论文标题
IEEE 802.15.4 DSME的新帽子减少机制支持物联网系统中的流量波动
New CAP Reduction Mechanisms for IEEE 802.15.4 DSME to Support Fluctuating Traffic in IoT Systems
论文作者
论文摘要
2015年，IEEE 802.15.4标准通过确定性和同步的多通道扩展（DSME）扩展，以提高工业应用中的可靠性，可伸缩性和能源效率。该扩展名提供了基于TDMA/FDMA的频道访问，其中时间分为两个交替阶段，一个竞争访问周期（CAP）和自由期（CFP）。在盖帽期间，可以分配传输插槽，可在CFP期间提供对共享介质的独家访问。 CFP在数据范围中的时间插槽的分数$τ$是关键值，因为它直接影响敏捷性和吞吐量。高通量要求CFP比CAP（即分数$τ$的高值）更长，因为应用程序数据仅在CFP期间发送。如果预期发送盖消息的预期等待时间很短，并且盖的长度足够长，可以容纳GTSS的必要（DE）分配，即分数$τ$的低值，则给出了高敏捷性。一旦根据应用程序的需求配置DSME，分数$τ$只能假设两个值之一，并且不能在运行时更改。在本文中，我们提出了两种DSME的扩展，允许对当前的流量模式采用$τ$。我们从理论上讲，通过模拟表明，所提出的扩展名在保持高吞吐量的同时对交通波动提供了高度的响应。
In 2015, the IEEE 802.15.4 standard was expanded by the Deterministic and Synchronous Multi-Channel Extension (DSME) to increase reliability, scalability and energy-efficiency in industrial applications. The extension offers a TDMA/FDMA-based channel access, where time is divided into two alternating phases, a contention access period (CAP) and a contention free period (CFP). During the CAP, transmission slots can be allocated offering an exclusive access to the shared medium during the CFP. The fraction $τ$ of CFP's time slots in a dataframe is a critical value, because it directly influences agility and throughput. A high throughput demands that the CFP is much longer than the CAP, i.e., a high value of the fraction $τ$, because application data is only sent during the CFP. High agility is given if the expected waiting time to send a CAP message is short and that the length of the CAPs are sufficiently long to accommodate necessary (de)allocations of GTSs, i.e., a low value of the fraction $τ$. Once DSME is configured according to the needs of an application, the fraction $τ$ can only assume one of two values and cannot be changed at run-time. In this paper, we propose two extensions of DSME that allow to adopt $τ$ to the current traffic pattern. We show theoretically and through simulations that the proposed extensions provide a high degree of responsiveness to traffic fluctuations while keeping the throughput high.
