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— Today's IEEE 802.11 WLANs (Wireless LANs) provide multiple transmission rates so that different rates can be exploited in an adaptive manner depending on the underlying channel condition in order to maximize the system performance. Many rate adaptation schemes have been proposed so far while most (if not all) of the commercial devices implement a simple(More)
—Link adaptation to dynamically select the data transmission rate at a given time has been recognized as an effective way to improve the goodput performance of the IEEE 802.11 wireless local-area networks (WLANs). Recently, with the introduction of the new high-speed 802.11a physical layer (PHY), it is even more important to have a well-designed link(More)
— IEEE 802.11a is a new high-speed physical layer (PHY) defined for the 5 GHz U-NII bands as a supplement to the existing IEEE 802.11 wireless LAN (WLAN) standard. In this paper, we give an overview of the IEEE 802.11a Orthogonal Frequency Domain Multiplexing (OFDM) PHY with eight different PHY rates as well as the distributed coordination function (DCF) of(More)
— In this paper, we demonstrate the energy-efficient Point Coordination Function (PCF) operation of IEEE 802.11a wireless LAN (WLAN) via both transmit power control (TPC) and physical layer (PHY) rate adaptation. First, we derive the energy-consumption performance analytically for uplink data transmissions under the PCF. From the evaluation results, we(More)
Reducing the energy consumption by wireless communication devices is perhaps the most important issue in the widely-deployed and exponentially-growing IEEE 802.11 Wireless LANs (WLANs). TPC (Transmit Power Control) and PHY (physical layer) rate adaptation have been recognized as two most effective ways to achieve this goal. The emerging 802.11h standard,(More)
The emerging wireless charging technology is a promising alternative to address the power constraint problem in sensor networks. Comparing to existing approaches, this technology can replenish energy in a more control-lable manner and does not require accurate location of or physical alignment to sensor nodes. However, little work has been reported on(More)
—In this paper, we investigate the transmission of H.263 video sequences over wireless networks with error recovery provided by a two-step adaptive hybrid ARQ scheme using RS codes. Each video frame is divided into data packets for transmission. For each packet transmission , by using a simple table-driven approach, the best RS code is selected from a given(More)