Abstract: A method for decoding an image based on an intra prediction, comprising: obtaining a first prediction pixel of a first region in a current block by using a neighboring pixel adjacent to the current block; obtaining a second prediction pixel of a second region in the current block by using the first prediction pixel of the first region; and decoding the current block based on the first and the second prediction pixels.

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.