Installation, maintenance, repair, upgrading of radio communication systems
Radio communication systems are used as transfer voice information and data transfer.
The range of UHF/VHF radio systems dependent on relief, suspension height of antennas, transmitter power. The maximum range is determined by the formula: D = 3.57 (Vh1+Vh2) D-range line of sight antenna height h1 and h2 communication range depends on the wavelength, transmitter power, receiver sensitivity, antenna-feeder devices q.
By type of communication radio system are divided into radial (conventional) and Trunking.
Radial construction principle
radial network systems, all radio stations are maintained at one frequency channel according to the principle "all hear all”. Channel access is possible only one station. Radial range radio communication systems limited transmitter power stations and radio propagation conditions.
Radial construction principle, is used for radio communications for small groups, and in the absence of increased requirements to reliability and quality of communication. Increased range, perhaps through the use of repeaters. This requires additional frequency bands. When moving in areas of multiple repeaters, it is necessary to switch on radio frequency channel.
Trunking principle of building radio networks
Trunking eliminate disadvantages radial systems. The system works on multiple pairs of frequencies, due to which the accessibility relation. Frequency resource is distributed among all subscribers. Clear channel has a connection. Radios don't work with each other directly. The relationship between them is organized through a dedicated Repeater (Website), or multiple sites (Base Stations). The Repeater transmits broadcast control information about the condition of the site (control channel). All radios take control information, and are broadcast only on permission of the site. The whole system is controlled by a central switch. There is a system without a dedicated control channel, clear channel is determined by scanning. Such systems have a large radius of action. May create several mutually independent groups. Ensures high availability and reliability of connection. Trunking systems have a high cost, typically used in corporate networks. Radio system can be classified as analog and digital. Radius of action above the analogue systems. But at greater distances the relationship can be fragile. In digital systems, the range is limited to sustainable communication. Usually, the range of analog and digital systems varies by 30%.
How to use radio communications
How to use radio systems is regulated by the law:
Ley 9-2014 de 9 de mayo General de Telecomunicaciones
Frequency distribution and power determined National radio frequency usage table
Cuadro nacional de atribución de frecuencias 787 2013
So under UN-3 Banda ciudadana CB-27, above the table of frequency allocations for civilian use designed range of CB-27 (26.960 -27.410 MHz). The range is divided into 40 channels. It is permitted to use equipment with capacity of up to 100 mW. To use permissible maximum power 4W (peak to 12W) authorization required. Authorization instructions can be found here: http://www.minetur.gob.es/telecomunicaciones/Espectro/radioaficionados/P...
Channel 9 (27.065 MHz) is reserved for emergency services and medical care. Under the UN-5 Usos de radio en embarcaciones, boating can be used 26.905 frequency MHz, 26.915 MHz, MHz, 26.925 26.935 MHz 26.945 MHz. Transmitters by capacity up to 5 Watts.
For free use for analog mobile radio is designed range 446-446.1 MHz (PMR-446). Permissible power 500 mW, band 12.5 kHz. The permitted channels: 446.00625 MHz F1 = F2 = 446.01875 MHz 446.03125 MHz F3 = F4 = 446.04375 MHz F5 = 446.05625 MHz F6 = 446.06875 MHz F7 = 446.08125 MHz F8 = 446.09375 MHz. technical standards are regulated by ETSI EN 300 296-2. No license required.
Range-446.2 446.1 MHz (PMR-446) intended for digital mobile radio communications. Permissible power 500 mW, band 6.25 kHz and 12.5 kHz. Technical standards regulated by EN 300 113-2 y EN 301 166-2. No license required.
Under UN-115 Dispositivos genéricos de corto alcance, unlicensed frequency bands may be used:
6765 - 6795 kHz 42 dBμA/m a 10 m 13,553 - 13,567 MHz 42 dBμA/m a 10 m 26,957 - 27,283 MHz 42 dBμA/m a 10 m 10 mW (p.r.a.) 40,660 - 40,700 MHz 10 mW (p.r.a.) 433,050 - 434,790MHz 1/10 mW (p.r.a.) 863 - 868 MHz 25 mW (p.r.a.) 868 - 870 MHz 5/25/500 mW (p.r.a.) 2400 - 2483,5 MHz 10 mW (p.i.r.e.) 5725 - 5875 MHz 25 mW (p.i.r.e.) 24,00 - 24,25 GHz 100 mW (p.i.r.e.) 61,0 - 61,5 GHz 100 mW (p.i.r.e.) 122 - 123 GHz 100 mW (p.i.r.e.) 244 - 246 GHz 100 mW (p.i.r.e.) 71,775 GHz 10 mW (p.i.r.e.) 71,375 GHz 10 mW (p.i.r.e.) 71,325 GHz 10 mW (p.i.r.e.)
Our specialists are ready to provide services and to perform the following kinds of works:
• 1.1. Check out the object. A survey object. Development of technical decisions on equipment, radio communication systems facility in accordance with customer requirements. Defining strategies for the use of the equipment.
• 1.2. Equipment selection
• 1.3. Calculation of the cost of equipment
• 1.4. Calculation of the cost of installation and commissioning working papers for the production of papers
• 1.5. Acquisition of equipment
• 1.6. Erection works
• 1.7. Carrying out of starting-up and adjustment works
• 1.8. Preparation of as-built documentation
• 1.9. Letting the user systems
• 1.10. Briefing
• 1.11. Survey of previously installed systems
• 1.12. Recovery documentation on previously installed systems
• 1.13. Search malfunction. Flaw detection equipment
• 1.14. Repair of installed systems
• 1.15. Modernization of installed systems
• 1.16. Service systems
• 1.17. Production measurements of basic technical parameters
• 1.18. Mapping specifications
• 1.19. Battery replacement
• 1.20. Migrating a previously installed equipment