Ishaq Isam, Hoebeke Jeroen, Moerman Ingrid, Demeester Piet
Said Khoury IT Center of Excellence (SKITCE), Al-Quds University, Abu Deis, Jerusalem 51000, Palestine.
Ghent University-iMinds, Department of Information Technology (INTEC), Technologiepark-Zwijnaarde 15, 9052 Ghent, Belgium.
Sensors (Basel). 2016 Jul 21;16(7):1137. doi: 10.3390/s16071137.
The Internet of Things (IoT) is expanding rapidly to new domains in which embedded devices play a key role and gradually outnumber traditionally-connected devices. These devices are often constrained in their resources and are thus unable to run standard Internet protocols. The Constrained Application Protocol (CoAP) is a new alternative standard protocol that implements the same principals as the Hypertext Transfer Protocol (HTTP), but is tailored towards constrained devices. In many IoT application domains, devices need to be addressed in groups in addition to being addressable individually. Two main approaches are currently being proposed in the IoT community for CoAP-based group communication. The main difference between the two approaches lies in the underlying communication type: multicast versus unicast. In this article, we experimentally evaluate those two approaches using two wireless sensor testbeds and under different test conditions. We highlight the pros and cons of each of them and propose combining these approaches in a hybrid solution to better suit certain use case requirements. Additionally, we provide a solution for multicast-based group membership management using CoAP.
物联网（IoT）正在迅速扩展到新领域，在这些领域中嵌入式设备发挥着关键作用，并且数量逐渐超过传统连接设备。这些设备的资源通常受到限制，因此无法运行标准的互联网协议。受限应用协议（CoAP）是一种新的替代标准协议，它实现了与超文本传输协议（HTTP）相同的原则，但针对受限设备进行了定制。在许多物联网应用领域，除了能够单独寻址外，设备还需要进行组寻址。目前物联网社区针对基于CoAP的组通信提出了两种主要方法。这两种方法的主要区别在于底层通信类型：多播与单播。在本文中，我们使用两个无线传感器测试平台并在不同测试条件下对这两种方法进行了实验评估。我们突出了每种方法的优缺点，并提出在混合解决方案中结合这些方法以更好地满足某些用例需求。此外，我们提供了一种使用CoAP进行基于多播的组成员管理的解决方案。
