LPD433

LPD433 (low power device 433 MHz) is a UHF band in which license free communication devices are allowed to operate in some regions. The frequencies correspond with the ITU region 1 ISM band of 433.050 MHz to 434.790 MHz. The frequencies used are within the 70-centimeter band, which is currently otherwise reserved for government and amateur radio operations in the United States and most nations worldwide.

LPD hand-held radios are authorized for licence-free voice communications use in most of Europe using analog frequency modulation (FM) as part of short range device regulations,^[1] with 25 kHz channel spacing, for a total of 69 channels. In some countries, LPD devices may only be used with an integral and non-removable antenna with a maximum legal power output of 10 mW.

Voice communication in the LPD band was introduced to reduce the burden on the eight (now sixteen)^[2] PMR446 channels over shorter ranges (less than 1 km).^[3]

LPD is also used in vehicle key-less entry device, garage or gate openers and some outdoor home weather station products.

Usage by country

ITU Region 1 (Europe)

United Kingdom

In the UK, LPD433 equipment that meets the respective Ofcom Interface Requirement can be used for model control, analogue/digitised voice and remote keyless entry systems.^[4] There is significant scope for interference however, both on frequency and on adjacent frequencies, as the band is far from free. The frequencies from 430 to 440 MHz are allocated on a secondary basis to licensed radio amateurs who are allowed to use up to 40 W (16 dBW) between 430 and 432 MHz and 400 W (26 dBW) between 432 and 440 MHz. Channels 1 to 14 are UK amateur repeater outputs and channels 62 to 69 are UK amateur repeater inputs. This band is shared on a secondary basis for both licensed and licence exempt users, with the primary user being the Ministry of Defence.^[5]

Ofcom, together with the RSGB Emerging Technology Co-ordination Committee have produced guidelines to help mitigate the side effects of interference to an extent.^[6][7]

Switzerland

Switzerland permits the use of all 69 LPD433 channels with a maximum power output of 10 mW.^[8][9]

Spain

According to a recently published (June 2021) resolution of the Spanish government,^[10] where it defines 'interface IR-266', non-specific mobile short-range devices may be used without authorization for voice applications with 'advanced mitigation techniques' (such as listening before talking^[11]) from 434.040 to 434.790 MHz, with channels narrower than 25 kHz and with a maximum 'apparent radiated power' of 10 mW. This would make the use of LPD433 channels 40 to 69 possible in Spain.

Other European countries

European remote keyless entry systems often use the 433 MHz band, although, as in all of Europe, these frequencies are within the 70-centimeter band allocated to amateur radio, and interference results. In Germany, before the end of 2008,^[12] radio control enthusiasts were able to use frequencies from channel 03 through 67 for radio control of any form of model (air or ground-based), all with odd channel numbers (03, 05, etc. up to ch. 67),^[13] with each sanctioned frequency having 50 kHz of bandwidth separation between each adjacent channel.

ITU Region 2 (America)

In ITU region 2 (the Americas), the frequencies that LPD433 uses are also within the 70-centimeter band allocated to amateur radio. In the United States LPD433 radios can only be used under FCC amateur regulations by properly licensed amateur radio operators.

ITU Region 3

Malaysia

In Malaysia, this band is also within the 70-centimeter band (430.000 – 440.000 MHz) allocated to amateur radio. Class B amateur radio holders are permitted to transmit up to 50 watts PEP power level.^[14] There is no licence requirement for LPD as long as it complies with requirement regulated by Malaysian Communications And Multimedia Commission (MCMC). As regulated by MCMC in Technical Code for Short Range Devices,^[15] remote control and security device are allowed up to 50 mW ERP and up to 100 mW ERP for Short Range Communication (SRC) devices. RFID are allowed up to 100 mW EIRP.

Channels

Channel	Frequency (MHz)	Channel	Frequency (MHz)	Channel	Frequency (MHz)
1	433.075	24	433.650	47	434.225
2	433.100	25	433.675	48	434.250
3	433.125	26	433.700	49	434.275
4	433.150	27	433.725	50	434.300
5	433.175	28	433.750	51	434.325
6	433.200	29	433.775	52	434.350
7	433.225	30	433.800	53	434.375
8	433.250	31	433.825	54	434.400
9	433.275	32	433.850	55	434.425
10	433.300	33	433.875	56	434.450
11	433.325	34	433.900	57	434.475
12	433.350	35	433.925	58	434.500
13	433.375	36	433.950	59	434.525
14	433.400	37	433.975	60	434.550
15	433.425	38	434.000	61	434.575
16	433.450	39	434.025	62	434.600
17	433.475	40	434.050	63	434.625
18	433.500	41	434.075	64	434.650
19	433.525	42	434.100	65	434.675
20	433.550	43	434.125	66	434.700
21	433.575	44	434.150	67	434.725
22	433.600	45	434.175	68	434.750
23	433.625	46	434.200	69	434.775

See also

• PMR446
• Personal radio service
• Family Radio Service
• General Mobile Radio Service
• Part 15
• ISM band
• NTIA Manual of Regulations and Procedures for Federal Radio Frequency Management

References

1. CEPT/ERC REC 70-03 Archived 2013-08-05 at the Wayback Machine (22 August 2011)
2. "ECC Decision (15) 05" (PDF). CEPT Electronic Communications Committee. Archived from the original (PDF) on 2017-08-19. Retrieved 2017-12-06.
3. "The Consumer Electronics Hall of Fame: Motorola T250 Talkabout Walkie-Talkies". IEEE Spectrum: Technology, Engineering, and Science News. Retrieved 2020-05-09.
4. "IR 2030 - UK Interface Requirements 2030 - Licence Exempt Short Range Devices" (PDF). Ofcom. July 2017. Archived (PDF) from the original on 2022-10-09. Retrieved 2017-12-06.
5. "United Kingdom Frequency Allocation Table 2013" (PDF). Ofcom. Archived (PDF) from the original on 2022-10-09. Retrieved 2014-01-07.
6. "Interference between Short Range Devices and Amateur Repeaters" (PDF). Ofcom. Archived (PDF) from the original on 2022-10-09. Retrieved 2014-01-07.
7. "Paper on SRD Mitigation Techniques" (PDF). R.S.G.B. Emerging Technology Co-ordination Committee. Archived (PDF) from the original on 2022-10-09. Retrieved 2014-01-07.
8. "Technical interfaces regulations". OFCOM (Swiss Federal Office of Communications). Retrieved 2020-10-03.
9. "Radiocommunications in Switzerland" (PDF). Bundesamt für Kommunikation. Archived (PDF) from the original on 2022-10-09. Retrieved 2020-10-03.
10. "Resolución de 12 de marzo de 2021, de la Secretaría de Estado de Telecomunicaciones e Infraestructuras Digitales, por la que se publican los requisitos técnicos actualizados de las interfaces radioeléctricas reglamentadas IR-264, IR-265 e IR-266 relativas a equipos de radio para dispositivos de corto alcance (SRD) no específicos, en la banda de frecuencias ICM de 433 MHz". Secretariat of State for Telecommunications and Digital Infrastructure of the Government of Spain. Retrieved 2022-10-16.
11. "ERC recommendation relating to the use of short range devices (SRD), Annex 1, Note 11". CEPT. Retrieved 2022-10-17.
12. RC-Network.de Fernsteuerfrequenzen für den Modellbau - Deutschland (Frequency bands for RC modeling - Germany) - "Am 31.12.2008 endet die Betriebserlaubnis für Fernsteuerungen im Frequenzbereich 433 MHz!" Archived 2016-03-23 at the Wayback Machine (As of 12/31/2008, RC use of the 433 MHz bands ends in Germany!)
13. "United Kingdom Radio Control Council: International Frequencies - Germany". UKRCC. UKRCC. Archived from the original on March 4, 2016. Retrieved July 13, 2013.
14. "Guidelines for Amateur Radio Services in Malaysia 2nd Edition" (PDF). Archived (PDF) from the original on 2022-10-09. Retrieved 11 Feb 2018.
15. "MCMC MTSFB TC T007:2014 - Specification for Short Range Devices" (PDF). Archived (PDF) from the original on 2022-10-09. Retrieved 11 Feb 2018.