Efficiency of Event-Based Sampling According to Error Energy Criterion

The paper belongs to the studies that deal with the effectiveness of the particular event-based sampling scheme compared to the conventional periodic sampling as a reference. In the present study, the event-based sampling according to a constant energy of sampling error is analyzed. This criterion is suitable for applications where the energy of sampling error should be bounded (i.e., in building automation, or in greenhouse climate monitoring and control). Compared to the integral sampling criteria, the error energy criterion gives more weight to extreme sampling error values. The proposed sampling principle extends a range of event-based sampling schemes and makes the choice of particular sampling criterion more flexible to application requirements. In the paper, it is proved analytically that the proposed event-based sampling criterion is more effective than the periodic sampling by a factor defined by the ratio of the maximum to the mean of the cubic root of the signal time-derivative square in the analyzed time interval. Furthermore, it is shown that the sampling according to energy criterion is less effective than the send-on-delta scheme but more effective than the sampling according to integral criterion. On the other hand, it is indicated that higher effectiveness in sampling according to the selected event-based criterion is obtained at the cost of increasing the total sampling error defined as the sum of errors for all the samples taken

Send-on-delta concept: an event-based data reporting strategy

Abstract: The paper addresses the issue of the send-on-delta data collecting strategy to capture information from the environment. Send-on-delta concept is the signal-dependent temporal sampling scheme, where the sampling is triggered if the signal deviates by delta defined as the significant change of its value. It is an attractive scheme for wireless sensor networking due to effective energy consumption. The quantitative evaluations of send-ondelta scheme for a general type continuous-time bandlimited signal are presented in the paper. The bounds on the mean traffic of reports for a given signal, and assumed sampling resolution, are evaluated. Furthermore, the send-on-delta effectiveness, defined as the reduction of the mean rate of reports in comparison to the periodic sampling for a given resolution, is derived. It is shown that the lower bound of the send-on-delta effectiveness (i.e. the guaranteed reduction) is independent of the sampling resolution, and constitutes the built-in feature of the input signal. The calculation of the effectiveness for standard signals, that model the state evolution of dynamic environment in time, is exemplified. Finally, the example of send-on-delta programming is shown

LON Technology in Wireless Sensor Networking Applications

In the paper a discussion on how to optimize LonWorks/EIA-709 sensornetworking technology for wireless applications, in presented. Main solutions offered byLocal Operating Networks (LON, LonWorks) platform attractive for wirelesscommunication, that is, the send-on-delta concept and the sleep mode, are displayed. Thepredictive p-persistent CSMA MAC protocol constituting the heart of the communicationcapability of LON networks is analysed in detail. Next, the message services are described,and the analytical evaluation of delivery reliability is derived. Performance evaluation basedon simulation results for unicast traffic is presented first. In order to highlight the robustnessof the predictive CSMA to overload situations, the saturation performance for a general caseload scenario including multicast transactions is reported. The methods of effectivemanagement of energy consumption in LonWorks networks are discussed. Finally, the LONdesign tradeoffs are summarized