In recent years, connection-based slotted-Aloha (CS-Aloha) has been proposed to improve the performance of random access networks. In this protocol, each node attempts to send a request to the access point (AP) before packet transmission. Once this attempt is successful, the node can transmit up to MM packets to the AP. Previous works indicated that the CS-Aloha can achieve a higher throughput than the classical slotted Aloha (S-Aloha), if MM is large enough. However, the impact of MM on the delay performance and stability is still unknown. To solve this problem, we model each node of the CS-Aloha as a vacation queueing system with limited service discipline, where we consider each batch of packet transmissions as a busy period, and the attempt process between two successive busy periods as a vacation period. We derive the delay distribution, which is turned out to be a geometric distribution. From this result, we further obtain the mean delay, the delay jitter, and the bounded delay region. Our analysis shows that increasing MM can accelerate the clean-up of the buffer in each node and thus decrease the attempt rate, which can reduce the average time needed by a node to make a successful attempt. As a result, a large MM can decrease the mean delay and the delay jitter, and enlarge the bounded delay region. Also, we obtain the condition to achieve the minimum mean delay under different values of MM .

中文翻译：

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基于连接的Slotted-Aloha的时延与稳定性分析


近年来，基于连接的时隙Aloha（CS-Aloha）被提出来提高随机接入网络的性能。在此协议中，每个节点在数据包传输之前尝试向接入点 (AP) 发送请求。一旦此尝试成功，节点就可以向 AP 传输最多 MM 数据包。之前的工作表明，如果 MM 足够大，CS-Aloha 可以实现比经典时隙 Aloha (S-Aloha) 更高的吞吐量。然而，MM对延迟性能和稳定性的影响仍然未知。为了解决这个问题，我们将CS-Aloha的每个节点建模为一个具有有限服务规则的假期排队系统，其中我们将每批数据包传输视为一个繁忙时段，并将两个连续繁忙时段之间的尝试过程视为一个假期时段。我们推导出延迟分布，结果证明这是一个几何分布。从这个结果中，我们进一步获得平均延迟、延迟抖动和有界延迟区域。我们的分析表明，增加MM可以加速每个节点中缓冲区的清理，从而降低尝试率，从而可以减少节点成功尝试所需的平均时间。因此，大MM可以降低平均延迟和延迟抖动，并扩大有界延迟区域。此外，我们还获得了在不同 MM 值下实现最小平均延迟的条件。