XLRS Radio System
Professional radio module for very Long Range up to 250Km and more, in Sub 1Ghz free ISM bands.
It is the 5th generation of RF modules designed and manufactured by Digital Micro Devices in Spain.
Up to 250Km maximum without repeaters for XLRS D4 and D5 systems with SATPRO, which covers almost any LOS need.
The radio module is a fundamental part of the XLRS system.
What makes this data link different?
Experience and safety in RF, it is the fifth generation of RF modules for radio control since 2007.
The modules are stable, very reliable in flight and have a long range with only 1W of maximum power.
We also have redundant systems with FHSS and encryption in different frequency bands or in different groups of channels.
Basic characteristics:
- Frequency Stability +-1ppm.
- Multiband ISM.
- RF Security.
- RF IP Addressing.
- FHSS.
- Radio XLRS 5G Generation.
Periodic RF range tests: in this case at 10Km with the fresnel zone partially obstructed by the mountain.
Learn more:
Frequency Stability ±1ppm
It is a very important parameter, especially if the temperature of the transmitter and the receiver are very different.
Controlled by TXCO. Better than ±1ppm.
This excellent stability, does that when the systems are far away or receive the signal very weak the devices continue to work correctly.
The master oscillator can be calibrated.
Systems with TXCO, practically don’t need it. To calibrate, you must have a frequency meter with a rubidium time base or stability better than 0.5ppm.
The systems with quartz crystal can be adjusted. (Only by qualified technical personnel).
Multiband ISM. 430Mhz to 950Mhz
Free Bands ISM (Industrial Scientific and Medical).
Regulatory compliant: CE Europa, FCC America, ETA India.
For the RF bands there are two different modules:
- 863Mhz, 866Mhz, 868Mhz, 902Mhz, 915Mhz and 950Mhz
- 430Mhz, 433Mhz, 458Mhz
Available and selectable by software.
Redundant in Real time and Dual band Simultaneous with redundant Smart base station (consult).
Flexible configuratión, multiples possibilities:
Preconfigured for normative CE (Europe), FCC (America), ETA (India), 433Mhz or Custom.
Channelization 25, 50, 100 or 150Khz
Fixed channel or FHSS with selective limit channels
Channel offset available in 1Khz steps. Max 100Khz.
Baud 25kb, 50kb, 100kb or 150kb. By default: 100kb.
Adjustable RF power. Max 1W or +30dBm (Max. Limited according normative)
Nivel of Carrier detect adjustable in 1dBm steps
LNA. Low Noise Amplifier selectable.
Blocking RF parameters with hardware password for the normative and security.
RF Security
5G: Fifth generation of RF modules manufactured by DMD.Evolution of RF modules tested for FPV-UAV since 2007 with more than 1.200hours FPV flight from our I+D technicians.
Stop to the Fail Safe or failures of RF, If setup is correct, rarely our pilots or some customer has had some fail safe in 12 years.
CRC32: Authenticated and secure RF packages.
RC Security: In addition, the RC (radio control) data packets are digital and are signed with CSUM and filtered for incoherent data. If there is strong RF interference or RF failure it does not deliver random data to the servos. The entry time in Fail safe is configurable.
FHSS: Spectrum extended by frequency hopping, with improved synchronization that allows several channels to interfere and the system to remain synchronized and immune.
The pseudorandom sequence is modulated by a custom password only for FHSS
New system with faster FHSS synch recoveries: <300miliseg. In the XLRS system the pseudo-random jump sequence also has user code.
Encryption of RF AES 128b packages. More information…
Password specific in the Radio Frequency network.
RF IP Addressing. Subnetworks
The RF system uses a 32-bit IP address.
Network and configurable IPs.
List of up to 16 authorized devices (LEA) or authorized subnets, to be used without selecting several UAVs.
Control “swarms” of Drones or UAvs. (Consult sales@dmd.es).
In another article we talk specifically about drone swarms or the use of the XLRS system for drone fleets.
FHSS, Frequency Hopping Spread Sprectrum
The frequency hop provides more robust communications than with a fixed channel. In many countries its use is mandatory.
Algorithm with improved synchronization that allows several channels to interfere and the system to remain synchronized and immune.
40 hops/seg. Dwell time: 25mSeg.
System with faster synch recoveries: <300miliseg.
Works with 50kb or 100kb of bandwidth.
Configurable start and end channels.
XLRS systems: coding and encryption jump frequency. 10 bytes of code.
Monitoring FHSS status in XLRS transmitters and XLRS receivers and in DMDStudio.
If you need a fixed channel, you can deactivate FHSS.
More info:
5 Generation XLRS Radio. Features
RF ISM Bands: 863,866, 868, 902, 915, 950Mhz.
Frequency: From 863 to 950Mhz, or 430 to 458Mhz.
RF Power by default: 500mW, 1000mW
RF Sensitivity: -110dBm, -113dBm (100Kb RF).
RF Channels: Max 255 for band. it depends on the configuration.
Separation channels: 25, 50, 100 or 150Khz according RF band.
Bandwidth (Radio Modem): 100kb default. Max 150kb.
Modulation: 2-GFSK. FHSS 40 hops/sec. or configurable fixed channel.
Selectivity, Adjacent channel: -60dB to 12.5Khz offset. (@LNA Off).
Blocking: -86dB to 10Mhz. (@LNA Off).
Frequency stability: TXCO. +-1ppm.
RF input trigger level: Configurable in dBm (NCD command).
Working Temperature: -25ºC to +85ºC.
RSSI: Digital. Calibrated +-1dBm.
RC Packages: 40 per second for RC and telemetry (25msec latency).
RF Module: Radio 5G DMD (WMX5H) (No to be confused with 5G of mobile telephony).
Upgradeable / Configurable: With DMDStudio software through Mini USB port.
More information about radio system…
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