High Capacity Ethernet Radio Relay Networks in Mobile Communications

The present paper studies the main characteristics of digital radio relays used by the largest mobile network operator (MNO) in Romania in order to develop a network supporting the newest technologies available on the market. The main contribution is the design of a high capacity Ethernet radio relay network in an area around Bucharest, Romania. The location was chosen on the criterion that it is a high-density traffic area where high-capacity radio links are in operation and use the newest digital radio relay features that are explained in this paper: high modulation scheme, adaptive radio modulation, radio traffic aggregation and cross-polarization interference cancellation. The network contains PDH and SDH links to transport the entire traffic in the area. We analyse several links between different sites that present particularities in the mobile operator's network. Finally, the most suitable parameters are chosen and the designed radio relay network is presented and analysed. It has been implemented in the MNO's network since 2015

Designing a Spintronic Based Magnetoresistive Bridge Sensor for Current Measurement and Low Field Sensing

An exchanged-biased anisotropic magnetoresistance bridge sensor for low currents measurement is designed and implemented. The sensor has a simple construction (single mask) and is based on results from micromagnetic simulations. For increasing the sensitivity of the sensor, the magnetic field generated by the measurement current passing through the printed circuit board trace is determined through an analytical method and, for comparative analysis, finite elements method simulations are used. The sensor performance is experimentally tested with a demonstrator chip. Four case studies are considered in the analytical method: neglecting the thickness of the trace, dividing the thickness of the trace in several layers, and assuming a finite or very long conductive trace. Additionally, the influence of several adjacent traces in the sensor area is evaluated. The study shows that the analytical design method can be used for optimizing the geometric selectivity of a non-contacting magnetoresistive bridge sensor setup in single trace, differential, and multi-trace (planar coil) configurations. Further, the results can be applied for developing highly performant magnetoresistance sensors and optimizations for low field detection, small dimensions, and low costs