Myoung-Hwan Lee

Multi-connectivity strategy for agile service delivery with low power discovery

To deliver services using wireless connectivity on mobile devices, service discovery with low power and service execution with fast connection are the essential factors. However, no single connectivity technology satisfies fast service execution with low power discovery because agile service delivery fundamentally requires consuming high power. Therefore, we propose a synergetic multi-connectivity strategy utilizing Bluetooth Low Energy (BLE) discovery and Wi-Fi Peer to Peer (P2P) fast connection for agile service delivery. Furthermore, we develop an adaptive BLE discovery algorithm to enhance the discovery performance. Finally, the experiment of the multi-connectivity scheme and the theoretical simulation of the discovery algorithm show that the proposed approach excellently provides the fast service delivery with low power discovery.

A cognitive link adaptation strategy with differentiated responses on Wi-Fi System-on-Chip

The dynamic change of wireless channel condition causes poor Wi-Fi quality of service. To cope with the channel variation of wireless communication, the essential strategy for the physical layer with multi-rate capability is the link adaptation. However, because definite guidelines for rate changes do not exist, most link adaptation algorithms can misleadingly increase transmission rates. Therefore, we propose a cognitive link adaptation scheme, sensing link adaptation urgency and responding with differentiated rate control such as the long-term rate adaptation with a short-term rate drop. To evaluate the proposed scheme, we implement the link adaptation scheme on Wi-Fi System-on-Chip, applying the optimal HW/SW partitioning technique to reduce the SW processing delay from heavy operating calculation for the algorithm. The experiment shows that the proposed algorithm increases the packet arrival rate in a real Wi-Fi environment by reducing transmission failure due to wrong rate changes.