Flexible Unicast-Based Group Communication for CoAP-Enabled Devices

Abstract

Smart embedded objects will become an important part of what is called the Internet of Things. Applications often require concurrent interactions with several of these objects and their resources. Existing solutions have several limitations in terms of reliability, flexibility and manageability of such groups of objects. To overcome these limitations we propose an intermediately level of intelligence to easily manipulate a group of resources across multiple smart objects, building upon the Constrained Application Protocol (CoAP). We describe the design of our solution to create and manipulate a group of CoAP resources using a single client request. Furthermore we introduce the concept of profiles for the created groups. The use of profiles allows the client to specify in more detail how the group should behave. We have implemented our solution and demonstrate that it covers the complete group life-cycle, i.e., creation, validation, flexible usage and deletion. Finally, we quantitatively analyze the performance of our solution and compare it against multicast-based CoAP group communication. The results show that our solution improves reliability and flexibility with a trade-off in increased communication overhead.

An Adaptive Solution for Congestion Control in CoAP-based Group Communications

“…In [17], authors propose to use an alternative unicast-based group communication solution for communication between CoAP devices. In order to facilitate the manipulation of a group of resources used by multiple smart objects, they create an intermediate level of aggregation.…”

“…3 shows an overview of the involved components. Moreover, in [17] authors have introduced the notion of profiles which allows the client to give more details about the behavior of the created entities. The most advantage of this approach is its reliability; this goes back to the fact that it relies on unicast messages based on CoAP reliability mechanism.…”

“…To overcome this situation, authors in [17] proposed a simple solution consisting of a delay inserted between consecutive requests; this led to a limitation in the rate at which requests are sent.…”

Device-to-Device Communications for 5G Internet of Things

“…However, multicast communication has some drawbacks: it does not provide reliable service in IP network and the group formation my result complex, especially in dynamic heterogeneous IoT scenarios. Thus, ad-hoc proxy must be exploited to forward data from/to a group of IoT devices by multiple unicast communications and to provide dynamic group management [36]. 5G systems shall provide efficient support for group IoT communication, by optionally leveraging on proximity communications to reduce energy consumption and traffic congestion.…”

Data Aggregation Gateway Framework for CoAP Group Communications

“…Moreover, a long delay due to repetitive request-response operations cannot be avoided, which cannot guarantee the timeliness of IoT services. To solve this problem, Ishaq et al [11] proposed a gateway-centric unicast solution. In this solution, additional gateways (GWs) are placed between the client and servers.…”