Minimum QoS Requirements Research Articles

EleVMate — A data-driven approach for ‘on-the-fly’ horizontal small datacentre scalability and VM starvation

The volume of data exchanged over the network has increased exponentially over the past few years, driving the need for a new solution. To address this issue, a new layer for computation and storage between the cloud and the user has been introduced to reduce the load on the network. To facilitate this solution, small datacentres have emerged characterized by their limited capacity in terms of computation and storage resources. These datacentres are managed by small fog service providers (SFSPs) and are used to host virtual machines (VMs) with QoS requirements that vary based on application and user subscription. Being limited in capacity, these SFSPs are unable to accept all incoming VM requests, forcing them to reject some VM requests based on QoS requirements. This causes an issue for VMs with minimum QoS requirements as they are kept waiting for unlimited time causing them to starve. VM starvation in SFSPs is a critical issue that has not been addressed in the literature. To address this issue, in this paper, we propose to support the SFSP by horizontally scaling up its resources using volunteer nodes. We propose, EleVMate, a novel management framework to manage the allocation of VMs to the SFSP nodes. Our solution works to prioritize the placement of priority VMs in these datacentres. We validated the solution using a publicly available VM dataset and we concluded that priority influences VM placement in SFSP. Last, our framework has improved the performance of the SFSP by reducing rejection rate by at least 4% with existing solutions.

Hybrid Learning based Radio Resource Management in 5G Heterogeneous Networks

Ultradensification using different types of small cells (SCs) is one of the key enabling solutions to meet the multiple stringent requirements of 5G cellular networks. However, radio resource management (RRM) in ultra-dense heterogeneous networks (HetNets) is not easy due to interferences in multi-tiered architecture and dynamic network conditions. Interferences in 5G HetNets can be efficiently managed only through the techniques which are adaptive and self-organizing to handle dynamic conditions in 5G HetNets. In this article, a machine learning (ML) based self-adaptive resource allocation scheme is proposed based on the combination of independent and cooperative learning and evaluated for ultra-dense 5G HetNets. The proposed scheme aims to improve the QoS of all users associated with different network tiers in ultra-dense HetNets simultaneously. The proposed solution adaptively optimizes the SCs transmit power either through independent learning or cooperative learning based on the varying density of small cells to minimize the interferences and ensure minimum QoS requirements for all users in different network tiers. The proposed scheme not only maintains the minimum required capacities for QoS provision to all users simultaneously but has also shown a significant improvement in the capacities of users in different network tiers in high interference scenarios as compared to the use of a single learning scheme.

Evaluation of Primary User Power Impact for Joint Optimization of Energy Efficiency in Cognitive Radio Networks

Energy efficiency (EE) is of great concern in cognitive radio networks since the throughput and energy consumption of secondary users (SUs) vary with the sensing time. However, the conditions of the detection probability and false alarm probability should be respected to better protect primary users (PUs) and to improve the sensing performance of SUs. Additionally, the PUs’ minimum averaged power provision should also be regarded as a key problem of interactive linking to SUs. Therefore, an integrated design between the PU and SUs is desired for the coordination of the whole cognitive radio system, especially regarding the satisfaction of EE and performance metrics. This study formulates sensing constraints in a unified way and calculates the minimum SNR of SUs, based on which the essential PU power provision is computed. Furthermore, EE is proved as a decreasing function with the PU’s active ratio, where the maximum EE is obtained corresponding to the minimum QoS requirements of the sensing process. Hence, a bisection-based method is proposed to maximize EE, which is considered as a concave function of SUs’ sensing time and has only one unique optimum. EE’s optimization was analyzed under different fusion rules for diverse SNR conditions. The optimum was also studied with sensing performance targets for various cases of PU power provision.

Intelligent UAV Deployment for a Disaster-Resilient Wireless Network.

Deployment of unmanned aerial vehicles (UAVs) as aerial base stations (ABSs) has been considered to be a feasible solution to provide network coverage in scenarios where the conventional terrestrial network is overloaded or inaccessible due to an emergency situation. This article studies the problem of optimal placement of the UAVs as ABSs to enable network connectivity for the users in such a scenario. The main contributions of this work include a less complex approach to optimally position the UAVs and to assign user equipment (UE) to each ABS, such that the total spectral efficiency (TSE) of the network is maximized, while maintaining a minimum QoS requirement for the UEs. The main advantage of the proposed approach is that it only requires the knowledge of UE and ABS locations and statistical channel state information. The optimal 2-dimensional (2D) positions of the ABSs and the UE assignments are found using K-means clustering and a stable marriage approach, considering the characteristics of the air-to-ground propagation channels, the impact of co-channel interference from other ABSs, and the energy constraints of the ABSs. Two approaches are proposed to find the optimal altitudes of the ABSs, using search space constrained exhaustive search and particle swarm optimization (PSO). The numerical results show that the PSO-based approach results in higher TSE compared to the exhaustive search-based approach in dense networks, consuming similar amount of energy for ABS movements. Both approaches lead up to approximately 8-fold energy savings compared to ABS placement using naive exhaustive search.

Energy Saving Multicast Mechanism for Scalable Video Service Using Opportunistic Scheduling

In this paper, we focus on energy-efficient opportunistic multicast scheduling design method and user sleeping mechanism for the scalable video transmission in a wireless network. The goal is to minimize the total energy consumption for the terminal when receiving streaming video with bandwidth constraint and users' minimum QoS requirements. To utilize opportunistic multicast scheduling, unequal erasure protection (UXP) scheme is used for scalable video at the application layer. Considering the encoding characteristics and unequal protection scheme of scalable video, the UXP frame-level QoS is defined. And a low-complexity scheduling algorithm is proposed by transforming frame-level QoS requirement into slot-level QoS requirement within each time slot dynamically. Performance evaluations are firstly conducted for general data service with unlimited number of transmission rates, and then extended to scalable video service with limited number of transmission rates. Simulation results show that our proposed algorithm has less energy consumption of all the multicast users than the conventional scheduling schemes with the same users' QoS requirements guaranteed in both homogeneous and heterogeneous networks.

QaASs: QoS aware adaptive security scheme for video streaming in MANETs

Real-time video streaming is delay sensitive. It has minimum bandwidth and QoS requirements. Achieving target QoS for video streaming is challenging in a decentralized and self-organized MANET. Cryptography algorithms offer confidentiality of shared data, but they have computation cost. Our work addresses the issue of delay overhead caused by the introduction of cryptography that directly affects video streaming performance. Our proposal is motivated by the possibilities of adaptive security and multimedia service. We make an effort to identify why, when and how to deploy adaptation. We propose QaASs (QoS aware Adaptive Security scheme), an adaptive mechanism that counters the effect of delay overhead by adapting cryptography and multimedia properties, providing QoS while maintaining a required level of security. We evaluate our proposal through implementation and simulation.

Packet Scheduling and Admission Control for QoS Provisioning in Integrated IEEE 802.11e and IEEE 802.16 Mesh Mode

The IEEE 802.11e standard defines the HCF, which can improve the QoS support in 802.11 networks. On the other hand, the IEEE 802.16 is a metropolitan area technology, which can provide QoS per each connection. However, its mesh mode loosely supports QoS per each packet. These two techniques may be integrated to cover a typical urban area. This integration should be such that the minimum QoS requirements of traffic streams traversing the mesh structure of 802.16 can be provided. For this purpose, a new framework for integration of these two standards is presented in this research. It includes a scheduling algorithm and an admission control mechanism for uplink. As such, the minimum QoS requirements of traffic streams are provisioned by introducing a heuristic scheduling algorithm. Besides, an admission control procedure is used to provide fairness among the traffic types as well. The scheduling algorithm for downlink traffic is also provided. We evaluate this framework by simulating a compound network under different traffic conditions and investigate its performance against increasing the number of mobile terminals.

Heterogeneous wireless access technology and its impact on forming and maintaining friendship through mobile social networks

SUMMARYAdvances in wireless access technology have enabled mobile users to gain access to online social networks anywhere and any time. This paper investigates friendship formation in online social networks with the support of heterogeneous wireless access. A network‐aware friendship formation model is proposed that takes the network communication cost into account. A social network‐aware scheduling scheme is also proposed that schedules user data into a wireless access subsystem satisfying the minimum QoS requirements and with the lowest delivery cost. Simulation results have verified the proposed model and showed the effectiveness of the proposed scheduling mechanism. Copyright © 2011 John Wiley & Sons, Ltd.

Pricing in Noncooperative Interference Channels for Improved Energy Efficiency

We consider noncooperative energy-efficient resource allocation in the interference channel. Energy efficiency is achieved when each system pays a price proportional to its allocated transmit power. In noncooperative game-theoretic notation, the power allocation chosen by the systems corresponds to the Nash equilibrium. We study the existence and characterize the uniqueness of this equilibrium. Afterwards, pricing to achieve energy-efficiency is examined. We introduce an arbitrator who determines the prices that satisfy minimum QoS requirements and minimize total power consumption. This energy-efficient assignment problem is formulated and solved. We compare our setting to that without pricing with regard to energy-efficiency by simulation. It is observed that pricing in this distributed setting achieves higher energy-efficiency in different interference regimes.

Decentralized Utility Maximization in Heterogeneous Multicell Scenarios with Interference Limited and Orthogonal Air Interfaces

Overlapping coverage of multiple radio access technologies provides new multiple degrees of freedom for tuning the fairness-throughput tradeoff in heterogeneous communication systems through proper resource allocation. This paper treats the problem of resource allocation in terms of optimum air interface and cell selection in cellular multi-air interface scenarios. We find a close to optimum allocation for a given set of voice users with minimum QoS requirements and a set of best-effort users which guarantees service for the voice users and maximizes the sum utility of the best-effort users. Our model applies to arbitrary heterogeneous scenarios where the air interfaces belong to the class of interference limited systems like UMTS or to a class with orthogonal resource assignment such as TDMA-based GSM or WLAN. We present a convex formulation of the problem and by using structural properties thereof deduce two algorithms for static and dynamic scenarios, respectively. Both procedures rely on simple information exchange protocols and can be operated in a completely decentralized way. The performance of the dynamic algorithm is then evaluated for a heterogeneous UMTS/GSM scenario showing high-performance gains in comparison to standard load-balancing solutions.

Energy optimization in wireless broadcasting through power control

We consider the problem of optimally controlling transmission power in a time-slotted wireless broadcast network. Fixed-length packets and AWGN channels are considered, and a simple ARQ scheme (Send-and-Wait) is used for error control. Packets are retransmitted until a minimum QoS requirement is met for each packet. Transmission powers are chosen from a finite set depending on the number of nodes that have received the packet successfully. The goal is to minimize the total energy expended for each successful packet transmission. The system is studied when the transmitter chooses between two distinct powers, and the results are then extended to multiple powers. It is observed that the optimal policy is always of the separation type. Also, the effect of varying the QoS requirement on the energy and service time is studied.

Interoperability criteria, mechanisms, and evaluation of system performance for transparently interoperating WLAN and UMTS-HSDPA networks

The main challenge in the development of future wireless communication systems is to provide users with a wide range of services across different radio access technologies through a single mobile terminal, while maintaining the minimum QoS requirements, and ideally with no limits on the coverage area, mobility or radio conditions. Thus, the need for seamless interworking between heterogeneous wireless communication systems consisting of multiple radio access technologies and overlapping networks emerges. In this article we address the main issues that arise while implementing the interoperability mechanisms between two different radio access networks, with emphasis on UMTS-HSDPA and WLAN (HIPERLAN/2). Two interoperability mechanisms are introduced and described in detail: initial user assignment (optimal network selection) and intersystem handover. Both mechanisms are activated via the optimization of a suitably defined cost function which takes into account all the appropriate system level parameters that trigger the interoperability process. Finally, we investigate the overall performance of the proposed mechanisms by means of a software simulation platform. A number of simulations have been carried out in order to demonstrate the performance enhancements achieved by the proposed mechanisms in terms of unsatisfied users, dropped handovers, and system throughput.

Unlocking the Advantages of Dynamic Service Selection and Pricing

Bandwidth limitations, resource greedy applications verbose mark-up languages and an increasing number of voice and data users are straining the air interface of wireless networks. Hence, novel approaches and new algorithms to manage wireless bandwidth are needed. In addition, usage based pricing is becoming increasingly prevalent (pre-paid cell phones, calling cards, non-contract minutes, etc.). This paper unlocks the potential to improving the performance of overall system behavior by allowing users to change service level and/or service provider for a (small) price. The ability to dynamically re-negotiate service gives the user the power to control QoS while minimizing usage cost. On the other hand, the ability to change service level pricing dynamically allows the service providers to manage traffic better, improve resource usage and most importantly maximize their profit. This provides a surprising win-win situation for BOTH the service providers AND the users. In this paper we present easy to implement on-line algorithms to minimize the overall usage cost to individual mobile users. This on-line algorithm continuously receives pricing information and evaluates minimum QoS requirements. The algorithm then determines appropriate service level, chooses a service provider and sets a time for re-negotiation dynamically. Our algorithm can handle many practical issues such as capacity limitations, arbitrary price fluctuations and loss/gain of service providers due to mobility. Our results do not assume any specific technologies and can be applied to any environment that can employ dynamic pricing, including wired networks. In fact, dynamic pricing is becoming increasingly desirable since service provider and capacity changes are a growing by-product of mobility. Arriving and departing users at/from a cell tower (or wireless LAN) can effectively reduce or increase the available bandwidth in a cell (or LAN transmission area) and represents a natural opportunity for a pricing change.

Evaluation of Interoperability Criteria and Mechanisms for Seamless Inter-Working Between UMTS-HSDPA and WLAN Networks Enhanced with MIMO Techniques

This article proposes criteria and mechanisms that achieve seamless inter-working between the multi-radio access technologies that will compose the fourth-generation (4G) wireless mobile environment. We address the problem of incorporating system interoperability in order to provide the user with seamless mobility across different radio access technologiess namely we focus on inter-working UMTS-High Speed Downlink Packet Access (HSDPA) and WLAN networks, as these two networks are believed to be major components of the 4G wireless network. Interoperability results in providing the user with a rich range of services across a wide range of propagation environment and mobility conditions, using a single terminal. Specifically, the article aims at defining the criteria and mechanisms for interoperability between the two networks. Our approach considers the use of Cost functions to monitor the essential parameters at the system level in order to trigger an interoperability procedure. Initial user assignment and inter-system handover are considered the incidents that initiate the interoperability algorithm execution. The overall objective of this work is to assess the performance of our developed interoperability platform and to optimize system performance by guarantying a minimum QoS requirement and maximizing network capacity.

Determining the call admission region for real-time heterogeneous applications in wireless TDMA networks

The call admission problem for a wireless packet-switched network supporting homogeneous applications-such as a cellular voice network-is an old one and has been extensively investigated in the past. The article investigates the call admission region for a TDMA (wireless) system supporting heterogeneous real-time VBR applications with distinct QoS requirements and traffic characteristics. The QoS is defined in terms of a maximum tolerable packet delay and dropping probability; packets may be dropped due to delay violations or channel-induced errors. The call acceptance region is investigated under the assumption that each user's per-frame resource (slot) requests are communicated to the scheduler (resource allocation authority). The call acceptance region is shaped by the QoS that can be delivered by the uplink scheduling policy. Some of the mechanisms employed to inform the scheduler of the users' requests along with the scheduling policies are discussed. While these scheduling policies identify QoS points in the call admission region, they cannot reveal the entire region. An approach is outlined on how to precisely determine the call admission region (largest set of QoS points delivered under any scheduling policy) for a TDMA system. This approach is shown to lead to the precise description of the reduced call admission region in the presence of channel errors. In order to demonstrate the performance improvement provided by an error control scheme, a simple QoS-sensitive forward error control protocol operating over on erroneous channel is employed, leading to an enlargement of the calculated call admission region. Finally, it is shown that feasible scheduling policies exist which do deliver at least the minimum QoS requirement of the applications whose associated QoS vector falls within the determined call admission region.