Static Context Header Compression Research Articles

Enabling Extremely Energy-Efficient End-to-End Secure Communications for Smart Metering Internet of Things Applications Using Static Context Header Compression

Smart metering IoT applications are among the most energy-critical in the current panorama. Metering sensors are battery-powered and are expected to have a lifetime exceeding ten years. In order to achieve such long operation duration, a generic header compression mechanism named Static Context Header Compression (SCHC) has been introduced and accepted as a standard by the Internet Engineering Task Force (IETF). This paper aims to demonstrate the energy savings enabled by the use of SCHC on a cellular IoT network by the means of real-life implementation and measurements. Experiments are conducted in a controlled environment for different scenarios and considering multiple parameters such as message size and radio conditions. Measurements show the high impact of this header compression mechanism, particularly when the radio conditions are bad and repetitions are used to improve the reliability of the transmission: a reduction of up to 40% in energy consumption is observed. Using SCHC over the non-IP transport mode (NIDD) of NB-IoT compared to the legacy IP mode also enables significant energy savings and allows the latency to be reduced while maintaining the interoperability provided by the IP layer.

Innovative security and compression for constrained IoT networks

Low-Power Wide-Area Networks (LPWAN) are a type of wireless communication technologies that enable efficient data transfer between low-power devices. This article explores the challenges of ensuring security in LPWANs and proposes a solution that combines two key mechanisms: Object Security for Constrained RESTful Environments (OSCORE) and Static Context Header Compression (SCHC). LPWANs are increasingly being used in Internet of Things (IoT) applications, but the features that endow these technologies with low power consumption and long range also make it necessary to adapt protocols and innovate in the approaches to achieve security while maintaining communications viable in technologies like these, in some cases with severe limitations. OSCORE provides end-to-end security for constrained devices, while SCHC enables efficient IP-based transmission over LPWANs. By combining these two protocols, the proposed solution aims to address the security and efficiency challenges of LPWANs, ensuring that IoT devices and data are protected from unauthorized access and manipulation. The article also presents experimental results demonstrating the feasibility and effectiveness of the proposed approach using a real-life scenario, with industrial-grade hardware. The study concludes that the use of OSCORE and SCHC in LPWAN networks can significantly enhance the security and privacy of IoT devices.

Assessing a Methodology for Evaluating the Latency of IPv6 with SCHC Compression in LoRaWAN Deployments

The Internet of Things (IoT) approach relies on the use of the Internet Protocol (IP) as a pervasive network protocol. IP acts as a "glue" for interconnecting end devices (on the field side) and end users, leveraging on very diverse lower-level and upper-level protocols. The need for scalability would suggest the adoption of IPv6, but the large overhead and payloads do not match with the constraints dictated by common wireless solutions. For this reason, compression strategies have been proposed to avoid redundant information in the IPv6 header and to provide fragmentation and reassembly of long messages. For example, the Static Context Header Compression (SCHC) protocol has been recently referenced by the LoRa Alliance as a standard IPv6 compression scheme for LoRaWAN-based applications. In this way, IoT end points can seamlessly share an end-to-end IP link. However, implementation details are out of the specifications' scope. For this reason, formal test procedures for comparing solutions from different providers are important. In this paper, a test method for assessing architectural delays of real-world deployments of SCHC-over-LoRaWAN implementations is presented. The original proposal includes a mapping phase, for identifying information flows, and a subsequent evaluation phase, in which flows are timestamped and time-related metrics are computed. The proposed strategy has been tested in different use cases involving LoRaWAN backends deployed all around the world. The feasibility of the proposed approach has been tested by measuring the end-to-end latency of IPv6 data in sample use cases, obtaining a delay of less than 1 s. However, the main result is the demonstration that the suggested methodology permits a comparison of the behavior of IPv6 with SCHC-over-LoRaWAN, allowing the optimization of choices and parameters during deployment and commissioning of both infrastructure components and software.

Packet Fragmentation Over Sigfox: Implementation and Performance Evaluation of SCHC ACK-on-Error

The static context header compression and fragmentation (SCHC) framework has been recently designed by the Internet engineering task force (IETF). SCHC provides adaptation layer functionality intended to efficiently support IPv6-based and other applications over low power wide area network (LPWAN) technologies. As of the writing, technology-specific profiles are being standardized in order to describe how SCHC can be tailored when used over a given underlying technology. In this article, we provide the first performance evaluation of SCHC over Sigfox, a flagship LPWAN technology. We focus on the main SCHC over Sigfox fragmentation mode, called ACK-on-Error, which offers low overhead, reliability, and reassembly functionalities. We provide a theoretical analysis and an experimental evaluation in real environments that correspond to two geographical zones with different Sigfox radio settings: 1) Barcelona (Spain) and 2) Santiago (Chile). The study focuses on modeling and evaluating packet transfer times, and the required number of uplink and downlink messages. The results show that a small change in packet sizes may significantly affect the transfer times, especially when no duty-cycle restrictions are enforced. Also, we observe that, under certain conditions, an increase in the fragment loss rate (FLR) may decrease the packet transfer time, and that the number of uplink and downlink messages is not proportional to such increase due to the fact that downlink messages are device-driven. The results provide useful insights for researchers, developers, implementers, and providers, with applicability to the application design, network planning, and resource management of Internet of Things (IoT) solutions.

Analysis of Web-Based IoT through Heterogeneous Networks: Swarm Computing over LoRaWAN.

The Internet of Things (IoT) leverages added valued services by the wide spread of connected smart devices. The Swarm Computing paradigm considers a single abstraction layer that connects all kinds of devices globally, from sensors to super computers. In this context, the Low-Power Wide-Area Network (LPWAN) emerges, spreading out connection to the IoT end devices. With the upsides of long-range, low power and low cost, LPWAN presents major limitations regarding data transmission capacity, throughput, supported packet length and quantity per day limitation. This situation makes LPWAN systems with limited interoperability integrate with systems based on REpresentational State Transfer (REST). This work investigates how to connect web-based IoT applications with LPWANs. The analysis was carried out studying the number of packets generated for a use case of REST-based IoT over LPWAN, specifically the Swarm OS over LoRaWAN. The work also presents an analysis of the impact of using promising schemes for lower communication load. We evaluated Constrained Application Protocol (CoAP), Static Context Header Compression (SCHC) and Concise Binary Object Representation (CBOR) to make transmission over the restricted links of LPWANs possible. The attained results show the reduction of 98.18% packet sizes while using SCHC and CBOR compared to HTTP and JSON by sending fewer packets with smaller sizes.

New Bit Pattern Based IPv6 Address Compression Techniques for 6LoWPAN Header Compression

Things in the world can be connected to the Internet through various technologies such as Wi-Fi, Bluetooth, IEEE 802.15.4 etc. Among all IPv6 over IEEE 802.15.4 looks promising for outdoor environments for connecting a very large number of resource constrained sensor nodes. 6LoWPAN is an adaptation layer to support IPv6 over IEEE 802.15.4 to overcome the challenge of the physical layer with respect to the limitation of 127 bytes of payload. 6LoWPAN supports header compression as one of its functions to reduce the number of bits in header by using compression techniques. Static Context Header Compression (SCHC) provides RuleID based header compression. This paper proposes further compression of address bits based on compressing leading zeros in IPv6 addresses. The proposed work is analysed with respect to Header compression HC1 of 6LoWPAN and SCHC techniques. The simulation results show compression of address bits are 10% to 40% more compared to traditional address compression of the 6LoWPAN address compression when continuous zeroes are present in the address. The compression of address bits provides sufficient space for sending data payload in one frame during communication.

Device Discovery and Context Registration in Static Context Header Compression Networks

Due to the limited bandwidth of Low-Power Wide-Area Networks (LPWAN), the application layer is currently often tied straight above the link layer, limiting the evolution of sensor networks distributed over a large area. Consequently, the highly efficient Static Context Header Compression (SCHC) standard was introduced, where devices can compress the IPv6 and upper layer protocols down to a single byte. This approach, however, assumes that every compression context is distributed before deployment, again limiting the evolution of such networks. Therefore, this paper presents two context registration mechanisms leveraging on the SCHC adaptation layer. This is done by analyzing current registration solutions in order to find limitations and optimizations with regard to very constrained networks. Both solutions and the current State-of-The-Art (SoTA) are evaluated in a Lightweight Machine to Machine (LwM2M) environment. In such situation, both developed solutions decrease the energy consumption already after 25 transmissions, compared with the current SoTA. Furthermore, simulations show that Long Range (LoRa) devices still have a 80% chance to successfully complete the registration flow in a network with a 50% Packet Error Ratio. Briefly, the work presented in this paper delivers bootstrapping tools to constrained, SCHC-enabled networks while still being able to reduce energy consumption.

Performance Analysis and Optimal Tuning of IETF LPWAN SCHC ACK-on-Error Mode

The Internet Engineering Task Force (IETF) Low Power Wide Area Network (LPWAN) Working Group has developed the Static Context Header Compression (SCHC) framework to enable IPv6 over LPWAN. In order to support 1280-byte packets, as required for IPv6, SCHC includes a fragmentation functionality, since relevant LPWAN technologies offer very short data unit sizes and do not provide native fragmentation mechanisms. SCHC offers 3 fragmentation modes: No-ACK, ACK-Always, and ACK-on-Error, the latter being especially promising due to its reliability and high efficiency. In this article, we develop a mathematical model to compute the most critical performance parameters for the SCHC ACK-on-Error mode, namely, the acknowledgment traffic incurred by a fragment receiver for the successful delivery of a fragmented packet. The model is used to evaluate the SCHC ACK-on-Error mode performance, as well as to optimally tune its main parameters when used over LoRaWAN and Sigfox, for different packet sizes. Additionally, we illustrate how our derived optimal settings allow to reduce the acknowledgment traffic in a number of scenarios.

Mobility Management With Session Continuity During Handover in LPWAN

In this article, we consider the mobility of an end device (ED) in low-power wide-area networks (LPWANs) and we focus on the continuity of the ED session with the application server when this ED is moving from the coverage of one operator to that of another one. One of the methods to achieve the continuity of the session after roaming is the use of an IPv6-based scheme. As LPWAN is characterized by a fixed message rate and very small bandwidth as well as asymmetric communication, an efficient header compression scheme is required. Recently, the Internet Engineering Task Force LPWAN working group has proposed a static context header compression (SCHC) to compress IPv6 into LPWAN through a rule-based mechanism. In this article, we first extend the SCHC scheme to support session continuity and the new scheme is called mobile SCHC (MSCHC). MSCHC consists of several contexts, instead of the static context for SCHC and we also improve the use of the memory by dividing the rules into layers. Then, we investigate the mobility of the ED to show how the continuity of the session can be achieved while transmitting and receiving data when the ED is roaming between different operators. The proposed solution is based on the use of light mobile IPv6 messages compressed with MSCHC. Finally, the proposed mechanism is implemented in the popular LoRaWAN technology, evaluated and compared with the existing solutions provided by the LoRaWAN v1.1 standard.

An End-To-End LwM2M-Based Communication Architecture for Multimodal NB-IoT/BLE Devices.

The wireless Internet of Things (IoT) landscape is quite diverse. For instance, Low-Power Wide-Area Network (LPWAN) technologies offer low data rate communication over long distance, whereas Wireless Personal Area Network (WPAN) technologies can reach higher data rates, but with a reduced range. For simple IoT applications, communication requirements can be fulfilled by a single technology. However, the requirements of more demanding IoT use cases can vary over time and with the type of data being exchanged. This is pushing the design towards multimodal approaches, where different wireless IoT technologies are combined and the most appropriate one is used as per the need. This paper considers the combination of Narrow Band IoT (NB-IoT) and Bluetooth Low Energy (BLE) as communication options for an IoT device that is running a Lightweight Machine to Machine/Constrained Application Protocol (LwM2M/CoAP) protocol stack. It analyses the challenges incurred by different protocol stack options, such as different transfer modes (IP versus non-IP), the use of Static Context Header Compression (SCHC) techniques, and Datagram Transport Layer Security (DTLS) security modes, and discusses the impact of handover between both communication technologies. A suitable end-to-end architecture for the targeted multimodal communication is presented. Using a prototype implementation of this architecture, an in-depth assessment of handover and its resulting latency is performed.

Impact of SCHC Compression and Fragmentation in LPWAN: A Case Study with LoRaWAN

The dawn of the Internet of Things (IoT) paradigm has brought about a series of novel services never imagined until recently. However, certain deployments such as those employing Low-Power Wide-Area Network (LPWAN)-based technologies may present severe network restrictions in terms of throughput and supported packet length. This situation prompts the isolation of LPWAN systems on islands with limited interoperability with the Internet. For that reason, the IETF’s LPWAN working group has proposed a Static Context Header Compression (SCHC) scheme that permits compression and fragmentation of and IPv6/UDP/CoAP packets with the aim of making them suitable for transmission over the restricted links of LPWANs. Given the impact that such a solution can have in many IoT scenarios, this paper addresses its real evaluation in terms not only of latency and delivery ratio improvements, as a consequence of different compression and fragmentation levels, but also of the overhead in end node resources and useful payload sent per fragment. This has been carried out with the implementation of middleware and using a real testbed implementation of a LoRaWAN-to-IPv6 architecture together with a publish/subscribe broker for CoAP. The attained results show the advantages of SCHC, and sustain discussion regarding the impact of different SCHC and LoRaWAN configurations on the performance. It is highlighted that necessary end node resources are low as compared to the benefit of delivering long IPv6 packets over the LPWAN links. In turn, fragmentation can impose a lack of efficiency in terms of data and energy and, hence, a cross-layer solution is needed in order to obtain the best throughput of the network.