Zi-Tsan Chou

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  • Zi-Tsan Chou
  • 2007 IEEE Wireless Communications and Networking…
  • 2007
In wireless ad hoc networks, IEEE 802.11 power management may completely fail if power-saving (PS for short) stations are out of synchronization. To fix this problem, Haas and Perlman (2001) proposed various cyclic quorum-based power management (CQPM) protocols, which, however, may also completely fail if some PS stations have different schedule repetition(More)
In this paper, we propose a new novel polling-based medium access control protocol, named UPCF (Unified Point Coordination Function), to provide power conservation and quality-of-service (QoS) guarantees for multimedia applications over wireless local area networks. Specifically, UPCF has the following attractive features. First, it supports multiple(More)
In IEEE 802.15.4 beacon-enabled wireless personal area networks (WPANs), the PAN coordinator will periodically broadcast beacon frames to let its associated end devices keep synchronized. One of the benefits in a beacon-enabled WPAN is that end devices can thus turn off their transceiver during the inactive periods to preserve their energy. Another benefit(More)
We propose a new MAC protocol, named Q-PCF (quality-of-service PCF), which provides QoS guarantees to real-time multimedia applications for WLANs. Specifically, Q-PCF has the following attractive features. First, it supports multiple priority levels and guarantees that high-priority stations always join the polling list earlier than low-priority stations.(More)
IEEE 802.16 broadband wireless access (BWA) systems support classes of traffic with differentiated quality of service (QoS). However, the detailed of how to schedule traffic are left unspecified. In this paper, based on this hierarchical QoS architecture, we propose a novel two-tier scheduling strategy, called two-tier scheduling algorithm (2TSA). The first(More)
Recently, the integration of smart antenna technology into existing wireless local area networks (WLANs) has been one of the hot spots of research work. In this paper, we design an IEEE 802.11-compliant medium access control (MAC) protocol, named M-HCCA, that fully takes advantage of multi-beam smart antennas equipped at the access point (AP) to not only(More)
The popularity of smart mobile devices has brought significant growth of data services for mobile service providers. Mobile users of data services are charged based on the amount of data used. Raising served data amount seemingly increases the profit; energy consumption rises correspondingly. Besides, spectral resources are licensed and limited for mobile(More)