Multicast Channel Research Articles

DRF codes: Deep SNR-robust feedback codes

We present a new Deep Neural Network (DNN)-based error correction code for fading channels with output feedback, called the Deep SNR-Robust Feedback (DRF) code. At the encoder, parity symbols are generated by a Long Short Term Memory (LSTM) network based on the message, as well as the past forward channel outputs observed by the transmitter in a noisy fashion. The decoder uses a bidirectional LSTM architecture along with a Signal to Noise Ratio (SNR)-aware attention NN to decode the message. The proposed code overcomes two major shortcomings of DNN-based codes over channels with passive output feedback: (i) the SNR-aware attention mechanism at the decoder enables reliable application of the same trained NN over a wide range of SNR values; (ii) curriculum training with batch size scheduling is used to speed up and stabilize training while improving the SNR-robustness of the resulting code. We show that the DRF codes outperform the existing DNN-based codes in terms of both the SNR-robustness and the error rate in an Additive White Gaussian Noise (AWGN) channel with noisy output feedback. In fading channels with perfect phase compensation at the receiver, DRF codes learn to efficiently exploit knowledge of the instantaneous fading amplitude (which is available to the encoder through feedback) to reduce the overhead and complexity associated with channel estimation at the decoder. Finally, we show the effectiveness of DRF codes in multicast channels with feedback, where linear feedback codes are known to be strictly suboptimal. These results show the feasibility of automatic design of new channel codes using DNN-based language models.

On‐chip all‐optical multicasting of mode‐division multiplexing QPSK signals

AbstractThe authors propose and experimentally demonstrate an on‐chip all‐optical multicasting (AOM) for 40 Gbit/s mode‐division‐multiplexed quadrature phase‐shift keying (MDM‐QPSK) signals based on a parallel dispersion‐engineered multimode non‐linear silicon waveguide. Five dual‐mode multicast wavelengths are successfully obtained on the generate idlers, and the power penalties of all the multicast channels are less than 1.1 dB at the bit error rate (BER) of 3.8 × 10−3. The dual‐mode AOM scheme has the potential to promote the ability of optical cross‐connect in practical hybrid multiplexed networks including MDM channels.

Reinforcement learning based joint trajectory design and resource allocation for RIS-aided UAV multicast networks

This paper investigates an unmanned aerial vehicle (UAV)-enabled multicast network, where the UAV serves as a mobile transmitter to send typical contents to its corresponding ground receivers. A reconfigurable intelligent surface (RIS) is deployed to enhance the service quality with a limited power supply in the UAV-enabled multicast network. It can reconfigure the signal propagation environment and improve the received power of ground receivers by adjusting the reflection coefficients. The sum rate maximization problem is formulated by jointly designing the UAV movement, RIS reflection matrix, and beamforming design from the UAV to users. This paper proposes a Beamforming control and Trajectory design algorithm based on a Multi-Pass Deep Q-Network (BT-MP-DQN). In the proposed algorithm, the UAV acts as an agent for periodically observing the state of the UAV multicast network and takes actions to adapt to the dynamic environment. Specifically, the movement of the UAV is discrete action, and the beamforming design is continuous action. The simulation results show that this proposed algorithm can effectively improve the achievable rate and satisfy the minimum rate of multicast group users. The deployment of the RIS is beneficial to network performance enhancement. In addition, the multicast network with UAV also outperforms the conventional multicast channel with a fixed-location transmitter.

An Efficient and Secure Multimessage and Multireceiver Signcryption Scheme for Edge-Enabled Internet of Vehicles

The Internet of Vehicles (IoV) is considered an enhancement of existing vehicular ad-hoc networks, which helps connect mobile vehicles to the Internet of Things (IoT) with the support of 5G networks. To assure the quality-of-service demand by the users, the edge computing paradigm of 5G networks can be incorporated in the IoV environment for supporting compute-intensive applications. The basic safety messages are typically transmitted using a multicast pattern in the IoV-enabled edge computing paradigm. The use of the multicast channel may accelerate the communication process; however, it is prone to various attacks due to the open nature of wireless networks. This article proposes a multimessage and multireceiver signcryption scheme for the multicast channel in a certificateless setting to solve the key escrow problem. The security of the partial private key is dependent on the secure channel, which increases the complexities of the system. Therefore, in the proposed scheme, we introduce a new idea that does not require a secure channel. The key generation center only sends the pseudo partial private key of the users on a public channel. Furthermore, the proposed scheme is based on hyper-elliptic curve cryptography (HECC), which has much smaller key sizes as compared to elliptic curve cryptography (ECC). The security proofs and performance comparison for our scheme are carried out. The findings show that the proposed scheme provides high security while using less computational and communication costs.

Enhancing Security in Multicellular Multicast Channels Reducing Interference Power with the Best Relay Selection

The capacity of wireless networks is fundamentally limited by interference. A few research has focused on the study of the simultaneous effect of interference and correlation, and less attention has been paid to the topic of canceling simultaneous effect of interference and correlation until recently. This paper considers a secure wireless multicasting scenario through multicellular networks over spatially correlated Nakagami-m fading channel in the presence of multiple eavesdroppers. Authors are interested to protect the desired signals from eavesdropping considering the impact of perfect channel estimation (PCE) with interference and correlation. The protection of eavesdropping is also made strong reducing the simultaneous impact of interference and correlation on the secrecy multicast capacity employing opportunistic relaying technique. In terms of the signal-to-interference plus noise ratio (SINR), fading parameter, correlation coefficient, the number of multicast users and eavesdroppers and the number of antennas at the multicast users and eavesdroppers, the closed-form analytical expressions are derived for the probability of non-zero secrecy multicast capacity and the secure outage probability for multicasting to understand the insight of the effects of aforementioned parameters. The results show that the simultaneous effects of correlation and interference at the multicast users degrade security in multicasting. Moreover, the security in multicasting degrades with the intensity of fading and the number of multicast users, eavesdroppers and antennas at the eavesdroppers. The effects of these parameters on the security in multicasting can be significantly reduced by using opportunistic relaying technique with PCE. Finally, the analytical results are verified via Monte-Carlo simulation to justify the validity of derived closed-form analytical expressions.

Secrecy Trade-off at the Physical Layer over Mixed Fading Multicast Channels Employing Antenna Diversity

Secrecy Trade-off at the Physical Layer over Mixed Fading Multicast Channels Employing Antenna Diversity

Reconfigurable Intelligent Surfaces for Energy Efficiency in Multicast Transmissions

Reconfigurable Intelligent surface (RIS), which can induce phase shift of the received signals and then forward them by its reflecting elements, possesses high energy efficiency (EE). This letter studies the EE for the RIS-assisted multicast communication. A multiple-antenna base station (BS) delivers common messages to a group of mobile users (MUs), The RIS is placed to maintain the transmission. First, this letter analyzes the equivalent multicast channel and total power consumption to formulate an EE maximization problem. Then, this letter proposes the functional algorithms by fractional programming and alternating optimization to obtain a locally optimal solution for this problem. Lastly, we show asymptotic behaviors of the EE when the numbers of reflecting elements, antennas, and MUs go to infinity.

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.

Improvements of the xAAL Home Automation System

The xAAL home automation system has been designed on the basis of distributed systems principles with messages passing and home network communications over IP. The proposal makes extensive use of standards and provides a clear separation of roles along the distributed system with no predominant actor. This allows openness and interoperability. This objective can be reached once all parts are convinced: consumers, manufacturers, service providers, etc. To get a broad adoption, the proposal comes with fine-tuned communication, architecture, security, and simplicity. Tests and experiments in the long term have led us to optimize the protocol, adjust the architecture, and rearrange device descriptions. This paper provides a full description of the improved system, with all details to make feasible compatible alternative implementations. It also discusses alternatives and all aspects that led us to make structuring choices: CBOR messages on an IP multicast channel, intranet communication, ciphering with Poly1305/Chacha20, structured and extensible abstract device description, and a distributed system architecture.

Efficient and Provably Secure Multireceiver Signcryption Scheme for Multicast Communication in Edge Computing

With the popularity of edge computing, edge nodes are connected with the Internet of Things (IoT) devices to process and analyze IoT-created data, and feedback corresponding results to users, devices, or data centers. In the edge computing environment, multicast is a typical communication pattern to support data transmitting between edges and devices. It allows the sender to send messages to multiple receivers in one broadcast message. To construct a secure multicast channel, the primary issue is to ensure the privacy and credibility of the transmitted message in the open wireless communication. Then, another essential issue for multicast channels is receiver anonymity, i.e., only the sender knows the receivers’ identities. Also, efficiency and provable security are critical in scheme design. In this article, we design a certificateless multimessage and multireceiver signcryption (CLMMSC) scheme by using the elliptic curve cryptography. To facilitate lightweight deployment, we adapt the certificateless mechanism to reduce the system operation and maintenance costs. Then, through security proofs, we demonstrate that the proposed scheme can achieve the expected security properties. The performance analysis shows that the proposed scheme has lower communication costs than previous CLMMSC schemes.

Performance Analysis of Device-to-Device Aided Multicasting in General Network Topologies

We consider a Device-to-Device (D2D) aided multicast channel, where a base station (BS) wishes to convey a common message to many receivers and these receivers cooperate with each other. We analyze the performance of a two-phase cooperative multicasting scheme requiring only statistical channel knowledge at the BS. Our analysis reveals that, as the number of receivers K grows, the two-phase scheme guarantees an average multicast rate of $\frac {1 }{ 2} \log _{2}(1 + \beta \ln \text {K})$ with high probability for any $\beta where $\beta ^\star $ depends on the network topology. This scheme undergoes a phase transition at threshold $\beta ^\star \ln \text {K}$ where transmissions are successful/unsuccessful with high probability when the Signal to Noise Ratio (SNR) is above/below this threshold. We also analyze the multicast outage rate when a target joint decoding probability is fixed. Finally, we propose two enhanced schemes by optimally allocating the time resource between two phases and combining received signals from two phases. 1 1 A part of the results presented in the current manuscript has been presented at the IEEE International Symposium on Information Theory 2018 [1] . The results are published in Chapter 3 of the P.h.D. Thesis of the first author [2] .

Theoretic analysis and elimination scheme of polarization crosstalk in wavelength multicasting system

A mathematical model of the polarization crosstalk using semiconductor optical amplifier (SOA) as four wave mixing (FWM) medium in wavelength conversion and multicasting system is deduced. A crosstalk elimination scheme for wavelength multicasting system is proposed, in which two independent FWM processes perform in two SOAs, and the crosstalk induced by polarization rotation can be removed. By employing the elimination scheme of polarization crosstalk, wavelength conversion and multicasting of 10 Gbit/s polarization multiplexing non-return-to-zero (NRZ) signal has been realized. The performance comparison is conducted between the multicast system with using the proposed crosstalk elimination scheme and without using crosstalk elimination scheme. The maximum Q factor and eye diagrams of seven multicast channels are evaluated. The results show that utilizing the crosstalk elimination scheme the performance of the system is improved remarkably. Bit error rate (BER) performance is also measured by simulation, the result shows that the maximum power difference of the 7 multicast channels for x and y polarization state are about 1 dB and 1.7dB at BER of 10−9.

Scalable Multicast Using MPLS in Software Defined Network

Multicast helps to deliver data to multiple receivers efficiently. One scalability challenge faced by multicast is the per-channel forwarding states being maintained in the network layer, which increases linearly with the number of established multicast channels. MPLS helps to alleviate this problem by removing forwarding states from non-branch routers on the multicast tree and label switch packets in non-branch routers. To reduce the number of forwarding states in branch routers, many solutions were proposed to merge multicast trees/subtrees from different channels. Software Defined Network (SDN) decouples the control plane from the data plane, which enables low cost commodity design in routers and flexible network feature deployments through software implementation in centralized controllers. Equipped with SDN’s flexible policy and packet processing action installation, multicast tree/subtree merging becomes more convenient in SDN. This paper proposes a new scalable multicast solution in SDN to further reduce the number of forwarding states in routers. In the new solution, first a 2 level MPLS label switching scheme is used to reduce the extra point to point LSPs needed when multicast trees are merged. Secondly, a new multicast tree construction algorithm is designed to pursue more aggressive subtree matching between channels by taking advantage of per channel packet dropping actions in SDN. Simulation results show that the new solution can achieve 10-20 percent reduction in the number of forwarding entries needed for multicast traffic’s forwarding.

Optimal Resource Allocation for a Single-Cell Multicast Transmission Scheme with a Supplementary Multicast Channel

Multicast transmission is an attractive solution when a large number of users receive the same content in a wide area, for example, as with mobile TV. Ever since the multimedia broadcast multicast service (MBMS) was introduced in the 3rd Generation Partnership Project (3GPP), continuing work on the multicast transmission has been done and its importance is growing in the fifth generation (5G) cellular networks. The use cases of multicast transmission have been enlarged from mobile TV and public safety to vehicular-to-everything (V2X) and unmanned aerial vehicles (UAV). Recently, for group communications in public safety networks and for geographical information sharing in automotive, airborne and social networks, multicast transmission has been targeted at fewer users in a relatively small area, which has stimulated extensive research on the single-cell multicast transmission scheme. In the proposed single-cell multicast transmission scheme, a supplementary multicast channel is additionally assigned in a single-cell multicast transmission scheme to exploit channel diversity. The resource allocation is adaptive to the channel variations of the users (responsive to users QoS needs), using channel feedback from the users, in contrast with previous approaches where resources were determined conservatively. An optimal resource allocation problem to minimize the required bandwidth while enabling every user to obtain the target multicast rate is formulated as a convex problem and an iterative algorithm is proposed in a computationally efficient way. Performance is evaluated mathematically and through intensive simulations, where other cell interference is considered using a fluid model. The proposed single-cell multicast transmission scheme provides benefits in comparison to existing multicast schemes in the simulations, under a set of various parameters including the number of multicast users and channel correlation between the multicast channels.

An Intelligent Channel Assignment Approach for Minimum Interference in Wireless Mesh Networks Using Learning Automata and Genetic Algorithms

Multi-radio multi-channel WMNs are innovative technical kind of WMNs, i.e., the nodes with multi radios and numerous channels for communication. In wireless mesh routers of WMNs, multiple network interfaces caused due to multiple channels typically increases the network throughput, i.e., in multi-channel WMN, whenever two neighboring nodes transfer information using the similar channel, they might interfere with one another and eventually decreases the throughput. Thus, there is a need for an effective approach to reduce network interference and significantly enhance throughput. This paper primarily concentrates on issues of multicasts channel assignment in WMNs to diminish the interference in the network. The adaptive decision-making strategy of learning automata and strong searching capability of the genetic algorithm is employed in this approach. The methodology combined multicast tree construction and channel assignment, to evade that channel assignment could not function well with the specific multicast tree. In this paper, the initial multicast tree construction by learning automata and the optimal channel assignment is performed by genetic algorithm. The experiment outcomes for the suggested methodology is carried out using NS2 and performance efficiency is matched with LAMR, LCA, and GA based multicast channel assignment approach and suggested higher performance using packet delivery ratio, an end to end delay, throughput and total cost.

Multi-Resolution Multicasting Using Grassmannian Codes and Space Shift Keying

In this paper, we develop a novel layered coding scheme for the multiple-input multiple-output multicast channel. In this scheme, information is encoded in two layers, a base low-resolution (LR) layer and refining high-resolution (HR) one. The LR layer is encoded using Grassmannian noncoherent codes and the HR layer is encoded in the indices of the active transmitter antennas using the so-called space shift keying modulation. An efficient algorithm is proposed to optimize the HR codebook. The LR information can be detected noncoherently without invoking any channel state information (CSI), whereas the HR information must be detected coherently and, thus, requires accurate CSI. Hence, receivers with perfect CSI can decode both the LR and HR information, whereas those with no CSI can only decode the LR information. For receivers with accurate CSI, we propose a computationally efficient two-step detector and we show that the noncoherent detector performance is not affected by the transmission of the incremental HR information encoded in the transmit antenna indices.

Subband CQI Feedback-Based Multicast Resource Allocation in MIMO-OFDMA Networks

Multicast transmission is one of the key enablers toward a more spectral- and energy-efficient distribution of multimedia content in current and envisaged cellular networks. In order to ensure that all users in a multicast group are able to correctly decode the received data, most multicast techniques adopt rather conservative strategies that select a very robust modulation and coding scheme (MCS) whose characteristics are determined by the propagation conditions experienced by the worst user in the group. Obviously, this robustness comes at the prize of a low spectral efficiency. Moreover, in the specific context of wideband communication systems, the selection of the multicast MCS has often relied on the use of wideband channel quality indicators (CQIs) providing rather imprecise information regarding the potential capacity of the multicast channel. Only recently has the per-subband CQI been used to improve the spectral efficiency of the system without compromising the link robustness. However, most subband-CQI multicast schemes proposed so far rely on overpessimistic assumptions that preclude the achievement of high data rates. In this paper, novel subband CQI-based multicast strategies are proposed that, relying on the selection of more spectrally efficient transmission modes, lead to increased data rates while still being able to fulfill prescribed quality of service metrics. To this end, a constrained optimization problem is posed that seeks to maximize the data rate of the whole multicast group while ensuring that the average block error rate for all users remains below a threshold and that a minimum data rate is guaranteed for all users in the group.

Joint interference optimization and user satisfaction improvement for multicast routing and channel assignment in wireless mesh networks

Multicast communication is a key technology for wireless mesh networks. In order to reduce co-channel interference in multicast transmission, we jointly study multicast tree construction and channel assignment in this paper. First, interference in multicast is analyzed and measured with considerations of hidden node problem and user coverage. Then, an algorithm called CIOMT is proposed to construct multicast routing tree, In which we find the path with minimum interference to root and add it to the constructing multicast tree, give an upper limit to the source-to-destination distance for QoS consideration, and tree structure is optimized to relieve interference among multicast links. Moreover, we propose a channel assignment algorithm for the constructed multicast tree with the name CIOCA. In CIOCA algorithm, in order to provide good service to the users as much as possible, we take the user coverage of each destination as the top priority in channel assignment, and the nodes are assigned the sending channels by descending order of priority. In each step, we find the channel with minimum interference to the whole tree, and assign it to the related nodes. For making full use of spectrum resources, the non-overlapping and overlapping channels are both taken into consideration. At last, simulation is done, and the results show the effectivity of the proposed multicast routing scheme. As far as user satisfaction is concerned, the proposed scheme has much better performance than the other two classic algorithms.

An Information-Theoretic Analysis of the Gaussian Multicast Channel With Interactive User Cooperation

We consider the transmission of a common message from a transmitter to three receivers over a broadcast channel, referred to as a multicast channel in this case. All the receivers are allowed to cooperate with each other over full-duplex non-orthogonal cooperation links. We investigate the information-theoretic upper and lower bounds on the transmission rate. In particular, we propose a three-receiver fully interactive cooperation scheme (3FC) based on superpositions of compress-forward (CF) and decode-forward (DF) at the receivers. In the 3FC scheme, the receivers interactively perform CF simultaneously to initiate the scheme, and then DF sequentially to allow a correlation of each layer of the DF superposition in cooperation with the transmitter toward the next receiver in the chain to improve the achievable rate. The analysis leads to a closed-form expression that allows for numerical evaluation, and also gives some insight on key points to design interactive schemes. The numerical results provided in the Gaussian case show that the proposed scheme outperforms the existing schemes and show the benefits of interaction.

Social‐Aware Cooperative Video Distribution via SVC Streaming Multicast

Scalable Video Coding (SVC) streaming multicast is considered as a promising solution to cope with video traffic overload and multicast channel differences. To solve the challenge of delivering high‐definition SVC streaming over burst‐loss prone channels, we propose a social‐aware cooperative SVC streaming multicast scheme. The proposed scheme is the first attempt to enable D2D cooperation for SVC streaming multicast to conquer the burst‐loss, and one salient feature of it is that it takes fully into account the hierarchical encoding structure of SVC in scheduling cooperation. By using our scheme, users form groups to share video packets among each other to restore incomplete enhancement layers. Specifically, a cooperative group formation method is designed to stimulate effective cooperation, based on coalitional game theory; and an optimal D2D links scheduling scheme is devised to maximize the total decoded enhancement layers, based on potential game theory. Extensive simulations using real video traces corroborate that the proposed scheme leads to a significant gain on the received video quality.