Multicasting in Heterogeneous Networks

Mobile devices, such as smart phones and tablet PCs, are becoming ubiquitous; it is increasingly popular for users to watch online streaming videos from their mobile devices. Because of the nature of wireless transmission, wireless routers (such as access points or base stations), they can get video transmissions from the video server and then send leads to several interested customers. In these videos, however, customers can be placed in different positions, and therefore they can deal with different wireless channels. In addition, customers may be interested in different video content, so different videos may have some popularity. Wireless heterogeneity and user interests make it difficult to break the bandwidth of wireless router video multicast. In this article, we propose a Utility-Based LayerEncoded Multicast Scheme, based on an instrument that takes into account the characteristics of the channels and heterogeneous users. The proposed approach that takes into account interests can improve the average visual quality to 9 db.

A Range-Division User Relay Selection Scheme and Performance Analysis in NOMA-based Cooperative Opportunistic Multicast Systems

The original user relay (UR) selection scheme of non-orthogonal multiple access-based cooperative opportunistic multicast scheme, which realizes inter-group cooperation between two multicast groups, ignores the distribution trend of candidate UR in the cell and adopts fixed efficient relay selection range (ERSR) to select UR. It results in high UR selection ratio. Then the coverage efficiency, defined as the ratio of successfully received users to URs, is low. To tackle this problem, a range-division user relay (RDUR) selection scheme is proposed in this paper. Firstly, it divides the circular coverage range of base station into several continuous annular areas (AAs). Secondly, different ERSRs are assigned to unsuccessfully received users in different AAs. Under different ERSR assignments, the performances of UR selection ratio and coverage ratio are analyzed. Lastly, the radius set of ERSR that optimizes system coverage efficiency is used to perform UR selection. From simulation results, with different radius sets, analytical results of UR selection ratio and coverage ratio match well with their simulated ones. It is proved that ERSR allocation affects UR selection ratio and coverage ratio. With RDUR scheme, coverage efficiency increases by at least 14% and capacity efficiency has also been improved.

A Novel Multicast Scheme with Grooming for Quality of Service (QoS) Provision and Resource Optimization over Optical Label Switching (OLS) Networks

Optical label switching is proposed for providing fast all-optical switching, covering all granularities transfer and assuring quality of service support. However, the important issue is improving optical resource and providing a steadiness between satisfying traffic demands and reducing resource utilization. This paper proposes a novel multicast approach which enables grooming using an upgraded core node architecture that switches suitably unicast and multicast connections. The proposed node architecture manages appropriately all optical resource including a fiber delay line and wavelength bandwidth, as well as traffic requirements. A new label framework is introduced to assure the required information exchange for handling suitably real-time traffic constraints and optical resource status. Moreover, innovative signaling and switching schemes are introduced to perform suitably lightpath and traffic constraints supervision. Theoretical model and simulation experiments are conducted for validating the proposed scheme and evaluating its performances and effectiveness. Finally, the proposal guarantees traffic requirements and reduces resource usage while improving resource availability.

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.