Multicast Content Delivery Research Articles

Towards efficient device-to-device multicast content delivery with social awareness

Frequent content retrieval leads to significant energy consumption in cellular networks. Thereby, device-to-device (D2D) communication is used for proximal content delivery. Be aware that social friends may have common content interests, D2D content delivery is further improved by considering social network. However, how to implement efficient D2D multicast with the aid of social relationship needs further consideration. In this paper, with a proposed architecture on combined networks, the cooperation range of content sharing is investigated for D2D multicast to minimize the average energy consumption of serving a content request. Based on combined networks, a cooperation group formation scheme is proposed. Simulation results verify our analyzes and the advantage of proposed scheme.

A Capacitated House Allocation Game for the Energy Efficient Relays Selection in 5G Multicast Context.

The upcoming fifth generation (5G) wireless networks making use of higher-frequency spectrum bands suffer from serious propagation issues due to high path loss and beam directivity requirements. This promotes the device-to-device communications to boost the transmission reliability at the network edges, providing remarkable benefits in terms of the energy and spectrum efficiency, essential for a wide class of sensors networks and Internet-of-Things. More in general, applications where devices are usually constrained in computational and transmission range capabilities. In such a context, the selection of the proper number of devices arranged as a relay plays a crucial role. Towards this goal, this paper proposes an efficient relay selection scheme minimizing both the delivery transmission delay and the overall energy consumption, i.e., the overall number of relays to be used. By focusing on a multicast content delivery application scenario the problem of interest is formulated as a one-sided preferences matching game. In addition, the strategy designed takes into account specific information, named reputation coefficient, associated to each device jointly with link propagation conditions for allowing the selection of suitable relays for disseminating the content among the devices. The effectiveness of the proposed solution is underpinned by computer simulations, and the performance is evaluated in terms of power consumption, end-to-end delay, and number of selected relays. As confirmed by results, the proposed approach improves network performance compared to the greedy approach, the random algorithm, a scheme previously proposed in literature, and with two game theory-based strategies.

User-Information-Aware D2D Multicast File Distribution Mechanism.

There are a large number of redundant transmissions in current D2D multicast content delivery systems, which seriously reduces the utilization efficiency of resources. This paper designs a novel user-information-aware D2D video distribution mechanism. More specifically, by predicting users’ video requests, the video can be pushed to potential service requesters while distributing video for service requesters. Firstly, the willingness of potential requesters to accept the pushed video is estimated based on the users’ interests, the popularity of the videos and the residual-energy of the users’ devices, and the user-demand-aware clustering algorithm is proposed. Secondly, considering social and interference information, the utility metric of D2D multicast is proposed to measure the value of content distribution service. Finally, this paper proposes a D2D video distribution mechanism to optimize the utility value. Simulation results show that the proposed mechanism significantly improves throughput, energy and spectrum efficiency compared to the traditional distribution mechanism.

Group Communications in Narrowband-IoT: Architecture, Procedures, and Evaluation

Narrowband-Internet of Things (NB-IoT) has been released by 3GPP to provide extended coverage and low energy consumption for low-cost machine-type devices. Requiring only a reasonably low-cost hardware update to the already deployed long term evolution base stations and being compatible with current core network and enhanced core solutions that aim to reduce the battery consumption and minimize the signaling, NB-IoT deployments are quickly increasing, making NB-IoT a dominating technology for low-power wide area networks. To this aim, in this paper, we focus on group communications (i.e., multicast) in NB-IoT to efficiently support the transmission of firmware, software, task updates, or commands toward a large set of devices. We discuss the architectural and procedural enhancements needed to support the unique features of group communications in machine-type environments, such as customer-driven group formation. We also extend the NB-IoT frame to include a channel for multicast transmissions. Finally, we propose two transmission strategies for multicast content delivery and evaluate their performance considering the impact on the downlink background traffic and the channel occupancy.

Coding, Multicast, and Cooperation for Cache- Enabled Heterogeneous Small Cell Networks

Caching at the wireless edge is a promising approach to dealing with massive content delivery in heterogeneous wireless networks, which have high demands on backhaul. In this paper, a typical cache-enabled small cell network under heterogeneous file and network settings is considered using maximum distance separable (MDS) codes for content restructuring. Unlike those in the literature considering online settings with the assumption of perfect user request information, we estimate the joint user requests using the file popularity information and aim to minimize the long-term average backhaul load for fetching content from external storage subject to the overall cache capacity constraint by optimizing the content placement in all the cells jointly. Both multicast-aware caching and cooperative caching schemes with optimal content placement are proposed. In order to combine the advantages of multicast content delivery and cooperative content sharing, a compound caching technique, which is referred to as multicast-aware cooperative caching, is then developed. For this technique, a greedy approach and a multicast-aware in-cluster cooperative approach are proposed for the small-scale networks and large-scale networks, respectively. Mathematical analysis and simulation results are presented to illustrate the advantages of MDS codes, multicast, and cooperation in terms of reducing the backhaul requirements for cache-enabled small cell networks.

Optimizing Cache Placement for Heterogeneous Small Cell Networks

In this letter, we study the optimization for cache content placement to minimize the backhaul load subject to cache capacity constraints for caching enabled small cell networks with heterogeneous file and cache sizes. Multicast content delivery is adopted to reduce the backhaul rate exploiting the independence among maximum distance separable coded packets.

Bandwidth and Cache Leasing in Wireless Information Centric Networks: a Game Theoretic Study

Information-centric networking (ICN) is a novel paradigm that aims at improving the performance of today's Internet by supporting caching and multicast content delivery on every network device. The main contribution of this paper is to propose a centralized strategy to stimulate third parties to jointly lease the unused bandwidth and storage available on wireless access points (APs) in an ICN. We formulate this problem as a combinatorial reverse auction run by a content provider (CP) willing to increase the number of users reached by its service. We show that the optimal allocation with partial coverage problem is NP-hard, provide greedy heuristics that guarantee the individual rationality and truthfulness properties, and compare their performance numerically. We evaluate the benefits of our proposed mechanisms in terms of the cost savings for the CP obtained by offloading its infrastructure through the caches and the reduced computational time to execute the allocation algorithms. We compare the results obtained in this centralized setting with those that can be observed when the mobile clients autonomously choose which AP they prefer to use, among those activated by the auction mechanism. We model this second scenario as a congestion game, showing that it exhibits the desired properties (i.e., existence and uniqueness of a Nash equilibrium) and by comparing its social welfare with the centralized case.

Algorithms for stochastic optimization of multicast content delivery with network coding

The usage of network resources by content providers is commonly governed by Service-Level Agreements (SLA) between the content provider and the network service provider. Resource usage exceeding the limits specified in the SLA incurs the content provider additional charges, usually at a higher cost. Hence, the content provider's goal is to provision adequate resources in the SLA based on forecasts of future demand. We study capacity purchasing strategies when the content provider employs network coded multicast as the media delivery mechanism, with uncertainty in its future customer set explicitly taken into consideration. The latter requires the content provider to make capacity provisioning decisions based on market predictions and historical customer usage patterns. The probabilistic element suggests a stochastic optimization approach. We model this problem as a two-stage stochastic optimization problem with recourse. Such optimizations are #P-hard to solve directly, and we design two approximation algorithms for them. The first is a heuristic algorithm that exploits properties unique to network coding, so that only polynomial-time operations are needed. It performs well in general scenarios, but the gap from the optimal solution is not bounded by any constant in the worst case. This motivates our second approach, a sampling algorithm partly inspired from the work of Gupta et al. [2004a]. We employ techniques from duality theory in linear optimization to prove that the sampling algorithm provides a 3-approximation to the stochastic multicast problem. We conduct extensive simulations to illustrate the efficacy of both algorithms, and show that the performance of both is usually within 10% of the optimal solution in practice.

Efficient IP-Based TV Service Over UMTS Networks

The problem of providing an efficient and low-cost video streaming service over wireless access networks is considered in this work. In order to tackle the "last mile" bottleneck for video delivery to the home, we propose a content-aware architecture, that incorporates popularity-dependent video patching with application-enabled multicast content delivery. The key idea is to exploit the Broadcast/Multicast Service Center (BM-SC) in Universal Mobile Telecommunications System (UMTS) networks, by forwarding individual requests for popular data to the BM-SC, and then to serve these requests efficiently by multicast content distribution. The proposed method offers a tremendous bandwidth saving, in comparison with the MAC-enabled multicasting currently exists in wireless networks. We analyze the conditions under which multicast content delivery offers a better QoS, in terms of service delay, over the individual service currently used for video streaming.

A Collaborative Wireless Access to On‐Demand Services

A collaborative access scheme that exploits the broadcast nature of the wireless communication in order to achieve multicast content delivery is presented in this paper. The key idea is that individual clients requesting for the same content can collaborate and share the same data channel. As opposed to broadcasting, this method enables the clients to determine online the delivered content, and thus supports on‐demand services. On the other hand, a multicast content delivery is much more efficient than a unicast content distribution, which must use a dedicated data channel per each and every client. This method is particularly suitable for sessions having a long‐time duration, for applications in which clients can subscribe to ahead of time, and for applications in which the clients receive the same information simultaneously. A multicast content distribution increases the network service throughput in terms of the expected number of clients served simultaneously, and therefore it offers a reduced waiting time for content delivery at highly loaded time periods. It is shown that the problem of maximizing the efficiency of distributing a content in a wireless network is NP‐hard. An approximation algorithm is therefore used, that for any 0 < ε < 1 finds an approximation solution with a relative accuracy ε. The proposed method does not require any hardware modification on the network equipment. Thus, it can be easily implemented.