Optimization of Arq Parameters of Stanag 5066 for the HFDVL Modem

The reliability of bidirectional communication link can be guaranteed with Automatic Repeat Request Procedures (ARQ). The standard STANAG 5066 describes the ARQ procedure for HF communications that can either be applied to existing HF physical layers modems or adapted to future physical layer designs. In this contribution the physical layer parameters of an HF modem (HFDVL), developed by the authors over the last decade, are chosen to optimize the performance of the ARQ procedure described in STANAG 5066. Besides the interleaving length, constellation size and coding type, the OFDM-based HFDVL modem permits the selection of the number of receiver antennas. It will be shown that this parameter gives additional degrees of freedom and permits reliable communication over low SNR HF communication links.

Fiber penetration and copper access regulation

Research question, methodology and messages to take home - Impact of copper (legacy networks)regulation(LLU and bitstream)on NGN adoption - Methodology: fixed effects regression and forecasting with s- curves(logistic) - Key message:(excessive) copper regulation discourages NGN adoption (deployment, investments), in particular an increase ofunbundling access charges and/or a decrease of wholesale access would increase penetration of fibre and cable modem.