DELAY TOLERANT NETWORKING SUPPORT FOR CREATION HIGH-ACCURACY MAGNETIC FIELD MAPS

Context. The main purpose of Correlation Extremal Navigation system is finding coordinates in case of absence of Global Positioning System signal and as a result high-accuracy maps as the main source of information for finding coordinates are very important. Magnetic field map as the main source of information can include errors values, as an example: not good enough equipment or human factor can cause error value of measurements. Objective. In order to create high-accuracy maps given work proposes to improve the process of creating magnetic field maps. The given work represents delay tolerant networking as an additional approach for data transmission between magnetic observatory and magnetic station and its improvement. Method. Improved Dijkstra’s algorithm together with Ford-Fulkerson’s algorithm for finding path with minimum capacity losses, earliest delivery time and maximum bit rate in case of overlapping contacts should be represented in the given work because nowadays, delay tolerant networking routing protocols do not take into account the overlap factor and resulting capacity losses and it leads to big problems Results. For the first time will be presented algorithm that chooses the route that guarantees the minimum of capacity losses, earliest delivery time and maximum bit rate in the delay tolerant networking with overlapping contacts and increases the probability of successful data transmission between magnetic stations and magnetic observatories. Conclusions. In order to perform high-accuracy measurement of magnetic field group of people allocate their equipment for magnetic field measurement in remote areas in order to avoid the influence of environment on measurements of magnetometer. Since magnitude of magnetic field can vary dependent on temperature, proximity to the ocean, latitude (diurnal variation of magnetic field) and magnetic storms magnetic station from time to time adjusts its measurements with a help of reference values of magnetic field (magnetic station sends request for reference values to magnetic observatory). The problem of the given approach is that remote areas usually are not covered by network (no Internet) and as a result the adjustment of measurements is impossible. In order to make adjustment of measurements possible and as a result improve accuracy of magnetic maps given work proposed the usage of Delay Tolerant Networking that delivers internet access to different areas around the world and represented its improvement to make its approach even better.The results are published for the first time.

An Efficient Routing Protocol with Overload Control for Group Mobility in Delay-Tolerant Networking

In delay-tolerant networking (DTN), messages are delivered to destination nodes by using opportunistic contacts between contact nodes, even if stable routing paths from source nodes to destination nodes do not exist. In some DTN network environments, such as military networks, nodes movement follows a group movement model, and an efficient DTN routing protocol is required to use the characteristics of group mobility. In this paper, we consider a network environment, where both intra- and intergroup routing are carried out by using DTN protocols. Then, we propose an efficient routing protocol with overload control for group mobility, where delivery predictability for group mobility is defined and proactive overload control is applied. Performance evaluation results show that the proposed protocol had better delivery ratios and overhead ratios than compared protocols, although the delivery latency was increased.