Low-power And Lossy Networks Applications Research Articles

MobiRPL: Adaptive, robust, and RSSI-based mobile routing in low power and lossy networks

This paper tackles the mobile routing issues in low-power and lossy networks (LLNs). The IPv6 standard routing protocol for LLNs, termed IPv6 routing protocol for low-power and lossy networks (RPL), has mostly been investigated in static LLNs and it has no explicit mechanism to support mobility. In addition, there is no mobile routing protocol that works well in mobile LLNs. Considering the importance of mobility support in many LLN applications, this work designs and implements MobiRPL, an adaptive, robust, and received signal strength indicator (RSSI)-based mobile routing scheme based on the RPL standard. To cope with network dynamics, the MobiRPL design focuses more on maintaining reliable routing topology than on minimizing energy consumption. This design choice significantly improves reliability while maintaining the acceptable energy consumption of mobile LLNs. We implement MobiRPL on Contiki OS, and evaluate its effectiveness extensively through Cooja simulation and testbed experiments. Our results from the testbed show that MobiRPL improves mobile nodes' packet delivery ratio by 11.3% compared to RPL and reduces the energy consumption of mobile nodes by 73.3% compared to the baseline scheme, i.e., the lightweight on-demand ad-hoc distance-vector routing protocol — next generation (LOADng).

Leveraging Multi-Instance RPL Routing Protocol to Enhance the Video Traffic Delivery in IoMT

Nowadays, the massive proliferation of real-world multimedia devices has paved the way to the emergence of a new paradigm called the Internet of Multimedia Things wherein Low-power and Lossy Networks (LLNs) are the main components of this new technology. RPL is an IPv6 routing protocol for LLNs designed by IETF to meet the requirements of a wide range of LLN applications such as Wireless Multimedia Sensor Networks where video traffic is expected to reach 6 times more than non-video traffic in 2025. The mono-instance version of RPL is far from satisfying the network’s Quality of Service (QoS) and the user’s Quality of Experience (QoE), as video in its compressed form is typically composed of various frames with different priorities requiring different QoS and QoE levels. In this paper, we exploit the multi-instance version of RPL for developing a new routing approach that improves the transport of a compressed video, composed of two types of frames with different priorities, by delivering each of them on the corresponding instance. The fundamental question we are addressing, is to find the best way to construct these instances: instances with Nodes Disjoint (ND) or Links Disjoint (LD). To do so, we designed a Multi-Instance routing protocol, named MI-RPL, and we performed extensive simulation experiments using the Cooja simulator. The comparison of MI-RPL-ND, MI-RPL-LD and RPL which regards to QoS and QoE performance metrics, confirms that multi-instance routing for video transmission in WMSN (and in particular MI-RPL-ND) is the best choice.

Load Balancing Under Heavy Traffic in RPL Routing Protocol for Low Power and Lossy Networks

RPL is an IPv6 routing protocol for low-power and lossy networks (LLNs) designed to meet the requirements of a wide range of LLN applications including smart grid AMIs, industrial and environmental monitoring, and wireless sensor networks. RPL allows bi-directional end-to-end IPv6 communication on resource constrained LLN devices, leading to the concept of the Internet of Things (IoT) with thousands and millions of devices interconnected through multihop mesh networks. In this article, we investigate the load balancing and congestion problem of RPL. Specifically, we show that most of the packet losses under heavy traffic are due to congestion, and a serious load balancing problem appears in RPL in terms of routing parent selection. To overcome this problem, this article proposes a simple yet effective queue utilization based RPL ( QU-RPL ) that achieves load balancing and significantly improves the end-to-end packet delivery performance compared to the standard RPL. QU-RPL is designed for each node to select its parent node considering the queue utilization of its neighbor nodes as well as their hop distances to an LLN border router (LBR). Owing to its load balancing capability, QU-RPL is very effective in lowering queue losses and increasing the packet delivery ratio. We implement QU-RPL on a low-power embedded platform, and verify all of our findings through experimental measurements on a real testbed of a multihop LLN over IEEE 802.15.4. We present the impact of each design element of QU-RPL on performance in detail, and also show that QU-RPL reduces the queue loss by up to 84 percent and improves the packet delivery ratio by up to 147 percent compared to the standard RPL.

An Energy-Efficient Region-Based RPL Routing Protocol for Low-Power and Lossy Networks

Routing plays an important role in the overall architecture of the Internet of Things. IETF has standardized the RPL routing protocol to provide the interoperability for low-power and lossy networks (LLNs). LLNs cover a wide scope of applications, such as building automation, industrial control, healthcare, and so on. LLNs applications require reliable and energy-efficient routing support. Point-to-point (P2P) communication is a fundamental requirement of many LLNs applications. However, traditional routing protocols usually propagate throughout the whole network to discover a reliable P2P route, which requires large amount energy consumption. Again, it is challenging to achieve both reliability and energy-efficiency simultaneously, especially for LLNs. In this paper, we propose a novel energy-efficient region-based routing protocol (ER-RPL), which achieves energy-efficient data delivery without compromising reliability. In contrast of traditional routing protocols where all nodes are required for route discovery, the proposed scheme only requires a subset of nodes to do the job, which is the key of energy saving. Our theoretical analysis and extensive simulation studies demonstrate that ER-RPL has a great performance superiority over two conventional benchmark protocols, i.e., RPL and P2P-RPL.

DualMOP-RPL

RPL is an IPv6 routing protocol for low-power and lossy networks (LLNs) designed to meet the requirements of a wide range of LLN applications including smart grid AMIs, home and building automation, industrial and environmental monitoring, health care, wireless sensor networks, and the Internet of Things (IoT) in general with thousands and millions of nodes interconnected through multihop mesh networks. RPL constructs tree-like routing topology rooted at an LLN border router (LBR) and supports bidirectional IPv6 communication to and from the mesh devices by providing both upward and downward routing over the routing tree. In this article, we focus on the interoperability of downward routing and supporting its two modes of operations (MOPs) defined in the RPL standard (RFC 6550). Specifically, we show that there exists a serious connectivity problem in RPL protocol when two MOPs are mixed within a single network, even for standard-compliant implementations, which may result in network partitions. To address this problem, this article proposes DualMOP-RPL , an enhanced version of RPL, which supports nodes with different MOPs for downward routing to communicate gracefully in a single RPL network while preserving the high bidirectional data delivery performance. DualMOP-RPL allows multiple overlapping RPL networks in the same geographical regions to cooperate as a single densely connected network even if those networks are using different MOPs. This will not only improve the link qualities and routing performances of the networks but also allow for network migrations and alternate routing in the case of LBR failures. We evaluate DualMOP-RPL through extensive simulations and testbed experiments and show that our proposal eliminates all the problems we have identified.

Towards efficient distributed service discovery in low-power and lossy networks

Low-power and Lossy Networks (LLNs) have been recognised as a promising technology to achieve ubiquity in the internet of things era. To realise this, service oriented architectures and the emerging IPv6 over low-power wireless personal area network (6LoWPAN) standard are identified as key paradigms. One of the main elements to succeed any service oriented approach is a proficient service discovery protocol. In this paper, we propose EADP: an efficient protocol to announce and discover services in 6LoWPAN networks. EADP adopts a fully distributed approach using an adaptive push---pull model to ensure fast discovery times, low energy consumption and low generated overhead with timely reaction to network dynamics. EADP achieves this by using context-awareness information, delivered by a trickle algorithm. EADP was implemented and evaluated in Contiki using the Cooja simulator. Simulation results show EADP's capability to realise fast discovery times with low cost in terms of energy and overhead. These achievements make EADP very suitable for pervasive LLN applications.