Abstract: A method of mobile video streaming according to an exemplary embodiment of the present invention includes three parts. The first part is for AP to measure the information of all clients such as ETX (Expected Transmission count metric) and RSSI (Receive Signal Strength Indicator) periodically for long-term channel quality and mobility patterns of each client. In the second part, AP estimates the buffer status, short-term channel quality, and mobility detection of each client based on only feedback from the target client and first part result. And lastly, AP performs a practical online scheduling to select the best network code set satisfying high Peak Signal-to-Noise Ratio (PSNR), a standard metric of video quality, during a GoP (Group of Picture) at all clients based on I-frame priority.

Abstract: A method of mobile video streaming according to an exemplary embodiment of the present invention includes three parts. The first part is for AP to measure the information of all clients such as ETX (Expected Transmission count metric) and RSSI (Receive Signal Strength Indicator) periodically for long-term channel quality and mobility patterns of each client. In the second part, AP estimates the buffer status, short-term channel quality, and mobility detection of each client based on only feedback from the target client and first part result. And lastly, AP performs a practical online scheduling to select the best network code set satisfying high Peak Signal-to-Noise Ratio (PSNR), a standard metric of video quality, during a GoP (Group of Picture) at all clients based on I-frame priority.

Abstract: A lossless handover method in vehicular wireless networks is disclosed which is capable of reducing a handover delay and reducing overhead caused by duplicate address detection (DAD) for a new Care-of-Address (CoA) by dividing a handover process into handover at road-sections and handover at intersections. In the handover method, a vehicle continues to use an original CoA configured at an original access router at road-sections even though an AR is changed, thereby reducing a handover delay. A new CoA is configured only at intersections to reduce a binding update time of a home agent which is remotely present in an external network at road-sections. When performing the DAD for a new CoA at intersections, since the vehicle performs the DAD as a background process while performing communication using an original CoA, overhead caused by the DAD can be reduced.

Abstract: A lossless handover method in vehicular wireless networks is disclosed which is capable of reducing a handover delay and reducing overhead caused by duplicate address detection (DAD) for a new Care-of-Address (CoA) by dividing a handover process into handover at road-sections and handover at intersections. In the handover method, a vehicle continues to use an original CoA configured at an original access router at road-sections even though an AR is changed, thereby reducing a handover delay. A new CoA is configured only at intersections to reduce a binding update time of a home agent which is remotely present in an external network at road-sections. When performing the DAD for a new CoA at intersections, since the vehicle performs the DAD as a background process while performing communication using an original CoA, overhead caused by the DAD can be reduced.

Abstract: We propose overhear-based transmitting control system in WLANs to improve performance of 802.11 wireless LANs. The main idea of this scheme is that when the transmission of a node fails, one of neighboring nodes with better channel quality retransmits the lost frame in substitution. To do so, every node should maintain overhear table to buffer the transmitted packets that is not yet acknowledged. We also present algorithms to retransmit lost packets, to maintain the overhear table and to compensate for the retransmission of packets of other nodes. The performance of this scheme is evaluated via simulations in terms of MPDU size and average path loss. It shows that in environments where the packet is likely to be lost more, the throughput gain of our proposed scheme performs better.

Abstract: We propose overhear-based transmitting control system in WLANs to improve performance of 802.11 wireless LANs. The main idea of this scheme is that when the transmission of a node fails, one of neighboring nodes with better channel quality retransmits the lost frame in substitution. To do so, every node should maintain overhear table to buffer the transmitted packets that is not yet acknowledged. We also present algorithms to retransmit lost packets, to maintain the overhear table and to compensate for the retransmission of packets of other nodes. The performance of this scheme is evaluated via simulations in terms of MPDU size and average path loss. It shows that in environments where the packet is likely to be lost more, the throughput gain of our proposed scheme performs better.