Multicast In Wireless Networks Research Articles

Multicasting in NOMA‐based UAV networks: Path design and throughput maximisation

In this paper, a new resource allocation framework for unmanned aerial vehicle (UAV) assisted multicast wireless networks is proposed in which the network users according to their request are divided into several multicast groups. Power domain non-orthogonal multiple access is adopted as the transmission technology using which the dedicated signals of multicast groups are superimposed and transmitted simultaneously as the UAV passes over the communication area for fixed and mobile users. The proposed scenarios are discussed from two perspectives, offline and online modes. In offline mode, the problem is implemented for fixed and mobile users whose locations are predictable (the location of users, over the communication time, is known at the beginning of the communication time) and in online mode for mobile users whose locations are unpredictable (the location of users, over the communication time, is unknown at the beginning of the communication time). Also, a scenario is proposed in which the online mode the number of mobile users can grow in each time slot. The problem of joint power allocation and UAV trajectory design as an optimisation problem that is non-linear and non-convex for two proposed scenarios is formulated. To solve the problem, an alternate search method, successive convex approximation, and geometric programming are adopted. Using simulation results, the performance of the proposed scheme is evaluated for different values of the network parameters.

Queueing Theoretic Models for Uncoded and Coded Multicast Wireless Networks With Caches

Queueing Theoretic Models for Uncoded and Coded Multicast Wireless Networks With Caches

Scheduling and Power Control for Wireless Multicast Systems via Deep Reinforcement Learning.

Multicasting in wireless systems is a natural way to exploit the redundancy in user requests in a content centric network. Power control and optimal scheduling can significantly improve the wireless multicast network’s performance under fading. However, the model-based approaches for power control and scheduling studied earlier are not scalable to large state spaces or changing system dynamics. In this paper, we use deep reinforcement learning, where we use function approximation of the Q-function via a deep neural network to obtain a power control policy that matches the optimal policy for a small network. We show that power control policy can be learned for reasonably large systems via this approach. Further, we use multi-timescale stochastic optimization to maintain the average power constraint. We demonstrate that a slight modification of the learning algorithm allows tracking of time varying system statistics. Finally, we extend the multi-time scale approach to simultaneously learn the optimal queuing strategy along with power control. We demonstrate the scalability, tracking and cross-layer optimization capabilities of our algorithms via simulations. The proposed multi-time scale approach can be used in general large state-space dynamical systems with multiple objectives and constraints, and may be of independent interest.

Opportunistic Relay in Multicast Channels With Generalized Shadowed Fading Effects: A Physical Layer Security Perspective

Through ordinary transmissions over wireless multicast networks are greatly hampered due to the simultaneous presence of fading and shadowing of wireless channels, secure transmissions can be enhanced by properly exploiting random attributes of the propagation medium. This study focuses on the utilization of those attributes to enhance the physical layer security (PLS) performance of a dual-hop wireless multicast network over κ - μ shadow-fading channel under the wiretapping attempts of multiple eavesdroppers. In order to improve the secrecy level, the best relay selection strategy among multiple relays is employed. Performance analysis is carried out based on the mathematical modeling in terms of analytical expressions of non-zero secrecy capacity probability, secure outage probability, and ergodic secrecy capacity over multicast relay networks. Capitalizing on those expressions, the effects of system parameters, i.e., fading, shadowing, the number of antennas, destination receivers, eavesdroppers, and relays, on the secrecy performance are investigated. Numerical results show that the detrimental impacts caused by fading and shadowing can be remarkably mitigated using the well-known opportunistic relaying technique. Moreover, the proposed model unifies secrecy analysis of several classical models, thereby exhibiting enormous versatility than the existing works.

Cache-Aware Network Coding-Based Scheduling for SVC Multicast in Wireless Networks with Hard Deadline Constraints

To provide multi-resolution video for heterogeneous users in wireless networks, Scalable Video Coding (SVC) encodes a video bit stream into one base layer and several enhancement layers, on the basis of their contribution in recovering the video correspondingly. However, a decoding dependency is introduced into these layers and artful operation is required for SVC streaming. Meanwhile, each SVC packet is associated with a hard time constraint so that users can recover their desired video quality timely. This paper focuses on the network coding assisted SVC multicast with hard deadline constraints. Specifically, we consider the cache-aware model where users are able to store all received packets and decode out the desired packets when sufficient packets are obtained. We analyze the effect of cached network coded packets on the SVC packets scheduling process and the video quality improvement, and value that effect through assigning proper weight for each packet. We also take multiple factors that affect quality of experience into consideration, such as channel condition, request’s deadline and user’s packets receiving status. Moreover, we adopt the instantly decodable network coding (IDNC) technique to schedule SVC packets. According to packets weighting on the vertices of a well-structured two-layered IDNC graph, an effective heuristic algorithm is proposed to schedule the most valuable SVC packets combinations within acceptable complexity. Extensive simulation results verify the effectiveness and the quality of experience enhancement accomplished by the proposed algorithm.

Hybrid Multicast and Device-to-Device Communications Based on Adaptive Random Network Coding

Random network coding (RNC) is an efficient coding scheme to improve the performance of wireless multicast networks, on the premise that a receiver is able to collect a full set of network-coded packets. However, in resource (time, bandwidth, and so on) constrained communications, a receiver may only receive a partial set of network coded packets, leading to poor system performance. On the other hand, device-to-device (D2D) communications utilize user proximity and spatial diversity to improve the communication efficiency. In this paper, we propose a hybrid multicast and D2D transmission scheme based on adaptive RNC (ARNC) to increase network throughput under packet erasure channels. In the proposed scheme, the packet encoding structure is optimized adaptively according to the network status, such that even if only a partial set of the coded packets are received, the user equipments (UEs) can still decode useful information and regenerate new encoded packet for D2D communications. In particular, the multicast mode and D2D mode are switched dynamically during a scheduling session according to the status of each UE. Under this hybrid mode, we can effectively overcome the effect of erasure channel and improve the overall network throughput. By comparing our scheme with other scheduling methods, we provide simulation results to corroborate the effectiveness of the proposed techniques.

Delivery Design for Coded Caching Over Wireless Multicast Networks

In wireless multicast networks, different users may have quite different link qualities to the server, which will degrade the multicast performance of the coded caching scheme. In order to effectively handle the asymmetric link qualities and fulfill the fairness delivery requirement by a different user, a parallel delivery scheme is proposed to organize the wireless multicast physical channels into multiple logic parallel partially shared links. Each parallel partially shared link connects the server to a subset of users, and each user can receive coded signals from multiple parallel partially shared links, in which the superposition coding and successive interference cancellation techniques will be utilized to guarantee the recovery of each requested file. Since the parallel partially shared links provide the basis to reasonably balance the traffic load and to allocate the delivery rate among users, this parallel delivery scheme is able to guarantee the fairness transmission requirements and to effectively reduce the required delivery time per bit (DTB), which is defined as the normalized time spent on satisfying all the users' demands, for both the centralized and decentralized placement.

Age of Information with network coding

We consider the timeliness in delivering a file containing a fixed number of packets through a multicast wireless network using network coding, which is known to improve throughput and reliability for multicast communications. Information timeliness is characterized by metrics related to the Age of Information (AoI). We investigate the impact of network parameters on the average AoI and the peak AoI, including the effect of the number of packets in a coding block, number of destinations, and the Galois field size used for packet encoding. With respect to the field size, the common assumption of an infinite field yields a lower bound on the time to deliver the file to all destinations, but the assumption is impractical. We characterize the AoI for a finite field and show that a large field size may be unnecessary, as the AoI decreases sharply with this parameter. Finally, we consider randomness in obtaining the packets before transmission, including queuing delays in our analysis, and show that optimizing AoI is not equivalent to minimizing delay, and there exists interesting trade-offs among network performance objectives.

Lyapunov Scheduling and Optimization in Network Coded Wireless Multicast Network

In this paper, we investigate network coding based scheduling in a single-hop wireless multicast network under queueing stability constraint. Specifically, Lyapunov optimization model is adopted and an optimal network coding scheduling algorithm is derived, which significantly reduces the computational complexity and queue length compared to existing solutions. Moreover, two scheduling policies based on linear programming and Lyapunov optimization model are proposed to jointly minimize the queue length and power consumption. Finally, extensive numerical results corroborate the effectiveness of our proposed algorithms.

Joint Power Allocation and Adaptive Random Network Coding in Wireless Multicast Networks

It is known that random network coding (RNC) can be used to improve the performance of wireless multicast networks. However, in the delay sensitive applications, no useful information can be recovered if a user cannot collect a full set of the encoded packets. This becomes more severe for multicast hard deadline constrained prioritized data because of the delivery time limitation and packet interdependency. Meanwhile, the performance of a multicast network is also limited by its bottleneck user(s) due to the heterogeneity of the underlying physical channels. Accordingly, we propose a cross-layer transmission scheme that utilizes beamforming at physical layer and adaptive RNC (ARNC) at network layer to maximize the overall network throughput. Under this joint-design, a smart antennas array that operates the beamforming is used to dynamically allocate the transmitting power among users, and the ARNC is adopted to achieve the network coding gain. In this way, the performance of each user is well balanced and the overall network throughput is increased observably. Furthermore, we propose a sample-based feedback scheme to reduce the system overhead. The analytical and simulation results are shown that the throughput of the network has increased by 30%~40% under our schemes compared with other RNC-based schemes.

Rate selection for wireless multicast system adopting incremental redundancy type hybrid-ARQ

We propose a rate selection method in wireless multicast systems where an incremental redundancy type hybrid automatic repeat request (HARQ-IR) scheme is employed under Rayleigh block-fading channels. We aim at maximizing the long-term average transmission rate (LATR) while the maximum number of retransmissions is limited to L — 1 and the probability that at least one user fails to decode a message within L (re)transmissions is limited to e. We consider two user-distribution scenarios: 1) Receivers are located at the same distance from the source and 2) receivers are uniformly distributed in a circular cell. For the former scenario, we derive two closed-form approximations for the LATR. Among the two, the simpler one is expressed as $\mu - {{Q^{-1}(1-0.5^{1/U})\sigma}\over{\sqrt L}}$ for a large L value where U, μ, σ, Q denote the number of receivers, the ergodic capacity, and the deviation of the mutual information for one HARQ round, and the complementary Gaussian cumulative distribution function, respectively. We also analyze the second scenario using point mass approximation. We show that the HARQ-IR scheme outperforms the conventional fixed-length coding and Chase-combining type HARQ schemes in wireless multicast network for both scenarios.

Design and Optimization of VoD Schemes With Client Caching in Wireless Multicast Networks

Due to the explosive growth in multimedia traffic, the scalability of video-on-demand (VoD) services has become increasingly important. By exploiting the potential cache ability at the client side, the performance of VoD multicast delivery can be improved through video segment precaching. In this paper, we address the performance limits of client-caching-enabled VoD schemes in wireless multicast networks with asynchronous requests. Both reactive and proactive systems are investigated. Specifically, for the reactive system where videos are transmitted on demand, we propose a joint cache allocation and multicast delivery scheme to minimize the average bandwidth consumption under the zero-delay constraint. For the proactive system where videos are periodically broadcasted, a joint design of the cache-bandwidth allocation algorithm and the delivery mechanism is developed to minimize the average waiting time under the total bandwidth constraint. In addition to the full access pattern where clients view videos in their entirety, we further consider the access patterns with random endpoints, fixed-size intervals, and downloading demand, respectively. The impacts of different access patterns on the resource-allocation algorithm and the delivery mechanism are elaborated. Simulation results validate the accuracy of the analytical results and also provide useful insights in designing VoD networks with client caching.

A Practical Layered Multiplexed-Coded Relaying Scheme for Wireless Multicast

We design and implement a practical layered multiplexed-coded decode-forward (LMDF) relaying strategy for a wide-band wireless multicast network. The proposed LMDF scheme relies on layering at the source, with the individual layers provided unequal power allocation through a simple bit-mapping operation to quadrature amplitude modulation constellations. At the relay, LMDF utilizes a multiplexed-coded approach that, with a single transmission, caters for the disparity in the number of layers decoded at different destinations. Under a practical setup of hard-decision decoding and coding across the subcarriers of orthogonal frequency division multiplexing (OFDM) modulated transmissions, we derive the information theoretic achievable rates of LMDF and use the IEEE 802.11 TGn channel model for performance evaluations. LMDF is then implemented using convolutional codes, with the relay's code optimized specifically keeping its multiplexed nature in mind. In addition to simulations, we also evaluate the performance of LMDF through a system-level implementation by using the National Instruments USRPs 2921. We conduct over-the-air experiments in an indoor office environment using an OFDM-based physical layer, and illustrate the considerable performance benefits of LMDF over benchmarks such as conventional two-hop decode-forward.

An Analysis of Network Coding Algorithms

Network coding is a network packet transmitting protocol, applied to increase the achievable throughput for the exchange of information between two terminals through one relay. Throughput efficiency this paper reviews latency and bandwidth efficient coding algorithm based on principles of network coding for retransmitting lost packets in wireless multicast network. It outlines the basic principles and important techniques for retransmission of packets in network coding.Network coding is new paradigm that allows the intermediate nodes in a network to create new packets by combining packets received on their incoming edges. The main application of the networking coding technique includes content distribution, peer to peer networks, and wireless ad-hoc networks.Such network is characterized by highly dynamic set of users and frequent topological changes. There are two main advantages of Network coding approach are potential throughput improvements and a high degree of robustness.

Ant based Pareto optimal solution for QoS aware energy efficient multicast in wireless networks

Most of the group communication technologies support real-time multimedia applications such as video conferencing and distributed gaming. These applications require quality-of-service (QoS) aware multicast routing protocol to deliver the same data stream to a predefined group of receivers. Since nodes in wireless networks are severely energy constrained due to finite battery source, hence it is of paramount importance that QoS aware multicast routing protocol be energy efficient. Transmission power control is one of the methods used to save energy. In this method, the nodes dynamically adjust the transmission power so that energy consumption in the tree is minimized. However, reduction in the transmission power increases the number of forwarding nodes in the multicast tree. This negatively impacts the QoS in terms of propagation delay, delay jitter, and packet loss etc. In wireless networks, there is a trade-off between the energy consumption and the QoS guarantees provided by the network. We unify these requirements into a multiobjective framework referred to as Energy Efficient QoS Multicast Routing (E2QoSMR). The goal is to simultaneously optimize the total power consumption and the QoS parameters in the multicast tree. We extend two algorithms based on metaphor of swarm intelligence for finding an energy efficient multicast tree satisfying the QoS guarantees. Extensive simulations have been conducted to validate the correctness and efficiency of the algorithms. The simulation result of the algorithms is compared with the nondominated sorting genetic algorithm, NSGA-III. The experimental results are consolidated by statistical analyses that demonstrate the ability of the algorithms to generate the Pareto optimal solution set.

Hash searching and network coding based constant retransmission for wireless multicast

This study is concerned with the network coding (NC) problem in error-prone wireless multicast networks. A hash searching and NC-based constant retransmission scheme (HSNCR) is proposed to make combination selection, where the retransmission of the packet losses can be carried out during the whole process of original packet transmission, and thus the HSNCR can increase the possibility of NC. Furthermore, this new scheme maximises the efficiency of every retransmission by only retransferring an optimum combination or maximum combination of original lost packets. To support HSNCR, an efficient hash searching approach is also designed for the combination selection of original lost packets. Simulation results show that the authors’ proposed scheme indeed outperforms previous works in reducing the number of retransmission.

Sustainable assessment of Heterogeneous Wireless Network Using WASPAS Method

Heterogeneous Wireless Network, Device-to-device (D2D) and heterogeneous networks are key to the success of 5G networks. Multimodal networks consist of fixed location base stations/small cells, each of which may have a different range and type of connection to a mobile network operator (MNO). Wireless networks in our environment use Different access technologies, via wireless LAN Wireless network and cellular that provide the service Services can be maintained while switching to a network It is called a wireless multicast network. WASPAS Method Weighted Sum Model (WSM) and Advantages of Weighted Product Model (wpm) uses. Integrating WSM and WPM, Ranking of WASPAS alternatives increases accuracy. That at the stage, WASPAS is an optimum calculates the additive parameter, it will be given in detail later. The WASPAS method of analysis is excellent the best solution. Short distance and negative-best is more than solution the long-range solution determines, but a comparison of these distances not considered significant Alternative: VoIP (protocol), Streaming, Web Browsing, and Transmission Control Protocol (TCP). Evaluation Preference: Allowed bandwidth, usage, Packet delay, packet jitter, packet Loss to calculate the final value. The result it is seen that Utilization is got the first rank where as is the Packet delay is having the lowest rank. The value of the dataset for Range of Heterogeneous Wireless Network in WASPAS (Weighted Aggregated Sum Product Assessment) method shows that it results in Utilization and top ranking.

A New Wireless Multicast Queuing Design Using Network Coding and Data-Flow Model

A queue stability analysis in a wireless multicast network with packet erasure channels is studied in this letter. In particular, a new queuing model consisting of several sub-queues is introduced, where each packet in a sub-queue is associated with an index set indicating its intended users. Our objective is to maximize the input rate under the queue stability constraints. We formulate it as a linear programming problem and propose a network coding-based packet scheduling scheme that finds the optimal solution. Finally, the simulation results corroborate our method.

Queue Stability Analysis in Network Coded Wireless Multicast Network

This letter considers a single hop wireless multicast network. We first introduce a new two-level queuing system consisting of a main queue and a virtual queue, where each packet in the virtual queue is associated with a user index set. Then, we propose a network coding based packet scheduling method to maximize the system input rate under the queue stability constraint. Our analytical and simulation results demonstrate the effectiveness of the proposed solution.

Layered Multiplexed-Coded Relaying in Wireless Multicast Using QAM Transmissions

We propose layered multiplexed-coded decode-and-forward (LMDF) relaying for a wireless multicast network. Splitting the message into two layers, the source encodes them separately and maps them to a quadrature amplitude modulation (QAM) constellation to achieve superposition, thus allowing partial message recovery at the relay and the destinations. The key component of LMDF is multiplexed coding at the relay that enables each destination to divert all channel resources toward decoding the layers that remain unrecoverable from the source’s transmission. We derive information theoretic achievable rates for LMDF and consider network outage as a performance measure. For a setup with 15 users uniformly spread around the relay, simulations indicate that LMDF outperforms conventional unlayered DF by 1.7 dB and superposition coding-based DF by 1.1 dB, while the respective gains in outage rate at individual users are up to 48.6% and 31.4%.