Hans Peter Bernhard, Achim Berger, Andreas Springer,
"Analysis of Delta-Sigma-synchronization in wireless sensor nodes"
: Industrial Informatics (INDIN), 2015 IEEE 13th International Conference on, Seite(n) 914-918, 7-2015
Original Titel:
Analysis of Delta-Sigma-synchronization in wireless sensor nodes
Sprache des Titels:
Englisch
Original Buchtitel:
Industrial Informatics (INDIN), 2015 IEEE 13th International Conference on
Original Kurzfassung:
We analyse the use of a ??-modulator in the nodes of a wireless sensor network, which is a new method to achieve long term synchronization. We consider star topology WSNs (Wireless Sensor Networks) with a central base station and address timing synchronization using low frequency realtime clocks. The WSN uses a beacon driven TDMA-protocol for bidirectional node/base communication. Between the beacons, which are sent by the base station, lie the superframe time intervals to handle data transmission from node to base. The ??-modulator is used to generate - at average - the accurate superframe duration for any rational number of clock ticks, by generating a sequence of superframes with different time durations, but each consisting of integer multiples of clock ticks. We discuss the synchronization accuracy based on the internal arithmetic of the ??-modulator and show by theory a relation between synchronization accuracy and word length of the internal arithmetic. Additionally the fractional part of a crystal clock module is responsible for variations in the synchronization quality. We present an equation that allows us to interpret measurements showing periodic variations of synchronization quality.