LP9 ISM Mesh Radio:
The 33-centimeter or 900 MHz band is a portion of the UHF radio spectrum internationally allocated to amateur radio on a secondary basis. It ranges from 902 to 928 MHz and is unique to ITU Region 2. The International Telecommunication Union (ITU), in its International Radio Regulations, divides the world into three ITU regions for the purposes of managing the global radio spectrum. Region 2 covers the Americas, Greenland and some of the eastern Pacific Islands.
It is primarily used for very local communications as opposed to bands lower in frequency. However, very high antennas with high gain have shown 33 centimeters can provide good long range communications almost equal to systems on lower frequencies such as the 70 centimeter band. The 70 centimeter band is the 430.000 – 440.000 MHz UHF band.
The Satelline LP9 Mesh radio operated in this 900 MHz band. It is primarily used by industrial, scientific, and medical (ISM) equipment. It can however, also be used for Wireless Datacommunication in region 2 for low powered unlicensed devices.
Signal propagation on the 33 centimeter band is very dependent on the transmitting and receiving antenna’s line of sight. Because of this, many wide-area coverage systems like repeaters are located on top of large hills and mountains which overlook a vast area. This ensures that the transmitting antenna is higher than terrestrial obstructions such as trees and buildings. The 33 centimeter band offers excellent building penetration characteristics since the wavelength is relatively small and can fit through windows more easily than signals lower in frequency.
In many areas, the 33 centimeter band also has a very low noise floor as compared to bands lower in frequency.
The system consists of data transfer and expansion modules. The data transceiver modules are used for serial data transfer and expansion modules for I/O signals
. I/O signals can also be connected directly to Modbus protocol devices with transceiver modules through RS-232 and RS-485 interfaces.