Private Mobile Communication Systems

What is Private Mobile Communications?

Private mobile communication (PMR) is a professional mobile radio system. Private mobile communications are mobile communications between base stations and land mobile / portable stations or between land mobile / portable radio stations.

The traditional users of PMR are taxi, security, railway, power supply and freight related companies. Radios as a safe and reliable way of radio communication have been known for many years and during these years the capabilities of radios have changed and improved and many additional functions have appeared.

PMR statistics

EMS services are provided to more than 220 PMR customers and one PAMR operator, a total of over 1500 land mobile radio service licenses and nearly 11,000 radio equipment licenses have been issued, and EMC is provided for approximately 3,000 radio frequency assignments. The largest number of customers and permissions issued is in the 146-174 MHz band, which is traditionally considered to be the main band for PMR communications.

Radio spectrum for PMR communication systems

30-80 MHz

In the 30-80 MHz band, over 100 terrestrial mobile service radio licenses and 137 frequency assignments have been granted. One of the biggest users of communication in this band is the State Forest Service, where voice communication is used in forestry to monitor forest management and use. In this band radio communication is also used by security companies, whose frequencies are used in transmitters of security alarm objects or for data transmission from repeaters to base stations. Visit our website for effective information about CB WORLD INFORMER now.

146-174 MHz

In the frequency band 146-174 MHz, narrowband PMR systems operate in 12.5 kHz and 25 kHz radio channel steps and can be divided into operating modes:

In duplex mode, a 4.6 MHz spacing between base and mobile frequencies is specified. In order to make efficient use of frequencies and to facilitate the planning of frequency assignments for both simplex and duplex modes, the 146-174 MHz band is divided into several sub-bands, each of which has specific frequency bands

Simplex and Duplex Frequency Bands:

SI - frequency bands for simplex operation;

DU - frequency bands designed to operate in duplex mode;

FB1 / 2/3/4 - Frequency bands in which base stations transmit

ML1 / 2/3/4 - Frequency bands for mobile stations.

In the 146-174 MHz band, more than 900 terrestrial mobile service radio network licenses have been issued and 1487 existing frequency assignments have been granted. Base station locations are shown on the map.

The 146-174 MHz band is mainly used for voice and security alarm radio network operation, but it is also used for other applications. The advantage of using this band is that, due to the propagation characteristics of the radio waves, it is possible to provide a higher radio network coverage compared to the UHF (300-3000 MHz) band. To increase the radio network coverage area, a repeater is often installed, that is, a station or antenna on a roof or tower of a tall building that receives signals from a mobile / portable station and transmits the received signal to other mobile or portable radio stations. With the transponder positioned higher than mobile or portable radio stations,

As one of the largest users of frequency in this frequency band is Latvenergo, whose voice radio base stations are located throughout the territory of Latvia, as it is necessary to provide communications at power transmission line infrastructure sites located all over Latvia and Latvian Railways and railway maintenance companies, who use frequencies on railway routes all over Latvia for communication purposes.

Security companies also use this band to operate alarm signaling radio networks, as do small radio networks with a small number of radios that require radio communication in limited (company) areas.

406.1-410 MHz

The 406.1-410 MHz frequency band is intended for simplex communication, mainly for radio networks, which use only portable and mobile radio stations for voice communication.

410-430 MHz

The 410-430 MHz frequency band is intended for narrowband mobile communications in duplex communication mode with 10 MHz duplex separation and operates on a large number of group radio networks.

440-450 MHz

The 440-450 MHz frequency band is intended for use in narrowband mobile communications and fixed radio systems in simplex mode. This band is mainly used for data networks, telemetry and telecommunication. In total, more than 220 licenses for the use of radio networks have been issued.

457.5-460 MHz / 467.5-470 MHz

The 457.5875-458.1125 MHz and 467.5875-468.1125 MHz bands are intended to be used exclusively for rail communication and are also actively used. In total, more than 120 licenses for the use of the radio network have been issued.