Effective capacity: A wireless link model for support of quality of service
Effective capacity: A wireless link model for support of quality of service
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DOI：
10.1109/twc.2003.814353
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发表时间：
2003-07-01
影响因子：
10.4
通讯作者：
Negi, R
中科院分区：
文献类型：
--
作者：
Wu, DP;Negi, R
为了促进下一代无线网络中的服务质量（QoS）的有效支持，它是必不可少的无线信道的连接级QoS指标，如数据速率，延迟和延迟违规概率建模。然而，现有的无线信道模型，即，物理层信道模型并不明确地根据这些QoS度量来表征无线信道。在本文中，我们提出并开发了一个链路层信道模型称为有效容量（EC）。在这种方法中，我们首先建立一个无线链路的两个EC功能，即，非空缓冲区的概率，和一个连接的Qos指数。然后，我们提出了一个简单而有效的算法来估计这些EC函数。这两个链路层EC功能的物理层类似物是边际分布（例如，Rayleigh-Ricean分布）和多普勒频谱。EC链路层建模和估计的主要优点是：1）易于转换为QoS保证，例如延迟界限; 2）实现简单;以及3）准确性，以及因此在准入控制和资源预留中的效率。我们说明了我们的方法的优势与一组模拟实验，这表明，实际的QoS度量是密切接近的QoS度量预测的EC链路层模型，在广泛的条件下。
To facilitate the efficient support of quality of service (QoS) in next-generation wireless networks, it is essential to model a wireless channel in terms of connection-level QoS metrics such as data rate, delay, and delay-violation probability. However, the existing wireless channel models, i.e., physical-layer channel models, do not explicitly characterize a wireless channel in terms of these QoS metrics. In this paper, we propose and develop a link-layer channel model termed effective capacity (EC). In this approach, we first model a wireless link by two EC functions, namely, the probability of nonempty buffer, and the Qos exponent of a connection. Then, we propose a simple and efficient algorithm to estimate these EC functions. The physical-layer analogs of these two link-layer EC functions are the marginal distribution (e.g., Rayleigh-Ricean distribution) and the Doppler spectrum, respectively. The key advantages of the EC link-layer modeling and estimation are: 1) ease of translation into QoS guarantees, such as delay bounds; 2) simplicity of implementation; and 3) accuracy, and hence, efficiency in admission control and resource reservation. We illustrate the advantage of our approach with a set of simulation experiments, which show that the actual QoS metric is closely approximated by the QoS metric predicted by the EC link-layer model, under a wide range of conditions.