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—The fairness concept has been widely studied in the area of data networks. The most well-known fairness criterion (max–min fairness) gives priority to the minimum-rate session. Kelly questioned its appropriateness in his works on the band-width sharing among the end-to-end flows and proposed another fairness criterion preferring short-distance flows to(More)
—Orthogonal frequency-division multiple access (OFDMA) systems are considered promising candidates for implementing next-generation wireless communication systems. They provide multiple channels that can be accessed via random access schemes. However, traditional random access schemes could result in an excessive amount of access delay. To address this(More)
—An important quality-of-service (QoS) issue in wireless multimedia networks is how to control handoff drops. In this paper, we propose admission-control algorithms that adaptively control the admission threshold in each cell in order to keep the handoff-dropping probability below a predefined level. The admission threshold is dynamically adjusted based on(More)
— The OFDMA systems are emerging for future cellular networks. Creating multiple data channels, they can support the flexible frequency reuse factor (FRF). Although FRF 1 is the best choice in terms of cell throughput, it causes intercell interference at the cell boundary, thereby being unable to serve the whole cell area. Therefore it was proposed to use(More)
—In this paper, we investigate two types of IQ-data transfer methods for cloud MIMO network operation. They are termed " after-precoding " and " before-precoding. " We formulate a cloud massive MIMO operation problem that includes the best IQ-transfer method and beamforming strategy (beamforming technique, the number of concurrently receiving users, the(More)
— It is well known that opportunistic scheduling by using feedback information significantly improves wireless network performance. Most opportunistic scheduling works have focused on the case where a single channel is shared by multiple users. However, emerging wireless technologies (e.g., MIMO, OFDMA, etc.) are characterized by multiple shared channels,(More)
By adopting multiple-input-multiple-output (MIMO) antenna technologies, IEEE 802.11 wireless LANs are evolving into high speed systems. While only one user can transmit at a time in the conventional IEEE 802.11 systems, we investigate the possibility of multiuser transmission by using MIMO antennas, which is now known as multiuser MIMO. The multiuser MIMO(More)
— IEEE 802.11e has established a new access mechanism , Hybrid Coordination Function (HCF), as a step towards provisioning QoS support. In this mechanism, a simple HCF scheduler is introduced to take QoS requirements of admitted flows into account and allocate Transmission Opportunities (TXOP), the time under which a station can send its burst of data(More)
— In this paper, we consider a simple but efficient medium access control (MAC) protocol that can be used in an ad hoc network with asynchronous multi-channel environments. The approach in our proposal is to use time offset between channels where each channel has its own frame starting time. We assume that the network runs in power saving mode (PSM) of the(More)