LPD433 (low power device 433 MHz) is a

UHF Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter ...

band in which license free communication devices are allowed to operate in some regions. The frequencies correspond with the ITU region 1

ISM band The ISM radio bands are portions of the radio spectrum reserved internationally for ''industrial, scientific, and medical'' (ISM) purposes, excluding applications in telecommunications. Examples of applications for the use of radio frequency (RF ...

of 433.050

MHz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose formal expression in terms of SI base u ...

to 434.790 MHz. The frequencies used are within the

70-centimeter band The 70-centimeter or 440 MHz band is a portion of the UHF radio spectrum internationally allocated to amateur radio and amateur satellite use. The ITU amateur radio allocation is from 430 to 440 MHz; however, some countries, such as ...

, which is currently otherwise reserved for government and

amateur radio Amateur radio, also known as ham radio, is the use of the radio frequency radio spectrum, spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emer ...

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 Frequency modulation (FM) is a signal modulation technique used in electronic communication, originally for transmitting messages with a radio wave. In frequency modulation a carrier wave is varied in its instantaneous frequency in proporti ...

(FM) as part of

short range device A short-range device (SRD), described by ECC Recommendation 70-03, is a radio-frequency transmitter device used in telecommunication that has little capability of causing harmful interference to other radio equipment. Short-range devices are l ...

regulations, CEPT/ERCbr> REC 70-03
(22 August 2011) with 25

kHz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose formal expression in terms of SI base uni ...

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)

PMR446 PMR446 ( Private Mobile Radio, 446 MHz) is a licence-exempt service or UHF CB in the UHF radio frequency band, as personal radio service or citizens band radio, and is available for business and personal use in most countries throughout th ...

channels over shorter ranges (less than 1 km). 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 The Office of Communications, commonly known as Ofcom, is the government-approved regulatory and competition authority for the broadcasting, internet, telecommunications and mail, postal industries of the United Kingdom. Ofcom has wide-rang ...

Interface Requirement can be used for model control, analogue/digitised voice and remote keyless entry systems. 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 A ministry of defence or defense (see American and British English spelling differences#-ce.2C -se, spelling differences), also known as a department of defence or defense, is the part of a government responsible for matters of defence and Mi ...

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

Switzerland

Switzerland permits the use of all 69 LPD433 channels with a maximum power output of 10 mW.

Spain

According to a recently published (June 2021) resolution of the Spanish government, 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) 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

allocated to

, and interference results. In Germany, before the end of 2008, 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), 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

allocated to

. 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. 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, 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 Radio-frequency identification (RFID) uses electromagnetic fields to automatically identify and track tags attached to objects. An RFID system consists of a tiny radio transponder called a tag, a radio receiver, and a transmitter. When tri ...

are allowed up to 100 mW EIRP.

Channels

References

{{Two-way radio Bandplans