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In this paper, we evaluate the capacity gains expected when introducing HSUPA+ capable devices in the network. We first develop a flow level capacity for a cell carrying legacy UMTS devices in addition to HSPA and HSPA+ ones. We show how to calculate the QoS for both real time and elastic traffic using queuing theory analysis. Our model is next applied to assess the user-perceived QoS, i.e. the blocking...
We consider opportunistic scheduling in a downlink OFDMA system to support heterogeneous services. Given the user's queue state information (QSI) and channel state information (CSI), the proposed sum waiting time based scheduling (SWBS) algorithm can guarantee QoS requirements for both real-time (RT) and non-real-time (NRT) service. The benefit is attained from scheduling heterogeneous services based...
The combined MIMO with adaptive modulation and coding (AMC) technology can provide high spectral efficiency and link robustness. While most existing adaptive algorithms focus on physical layer, cross-layer analysis on the queuing behavior of MIMO-AMC systems is necessary, but remains open. In this paper, under the conditions of unsaturated traffic and finite-length buffer, we investigate the queuing...
The emerging broadband wireless access (BWA) technology based on IEEE 802.16 is one of the most promising solutions to provide ubiquitous wireless access to the broadband service at low cost. This paper proposes an efficient uplink bandwidth request-allocation algorithm for variable-rate realtime services in IEEE 802.16 BWA networks. In order to minimize bandwidth wastage without degrading quality...
In this paper, a novel performance analytical model, which uses discrete Markov and M/M/1/K theory, is presented for IEEE 802.11 based wireless networks with finite load. Delay and loss caused by MAC contention and buffer queuing are studied in detail. This model and analysis give an in-depth insight and understanding to the unfairness between uplink and downlink flows that are forwarded by access...
In this paper, the influence of wireless channel fading on packet loss and delay for wireless local area networks is studied in detail. It shows that in CSMA/CA MAC scheme, packets with bad channel state will engross MAC buffer and deteriorate other downlink flows' performance. To overcome this problem, a novel channel state aware scheduling algorithm is presented to reduce the QoS degradation caused...
A downlink wireless system is considered where a single base station serves two users simultaneously based on the information available at the PHY and MAC layers. Two new quality of service (QoS) oriented scheduling algorithms are proposed that consider both channel state and direction of arrival information available at the PHY layer and queue length information available at the MAC layer to schedule...
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