2 470 – 702 MHz: -54 dBm2 2400 – 2483.5 MHz: -40 dBm3 2483.5 – 2500 MHz: -40 dBm3 5150 – 5350 MHz *: -33 dBm2 5725 – 5850 MHz: -40 dBm3 |
48.5 – 72.5 MHz: -54 dBm2 76 – 118 MHz: -54 dBm2 167 – 223 MHz: -54 dBm2 470 – 702 MHz: -54 dBm2 2400 – 2483.5 MHz: -40 dBm3 2483.5 – 2500 MHz: -40 dBm3 5150 – 5350 MHz: -40 dBm3 5470 – 5705 MHz: -40 dBm3 5705 – 5715 MHz: -40 dBm2 5715 – 5725 MHz: -30 dBm2 5725 – 5850 MHz *: -33 dBm2 5850 – 5855 MHz: -30 dBm2 5855 – 7125 MHz: -40 dBm3 |
| Dynamic Frequency Selection (DFS) (5250-5350 MHz only) |
Not applicable | Detection Threshold: ≤ -62 dBm, Detection Probability: ≥ 60%, Channel Availability Check Time: ≥ 60 s, Channel Move Time: ≤ 10 s, Channel Close Transmit Time: ≤ 1 s, Non-occupancy Period: ≥ 30 min |
Not applicable |
| Transmit Power Control (TPC) (5250-5350 MHz only) |
Not applicable | ≥ 6 dB | Not applicable |
| Detection = RMS. RBW = 100 kHz RBW = 1 MHz *: In band spurious emissions |
DSSS: Direct Sequence Spread Spectrum EIRP: Equivalent Isotropically Radiated Power FHSS: Frequency Hopping Spread Spectrum RBW: Resolution Bandwidth |
Table 1: General technical requirements
Radio equipment operating in the 5250-5350 MHz frequency band must incorporate transmit power control (TPC) and dynamic frequency selection (DFS) functions and shall not include any feature designed to turn off the DFS function. TPC is a feature that enables a device to dynamically switch between several transmission power levels in the data transmission process. For equipment without TPC function, limits of Pe.i.r.p and PSDe.i.r.p. shall be 3 dB lower. DFS is a mechanism that dynamically detects signals from other systems and avoids co-channel operation with these systems.
Wireless LAN equipment with public network IP address allocation function shall support IPv6 protocol and enable the IPv6 address allocation function by default.
Adaptivity
Adaptivity is an automatic channel access mechanism by which a device limits its transmissions and gains access to an operating channel. It is intended to detect transmissions from other wireless LAN devices operating in the band. To comply with the requirements of MIIT 2021 No. 129, equipment operating in the 2400-2483.5 MHz, 5150-5350 MHz, and 5725-5850 MHz frequency bands shall implement an adaptivity mechanism. Adaptivity requirements are similar to the requirements in ETSI EN 300 328 (2400-2483.5 MHz frequency band) and ETSI EN 301 893 (5150-5350 MHz, and 5725-5850 MHz frequency bands).
Equipment operating in the 2400-2483.5 MHz frequency band shall implement either a “Listen Before Talk” (LBT) or a “Detect And Avoid” (DAA)-based channel access mechanism. Adaptivity parameters and specifications for this frequency band are summarized in Table 2.
|
Channel Access Mechanism |
Listen Before Talk (LBT) | Detect And Avoid (DAA) | |||
|
Equipment Type |
FHSS | Non-FHSS | FHSS | Non-FHSS | |
| Frame Based Equipment | Load Based Equipment | ||||
| CCA Observation Time | ≥0.2% COT; ≥16 µs | ≥16 µs | ≥16 µs | – | – |
| Silent Period | – | – | – | 1 s or 5 x Hopping Frequencies x COT, whichever is greater | 1 s |
| Duty Cycle of SCST | ≤10% | ≤10% | ≤10% | ≤10% | – |
| Channel Occupancy Time (COT) | <60 ms | 1 ms ≤ COT ≤ 10 ms | ≤13 ms | ≤40 ms | ≤40 ms |
| Idle Period | ≥5% COT; ≥100 µs | ≥5% COT | – | ≥5% COT; ≥100 µs | ≥5% COT; ≥100 µs |
| Detection Threshold Level (TL) | TL ≤ -70 dBm/MHz + 10 × lg (100 mW / Pout) Pout: EIRP Power in mW | ||||
| Unwanted Signal Parameters | 2395 MHz or 2488.5 MHz: -35 dBm, Continuous Wave (CW) | ||||
CCA: Clear Channel Assessment
FHSS: Frequency Hopping Spread Spectrum
SCST: Short Control Signaling Transmissions
Table 2: Adaptivity parameters and required specifications (2400-2483.5 MHz)
Equipment operating in the 5150-5350 MHz and 5725-5850 MHz frequency bands shall implement an LBT-based channel access mechanism. Adaptivity parameters and specifications for these frequency bands are summarized in Table 3.
| Channel Access Mechanism | Listen Before Talk (LBT) | |
| Equipment Type | Frame Based Equipment | Load Based Equipment |
| Fixed Frame Periods (FFP) | 1ms ≤ FFP ≤ 10ms | – |
| CCA Observation Time | ≥16 µs | ≥25 µs |
| Channel Occupancy Time (COT) | ≤95% FFP | ≤20 ms |
| Idle Period | ≥5% COT, ≥100µs | – |
| SCST Transmissions | ≤50 within 50 ms | ≤50 within 50 ms |
| Total SCST Transmissions Duration | 2500 µs | 2500 µs |
| Duty Cycle of SCST | ≤10% | ≤10% |
| Detection Threshold Level (TL) | ≤-75 dBm/MHz | |
CCA: Clear Channel Assessment
SCST: Short Control Signaling Transmission
Table 3: Adaptivity parameters and required specifications (5150-5350 MHz and 5725-5850 MHz)
For equipment operating in the 2400-2483.5 MHz frequency band, and not supporting any one of the above adaptivity mechanisms, and for the electronic toll collections (ETC) equipment operating in the 5725-5850 MHz frequency band, an “equivalent usage rate” mechanism applies. “Equivalent usage rate” (EU) shall not be greater than 10%, as calculated by using the following formula:
Where EU is the equivalent usage rate, DC is the duty cycle, and Plimit is EIRP power limit.
Equipment Authorization Procedure
Equipment authorization procedure “Radio Transmission Equipment Type Approval” applies to equipment operating in the 2400-2483.5 MHz, 5150-5350 MHz, and 5725-5850 MHz frequency bands, except for low-power short range devices (SRDs) and ISM equipment. All certified equipment is listed on the MIIT online service platform.
Regulations for the low power SRDs and ISM equipment are stipulated in China MIIT 2019 No. 52. Type approval is not required, but certain statements must be included in the user manual accompanying the equipment. Required technical parameters for the low-power short-range devices (SRDs) and ISM equipment operating in the 2400-2483.5 MHz and 5725-5850 MHz are listed in Table 4 for reference.
| Parameter | Limits / Specifications | |
| Frequency Band (MHz) | 2400-2483.5 | 5725 – 5850 |
| EIRP Power, Pe.i.r.p | 10 mW | 25 mW |
| Frequency Tolerance | 75 kHz | 100 x 10 -6 |
Table 4: Technical requirements for the low-power SRDs and ISM equipment
Transition
The requirements of MIIT 2021 No. 129 came into effect January 1, 2022, with a transitional period until October 15, 2023. The Regulation supersedes previous issued relevant regulations including, but not limited to, the following four regulations:
- “Notice on Adjusting 2.4 GHz Frequency Band Transmit Power Limits and Relevant Matters”
- “Notice on the Use of 5.8 GHz Frequency Band”
- “Notice on the Special Use of Intelligent Traffic Management of 5.8 GHz Frequency Band Wireless Short Range Communication Systems and Relevant Matters”
- “Notice on Use of 5150-5350 MHz Frequency Band Wireless Access Systems and Relevant Matters”
Effective October 15, 2023, equipment that falls under the scope of this regulation must comply with the technical requirements stipulated in MIIT 2021 No. 129. Prior to October 15, 2023, equipment may comply with technical requirements stipulated in the precedent regulations. Certificates applicable to equipment complying with the precedent regulations and certified after January 1, 2022 will expire on December 31, 2025.
Conclusion
Technical requirements from China MIIT 2021 No. 129 are significantly different from their precedent regulations. Complying with adaptivity, DFS, and TPS is now required. Spurious emissions limits apply to additional frequency bands. An EU rate adaptivity mechanism is introduced. Addressing these new technical requirements at the early stage of product development will help shorten the overall design cycle and speed up the introduction of new products to China’s market.
Acknowledgments
The author would like to thank Jessy Zhang of G&M Compliance for providing relevant information regarding China MIIT 2021 No. 129.
The author wishes to express her sincere appreciation to Wayne Owens of HYTORC for his support.
References
- “Notice on Strengthening and Standardizing the Radio Management of 2400 MHz, 5100 MHz, and 5800 MHz bands,” China MIIT 2021 No. 129, issued October 13, 2021.
- Interpretation on “Notice on Strengthening and Standardizing the Radio Management of 2400 MHz, 5100 MHz, and 5800 MHz bands,” issued October 14, 2021.
- “Low Power Short Range Devices Regulations,” China MIIT 2019 No. 52.
- “Low Power Short Range Devices Categories and Technical Requirements,” China MIIT 2019 No. 52 Attachment.
- “Notice on the Use of 5.8 GHz Frequency Band,” China MIIT 2002 No. 277, issued September 5, 2009.
- “Notice on Adjusting 2.4 GHz Frequency Band Transmit Power Limits and Related Matters,” China MIIT 2002 No. 353, issued May 30, 2019.
- “Notice on the Use of 5150-5350 MHz Frequency Band Wireless Access Systems and Related Matters,” China MIIT 2012 No. 620, issued January 30, 2013.
- “Notice on the Special Use of Intelligent Traffic Management of 5.8 GHz Frequency Band Wireless Short Range Communication Systems and Related Matters,” China MIIT 2003 No. 225.
- “Wideband transmission systems; Data transmission equipment operating in the 2,4 GHz band; Harmonised Standard for access to radio spectrum,” ETSI EN 300 328 V2.2.2 (2019-07).
- “5 GHz RLAN; Harmonised Standard covering the essential requirements of article 3.2 of Directive 2014/53/EU,” ETSI EN 301 893 V2.1.1 (2017-05).
