Packet Coding Research Articles

Application Research of Intelligent Search System Based on Clustering Algorithm

In this paper, a multi-agent oriented personalized information retrieval method is proposed. The system is composed of 5 agents and 2 other components. The design highlights the personalization and real-time of the information obtained by users, and has the characteristics of intelligent retrieval and active retrieval. Then this paper studies it from three aspects: user model, system learning model and individual information model. Then a grouping gravity search algorithm is proposed. Compared with conventional gravity search, group gravity search is carried out for a specific decoding strategy. This algorithm is a new gravity search algorithm suitable for packet coding, which makes the packet search process approximate to the iterative optimization of classical gravity algorithm. Finally, the effectiveness of the proposed method is verified on various typical experimental cases. Experiments show that the proposed algorithm has higher classification performance than other intelligent group algorithms.

Adaptive Packet Coding for Reliable Underwater Acoustic Communications

This work investigates adaptive random linear packet coding (RLPC) for reliable underwater acoustic (UWA) communications. Our goal is to minimize the total transmission time of data blocks by adjusting the packet coding rate. We first consider the application of RLPC with the conventional automatic repeat request (ARQ) scheme. We dynamically adjust the coding rate to fit the time variations of UWA channels by choosing the optimal number of packets in each transmission. The optimal number of packets in each transmission is obtained based on a dynamic programming (DP) algorithm according to the feedback messages, which contain the number of successfully transmitted packets in the last transmission and the channel state information. Furthermore, considering the long propagation delay of UWA communications, we propose a modified juggling-like ARQ (J-ARQ) for the RLPC scheme, for which the duration of each transmission can be adjusted based on the characteristics of RLPC. A two-step DP algorithm is proposed to find out the optimal solutions for this case. Simulation results show that the proposed schemes can improve the throughput efficiency and reduce the outage probability.

ROFC-LF: Recursive Online Fountain Code With Limited Feedback for Underwater Acoustic Networks

Online fountain codes (OFCs) have many advantages, such as low overhead, online feedback and optimal encoding, due to the feedback of the instantaneous decoding state. This paper analyzes the characteristics of underwater acoustic networks (UANs) as well as the issues of existing OFCs applied in UANs. Aiming at these issues, two optimization objectives of OFCs are put forward for UANs. In addition, a recursive OFC with limited feedback (ROFC-LF) is presented for UANs. The ROFC-LF reduces the consumption of bandwidth and energy caused by the transmission of useless coding packets. Through limited feedback, the problem of low channel utilization in UANs with half-duplex communication is solved. Furthermore, a data transmission mechanism based on the ROFC-LF for UANs is presented. The theoretical analysis and simulation results show that the proposed transmission mechanism based on the ROFC-LF scheme outperforms the existing OFC schemes in terms of overhead, computational complexity, coding efficiency and energy consumption. Consequently, the ROFC-LF is suitable for UANs with constrained resources.

Dynamic Lightweight Mechanism for Security and Performance in Internet of Things

Communication between machines has become commonplace in recent years, and the Internet of Things (IoT) is gaining notoriety. Congestion control is a prevalent issue in the transportation system, and GPS devices, which drivers and traffic authorities alike utilise, are well-suited to the job. Traffic density is expanding at an alarming rate, making it impossible for drivers to see and handle all of the possible scenarios in a traffic area they are ready to enter. It's also becoming increasingly difficult to maintain security and integrity due to a growing number of assaults by hackers that send harmful code or bogus packets. There are a few new technologies that have yet to be put into practise under the Internet of Things umbrella, including ubiquitous computing (IoT).

ALOHA Receivers: A Network Calculus Approach for Analyzing Coded Multiple Access With SIC

Motivated by the need to hide the complexity of the physical layer from performance analysis in a layer 2 protocol, a class of abstract receivers, called Poisson receivers, was recently proposed by Yu <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">et al.</i> (2021) as a probabilistic framework for providing differentiated services in uplink transmissions in 5G networks. In this paper, we further propose a deterministic framework of ALOHA receivers that can be incorporated into the probabilistic framework of Poisson receivers for analyzing coded multiple access with successive interference cancellation. An ALOHA receiver is characterized by a success function of the number of packets that can be successfully received. Inspired by the theory of network calculus, we derive various algebraic properties for several operations on success functions and use them to prove various closure properties of ALOHA receivers, including (i) ALOHA receivers in tandem, (ii) cooperative ALOHA receivers, (iii) ALOHA receivers with traffic multiplexing, and (iv) ALOHA receivers with packet coding. By conducting extensive simulations, we show that our theoretical results match extremely well with the simulation results.

Efficient simulation execution of cellular automata on GPU

Graphics Processing Units (GPUs) can be used as convenient hardware accelerators to speed up Cellular Automata (CA) simulations, which are employed in many scientific areas. However, an important set of CA have performance constraints due to GPU memory bandwidth. Few studies have fully explored how CA implementations can take advantage of modern GPU architectures, mainly in the case of intensive memory usage. In this paper, we make a thorough study of techniques (stencil computing framework, look-up tables, and packet coding) to efficiently implement CA on GPU, taking into account its detailed architecture. Exhaustive experiments to validate these implementation techniques for a number of significant memory-bounded CA are performed. The CA analysed include the classical Game of Life, a Forest Fire model, a Cyclic cellular automaton, and the WireWorld CA. The experimental results show that implementations using the presented techniques can significantly outperform a baseline standard GPU implementation. The best performance results of all known implementations of memory bounded CA were obtained. Moreover, some of the techniques, like look-up tables or temporal blocking, are indeed relatively easy to implement or to apply when the transition rules are simple. Finally, detailed descriptions and discussions of the indicated techniques are included, which may be useful to practitioners interested in developing high performance simulations in efficient languages based on CA on GPU.

An Analysis of Probabilistic Forwarding of Coded Packets on Random Geometric Graphs

An Analysis of Probabilistic Forwarding of Coded Packets on Random Geometric Graphs

Age of Information With Joint Packet Coding in Industrial IoT

This letter studies the information freshness in an industrial Internet of Things (IIoT) network, measured by Age of Information (AoI). We consider a scenario where a sink node collects information update packets from different sensors and then uploads the collected packets to an edge server. This scenario has two main requirements: high information freshness (low AoI) and high reliability (low packet error rate, PER). Since update packets are usually short in practice, previous works usually packed and encoded multiple short packets from different sensors into a long packet to improve PER performances. However, while such a joint coding approach improves reliability, it generally leads to longer delay and hence possibly higher AoI. This letter investigates the AoI performance tradeoff by examining the number of packets to be jointly encoded. We consider two AoI metrics, average AoI and bounded AoI. In particular, bounded AoI is the threshold below which the instantaneous AoI falls for a given percentage of the time. Our theoretical analysis and numerical results show that there exist optimal numbers of jointly coded packets that minimize the average AoI and the bounded AoI. Specifically, a smaller number of packets is usually sufficient to achieve both high information freshness and high reliability.

Improving The Performance Of Wireless Sensor Network With Multi Factor Strategies

In the design of wireless sensor network (WSN), packet delivery ratio(PDR) is an import parameter to be maximized. PDR plays an important role for improving the performance of WSN. With the existing schemes, a secure zone-based routing protocol was implemented for life time improvement in WSNs. In multi - hop communication, a new routing criterion was formulated for packet transmission. Security against message tampering, dropping and flooding attacks were incorporated in the routing metric. The approach skipped risky zones as a whole from routing and choose alternative path to route a packet in secured manner with less energy consumption. Though energy conservation and attack resilience are achieved, congestion in WSN is increased and because of it packet delivery ratio is diminished. To address this problem, we propose a solution to improve the packet delivery ratio with a multi factor strategy involving routing, differentiation of flows, flow-based congestion control with retransmission and redundant packet coding. Detailed analysis and simulations are undertaken to evaluate the efficiency of the contemplated work compared to the existing solutions.

Control system of 4-DOF palletizing robot based on improved R control multi-objective trajectory planning

To realize efficient palletizing robot trajectory planning and ensure ultimate robot control system universality and extensibility, the B-spline trajectory planning algorithm is used to establish a palletizing robot control system and the system is tested and analyzed. Simultaneously, to improve trajectory planning speeds, R control trajectory planning is used. Through improved algorithm design, a trajectory interpolation algorithm is established. The robot control system is based on R-dominated multi-objective trajectory planning. System stack function testing and system accuracy testing are conducted in a production environment. During palletizing function testing, the system’s single-step code packet time is stable at approximately 5.8 s and the average evolutionary algebra for each layer ranges between 32.49 and 45.66, which can save trajectory planning time. During system accuracy testing, the palletizing robot system’s repeated positioning accuracy is tested. The repeated positioning accuracy error is currently 10−1 mm and is mainly caused by friction and the machining process. By studying the control system of a four-degrees-of-freedom (4-DOF) palletizing robot based on the trajectory planning algorithm, the design predictions and effects are realized, thus providing a reference for more efficient future palletizing robot design. Although the working process still has some shortcomings, the research has major practical significance.

Hidden Markov Model-Based Encoding for Time-Correlated IoT Sources

As the use of Internet of Things (IoT) devices for monitoring purposes becomes ubiquitous, the efficiency of sensor communication is a major issue for the modern Internet. Channel coding is less efficient for extremely short packets, and traditional techniques that rely on source compression require extensive signaling or pre-existing knowledge of the source dynamics. In this work, we propose an encoding and decoding scheme that learns source dynamics online using a Hidden Markov Model (HMM), puncturing a short packet code to outperform existing compression-based approaches. Our approach shows significant performance improvements for sources that are highly correlated in time, with no additional complexity on the sender side.

Poisson Receivers: A Probabilistic Framework for Analyzing Coded Random Access

In this paper, we develop a probabilistic framework for analyzing coded random access. Our framework is based on a new abstract receiver (decoder), called a Poisson receiver, that is characterized by a success probability function of a tagged packet subject to a Poisson offered load. We show that various coded slotted ALOHA (CSA) systems are Poisson receivers. Moreover, Poisson receivers have two elegant closure properties: (i) Poisson receivers with packet routing are still Poisson receivers, and (ii) Poisson receivers with packet coding are still Poisson receivers. These two closure properties enable us to use smaller Poisson receivers as building blocks for analyzing a larger Poisson receiver. As such, we can analyze complicated systems that are not possible by the classical tree evaluation method. In particular, for CSA systems with both spatial diversity and temporal diversity, we can use the framework of Poisson receivers to compute the exact (asymptotic) throughput. We demonstrate that our framework can be used to provide differentiated services between ultra-reliable low-latency communication (URLLC) traffic and enhanced mobile broadband (eMBB) traffic. By conducting extensive simulations, we also verify that our theoretical results match extremely well with the simulation results.

Improving Packet Delivery Ratio in Wireless Sensor Network with Multi Factor Strategies

In the design of wireless sensor network (WSN), packet delivery ratio is an import parameter to be maximized. In existing schemes, a secure zone-based routing protocol was implemented for life time improvement in WSNs. In multi - hop communication, a new routing criterion was formulated for packet transmission. Security against message tampering, dropping and flooding attacks was incorporated in the routing metric. The approach skipped risky zones as a whole from routing and chooses alternative path to route a packet in secured manner with less energy consumption. Though energy conservation and attack resilience are achieved, congestion in WSN is increased and because of it packet delivery ratio is diminished. To address this problem, we propose a solution to improve the packet delivery ratio with a multi factor strategies involving routing, differentiation of flows, flow-based congestion control with retransmission and redundant packet coding. Detailed analysis and simulations are undertaken to evaluate the efficiency of the contemplated work compared to the existing solutions.

An effective transmit packet coding with trust-based relay nodes in VANETs

Vehicular ad-hoc networks (VANETs) are characterized by limited network resources such as limited bandwidth and battery capacity. Hence, it is necessary that unnecessary use of network resources (such as unnecessary packet transfers) is reduced in such networks so that the available power can be conserved for efficient multicast communications. In this paper, we have presented a Transmit Packet Coding (TPC) Network Coding in VANET to ensure reliable and efficient multicasting. With network coding, the number of transmitted packets over the network can be reduced, ensuring efficient utilization of network devices and resources. Here, the trust-based graph optimization is performed using Cuckoo search algorithm to select the secure relay nodes. The experimental results showed the superiority of the presented approach compared to the existing techniques in terms of throughput, latency, hop delay, packet delivery ratio, network decoder outage probability, and block error rate.

Probabilistic Forwarding of Coded Packets on Networks

We consider a scenario of broadcasting information over a network of nodes connected by noiseless communication links. A source node in the network has some data packets to broadcast. It encodes these data packets into $n$ coded packets in such a way that any node in the network that receives any $k$ out of the $n$ coded packets will be able to retrieve all the original data packets. The source transmits the $n$ coded packets to its one-hop neighbours. Every other node in the network follows a probabilistic forwarding protocol, in which it forwards a previously unreceived packet to all its neighbours with a certain probability $p$ . We say that the information from the source undergoes a “near-broadcast” if the expected fraction of nodes that receive at least $k$ of the $n$ coded packets is close to 1. The forwarding probability $p$ is chosen so as to minimize the expected total number of transmissions needed for a near-broadcast. We study how, for a given $k$ , this minimum forwarding probability and the associated expected total number of packet transmissions varies with $n$ . We specifically analyze the probabilistic forwarding of coded packets on two network topologies: binary trees and square grids. For trees, our analysis shows that for fixed $k$ , the expected total number of transmissions increases with $n$ . On the other hand, on grids, a judicious choice of $n$ significantly reduces the expected total number of transmissions needed for a near-broadcast. Behaviour similar to that of the grid is also observed in other well-connected network topologies such as random geometric graphs and random regular graphs.

Grouped Packet Coding: A Method for Reliable Communication Over Fading Channels With Long Delays

In this paper, we investigate an automatic repeat request (ARQ) for reliable transmission over half-duplex links. We design a method based on grouped packet coding (GPC) that combines a stop-and-wait (S&W) ARQ procedure with random linear packet coding and selective acknowledgments applied to groups of coded packets. Our goal in doing so is to boost the throughput efficiency on poor-quality links with long delay. Such links are notably encountered in underwater acoustic channels, where the bit error rate may be as high as 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> and round-trip delays can be measured in thousands of bits. To quantify the benefits of the proposed S&W-GPC method, we evaluate its throughput efficiency analytically and compare it with the throughput efficiency of standard S&W methods, as well as the benchmark efficiency of full-duplex methods. Our results show that S&W-GPC outperforms all other techniques on half-duplex links with long delay, as well as rateless packet coding on full-duplex links with long delay. We present results for a point-to-point link, as well as for a multicast network. In addition to the performance analysis, we offer guidelines for an optimal system design, which involves a judicious choice of the packet size, packet coding, and grouping parameters.

Modeling the Delivery of Coded Packets in D2D Mobile Caching Networks

Caching popular files on the mobile nodes have been seen as a promising solution to improve the network performance. In this paper, we analyze the delivery of coded packets of the requested file in a mobile caching network of nodes each with a few pre-cached packets of different files from a large file library. To model the packet delivery process, we develop a two-dimensional Markov chain framework where each request has a deadline requirement. For the delivery of packets, we consider the mobility aspect of caching network where the nodes request the files from other neighbors while moving among different cells and offload the requested files on the device-to-device link. To characterize the network performance, we derive closed-form expressions for file outage probability, the average delay in receiving file, and average throughput to provide some valuable insights on different parameter settings. The simulation results not only verify the accuracy of the analysis but also shed some light on the scenarios where the performance gap between the mobile and fixed caching networks is prominent.

Secure ARQ Protocol for Wireless Communications: Performance Analysis and Packet Coding Design

In this paper, we consider secure transmission of a private file, which comprises multiple packets. A network-coding assisted automatic-repeat-request (ARQ) scheme is proposed to improve the security at both file level and packet level. Specially, the ARQ protocol degrades the intercept probability of the whole file at the eavesdropper, while the network coding guarantees the per-packet security. The closed-form intercept probability and outage probability of the whole file and each packet are analytically presented, and we then investigate the tradeoff between the security performance and the outage probability. The proposed scheme is further extended to the cooperative ARQ scenario, and simulation results are provided to corroborate our theoretical findings.

Joint Power and Rate Control for Packet Coding Over Fading Channels

We consider random linear packet coding for fading channels with long propagation delays, such as underwater acoustic channels. We propose a scheme in which the number of coded packets to transmit is determined to achieve a prespecified outage/reliability criterion and investigate joint power and rate control with constrained resources. Using the channel state information that is obtained via feedback from the receiver, the transmitter adjusts its power and the number of coded packets so that the average energy per successfully transmitted bit of information is minimized. Two optimization constraints are imposed: 1) the transmit power should not exceed a maximum level; and 2) the number of coded packets should not exceed a maximum value dictated by the desired throughput and delay. We further extend the results to take into account the effect of inevitable channel estimation errors, and consider the case in which the transmitter has only an estimate of the channel gain. We design adaptation policies for such a case based on minimum mean square error (MMSE) channel estimation, taking into account the effect of channel estimation errors in an optimal manner to satisfy the required outage/reliability criterion. Finally, we compare the proposed technique to standard automatic repeat request (ARQ) protocols for underwater communications in terms of the throughput efficiency. Analytical results show that substantial energy savings and improvements in throughput efficiency are available from adaptive power/rate control. We also present experimental results obtained using channel gains measured during the Surface Process Acoustic Communication Experiment (SPACE-08), an at-sea underwater experiment conducted off the coast of Martha's Vineyard in fall 2008.

Social Norm Incentives for Network Coding in Manets

The performance of mobile ad hoc network transmissions subject to disruption, loss, interference, and jamming can be significantly improved with the use of network coding (NC). However, NC requires extra work for forwarders, including additional bandwidth consumption due to transmitting overheads for redundant NC packets and additional processing due to generating the NC packets. Selfish forwarders may prefer to simply forward packets without coding them to avoid such overhead. This is especially true when network coding must be protected from pollution attacks, which involves additional, often processor intensive, pollution detection procedures. To drive selfish nodes to cooperate and encode the packets, this paper introduces social norm-based incentives. The social norm consists of a social strategy and a reputation system with reward and punishment connected with node behavior. Packet coding and forwarding are modeled and formalized as a repeated NC forwarding game. The conditions for the sustainability (or compliance) of the social norm are identified, and a sustainable social norm that maximizes the social utility is designed via selecting the optimal design parameters, including the social strategy, reputation threshold, reputation update frequency, and the generation size of network coding. For this game, the impacts of packet loss rate and transmission patterns on performance are evaluated, and their impacts on the decision of selecting the optimal social norm are discussed. Finally, practical issues, including distributed reputation dissemination and the existence of altruistic and malicious users, are discussed.