DVB-S2网络中优化资源分配的新方案

自适应编码调制技术根据信道环境自适应地调整传输参数来提高频谱效率,但是卫星网络中信道的时变特征对该技术的使用造成了一些限制。提出一种基于预测的信噪比估计算法,来应对回路延时带来的不利影响。在预测值基础上,提出一种新的编码调制方案选择算法来选择更强健的编码调制方案。最后,提出一种滑动窗口技术来应对编码调制方案的频繁转换及其引起的系统性能振荡。仿真结果表明,新方案能够使网络资源得到更有效的利用。     

一种基于网络优化的动态信道分配策略

该文提出了一种在CDMA网络中基于网络优化的动态信道分配策略,它针对恒定比特率(CBR)业务建立了一种整数规划的数学模型,它不是每个时隙进行一次信道分配而是若干个时隙根据当前所有用户的状态统筹做一次调度,目的是使得用户QoS和系统性能得到折中考虑。通过仿真,相对于传统话音优先和按照优先级排队的分配算法,这种优化算法在保证业务的QoS的同时使得信道利用率得到提高。     

A Bidding Algorithm for Optimized Utility-Based Resource Allocation in Ad Hoc Networks

This article proposes a scheme for bandwidth allocation in wireless ad hoc networks. The quality of service (QoS) levels for each end-to-end flow are expressed using resource-utility functions, and our algorithms aim to maximize aggregated utility. The shared channel is modeled as bandwidth resources defined by maximal cliques of mutual interfering links. We propose an entirely novel resource allocation algorithm that employs auction mechanisms where flows are bidding for resources. The bids depend both on the flow's utility function and the intrinsically derived shadow prices. Then we combine it with a utility-aware on-demand shortest path routing algorithm where shadow prices are used as a natural distance metric. We also show that the problem can be formulated as a linear programming problem. Thus we can compare the performance of our scheme to the centralized optimal LP solution, registering results very close to the optimum. We isolate the performance of the price-based routing and show its advantages in hotspot scenarios, and also propose an asynchronous version that is more feasible for ad hoc environments. Experimental results of a comparison with the state-of-the-art approach based on Kelly's utility maximization framework show that our approach exhibits superior performance for networks with both increased mobility or increased allocation period.     

A Utility-Based Joint Resource Allocation Approach for Multi-Service in CoMP Networks

One of the premier mechanisms used in extracting unobserved signals from observed mixtures in signal processing is employing a blind source separation (BSS) algorithm or technique. A prominent role in the sphere of multicarrier communication is played by orthogonal frequency division multiplexing (OFDM) techniques. A set of remedial solutions taken to mitigate deteriorative effects caused within the air interface of an OFDM transmission with aid of BSS schemes is presented. Two energy functions are used in deriving the filter coefficients. They are optimized and performance is justified. These functions with the iterative fixed point rule for receive signal are used in determining the filter coefficients. Time correlation properties of the channel are taken advantage for BSS. It is tried colored noise and interference components to be removed from the signal mixture at the receiver. The method is tested in a slow fading channel with a receiver containing equal gain combining to treat the channel state information values. The importance is that, these solutions can be noted as quite low computational complexity mechanisms.     

An Evolutionary Game-Theoretic Approach for Base Station Allocation in Wireless Femtocell Networks

Wireless Personal Communications - A set of moving nodes communicating with each other without any infrastructure is considered a mobile ad hoc network (MANET). Stability is a big problem with this...     

Deep Learning Based Resources Allocation for Internet-of-Things Deployment Underlaying Cellular Networks

Mobile Networks and Applications - Resources allocation (RA) is a challenging task in many fields and applications including communications and computer networks. The conventional solutions of such...     

基于改进遗传算法的分布式资源动态调度技术

在网络中心战条件下,为了解决分布式作战资源的动态最优部署问题,提出了一种分布式资源的动态调度算法。首先针对资源动态调度问题建立了数学模型,接着,借鉴粒子群算法的思想,使用遗传算法解决了资源调度任务指派的快速寻优问题。仿真验证表明资源调度算法是有效的,并且该算法可使分布式系统的任务处理能力和处理资源利用率大幅度提高。     

一种基于P2P的关键词搜索新方法

结构化对等(P2P)网络是基于文件标识符的分布武系统,它能够很好地支持对文件标识符的等值查询,但对于其他的复杂查询,则需要进行进一步扩展,现有的一些技术虽然在结构化对等网络实现了关键词搜索,但是仍然存在诸如负载不均衡,结构复杂,不易于部署和效率低等问题,对此提出了一种基于结构化对等网络的关键词搜索新方法,将构建在一般分布式哈希表上的倒排索引与top-k查询算法结合起来,以较少的代价实现关键词搜索.同时有效地克服了数据分布不均匀带来的负载不均衡问题.     

Multi-Stage Hierarchical Channel Allocation in UAV-Assisted D2D Networks:A Stackelberg Game Approach

UAV-assisted D2D networks can provide auxiliary communication for areas with poor communication facilities by using the characteristics of easy deployment of unmanned aerial vehicle(UAV),then it becomes a promising technology.However,the coexistence of UAV and D2D aggravates the conflict of spectrum resources.In addition,when the UAV performs the communication service,it will inevitably cause the location change,which will make the original channel allocation no longer applicable.Inspired by the influence of frequent channel switching on channel allocation,we define the communication utility as a tradeoff between the throughput and channel switching cost.In the considered model,we investigate the multi-stage hierarchical spectrum access problem with maximizing aggregate communication utilities in UAV-assisted D2D networks.In particular,due to the hierarchical feature of the considered network,we adopt Stackelberg game to formulate this spectrum access problem where both the throughput and channel switching cost are considered.We prove that the proposed game has a stable Stackelberg equilibrium(SE),and the heterogeneous network based channel allocation(HN-CA)algorithm is proposed to achieve the desired solution.Simulation results verify the validity of the proposed game and show the effectiveness of the HN-CA algorithm.     

An Efficient and Fair Strategy for Radio Resources Allocation in Multi-radio Wireless Mesh Networks

A Load and Interference aware Resource Allocation strategy (LIRA) is proposed for multi-radio Wireless Mesh Networks (WMNs), combining multiple mechanisms that efficiently optimise radio resources (rate, power and channel) to guarantee max–min fair capacity to every aggregating Mesh Access Point (MAP). LIRA is composed of a rate adaptation and power control mechanism, sensitive to the fat-tree traffic specificities of WMNs, using the highest bit rates at MAP gateways and using, for the ramified links, the minimum ones that satisfy their capacity needs. This enables to efficiently reduce the transmitted power and interference, advantageous for channel reutilisation. LIRA also integrates a load and interference aware channel assignment mechanism, allowing the simultaneous operation of all links without interference. When this is not achievable, two auxiliary mechanisms of channel sharing and interference-free channel reuse can be sub-sequentially used, reducing the capacity of certain MAPs to guarantee fairness to all nodes. LIRA’s gateway flow-control mechanism guarantees that all MAPs respect the allocated capacity, guaranteeing that every MAP is able to operate at its max–min fair capacity. The performance of LIRA is evaluated through simulation, considering IEEE 802.11a. For a classical hexagonal deployment of 19 MAPs with an Internet gateway, it is shown how with only 5 channels LIRA guarantees to every MAP a max–min fair capacity of 3.2 Mbit/s, without packet loss, and delay below 6 ms. It guarantees a max–min fair throughput to every MAP, having a capacity usage efficiency of 66.7 %, an energy efficiency of 26.5 Mbit/J and spectrum efficiency of 0.58 bit/s/Hz. For a more challenging scenario with 27 MAPs and 4 gateways, it is shown how LIRA uses its mechanisms in heterogeneous conditions to also guarantee max–min fair throughput to every MAP, between 5 and 11 Mbit/s, without packet loss, and a delay below 12 ms. Any system improvement will enable to reach higher WMN performance levels using the proposed strategy.     

A New Power Allocation Algorithm in Cognitive Radio Networks

Most resource allocation algorithms are based on interference power constraint in cognitive radio networks. Instead of using conventional primary user interference constraint, we give a new criterion called allowable signal to interference plus noise ratio （SINR） loss constraint in cognitive transmission to protect primary users. Considering power allocation problem for cognitive users over flat fading channels, in order to maximize throughput of cognitive users subject to the allowable SINR loss constraint and maximum transmit power for each cognitive user, we propose a new power allocation algorithm. The comparison of computer simulation between our proposed algorithm and the algorithm based on interference power constraint is provided to show that it gets more throughput and provides stability to cognitive radio networks.     

A Resource Allocation Approach for the Generation of Service-Dependent Demand Matrices for Communications Networks

Estimating point-to-point demands from partially available information, such as total demand volumes originating and terminating at nodes and traffic volumes routed on links, has significant applications in various areas, such as communications network planning and transportation planning. Existing methods include matrix and link scaling methods, statistical methods, more complex mathematical programming models, and forecasting using demographic data. We present a new mathematical programming model based on equitable resource allocation. The model considers multiple services, e.g., data, video, and voice, and generates a point-to-point demand matrix for each service. Originating and terminating demands for each service and link loads, aggregated over all services, are viewed as resources. Each point-to-point demand is associated with a performance function that measures its weighted, normalized deviation from a target defined by a service-dependent community of interest matrix. The model formulation has a lexicographic minimax objective function and multiple knapsack resource constraints. The model has an intuitively appealing interpretation and a specialized algorithm can generate demand matrices for large network problems very fast.     

Utility Based Short-term Throughput Driven Scheduling Approach for Efficient Resource Allocation in CDMA Wireless Networks

In this paper, we address the problem of efficient recourse allocation in CDMA wireless networks supporting multimedia services with various and often diverse QoS prerequisites, placing special emphasis on real-time services’ essential requirements satisfaction. We first provide an analytical framework for studying real-time users’ short-term delay and throughput properties under fundamental opportunistic scheduling policies. The corresponding results demonstrate that probabilistic delay constraints are insufficient indicators of real-time services’ QoS prerequisites, while probabilistic short-term throughput requirements are more appropriate in asserting their performance expectations. Based on these observations and results, we propose and develop a scheduling policy for efficiently supporting heterogeneous services that include delay-tolerant non-real-time and delay-sensitive real-time services, over a wireless CDMA system under a common utility based framework. A user’s utility characterizes his degree of satisfaction for the received service as well as QoS expectations fulfillment, in a normalized way. Aiming at the maximization of users’ utilities, both non-real-time services’ long-term and real-time services’ short-term throughput QoS requirements are met, under the proposed opportunistic scheduler. Finally, via modeling and simulation it is demonstrated that significant performance improvements concerning both types of services’ QoS requirements satisfaction are achieved through the proposed scheduling approach.     

Optimized Power Allocation for Layered-Steered Space-Time Codes

Layered Steered Space-Time Codes (LSSTC) is a recently proposed multiple-input multiple-output system that combines the benefits of vertical Bell Labs space-time (VBLAST) scheme, space-time block codes and beamforming. We suggest a new downlink scheme employing LSSTC with asymmetric power allocation, by assuming that the user feeds the BS with the average signal-to-noise ratio per VBLAST layer through the uplink feedback channel. The motivation behind proposing such a system is to enhance the error performance by assigning power to the layers in an optimal manner. We refer to the system proposed as the optimal power allocation LSSTC (OPA-LSSTC). Our analysis is general such that it includes asymmetric layered systems in which each layer may have different number of antennas and also the power can be assigned to layers asymmetrically.     

一种基于新一代蜂窝移动通信的无线资源分配方案

新一代的蜂窝移动通信系统要求支持多种业务,从高质量的交互式实时业务到基于TCP连接的完全可靠服务。对于现有的无线链路,用户各种业务量的增加造成无线资源相对使用不平衡,大大降低了无线网络的吞吐量。本文提出了一种基于新一代蜂窝通信的无线资源分配方案,并利用OPNET建立仿真平台对该方案进行验证。仿真结果表明,各种不同优先等级的业务都能得到自己满意的服务质量,链路总的吞吐量达到了1 0 0 Mbit/s     

A Dual Feedback Approach of Request-Based Bandwidth Allocation for Real-Time Service in Broadband Wireless Access Networks

We propose an efficient request-based uplink bandwidth allocation algorithm for variable-rate real-time service in broadband wireless access networks. By introducing a notion of target delay under the framework of dual feedback, the proposed algorithm can regulate delay while minimizing delay jitter and bandwidth waste.     

为分组网而优化VoP处理器

将话音业务转移到以数据为中心的分组交换网具有商业意义.降低的成本、优化的网络资源和可产生新收益来源的新业务是驱使这种转移的全部因素.     

Optimized Hash Tree for Authentication in Sensor Networks

Authentication based on the Merkle tree has been proposed as an energy efficient approach in a resource constrained sensor network environment. It replaces complicated certificate verification with more power efficient hash computations. While previous works assumed complete binary Merkle tree structures, which can be used efficiently only in sensor networks with a specific number of sensor nodes, we investigate incomplete Merkle trees to support any number of sensors. For the incomplete Merkle tree, we demonstrate that an optimal structure can be found through mathematical analysis and simulation. A novel tree indexing scheme is also proposed to reduce communication overhead and save sensors resources during authentication     

Cross Layer Approach and ANFIS based Optimized Routing in Wireless Multi-Hop Ad Hoc Networks

Wireless Personal Communications - Mobile ad hoc networks are non-dependent on any wired infrastructure and provide exceptional benefits during typical situations like conference, fair/exhibition,...     

Optimal Allocation of Limited Optical-Layer Resources in WDM Networks Under Static Traffic Demand*

In this paper, four heuristic algorithms for the optimal allocation of limited optical-layer resources in WDM networks (virtual-topology optimization by routing and wavelength assignment) under static traffic demand are compared. While some previous papers assumed that all connection requests must be necessarily satisfied, in this work algorithms are studied aiming at comparing their ability in minimizing both the usage of optical-layer resources and the number of connection requests that cannot be allocated. This paper reports the results obtained on a 13-nodes simplified topology of the pan-European optical transport network designed in the COST239 Project. The results of a few hundreds simulations with different traffic matrices have been gathered, by considering separately the cost of resources allocated and the percentage of rejected connections. One algorithm resulted best performing, because in most tests it allocated the lowest cost of optical-layer resources. On the other hand, the four algorithms exhibited comparable performance with respect to the percentage of rejected connections.