Deterministic Contention Resolution on a Shared Channel
Deterministic Contention Resolution on a Shared Channel
复制标题
共享通道上的确定性争用解决方案
DOI：
10.1109/icdcs.2019.00054
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Grzegorz Stachowiak
中科院分区：
文献类型：
--
作者：
G. D. Marco;D. Kowalski;Grzegorz Stachowiak
共享通信信道（也称为多路访问信道）是通信和分布式计算中最流行和最广泛研究的模型之一。在这个模型中，站点能够通过发送和监听共享信道来进行通信。一个基本的问题，称为竞争解决，是允许任何站成功地传递其消息时，几个站同时在信道上传输解决出现的冲突。尽管有很长的历史，许多基本的问题仍然是开放的现实情况下，多达k个站的n在不同的时间加入通道。在这项工作中，我们探讨了竞争者的知识（或线性估计），竞争者的延迟和信道利用率的非自适应确定性算法的影响。我们表明，如果竞争者的数量k（或它的线性上限）是已知的，并确认他们的成功传输后关闭的站，信道承认有效的解决方案。在相同的设置中，我们表明，无知的竞争k使信道效率几乎二次方，即使站可以关闭后，bridgments。我们提出了一个算法，几乎匹配这种复杂性（未知k），即使不提供的dumegments实现。我们展示了如何上述算法可以进一步改善，如果站可以关闭确认。令人惊讶的是，我们的研究结果意味着竞争的知识对异步信道的确定性利用率的确定性算法的指数影响-它是已知的，对于同步信道，此功能不影响渐近的信道利用率。第二个含义是关于重叠的影响-如果k（的一些估计）是已知的，则它们以指数方式提高确定性信道利用率，而不像在随机算法的情况下，其中提高仅是多项式，而它们在未知竞争的情况下不是特别有帮助。最后，请注意，非自适应算法使用固定的传输时间表，这可以自然地转换为无线电或蜂鸣模型中的代码-在这种情况下，我们的研究结果表明，在哪些条件下，这样的代码可能是有效的。
A shared communication channel (also known as a multiple access channel) is among the most popular and widely studied models of communication and distributed computing. In this model, stations are able to communicate by transmitting and listening to a shared channel. A fundamental problem, called contention resolution, is to allow any station to successfully deliver its message by resolving the conflicts that arise when several stations transmit simultaneously on the channel. Despite a long history, many fundamental questions remain open in the realistic scenario when up to k stations out of n join the channel at different times. In this work we explore the impact of asynchrony, knowledge (or linear estimate) of contenders, and acknowledgments, on latency and channel utilization of non-adaptive deterministic algorithms. We show that if the number of contenders k (or a linear upper bound on it) is known and the stations switch-off after acknowledgment of their successful transmissions, the channel admits efficient solutions. In the same settings, we show that the ignorance of contention k makes the channel nearly quadratically less efficient, even if the stations could switch-off after acknowledgments. We present an algorithm which nearly matches this complexity (for unknown k) which is achieved even if acknowledgments are not provided. We show how the above algorithm could be further improved if stations could switch off upon acknowledgment. Surprisingly, our results imply an exponential impact of knowledge of contention on deterministic utilization of asynchronous channel by deterministic algorithms — it is known that for synchronized channel this feature does not influence asymptotically the channel utilization. The second implication concerns the impact of acknowledgments — they exponentially improve deterministic channel utilization if (some estimate of) k is known, unlike in the case of randomized algorithms where the improvement is only polynomial, while they are not particularly helpful in case of unknown contention. Finally, note that non-adaptive algorithms use fixed transmission schedules, which could be naturally translate into codes in the radio or beeping model — in this context our results indicate under which conditions such codes could be efficient.
多路访问信道上的对抗性排队
影响因子：
1.3
作者：
Chlebus B
通讯作者：
Chlebus B