On Efficiency and Validity of Previous Homeplug MAC Performance Analysis

The Medium Access Control protocol of Power Line Communication networks (defined in Homeplug and IEEE 1901 standards) has received relatively modest attention from the research community. As a consequence, there is only one analytic model that complies with the standardised MAC procedures and considers unsaturated conditions. We identify two important limitations of the existing analytic model: high computational expense and predicted results just prior to the predicted saturation point do not correspond to long-term network performance. In this work, we present a simplification of the previously defined analytic model of Homeplug MAC able to substantially reduce its complexity and demonstrate that the previous performance results just before predicted saturation correspond to a transitory phase. We determine that the causes of previous misprediction are common analytical assumptions and the potential occurrence of a transitory phase, that we show to be of extremely long duration under certain circumstances. We also provide techniques, both analytical and experimental, to correctly predict long-term behaviour and analyse the effect of specific Homeplug/IEEE 1901 features on the magnitude of misprediction errors

Modeling, Analysis and Impact of a Long Transitory Phase in Random Access Protocols

In random access protocols, the service rate depends on the number of stations with a packet buffered for transmission. We demonstrate via numerical analysis that this state-dependent rate along with the consideration of Poisson traffic and infinite (or large enough to be considered infinite) buffer size may cause a high-throughput and extremely long (in the order of hours) transitory phase when traffic arrivals are right above the stability limit. We also perform an experimental evaluation to provide further insight into the characterisation of this transitory phase of the network by analysing statistical properties of its duration. The identification of the presence as well as the characterisation of this behaviour is crucial to avoid misprediction, which has a significant potential impact on network performance and optimisation. Furthermore, we discuss practical implications of this finding and propose a distributed and low-complexity mechanism to keep the network operating in the high-throughput phase.Comment: 13 pages, 10 figures, Submitted to IEEE/ACM Transactions on Networkin

State-of-the-art in Power Line Communications: from the Applications to the Medium

In recent decades, power line communication has attracted considerable attention from the research community and industry, as well as from regulatory and standardization bodies. In this article we provide an overview of both narrowband and broadband systems, covering potential applications, regulatory and standardization efforts and recent research advancements in channel characterization, physical layer performance, medium access and higher layer specifications and evaluations. We also identify areas of current and further study that will enable the continued success of power line communication technology.Comment: 19 pages, 12 figures. Accepted for publication, IEEE Journal on Selected Areas in Communications. Special Issue on Power Line Communications and its Integration with the Networking Ecosystem. 201

How CSMA/CA With Deferral Affects Performance and Dynamics in Power-Line Communications

Power-line communications (PLC) are becoming a key component in home networking, because they provide easy and high-throughput connectivity. The dominant MAC protocol for high data-rate PLC, the IEEE 1901, employs a CSMA/CA mechanism similar to the backoff process of 802.11. Existing performance evaluation studies of this protocol assume that the backoff processes of the stations are independent (the so-called decoupling assumption). However, in contrast to 802.11, 1901 stations can change their state after sensing the medium busy, which is regulated by the so-called deferral counter. This mechanism introduces strong coupling between the stations and, as a result, makes existing analyses inaccurate. In this paper, we propose a performance model for 1901, which does not rely on the decoupling assumption. We prove that our model admits a unique solution for a wide range of configurations and confirm the accuracy of the model using simulations. Our results show that we outperform current models based on the decoupling assumption. In addition to evaluating the performance in steady state, we further study the transient dynamics of 1901, which is also affected by the deferral counter.Comment: To appear, IEEE/ACM Transactions on Networking 201

A Proximity based Retransmission Scheme for Power Line Ad-hoc LAN

Power line as an alternative for data transmission is being explored, and also being used to a certain extent. But from the data transfer point of view, power line, as a channel is highly dynamic and hence not quite suitable. To convert the office or home wiring system to a Local Area Network (LAN), adaptive changes are to be made to the existing protocols. In this paper, a slotted transmission scheme is suggested, in which usable timeslots are found out by physically sensing the media. Common usable timeslots for the sender-receiver pair are used for communication. But these will not ensure safe packet delivery since packets may be corrupted on the way during propagation from sender to receiver. Therefore, we also suggest a proximity based retransmission scheme where each machine in the LAN, buffers good packet and machines close to the receiver retransmit on receiving a NACK.Comment: Already published in IJDP

Powerline Communication System-on-Chip in 180 nm Harsh Environment SOI Technology

Broadband powerline communication systems using Orthogonal Frequency Division Multiplexing (OFDM) can utilize existing power lines to transmit data packets alongside power distribution. Recent standards focus towards high speed multi-media in-house streaming. With improvements towards robustness and throughput new standards increase the speed and reliability of in-house powerline systems. A very different approach is the use of powerline communication systems in a deep drilling environment where temperatures of more than 150°C and pressure levels up to 30 000 psi are present. Typical applications in this environment usually do not require more than several kbit/ys per node and are more reliant on a stable and continuous connection. Here, a powerline communication system can reduce the amount of wiring needed and increase communication robustness significantly. This work provides a harsh environment suitable, reliable and standard compliant communication ASIC that is manufactured in XFAB 180 nm Silicon-On-Insulator (SOI) technology allowing operating temperatures of up to 175°C. The die size is 5.25 mm x 5.25 mm and contains a complete Homeplug 1.0 communication stack with an environment for boot, interfacing and debugging. The data rate is as high as 6.1 Mbit/s using the fastest transmission mode and reaches the theoretical maximum of 0.55 Mbit/s in the robust OFDM (ROBO) mode which is of particular interest for harsh environment applications. To the best of the authors knowledge, this is the first OFDM-based powerline communication ASIC which is particularly designed for harsh environment.© 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works

What is about future high speed power line communication systems for in-vehicles networks?

International audienceThis paper deals with alternative automotive networks involved by the X-by-wire and X-tainment applications. New market demands like navigation, multimedia, security, safety and individualized options introduce more and more electronic control units. Furthermore, the automotive industry has to face a great challenge in its transition from mechanical engineering towards mechatronical products. In the last decades, the power line technology has received an increasing attention and spans several applications both in indoor, outdoor and in-vehicle data communications. To fulfil theses demands of intra-car communications, techniques based on power line communication (PLC) seem to be a good candidate. These techniques offer both high data rate and good adequacy with power line properties. This paper revisits the work carried out in using PLC within the automotive domain. Different solutions are discussed and results are given for different applications

A Case Study on Multi-Softcore Aided Hardware Architectures for Powerline MAC-Layer

Powerline communication is a promising technology for connecting Internet of Things (IoT) applications, where devices have strict limitations regarding available installation space and power dissipation. Especially the wiring of these devices benefits from not having additional cables for network connection. Thus, saving costs and additional installation effort. In this paper a very resource-efficient implementation of a HomePlug 1.0.1 [5] compatible powerline MAC layer, which is used to control the data flow and link status of a powerline connection, is presented. The MAC layer is implemented in two variants, using state machines and softcore processors. A comparison of the two approaches shows that the softcore design used up to 78 % less FPGA ressources and is superior in terms of flexibility and maintainability

When priority resolution goes way too far: An experimental evaluation in PLC networks

Power Line Communication (PLC) devices are increasingly used and available. However, research carried out at the Medium Access Control (MAC) layer is limited. This article addresses Quality of Service (QoS) mechanisms defined in the widely implemented Homeplug and IEEE 1901 standards. By means of a testbed constructed from off-the-shelf components we identify a number of issues with a potentially significant impact on user satisfaction: i) a pronounced starvation and variability of lower-priority traffic when different access categories are combined and ii) an oscillatory behaviour in higher-priority and high-traffic configurations. We also determine the underlying causes of such findings and propose possible solutions. Our contributions are of relevance to both the research community and manufacturers, as we identify crucial aspects to be revisited in order to guarantee successful advancement and further adoption of the technology