Hopfield neural‐network‐based dynamic resource allocation scheme for non‐real‐time traffic in wireless networks

Dynamic resource allocation (DRA) plays a fundamental role in current and future wireless networks, including 3G systems. In this paper, a scheduling DRA scheme for non‐real‐time (NRT) packet services in wireless system is proposed based on the use of Hopfield neural networks (HNN). The scheme exploits the fast response time of HNN for solving NP optimization problems and has been particularized for the downlink transmission in a UMTS system, although it could be easily extended to any other radio access technology. The new DRA scheme follows a delay‐centric approach, since it maximizes the overall system resource utilization while minimizing the packet delay. Simulation results confirm that the proposed HNN‐based DRA scheme is effective in supporting different types of NRT services, while achieving efficient utilization of radio resources. Copyright © 2008 John Wiley & Sons, Ltd.     

A Cross-Layer Packet Scheduling Scheme for Multimedia Broadcasting via Satellite Digital Multimedia Broadcasting System [Advances in Mobile Multimedia]

In recent years, multimedia content broadcasting via satellite has attracted increased attention. The satellite digital multimedia broadcasting (S-DMB) system has emerged as one of the most promising alternatives for the efficient delivery of multimedia broadcast multicast service (MBMS). The design of an efficient radio resource management (RRM) strategy, especially the packet scheduling scheme, becomes a key technique for provisioning multimedia services at required quality of service (QoS) in S-DMB. In this article, we propose a novel cross-layer packet scheduling scheme that consists of a combined delay and rate differentiation (CDRD) service prioritization algorithm and a dynamic rate matching (DRM)-based resource allocation algorithm. The proposed scheme considers multiple key factors that span from the application layer to the physical layer, aiming at simultaneously guaranteeing diverse QoS while utilizing radio resources efficiently under the system power and resource constraints. Simulation results demonstrate that the proposed cross-layer scheme achieves significantly better performance than existing schemes in queuing delay, jitter, and channel utilization.     

A new satellite communication bandwidth allocation combined services model and network performance optimization

With the rapid development of online to offline economy, new services compositions would take up a great part in the satellite communication. More and more new services compositions request more bandwidth and network resources, which lead to serious traffic congestion and low channel utilization. Suffering from isolated link connection and changeable delay under the satellite environment, current bandwidth allocation schemes could not satisfy with the demand of low delay and high assess rate for new satellite services. This paper focuses on bandwidth allocation method for satellite communication services compositions. The novel models of services compositions with single‐hop Poisson distribution are designed to simulate original traffic arrival. Isolated independent coefficients take an original distribution to adapt to isolated disconnections. Services queue waiting time would be judged by acceptable delay threshold. Models provide new services compositions with more precise arrival distributions. In order to improve traffic congestion, the method combined services models, and a network performance is proposed. Optimal reserved bandwidth is set according to the priority and arrival distribution of different services compositions, which classify services with feedback transmission performance. We design minimum fuzzy delay tolerant intervals to calculate delay tolerant threshold, which adapt random delay changes in the services network with delay tolerant features. The simulation in OPNET demonstrates that the proposed method has a better performance of queuing delay by 16.3%, end‐to‐end delay by 18.7%, and bandwidth utilization by 13.2%. Copyright © 2016 John Wiley & Sons, Ltd.     

下一代通信网络中基于策略机制的无线资源管理

下一代无线通信系统是一种异构的网络体系，集成多种无线接入技术（Radio Access Technology，RAT）的同时提供多种窄带和宽带多媒体业务。这样的网络环境需要先进的RRM方法来处理复杂多变的无线信道、网络资源的动态配置及保障不同特征业务的服务质量（QoS），给无线资源管理（Radio Resource Management，RRM）带来了巨大的技术挑战。本文通过引入对网络进行策略控制的思想，提出了一种基于策略机制的通用方法，致力于解决下一代异构（heterogeneous）网络中的无线资源管理。文中着重讨论了基于策略机制的网络接入控制、切换，以及基于策略机制的QoS管理，给出了各功能模块的工作原理和通信过程的分析与设计。     

Rain granularity effects on bandwidth demand for faded DVB‐RCS systems

Broadband satellite communication networks, operating at Ka band and above, play a vital role in today's worldwide telecommunication infrastructure. The problem, however, is that rain can be the most dominant impairment factor for radio propagation above 10 GHz. This paper studies bandwidth and time slot allocation problem for rain faded DVB‐RCS satellite networks. We investigate how using finer rain granularity can improve bandwidth utilization in DVB‐RCS return links. The paper presents a mathematical model to calculate the bandwidth on demand. We formulate the radio resource allocation as an optimization problem and propose a novel algorithm for dynamic carrier bandwidth and time slots allocation, which works with constant bit rate type of traffic. We provide theoretical analysis for the time slot allocation problem and show that the proposed algorithm achieves optimal results. The algorithm is evaluated using a MATLAB simulation with historical rain data for the UK. Copyright © 2014 John Wiley & Sons, Ltd.     

Next-generation wireless communications concepts and technologies

Next-generation wireless (NextG) involves the concept that the next generation of wireless communications will be a major move toward ubiquitous wireless communications systems and seamless high-quality wireless services. This article presents the concepts and technologies involved, including possible innovations in architectures, spectrum allocation, and utilization, in radio communications, networks, and services and applications. These include dynamic and adaptive systems and technologies that provide a new paradigm for spectrum assignment and management, smart resource management, dynamic and fast adaptive multilayer approaches, smart radio, and adaptive networking. Technologies involving adaptive and highly efficient modulation, coding, multiple access, media access, network organization, and networking that can provide ultraconnectivity at high data rates with effective QoS for Next Gare are also described     

Integrated Services on High Altitude Platform: Receiver Driven Smart Selection of HAP-Geo Satellite Wireless Access Segment and Performance Evaluation

A renewed interest in the development of high-altitude platforms (HAPs), which are stratospheric aircraft or airship carrying payloads tailored for a wide range of applications in telecommunications and remote sensing, is becoming progressively widespread. HAPs offer a reduced propagation delay and they are especially suitable for interactive multimedia services. In this paper, the inter-working between HAP and satellite segments in an integrated QoS architecture has been addressed. A new way to manage integrated services over a new hybrid wireless platform has been proposed. A smart terminal device has been considered in order to perform an intelligent switching on the wireless access segment. The switching criteria applied in the HAP/satellite architecture is based on the available bandwidth and on the admissible data packet end-to-end delay. Performance evaluations of the integrated HAP–satellite platform have been evaluated in terms of bandwidth utilization and number of admitted calls. The simulations show an improvement of admitted calls, reduced data packet end-to-end delay and increased bandwidth utilization.     

A Cross-Layer Delay Differentiation Packet Scheduling Scheme for Multimedia Content Delivery in 3G Satellite Multimedia Systems

The design of efficient packet scheduling algorithms, which play a key role in the radio resource management (RRM), is crucial for the multimedia delivery in the satellite digital multimedia broadcasting (SDMB) system. In this paper, a novel packet scheduling scheme, which uses the cross-layer approach in its design, is proposed. This scheme comprises a new service prioritization algorithm and a dynamic rate matching based resource allocation algorithm, aimed at utilizing both the applications' QoS attributes and the physical layer data rate information. The performance of the proposed scheme has been evaluated via simulation. In comparison with existing schemes, the proposed scheme achieves significant performance gain on delay, delay variation and physical channel utilization.      

B3G系统中一种新的无线资源分配策略

如何合理地利用有限的无线资源,保证链路里传输的各种业务的QoS,同时提供较低的操作和管理开销,从而保证实现B3G系统中的新业务的发展,是无线资源分配策略设计的重点。提供了B3G系统中一种新的无线资源分配策略,并利用OPNET Modeler建立了一个仿真平台对协议算法进行了验证。仿真结果显示,该策略具有很高的资源分配效率,并能针对不同业务的不同需求提供不同的时延保障,对B3G系统QoS框架中的3种业务都能提供良好的支持,并已应用于B3G原型系统。     

Adaptive radio resource management for maximizing reward and balancing loads in 4G hybrid universal mobile telecommunications system and long term evolution communications

The universal mobile telecommunications system (UMTS) and long term evolution (LTE)/LTE‐advanced specifications have been proposed to offer high data rate for the forwarding link under high‐mobility wireless communications. The keys include supporting multi‐modes of various coding schemes (e.g., VSF‐OFCDM, OFDM, OFDMA), multiple‐input multiple‐output, relay networks, and so on. To balance loads among different communication interfaces is one of the most important issues that should be addressed for achieving efficient radio resource allocations. In a shared packet service, the 3GPP UMTS adopts the VSF‐OFCDM interface to allocate orthogonal codes of an OVSF code tree in two‐dimension (2D) spreading at the time and frequency domains. However, it easily leads to high packet loss rate and high bandwidth waste rate, because it does not consider interference and the adaptive modulation and coding scheme simultaneously. Conversely, although the LTE/LTE‐advanced interface offers a high data rate, it suffers from unbalanced loads and moderate reward. This paper thus proposes an adaptive radio resource allocation for balancing loads between the UMTS and LTE/LTE‐advanced interfaces according to various interference and mobility environments. In addition, an adaptive multi‐code allocation is proposed for the UMTS to minimize the bandwidth waste rate while guaranteeing quality of service. Numerical results indicate that the proposed approach outperforms other approaches in fractional reward loss and system utilization. Copyright © 2013 John Wiley & Sons, Ltd.     

A self‐organized resource allocation scheme for heterogeneous macro‐femto networks

This paper investigates the radio resource management (RRM) issues in a heterogeneous macro‐femto network. The objective of femto deployment is to improve coverage, capacity, and experienced quality of service of indoor users. The location and density of user‐deployed femtos is not known a‐priori. This makes interference management crucial. In particular, with co‐channel allocation (to improve resource utilization efficiency), RRM becomes involved because of both cross‐layer and co‐layer interference. In this paper, we review the resource allocation strategies available in the literature for heterogeneous macro‐femto network. Then, we propose a self‐organized resource allocation (SO‐RA) scheme for an orthogonal frequency division multiple access based macro‐femto network to mitigate co‐layer interference in the downlink transmission. We compare its performance with the existing schemes like Reuse‐1, adaptive frequency reuse (AFR), and AFR with power control (one of our proposed modification to AFR approach) in terms of 10 percentile user throughput and fairness to femto users. The performance of AFR with power control scheme matches closely with Reuse‐1, while the SO‐RA scheme achieves improved throughput and fairness performance. SO‐RA scheme ensures minimum throughput guarantee to all femto users and exhibits better performance than the existing state‐of‐the‐art resource allocation schemes.Copyright © 2014 John Wiley & Sons, Ltd.     

Optimal Radio Resource Partition for Joint Contention- and Connection-Oriented Multichannel Access in OFDMA Systems

The IEEE 802.16e world interoperability for microwave access (WiMax) system plays an important role in the future wireless metropolitan area network (WMAN). Orthogonal frequency division multiple access (OFDMA), adopted in the IEEE 802.16 e WiMax system, has many advantages in the physical layer, but also poses many challenges for radio resource allocation. One of interesting radio resource allocation issue in the OFDMA system is to partition the overall radio resource (bandwidth and time duration) into two portions: one for random access and the other for connection-oriented access. In the IEEE 802.16 e WiMax system, a truncated binary backoff algorithm is adopted to resolve the contention in random access, while the time-division OFDMA is used for the connection-oriented access. The main contribution of this paper is to design an analytical approach to determine the optimal amount of reserved radio resource in both time and frequency domains for random access, with the objective of maximizing the overall efficiency of radio resource while satisfying the delay requirements for supporting real-time services. Furthermore, an analytical model for calculating the access latency and the efficiency of the reserved radio resources is developed.     

Efficient resource utilization through carrier grouping forhalf-duplex communication in GSM-based MEO mobile satellitenetworks

In the near future, existing terrestrial radio networks are envisioned to integrate with satellite systems in order to provide global coverage. In order to establish communication for both nonhand-held and hand-held user terminals, the radio link design must allow full- and half-duplex operation, respectively, where the latter is desirable when radiation power restrictions are imposed. In addition, due to user mobility and wireless channel volatility, sophisticated resource management is required, so as to enhance system capacity. However, a major inherent problem of the satellite link is propagation delay, which may lead to inefficient resource allocation and reduced spectral efficiency. We address the resource allocation problem that arises in the context of a medium-Earth-orbit (MEO) satellite system with half-duplex communication capabilities. MEO satellite systems are characterized by large propagation delays and large intrabeam delay variations, which are shown to result in resource consumption. We propose a channel classification scheme, in which the available carriers are partitioned into classes and each class is associated with a range of propagation delays to the satellite. The suggested infrastructure results in better channel utilization and reduced call blocking rate and can be implemented with low signaling load     

Radio resource management for cellular CDMA systems supporting heterogeneous services

A novel radio resource management (RRM) scheme for the support of packet-switched transmission in cellular CDMA systems is proposed by jointly considering the physical, link, and network layer characteristics. The proposed resource management scheme is comprised of a combination of power distribution, rate allocation, service scheduling, and connection admission control. Power distribution allows individual connections to achieve their required signal-to-interference-plus-noise ratio, while rate allocation guarantees the required delay/jitter for real-time traffic and the minimum transmission rate requirement for non-real-time traffic. Efficient rate allocation is achieved by making use of the randomness and burstiness; of the packet generation process. At the link layer, a packet scheduling scheme is developed based on information derived from power distribution and rate allocation to achieve quality of service (QoS) guarantee. Packet scheduling efficiently utilizes the system resources in every time slot and improves the packet throughput for non-real-time traffic. At the network layer, a connection admission control (CAC) scheme based on the lower layer resource allocation information is proposed. The CAC scheme makes use of user mobility information to reduce handoff connection dropping probability (HCDP). Theoretical analysis of the grade of service performance, in terms of new connection blocking probability, HCDP, and resource utilization, is given. Numerical results show that the proposed RRM scheme can achieve both effective QoS guarantee and efficient resource utilization.     

Radio resource management with QoS guarantees for LTE-A systems: a review focused on employing the multi-objective optimization techniques

The increasing number of subscribers’ demand has led to the evolution of future wireless networks that support multimedia applications and require ensuring the quality of services it provides. As the radio resource is becoming scarce, it is turning out to be a vital issue that how should the demands for higher data rates with limited resources is met for the evolving long term evolution-advanced (LTE-A) systems. Moreover, the efficiency and performance of resource management can be further improved by autonomously assigning and managing resources among various users and applications. We have surveyed various radio resource management (RRM) techniques being used for resource sharing in LTE-A networks that focus on the potential of multi-objective optimization algorithms for achieving desired QoS in LTE-A system. In this paper, we present a comprehensive review of RRM techniques, scheduling, and QoS along with a focus on implementing the multi-objective optimization techniques for efficient resource allocation.     

Resource Allocator for Non Real-Time Traffic in Wireless Networks Using Fuzzy Logic

Providing efficient access to a large user population with variantservice requirements in wireless communications networks poses a verychallenging problem. Resource allocation in the wireless domain shouldtake into account bandwidth limitations and fading effects inherent towireless channels, while accommodating for resource constraintsencountered in wireline networks. In this paper, a fuzzy resourceallocator is proposed in order to facilitate the efficient allocation ofnetwork resources in the wireless domain. The network preferentiallyallocates its resources to real-time (RT) traffic sources. Usingeffective transmission rate statistics of non real-time (NRT) trafficdsources as a measure of fading channel conditions, the fuzzy allocatoroptimally allocates the remaining resources to NRT traffic. Simulationsshow that the fuzzy allocator can reduce delay and incurs fewerretransmissions for NRT traffic. An overall improvement in wirelesschannel utilization is demonstrated.     

Q-Win – A New Admission and Handoff Management Scheme for Multimedia LEO Satellite Networks

Low Earth Orbit (LEO) satellite networks are deployed as an enhancement to terrestrial wireless networks in order to provide broadband services to users regardless of their location. In addition to global coverage, these satellite systems support communications with hand-held devices and offer low cost-per-minute access cost, making them promising platform for Personal Communication Services (PCS). LEO satellites are expected to support multimedia traffic and to provide their users with the negotiated Quality of Service (QoS). However, the limited bandwidth of the satellite channel, satellite rotation around the Earth and mobility of end-users makes QoS provisioning and mobility management a challenging task. One important mobility problem is the intra-satellite handoff management. The main contribution of this work is to propose Q-Win, a novel call admission and handoff management scheme for LEO satellite networks. A key ingredient in our scheme is a companion predictive bandwidth allocation strategy that exploits the topology of the network and contributes to maintaining high bandwidth utilization. Our bandwidth allocation scheme is specifically tailored to meet the QoS needs of multimedia connections. The performance of Q-Win is compared to that of two recent schemes proposed in the literature. Simulation results show that our scheme offers low call dropping probability, providing for reliable handoff of on-going calls, good call blocking probability for new call requests, while maintaining bandwidth utilization high.     

Dynamic Bandwidth and Carrier Allocation for Video Broadcast/Multicast Over Multi-Cell Environments

Recently, broadcast/multicast over cellular networks has been actively discussed over commercial wireless mobile terminals. Compared to conventional terrestrial or satellite broadcasting systems, the quality-of-service (QoS) for edge users is an important issue due to inter-cell interference over multi-cell environments. In this paper, we introduce a dynamic bandwidth and carrier allocation (DBCA) technique by fully utilizing different visual importance of each layer in multi-layer video for broadcast/multicast services when the number of users is limited over macro/micro/femto cell environments. To ensure an acceptable video quality for edge users, the bandwidth and the loading ratio are dynamically controlled to enhance the utility through the radio resource control in accordance with the visual importance. The simulation results show that DBCA exhibits much better QoS by sending visually more important data with high priority in the cell border region.     

Hierarchical Dynamic Bandwidth Allocation Algorithm for Multimedia Services over Ethernet PONs

In this paper, we propose a new dynamic bandwidth allocation (DBA) algorithm for multimedia services over Ethernet PONs (passive optical networks). The proposed algorithm is composed of a low‐level scheduler in the optical network unit (ONU) and a high‐level scheduler in the optical line terminal (OLT). The hierarchical DBA algorithm can provide expansibility and efficient resource allocation in an Ethernet PON system in which the packet scheduler is separated from the queues. In the proposed DBA algorithm, the OLT allocates bandwidth to the ONUs in proportion to the weight associated with their class and queue length, while the ONU preferentially allocates its bandwidth to queues with a static priority order. The proposed algorithm provides an efficient resource utilization by reducing the unused remaining bandwidth caused by the variable length of the packets. We also define the service classes and present control message formats conforming to the multi‐point control protocol (MPCP) over an Ethernet PON. In order to evaluate the performance, we designed an Ethernet PON system on the basis of IEEE 802.3ah “Ethernet in the first mile” (EFM) using OPNET and carried out simulations. The results are analyzed in terms of the channel utilization, queuing delay, and ratio of the unused remaining bandwidth.     

Efficient Uplink Bandwidth Request with Delay Regulation for Real-Time Service in Mobile WiMAX Networks

The emerging broadband wireless access technology based on IEEE 802.16 is one of the most promising solutions to provide ubiquitous wireless access to the broadband service at low cost. This paper proposes an efficient uplink bandwidth request-allocation algorithm for real-time services in Mobile WiMAX networks based on IEEE 802.16e. In order to minimize bandwidth wastage without degrading quality of service (QoS), we introduce a notion of target delay and propose dual feedback architecture. The proposed algorithm calculates the amount of bandwidth request such that the delay is regulated around the desired level to minimize delay violation and delay jitter for real-time services. Also, it can increase utilization of wireless channel by making use of dual feedback, where the bandwidth request is adjusted based on the information about the backlogged amount of traffic in the queue and the rate mismatch between packet arrival and service rates. Due to the target delay and dual feedback, the proposed scheme can control delay and allocate bandwidth efficiently while satisfying QoS requirement. The stability of the proposed algorithm is analyzed from a control-theoretic viewpoint, and a simple design guideline is derived based on this analysis. By implementing the algorithm in OPNET simulator, its performance is evaluated in terms of queue regulation, optimal bandwidth allocation, delay controllability, and robustness to traffic characteristics.