No abstract

The article presents the concept of creating model of delays occurring in telecommunication system taking into account all sources of delays generated during data transmission between the source and destination nodes. Proposed model takes into account the existence of intermediary network devices that play a significant role in the general delay budget. The paper presents two measurement systems used to measure delays in 802.11 g based wireless networks and ones using ZigBee standard. Both systems were built based on the authors' concepts of hardware and software allowing measurement of delays by using additional connection for the synchronization of internal clocks. Described measurement systems selected amount of experiments was performed for varied network structures.

Data processing algorithms are important parts of modern measurement systems. These algorithms are often delivered to the user as complex program and their numerical structure is not known. Therefore also influence of algorithm on processed data accuracy is not known. One of the methods to evaluate uncertainty propagation through algorithm is based on matrix form of algorithm. Coefficient matrix of algorithm represents its numerical operations and it is a basis to algorithm accuracy evaluation. The paper presents a method how to identify this coefficient matrix when algebraic form of the algorithm is known or is difficult to use. Identified matrix form of algorithm is then used to estimate uncertainty propagation through exemplary algorithms. Results are compared with experiments.

This study presents the operation basis of GPS global positioning system and augmentation systems used to increase positioning accuracy. Furthermore, selected measurement results for an EGNOS-augmented GPS receiver positioning are included along with an analysis of GIS measurements accuracy, performed using dierential corrections. This analysis takes into consideration the impact of the number of measurement series and satellite constellation on the accuracy of positioning achieved in praxis using the EGNOS system.

The paper presents the concepts of model construction on transmission delays in systems with wireless interfaces using random series of function. It is a new method of modelling that allows us to use probabilistic description of time required to realise tasks in various devices. It also allows us to use time domain delta function series in order to describe the time of transmission of data between transmitter and receiver. In description of delays probability density function is applied. The model also takes into account existence of intermediary network devices that play a signicant role in overall budget of delay.