The solution is to mix the header and the data transmission. In our approach, when the system operates in a robust mode, the legacy header and the legacy data container are both observed as modulation symbols.
Co-existence
Perhaps the most interesting feature is that the robust mode implementation can coexist with the usual implementation of a wireless system. The investment in current systems and terminals is therefore protected. The concept can be applied practically in any packet-based wireless system (WiFi, LTE, Bluetooth, GPRS, UMTS, WiMAX, TETRA, satellite systems, etc.)
Reliable Bits in Harsh Environments and Extreme Interference
Sending Critical Messages when the usual Wireless Links Fail
The wireless systems require certain minimal quality level in order to keep the wireless connection alive. When the conditions are statistically good, the wireless connection manages to achieve a high data throughput, despite occasional errors. A good example is a WiFi system: If the interference is below a certain level, the connection works fine. However, for technologies that operate in the unlicensed bands, such as WiFi or Bluetooth, the interference is highly unpredictable and can completely stop the wireless connection. This happens, for example, when some equipment emits noise because of a technical fault condition or radio jamming is used on purpose.
A system has been built to enable transmission of alarm signals in case of severe interference from jamming caused by a criminal act. Standard off-the-shelf WiFi modems and PC’s are updated with RESEIWE technology to create a robust emergency channel. When jamming occurs, the normal WiFi connection gets completely blocked. RESEIWE technology is a viable way to cope with such a situation, since it manages to send critical messages even under very harsh interference.
