Enhancing Block-Wise Transfer with Network Coding in CoAP

CoAP (Constrained Application Protocol) with block-wise transfer (BWT) option is a known protocol choice for large data transfer in general lossy IoT network environments. Lossy transmission environments on the other hand lead to CoAP resending multiple blocks, which creates overheads. To tackle this problem, we design a BWT with network coding (NC), with the goal to reducing the number of unnecessary retransmissions. The results show the reduction in the number of block retransmissions for different values of blocksize, implying the reduced transfer time. For the maximum blocksize of 1024 bytes and total probability loss of 0.5, CoAP with NC can resend up to 5 times less blocks.Comment: 4 pages, 2 figures, submitted to Euro-Par 201

Increasing Fault Tolerance and Throughput with Adaptive Control Plane in Smart Factories

Future smart factories are expected to deploy an emerging dynamic Virtual Reality (VR) applications with high bandwidth wireless connections in the THz communication bands, where a factory worker can follow activities through 360{\deg}video streams with high quality resolution. THz communications, while promising as a high bandwidth wireless communication technology, are however known for low fault tolerance, and are sensible to external factors. Since THz channel states are in general hard to estimate, what is needed is a system that can adaptively react to transceiver configurations in terms of coding and modulation. To this end, we propose an adaptive control plane that can help us configure the THz communication system. The control plane implements a workflow algorithm designed to adaptively choose between various coding and modulation schemes depending on THz channel states. The results show that an adaptive control plane can improve throughput and signal resolution quality, with theoretically zeroed bit error probability and a maximum achievable throughput in the scenarios analayzed.Comment: This paper is uploaded here for research community, thus it is for non-commercial purpose

Benchmarking Buffer Size in IoT Devices Deploying REST HTTP

A few potential IoT communication protocols at the application layer have been proposed, including MQTT, CoAP and REST HTTP, with the latter being the protocol of choice for software developers due to its compatibility with the existing systems. We present a theoretical model of the expected buffer size on the REST HTTP client buffer in IoT devices under lossy wireless conditions, and validate the study experimentally. The results show that increasing the buffer size in IoT devices does not always improve performance in lossy environments, hence demonstrating the importance of benchmarking the buffer size in IoT systems deploying REST HTTP.Comment: This paper is uploaded here for research community, thus it is for non-commercial purpose

Error Correction with Systematic RLNC in Multi-Channel THz Communication Systems

The terahertz (THz) frequency band (0.3-10THz) has the advantage of large available bandwidth and is a candidate to satisfy the ever increasing mobile traffic in wireless communications. However, the THz channels are often absorbed by molecules in the atmosphere, which can decrease the signal quality resulting in high bit error rate of received data. In this paper, we study the usage of systematic random linear network coding (sRLNC) for error correction in generic THz systems with with 2N parallel channels, whereby N main high-bitrate channels are used in parallel with N auxiliary channels with lower bit rate. The idea behind this approach is to use coded low-bit rate channels to carry redundant information from high-bit rate channels, and thus compensate for errors in THz transmission. The analytical results evaluate and compare the different scenarios of the THz system in term of the amount of coding redundancy, a code rate, transmission rate of auxiliary channels, the number of THz channels, the modulation format and transmission distance as required system configurations for a fault tolerant THz transmission.Comment: 6 pages, 5 figure

An Experimental Study of Network Coded REST HTTP in Dynamic IoT Systems

REST HTTP is the communication protocol of choice for software developers today. In IoT systems with unreliable connectivity, however, a stateless protocol like REST HTTP needs to send a request message multiple times, and it only stops the retransmissions when an acknowledgement arrives at the sender. In our previous work, we studied the usage of random linear network coding (RLNC) for REST HTTP protocol to reducing the amount of unnecessarily retransmissions. In this paper, we experimentally validate the study and analyze REST HTTP with and without RLNC in a simple testbed in dynamic IoT systems. The measurements show notable improvements in bandwidth utilization in terms of reducing the retransmissions and delay when using network-coded REST HTTP.Comment: 7 pages, 5 figures, accepted at IEEE International Conference on Communications (ICC), Dublin, Ireland, 202

Improving THz Quality-of-Transmission with Systematic RLNC and Auxiliary Channels

In this paper, we propose a novel solution that can improve the quality of THz transmission with systematic random linear network coding (sRLNC) and a low-bitrate auxiliary channel. To minimize complexity of channel coding, we complement a generic low complexity FEC code by a low complexity sRLNC. To increase the overall throughput of THz transmission, we propose to send the native data and coding redundancy in parallel over 2 differently configured THz channels, i.e., over 1 high bit rate main channel and 1 low bit rate low error rate auxiliary channel. The results show, that the main THz channel supported by low bit rate auxiliary channel can use a higher level modulation format and sent over longer distances with a higher throughput.Comment: 7 pages, 6 figures, accepted at IEEE ICC'20 Workshop - TeraCo

Performance Analysis of MDPC and RS codes in Two-channel THz Communication Systems

We analyze whether a multidimensional parity check (MDPC) or a Reed-Solomon (RS) code in combination with an auxiliary channel can improve the throughput and extend the THz transmission distance. While channel quality is addressed by various coding approaches, and an effective THz system configuration is enabled by other approaches with additional channels, their combination is new with the potential for significant improvements in quality of the data transmission. Our specific solution is designed to correct data bits at the physical layer by using a low complexity erasure code (MDPC or RS), whereby original and parity data are transferred over two separate and parallel THz channels, including one main channel and one additional channel. The results are theoretically analyzed to see that our new solution can improve throughput, support higher modulation levels and transfer data over the longer distances with THz communications.Comment: This paper is uploaded here for research community, thus it is for non-commercial purpose