What is SRD?
This page describes what is SRD and mentions SRD(Short Range Device) basics. The low power wireless devices are usually known as short range devices or SRDs. Following are the applications of SRDs.
As mentioned SRDs are basically operates at low power and covers lower range. SRDs operate on non-interference and non-protected modes. In order to choose the SRD, interference analysis need to be done in the same as well as adjacent frequency bands.
There are many applications of SRDs due to which they have become popular.
The typical applications are as follows:
• Local Area Networks(LANs), e.g. HIPERLANs, RLANs
• Alarms
• Telematics
• Auto vehicle identification in Railways
• Alert based on movement
• Microphones
• RF ID systems
• Very Low power medical implants
• Inductive applications
• Wireless Audio applications
Frequency bands used by SRDs(Short Range Devices)
There are different frequency bands and ERPs for non specific SRDs and license free SRDs in Europe. Following frequency bands are used by SRDs in Europe.
SRD frequency bands-Non Specific Use
| Frequency Band | ERP |
|---|---|
| 433.05 to 434.79 MHz | +10 dBm |
| 433.05 to 434.79 MHz | 0 dBm |
| 433.05 to 434.79 MHz | +10 dBm |
| 868 to 868.6 MHz | +14 dBm |
| 868.7 to 869.2 MHz | +14 dBm |
| 869.3 to 869.4 MHz | +10 dBm |
| 869.4 to 869.65 MHz | +27 dBm |
| 869.7 to 870 MHz | +7 dBm |
| 2400 to 2483.5 MHz | +7.85 dBm |
SRD frequency bands-License free Use
| Frequency Band | ERP |
|---|---|
| 402 to 405 MHz | -16 dBm |
| 868.6 to 868.7 MHz | +10 dBm |
| 869.2 to 869.25 MHz | +10 dBm |
| 869.25 to 869.3 MHz | +10 dBm |
| 869.65 to 869.7 MHz | +14dBm |
| 863 to 865 MHz | +10 dBm |
| 863 to 865 MHz | +10 dBm |
| 1785 to 1800 MHz | +7.85 dBm |
| 2400 to 2483.5 MHz | +17.85 dBm |
| 2446 to 2454 MHz | +24.85 dBm |
| 2400 to 2483.5 MHz | +11.85 dBm |
| 2446 to 2454 MHz | +24.85 dBm |
| 2446 to 2454 MHz | +33.85 dBm |
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