Ievgenii Tsokalo

Performance evaluation of MAC backoff algorithm in Narrowband PLC

This paper investigates the backoff algorithm for Narrowband Power Line Communications (PLC) Medium Access Control (MAC) protocol. Specifically, the paper considered the MAC designed by Yitran and implemented within its Differential Code Shift Keying (DCSK) technology. In this algorithm width of the contention window is calculated based on the estimated number of active nodes in the network. Further the performance of the algorithms were evaluated under different saturated throughput conditions and varying number of active nodes, in a fully meshed network. Comparison were also made between the simulated and the polynomial backoff algorithms dynamic characteristics. Simulation results show that the algorithm under investigation has an excellent performance under the saturated throughput, although its dynamic characteristic can be further improved.

Enhancement of backoff algorithm in CSMA/CA protocols for broadband PLC

Improvement of communication protocols for energy management purposes has become a challenging part of smart grid systems development. Powerline communications (PLC) has many advantages for being used in this area. Many PLC communication protocols use CSMA/CA channel access schemes on Multiple Access Protocol (MAC) layer. This paper presents an enhancement of the CSMA/CA broadband PLC protocols operation by application of special method for backoff generation. The proposed improvement is applicable to different CSMA/CA protocols. The resulting CSMA/CA schemes maintain interoperability with the original ones. The performance of the improved algorithm is shown by means of a mathematical model and by simulation.

Approaching the limits in routing in power line communication exploiting Network Coding

We address the single-source-destination routing problem in a mesh network with a broadcast channel, time-division multiplexing (TDM) and no spatial reuse, which is a special type of the PLC channel. First, the outer bound on the achievable data rate is evaluated. We show that the routing protocols (RPs) with static routing do not allow approaching this data rate limit. Then, we study RP with opportunistic routing (ORP). We show that its main disadvantage, extensive feedback, can be successively reduced when using Network Coding (NC). We propose the basic routing rules (BRR) based on ORP with NC. Then, we demonstrate that the data rate achievable with BRR approaches the outer bound when the coding window increases. Finally, we provide the simulation results, which prove the concept. In the considered scenarios, BRR allow the data rate up to 10% higher than RPs with static routing, which is just 5–10% away from the theoretical outer bound limit.

CSMA/CD in PLC: Test with full G.hn and IP/UDP protocol stack

In this paper, we advocate implementing carrier sense multiple access with collision detection (CSMA/CD) in the broadband power line communication (BB-PLC) standard, G.hn, and show the gain in data rate obtained over carrier sense multiple access with collision avoidance (CSMA/CA). The use of CSMA/CD is made feasible due to the recent implementation of in-band full duplex operation in BB-PLC. We provide this implementation on a G.hn model using the NS-3 simulator, which we have made available as open-source. Our G.hn model implements physical and data link layers, including repeating function that makes it possible to simulate the long line network topologies (e.g., the network for electricity metering purpose). We also add IP/UDP layers to accomplish the higher layer protocol stack. We also provide analytical calculations of efficiency gains and validate them through our simulation results. We show that the highest achievable data rate with CSMA/CD is up to 5% higher than with CSMA/CA. Furthermore, we demonstrate that the protocol with CSMA/CD is less dependent on the number of active senders and has a smaller range of optimal contention window sizes (CW) for the same range of active senders, in comparison to CSMA/CA. This also simplifies the protocol implementation as the back-off algorithm for CSMA/CD does not vary CW as much as for CSMA/CA.

Intraflow network coding on the data link layer for broadband PLC

This paper carries out a performance evaluation of network coding (NC) for power line communication (PLC) systems based on simulation and theoretical results. NC is deployed at the data link layer (DLL) where it could potentially improve the routing protocol, the MAC scheduler and the ARQ mechanisms. In this paper we focus solely on the combination of NC and ARQ mechanisms. Nevertheless, based on the G.hn standard, we are able to achieve a significant improvement in data rate and latency. We show the optimal setup of NC parameters like generation and symbol size to achieve the best performance of the ARQ mechanism in PLC systems.

Modeling approach of broadband in-home PLC in network simulator 3

A modeling of communication networks is often done in hierarchical way. So, in PLC there are multiple models of channel, physical, datalink and other layers, which are realized separately in multiple programming environments. Nevertheless it is often advantages to do a cross-layer optimization of communication protocols. For this purpose multiple separate models have to be unified in one simulation environment. This paper describes a modeling approach of the PLC channel, the topology generator, the physical and datalink layer in ns-3 together. With this approach the authors show that Linear-Periodic Time-Variant (LPTV) property of the PLC channel is useful to be considered for the design of MAC scheduler. The developed simulator is set up for in-home PLC environment. It means that noise, impedance models and topology generator are described as stochastic models, which base on statistical measurement results in this environment.