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Long-range high-reliability telemetry in unlicensed frequency bands

: Mayer, F.; Perthold, R.

Fifth Annual Wireless Symposium 1997. Proceedings
Hasbrouck Heights, NJ: Penton Publ., 1997
Annual Wireless Symposium <5, 1997, Santa Clara/Calif.>
Fraunhofer IIS A ( IIS) ()
dezentrales Kommunikationssystem; digital signal-processor; digitaler Signalprozessor; distributed control system; Drahtloses Netzwerk; DSP; Feldbus; fieldbus; Funktransceiver; radio transceiver; reliability; Wireless Networks; Zuverlässigkeit

With the highly respected digital high speed spread spectrum techniques emerging, the traditional and well optimized narrow band telemetry systems seem to loose some importance. However, by combining old fashioned but well proven narrow band radio transmission with modern DSP-technology and intelligent networking alorithms, efficient and robust telemetry networks can be created. First, the paper will describe differences between narrow band and wide band solutions when operatied in an non-exclusive frequency band, which is the typical situation in Europe. The concept of an air interface will be described, which can operate both in unlicensed and licensed frequency bands, depending on the requirements for system availability and cost. Digital Signal Processing can improve the performance of such an air interface significantly compared to the classical telemetry receiver structures. The potential of such a narrow band telemetry system when combined with modern DSP-technology, advanced ne twork and MAC protocols will be explained. Finally, the advantages and limitations of such wide range telemetry applications will be derived considering practical applications.