Performance Analysis of MAC for Power-Line Communications

We investigate the IEEE 1901 MAC protocol, the dominant protocol for high data rate power-line communications. 1901 employs a CSMA/CA mechanism similar to – but much more complex than – the backoff mechanism of 802.11. Because of this extra complexity, and although this mechanism is the only widely used MAC layer for power-line networks, there are few analytical results on its performance. We propose a model for the 1901 MAC that comes in the form of a single fixed-point equation for the collision probability. We prove that this equation admits a unique solution, and we evaluate the accuracy of our model by using simulations

Analysis and Enhancement of CSMA/CA with Deferral in Power-Line Communications

Power-line communications are employed in home networking to provide easy and high-throughput connectivity. The IEEE 1901, the MAC protocol for power-line networks, employs a CSMA/CA protocol similar to that of 802.11, but is substantially more complex, which probably explains why little is known about its performance. One of the key differences between the two protocols is that whereas 802.11 only reacts upon collisions, 1901 also reacts upon several consecutive transmissions and thus can potentially achieve better performance by avoiding unnecessary collisions. In this paper, we propose a model for the 1901 MAC. Our analysis reveals that the default configuration of 1901 does not fully exploit its potential and that its performance degrades with the number of stations. Based on analytical reasoning, we derive a configuration for the parameters of 1901 that drastically improves throughput and achieves optimal performance without requiring the knowledge of the number of stations in the network. In contrast, 802.11 requires knowing the number of contending stations to provide a similar performance, which is unfeasible for realistic traffic patterns. We confirm our results and enhancement with testbed measurements, by implementing the 1901 MAC protocol on WiFi hardware.Publicad

Modeling of Contention-free and Contention MAC Protocols for Broadband over Power Line Networks

Although the power lines were designed to deliver electric power, not for communications, a large volume of research on Broadband over Power line communications (BPLC) had appeared over the decades. The successful transmission of data over the power lines will make the BPL technology a cost-effective solution for the so-called “last miles” in communication networks [1]. Recently, this effort received a significant boost by the approval of the IEEE P1901 standard [20]. This standard specifies the regulations for the operation of the Physical and MAC layers of the BPL network. It proposes two major MAC protocols – Time Division Multiplexing Access (TDMA) for the contention-free access and Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) for the contention access. In this thesis, we present the performance models of the contention-free access and the contention access mechanisms. For the contention-free transmission mode, we determine analytically the probability distribution of the number of beacon periods that it takes to transmit a MAC frame over multi-hop communications subject to transmission errors, then, we developed an analysis that determines the network capacity, the number of users that the system may support. Also, we determine the MAC efficiency of the network when it’s operating under both contention-free and contention mode. These results may be helpful in the design of BPL networks

Analyzing and Boosting the Performance of Power-Line Communication Networks

Power-line communications are employed in home networking to provide easy and high-throughput connectivity. IEEE 1901, the MAC protocol for power-line networks, employs a CSMA/CA protocol similar to that of 802.11, but is substantially more complex, which probably explains why little is known about its performance. One of the key differences between the two protocols is that whereas 802.11 only reacts upon collisions, 1901 also reacts upon several consecutive transmissions and thus can potentially achieve better performance by avoiding unnecessary collisions. In this paper, we propose a model for the 1901 MAC. Our analysis reveals that the default configuration of 1901 does not fully exploit its potential and that its performance degrades with the number of stations. We derive analytically the optimal configuration parameters for 1901; this drastically improves throughput and achieves optimal performance without requiring the knowledge of the number of stations in the network. In contrast, to provide a similar performance, 802.11 requires knowing the number of contending stations, which is unfeasible for realistic traffic patterns. Our solution can be readily implemented by vendors, as it only consists in modifying existing MAC parameters. We corroborate our results with testbed measurements, unveiling a significant signaling overhead in 1901 implementations

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

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

Application-layer Performance Analysis of PRIME in Smart Metering Networks

This paper assesses the performance of actual PRIME v1.3.6 and PRIME v1.4 systems when used for Smart Metering applications. The analysis is performed at the application level using the DLMS/COSEM stack. Hence, it considers performance indicators that are of practical interest for distribution system operators, such as the availability and the average time needed to read the energy load profile of all the meters. To this end, two test networks with 112 smart meters have been deployed in the laboratory (to ensure the stability of the network). In one of them all the Service Nodes communicate directly with the Base Node, while there exist up to 5 switching levels in the other tested network. First, the PRIME v1.3.6 system is evaluated, stressing the significant performance gain that can be obtained by implementing some MAC layer strategies, which are compatible with the specification but not specifically defined on it. Then,the improvement offered by the PRIME v1.4 system is assessed.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech