Individual Quality Of Service Requirements Research Articles

User Scheduling and Power Allocation for Precoded Multi-Beam High Throughput Satellite Systems With Individual Quality of Service Constraints

For extensive coverage areas, multi-beam high throughput satellite (HTS) communication is a promising technology that plays a crucial role in delivering broadband services to many users with diverse Quality of Service (QoS) requirements. This article focuses on multi-beam HTS systems where all beams reuse the same spectrum. In particular, we propose a novel user scheduling and power allocation design capable of providing guarantees in terms of the individual QoS requirements while maximizing the system throughput under a limited power budget. Precoding is employed in the forward link to mitigate mutual interference among the users in multiple-access scenarios over different coherence time intervals. The combinatorial optimization structure from user scheduling requires an extremely high cost to obtain the global optimum even when a reduced number of users fit into a time slot. Therefore, we propose a heuristic algorithm yielding a good trade-off between performance and computational complexity, applicable to a static operation framework of geostationary (GEO) satellite networks. Although the power allocation optimization is signomial programming, non-convex on a standard form, the solution can be lower bounded by the global optimum of a geometric program with a hidden convex structure. A local solution to the joint user scheduling and power allocation problem is consequently obtained by a successive optimization approach. Numerical results demonstrate the effectiveness of our algorithms on GEO satellite networks by providing better QoS satisfaction combined with outstanding overall system throughput.

Quality ensured non‐orthogonal multiple access based downlink scalable video coding multicasting over cognitive radio network

AbstractThe combination of the cognitive radio network (CRN) and non‐orthogonal multiple access (NOMA) technologies for scalable video coding (SVC) can be considered as a promising approach for quality‐driven video transmission over a fifth‐generation (5G) network. Advanced techniques such as efficient channel allocation, advanced sensing strategy, and optimum power allocation can combinedly improve the overall system performance. In this context, we propose an intergroup content‐aware proportionate channel allocation policy, sensing time optimization strategy and quality of service (QoS) ensured intragroup power allocation scheme for downlink SVC multicasting over CRN using NOMA technology to enhance the quality of experience (QoE) of secondary users (SUs). We propose an optimum power allocation strategy for different NOMA layers to maximize the weighted sum rate of different SVC groups ensuring the individual QoS requirements. Although the power allocation problem seems to be nonconvex, however, it can be transformed into a convex function under some specific conditions which are discussed in this article. Extensive simulation reveals that our proposed power allocation scheme for NOMA with QoS constraint outperforms the other two conventional schemes, that is, NOMA fixed power allocation and NOMA without QoS constraint in terms of average weighted sum rate and average QoE of SUs.

A novel multi‐quality of service system design: Integration of hybrid free space optical/RF, cognitive hybrid and free space optical links

AbstractThe proposed system design presents a novel configuration that is created by the integration of several standalone free space optical (FSO) links, a hybrid FSO/RF and some cognitive or pseudo hybrid links. The objective is to allow different quality‐of‐service (QoS) links within a system as a whole. In addition to individual QoS requirements, a constraint on the overall system QoS, in the form of minimum system outage, is also ensured. The design methodology aims at identifying the optimal number of standalone FSOs and cognitive hybrid links which can be supported by a single hybrid FSO/RF link. Atmospheric turbulence and pointing errors are considered for the analysis. Simulation results are used to corroborate the analytical findings.

Analog Transmission of Correlated Sources Over BC With Distortion Balancing

Analog transmission of correlated information over Gaussian broadcast channels (BCs) using analog joint source–channel coding (JSCC) is addressed. This communication strategy has attractive advantages, such as low complexity, minimal delay, graceful degradation, and adaptation to time-varying environments. In this paper, we focus on the optimization of parametric continuous mappings that satisfy individual quality of service requirements over Gaussian BCs. This optimization is based on the balancing of the user distortions to ensure the feasibility of the resulting optimization problems. An analysis of the overall distortion corresponding to the considered mappings is carried out to design algorithms that determine the optimal values for the mappings parameters. Results show that the proposed analog JSCC scheme provides near optimal performance and an adequate balancing of the individual distortions.

Uplink Scheduler for SC-FDMA-Based Heterogeneous Traffic Networks With QoS Assurance and Guaranteed Resource Utilization

Assuring quality-of-service (QoS) and guaranteeing effective utilization of resources in a network with heterogeneous traffic is difficult due to the conflicting requirements associated with the different types of traffic. Nevertheless, emerging high-bandwidth third/fourth-generation (3G/4G) technologies, such as Long-Term Evolution (LTE) and LTE-Advanced, are expected to meet the demands of new applications by providing high data rates while simultaneously satisfying each of the individual QoS criteria. The relevant standards recommend single-carrier frequency-division multiple access (SC-FDMA) as the preferred uplink transmission scheme. In this paper, we have formulated the uplink scheduling problem for SC-FDMA-based heterogeneous traffic systems considering both standard specific constraints and individual user QoS requirements. To capture the QoS requirements of different types of traffic, we adopt a utility function that is already used for the downlink operation of code-division multiple-access (CDMA)-based systems. We also consider an opportunity cost function that is based on granular resource utilization to increase the usefulness of our results in practical situations. We have used the dual decomposition method to solve the resulting problem. Given the high computational complexity of the optimal solution, we have also proposed a suboptimal algorithm that is less complex but which offers acceptable performance. In our evaluation of the performance of our proposed uplink scheduling scheme, we assume that the offered traffic is a combination of best effort traffic, traffic with specified delay bounds, and traffic with specified throughput requirements. An extensive set of simulation results demonstrate the efficacy and effectiveness of our scheme compared with existing solutions employed by LTE, which is a representative SC-FDMA-based system.

Achieving high robustness and performance in QoS-aware route planning for IPTV networks

Quality of Service (QoS)-aware network planning in internet protocol television (IPTV) networks becomes increasingly important for network operators and Internet Service Providers (ISP) alike as different components of IPTV traffic have different and stringent QoS requirements. Proposing a routing algorithm to meet individual QoS parameters is a tedious task, since providing guarantee of meeting individual parameters in a stochastic system is impossible. Therefore, we propose optimum allocation of bandwidth where bandwidth requirements are evaluated based on accurate empirical effective bandwidth estimation for different classes of traffic by simulating a path as a First-in–First-out (FIFO) queue [2], whereby meeting the individual QoS requirements of each class of traffic. The route planning problem was formulated as a residual bandwidth optimization problem and solved using Genetic Algorithm–Variable Neighborhood Search (GA–VNS) hybrid algorithm. Although the standard evolutionary algorithms do not perform well on constrained optimization problems [4], GA–VNS was found to perform well on this particular problem [9]. This paper proposes new and novel adjustments and parameter settings to best suit the problem in terms of robustness and performance. The use of dynamically switching between two cost functions to meet the above requirements, the reduction of the difficulty of the problem in the initial generations to find a feasible solution and the use of a variation of the original VNS algorithm, besides the use of specific operators and general parameter settings are some of the recommendations of this paper. The proposed recommendations are based on extensive experiments on the performance and analysis carried out on different network topologies including Abilene topology. The proposed algorithm performed better than the recently proposed specialized constrained handling algorithms proposed in the literature, i.e. problem specific solutions are more desirable than black-box optimization for this problem. The proposed route planning mechanism was also found to produce good results even under dynamic traffic conditions.

Joint Load Balancing of Radio and Transport Networks in the LTE Systems

Load Balancing (LB) is an important mechanism often used in the cellular networks to offload the excessive traffic from high-load cells (hot spots) to low-load cells. Extensive studies have shown that the system level performance with LB can be greatly enhanced in terms of e.g. higher overall system throughput, lower user blocking ratio and better QoS (Quality of Service) for the users at the cell boundaries. However, so far the conventional LB solutions are mainly focusing on Radio Networks (RN), and little consideration of the impact from Transport Networks (TN) has been taken into account in the LB mechanisms. This paper proposes a joint load balancing framework for the Long Term Evolution system. The proposed LB takes into consideration the joint impact of RN and TN by combining the network-wide utilities to achieve overall network optimizations. In this paper, we suggest different utilities for GBR and nGBR service categories. For each service category, the proposed utilities consider multiple QoS classes with different services (e.g. VoIP, video and FTP) and aim to guarantee their individual QoS requirements. The presented numeric results show that the proposed mechanism can outperform the conventional RN-only LB, especially for the situation that the TN last mile link is the bottleneck and its deploy-ment is heterogeneous.

Wireless intelligent ATM network and protocol design for future personal communication systems

This paper presents the wireless intelligent ATM (WIATM) network, designed to provide wireless broadband integrated services. The WIATM network takes advantage of the ATM-cell relay paradigm for integrated services through a radio link with quality of service (QoS) guarantee. The design of the WIATM network architecture is an independent wireless network, which is consistent with the inherent cellular/PCS network architecture, as a wireless customer premises equipment/network (CPE/CPN) to access the ATM transport network in the B-ISDN infrastructure. An independent network architecture design separates the wireless access network from the ATM backbone network; this provides flexibility for wireless resource management with low rate source codecs with minimal tolerable QoS considered to increase the spectral efficiency, and mobility support by taking advantage of the functionalities of the IS-41 circuit-switching handoff procedures. The protocol design of the air interface is to meet the QoS requirements of wireless B-ISDN services and to be compatible with that of B-ISDN UNI. A hybrid concatenated error control scheme distributed through the protocol layers is used to target individual QoS requirements of different services. The convolutional coding and interleaving in the wireless physical layer protocol are used to guarantee QoS of voice services. A concatenated coding with additional 36 bit BCH code in the wireless ATM layer, which replaces the VCI/VPI of the ATM header field, improves the QoS up to the requirement of video services. The VCI/VPI field in WIATM is an overlapped routing information routing with the address control by radio port controller, and is thus not needed in the wireless ATM layer protocol. The retransmission scheme for data service only is added in the wireless data link layer, which is on top of wireless AAL, to meet its QoS requirement. Examples of signaling flows for call registration, call setup, and supporting handoff are shown in the design of the wireless network layer protocol. The AIN (advance intelligent network) signaling functionalities are considered for multimedia service control in the access network and interconnection to the ATM network. A parent-child creative basic call state model (BCSM) for wireless integrated services is introduced in both call origination and termination.

Resource management in wide-area ATM networks using effective bandwidths

This paper is principally concerned with resource allocation for connections tolerating statistical quality of service (QoS) guarantees in a public wide-area ATM network. Our aim is to sketch a framework, based on effective bandwidths, for call admission schemes that are sensitive to individual QoS requirements and account for statistical multiplexing. Results approximating the effective bandwidth required by heterogeneous streams sharing buffered links, including results for the packetized generalized processor sharing service discipline, are described. Extensions to networks follow via the concept of decoupling bandwidths, motivated by a study of the input-output properties of queues. Based on these results we claim that networks with sufficient routing diversity will inherently satisfy nodal decoupling. We then discuss on-line methods for estimating the effective bandwidth of connection. Using this type of traffic monitoring we propose an approach to usage parameter control (i.e., policing) for effective bandwidth descriptors. Finally, we suggest how on-line monitoring might be combined with admission control to exploit unknown statistical multiplexing gains and thus increase utilization. >