Evaluation of QUIC-based MASQUE proxying

We designed RRMAC, a time division multiple access (TDMA) scheme guaranteeing hard real-time and reliable communication in a multi-hop convergecast network. We performed experiments to compare the performance of RRMAC and IEEE 802.15.4 and showed the advantages of RRMAC is WSN applications which require highly reliable real-time data transmission.

The prime characteristics of Mobile Ad Hoc Network (MANET) are infrastructure free, absence of centralized authority and dynamic nature of nodes which are more vulnerable to security attacks. Reliability and security are prime issues to protect information and nodes in a network during communication which has received more research interest in designing a dynamic secured routing scheme. QoS is set of service requirement that needs to be satisfied by the network during the data transmission in the network. From the perception of QoS best effort protocols ensure optimum network operation in a unpredictable mobile environment. The multimedia applications are intolerable towards delay and reliability which are the features of mobile network, hence the potentials of MANET were not utilized in multimedia applications. These issues of delay and reliability of packet transmission in MANET are contributed by stability of the communication link even during the mobility of the nodes Its a necessity to analyze the performance of various secured routing protocols based on the stability of the communication link in case of mobility of nodes during data transfer. This paper is focused on a comparative study of various secured reactive routing protocols in MANET signifying the connectivity stability during the mobility of the nodes.

Wireless communications are confronted to different kinds of interferences. Such interference has significant impact on the reliability of packet transmissions. Due to very low power communication, wireless body area networks are potentially susceptible to interfere with coexisting wireless systems, including other WBANs that might exist in their vicinity. We employ cognitive radios (CRs) for proactive interference sensing in such systems. Our approach insures the channel quality evaluation reducing the packet loss rate and mitigate interferences. On one hand, the intra-WBAN interference is managed through FTDMA protocol. On the other hand, if a high intensity of interference is detected, this solution allows switching channel transmission, thereby ensuring the coexistence of WBANs. Moreover, we modeled the functioning of this method using the Markov's chains in continuous time. The Transmission error rate is introduced as a measure to quantify the effectiveness of the proposed schemes.

Reliable transmission of the control packets is one of the key requirements of deploying an Industrial Wireless Network (IWN) for automation purposes. The use of error-prone wireless channel, transmission of control packets having hard real-time traffic over IWN have made reliable transmission assurance highly challenging. This paper intends in addressing this challenge through reliability optimization of the hard real-time traffic transmitted over IWN. ReliaMAC is a novel scheme that is proposed to support reliable transmission of hard real-time traffic using redundancy bits added to each double MAC frame. Optimization of transmission reliability is used to identify the optimum number of nodes in an IWN that can support reliable transmission of the hard real-time traffic to a maximum extent. Network simulation results revealed the effectiveness of ReliaMAC in improving reliability of hard real-time communication on IWNs.

Vehicular Ad Hoc Networks (VANETs) have been attracting more and more attention. However, due to the fast movement of vehicles and dynamic topology change, designing an efficient routing protocol in the complex urban environment is quite challenging. In this paper, an Intersection-based Geographic Routing with Transmission Quality guaranteed in Urban VANETs (IGRTQ) is proposed. As a selection guidance of the best route, each road segment is assigned with a weight based on the collected information related to the delay and connectivity of each road segment. Based on the weight information, the road segment can be dynamically selected one by one to form the optimized routing path, avoiding the local maximum and data congestion. An improved greedy strategy is further proposed to forward the packet along the selected road segment, ensuring the fast and reliable packet transmission. Simulation results show that the proposed protocol provides higher packet delivery ratio and lower end-to-end delay compared to the existing protocols.

For wireless multicast applications like multimedia conferencing, voice over IP and video/audio streaming, a reliable transmission of packets within short delivery delay is needed. Moreover, reliability is crucial to the performance of error intolerant applications like file transfer, distributed computing, chat and whiteboard sharing. Forward Error Correction (FEC) is frequently used in wireless multicast to enhance Packet Error Rate (PER) performance, but cannot assure full reliability unless coupled with Automatic Repeat Request forming what is knows as Hybrid-ARQ. While reliable FEC can be deployed at different levels of the protocol stack, it cannot be deployed on the MAC layer of the unreliable IEEE802.11 WLAN due to its inability to exchange ACKs with multiple recipients. In this paper, we propose a Multicast MAC protocol that enhances WLAN reliability by using Adaptive FEC and study it's performance through mathematical analysis and simulation. Our results show that our protocol can deliver high reliability and throughput performance.

Reliable multicast in wireless ad hoc networks is important for the applications such as distributed computing, chat, and whiteboard. Due to the wireless channel characteristics, obtaining the reliability in multicast packet transmission is a difficult and challenging task. Even though IEEE 802.11 is widely adopted medium access control (MAC) protocol in wireless ad hoc networks, it does not support reliable multicast. Thus, several MAC layer protocols have been proposed that can provide reliable multicast. In this paper, we propose the reliable multicast MAC protocol which is based on the orthogonal frequency division multiple access (OFDMA) systems. The proposed method reduces the overhead required for control packets. Analysis results validate the reliability and efficiency of our multicast MAC protocol.KeywordsMedium Access ControlMedium Access Control ProtocolPacket DelayControl PacketOrthogonal Frequency Division Multiple AccessThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

In this study, a triangular fuzzy-based spectral cluster routing (TF-SCR) mechanism is proposed in order to improve network lifetime and reliability of data packet transmission in WSN with minimum routing overhead. The designed TF-SCR mechanism contains three steps, namely preprocessing, clustering and post-processing. TF-SCR mechanism initially carried out preprocessing where the residual energy and received signal strength of all sensor nodes in WSN is determined. After preprocessing, TF-SCR mechanism performs clustering process with the application of spectral clustering in which the sensor nodes in WSN are grouped based on residual energy level. After completing clustering process, TF-SCR mechanism implements post-processing step where triangular fuzzy membership function is applied to select the sensor node with higher residual energy and signal strength as cluster head for routing data packets to sink nodes in WSN. This helps for TF-SCR mechanism to obtain energy-efficient routing in WSN. Thus, TF-SCR mechanism enhances the network lifetime and reliability of data broadcasting in WSN as compared to state-of-the-art works. The simulation of TF-SCR mechanism is conducted on factors such as energy consumption, network lifetime, routing overhead and reliability with respect to a number of sensor nodes and data packets. The simulation results demonstrate that the TF-SCR mechanism is able to improve the network lifetime and also minimize the overhead of routing with minimal energy consumption as compared to state-of-the-art works.

As the Arctic Ocean becomes increasingly accessible due to the continuous sea-ice retreat during the last decades, UnderWater Acoustic (UWA) communications will play a pivotal role in future underwater Arctic exploration/exploitation activities that will inevitably emerge. In this paper, we aim to improve the reliability of short packet transmission typically needed for low-latency low-packet-loss communications. In particular, we compare the Packet Error Rates (PERs) of convolutional, turbo, Low-Density Parity-Check (LDPC) and polar codes. These four codes are implemented in the physical layer of a software modem, which uses single-carrier, Binary Phase Shift Keying (BPSK) modulation achieving 360 bits/s over the 3830-6170 Hz band. The modem transmitted 128-, 256-, 384-bit long packets over various UWA links north-west off the Svalbard Islands in June 2021. The packets were recorded in a linear hydrophone array and our offline analysis shows that there is an enormous reduction in the PER for all codes as the number of the used hydrophones increases from one to four. In addition, our results confirm the superiority of the polar code for all packet lengths and number of hydrophones.

Multi-user MIMO (MU-MIMO) using Tomlinson-Harashima precoding (THP) has great potential to achieve high system capacity in wireless systems. On the other hand, hybrid ARQ (HARQ) is essential to realize the reliable wireless packet transmission and therefore, the combination of THP with HARQ can be seen as a promising approach to achieve reliable high-capacity wireless transmissions. However, this combination has a problem of severe performance degradation due to the accumulation of modulo loss which is the inherent drawback of THP. In this paper, we propose the HARQ scheme to cancel the accumulation of modulo loss in Multi-user MIMO THP systems. The main feature of the proposed approach is to add the same perturbation vector as the initial transmit packet to the retransmit packets in order to prevent the accumulation of modulo loss. The effectiveness of the proposed scheme is demonstrated in comparison with the conventional packet combining scheme by means of computer simulations.

Within the past few years, the variety of real-time multimedia streaming services on the Internet has grown steadily. Performance of streaming services is very sensitive to traffic congestion and results very often in poor service quality on today's best effort Internet. Reasons include the lack of any traffic prioritization mechanisms on the network level and its dependence on the cooperation of several Internet Service Providers and their reliable transmission of data packets. Therefore, service differentiation and its reliable delivery must be enforced on a business level through the introduction of service contracts between service providers and their customers. However, compliance with such service contracts is the crucial point that decides about successful improvement of the service delivery process. For that reason, an agent-based monitoring framework has been developed and introduced enabling the use of mobile agents to monitor compliance with contractual agreements between service providers and service customers. This framework describes the setup and the functionality of different kinds of mobile agents that allow monitoring of service contracts across domains of multiple service providers.

Aiming at the high-performance requirements of Internet of Things (IoT) scenarios, a cognitive radio-inspired nonorthogonal multiple access (CR-NOMA) scheme in short packet communication is investigated. Primary and secondary users share the same nonorthogonal communication resource block to achieve high spectral efficiency. A priority selection combination method is designed and employed by the primary user considering the nonnegligible decoding error rate in short packet communication. We focus on the transmission performance of the secondary users while ensuring the reliable communication of the primary user as a priority. To characterize the performance of the CR-NOMA network, approximate closed-form expressions of the average block error rate (BLER) for primary and secondary users are derived and analyzed. The results show that the communication reliability and throughput of the primary user with the CR-NOMA scheme are enhanced compared with the no-CR scheme. Meanwhile, the secondary users can also achieve reliable communication on the premise of improving the performance of the primary user through spectrum sharing. A performance tradeoff between primary and secondary users can be achieved through power allocation. Furthermore, there is a tradeoff between BLER and throughput, and the maximum throughput can be achieved by choosing an optimal blocklength.

To achieve reliable packet transmission over a wireless link without feedback, we propose a layered coding approach that uses error-correction coding within each packet and erasure-correction coding across the packets. This layered approach is also applicable to an end-to-end data transport over a network where a wireless link is the performance bottleneck. We investigate how to optimally combine the strengths of error- and erasure-correction coding to optimize the system performance with a given resource constraint, or to maximize the resource utilization efficiency subject to a prescribed performance. Our results determine the optimum tradeoff in splitting redundancy between error-correction coding and erasure-correction codes, which depends on the fading statistics and the average signal to noise ratio (SNR) of the wireless channel. For severe fading channels, such as Rayleigh fading channels, the tradeoff leans towards more redundancy on erasure-correction coding across packets, and less so on error-correction coding within each packet. For channels with better fading conditions, more redundancy can be spent on error-correction coding. The analysis has been extended to a limiting case with a large number of packets, and a scenario where only discrete rates are available via a finite number of transmission modes.

An adaptive virtual relaying set scheme for loss-and-delay sensitive WSNs

Data transmission in Network-on-Chips (NoCs) is a serious problem due to cross talk faults happening in adjacent communication links. This paper proposes an efficient flow-control method to enhance the reliability of packet transmission in Network-on-Chips. The method investigates the opposite direction transitions appearing between flits of a packet to reorder the flits in the packet. Flits are reordered in a fixed-size window to reduce: 1) the probability of cross talk occurrence, and 2) the total power consumed for packet delivery. The proposed flow-control method is evaluated by a VHDL-based simulator under different window sizes and various channel widths. Simulation results enable NoC designers to make a trade-off between window size, reliability and power consumption of packet delivery. This method is also compared with other cross talk tolerant methods in terms of reliability and power consumption. Comparison results confirm that the method is a cost efficient solution to overcome the cross talk problem.