Adaptive resource sharing in wireless networks

We propose a state-dependent method for allocating and sharing resources based on the least busy algorithm for a wireless system consisting of several overlaid wireless networks. The model is an approximation that utilizes capacity, reservation and different degrees of mobility of users to characterize the system as a network of queues. We use the network net revenue to compare reservation policies. We show how the use of reservation improves network-wide performance.     

Radio resource allocation in fixed broadband wireless networks

We consider use of fixed broadband wireless networks to provide packet services for telecommuting and Internet access. Each cell is divided into multiple sectors, each of them served by a sector antenna colocated with the base station (BS), and user terminals also use directional antennas mounted on the rooftops of homes or small offices and pointed to their respective BS antennas. To support a target data rate of 10 Mb/s, a bandwidth of several MHz is required. Since radio spectrum is expensive, the bandwidth needs to be reused very aggressively. Thus, efficient strategies for frequency reuse and managing cochannel interference are critically important. We propose several algorithms for dynamic radio-resource allocation in the fixed wireless networks. In particular, a method to be referred to as the staggered resource allocation (SRA) method uses a distributed scheduling algorithm to avoid major sources of interference while allowing concurrent packet transmission and meeting signal-to-interference objectives. The performance of the method is studied by analytic approximations and detailed simulation. Our results show that the combination of directional antennas plus the SRA method is highly effective in controlling cochannel interference. For reasonable system parameters, the SRA method delivers a throughput in excess of 30% per sector while permitting a given frequency band to be reused in every sector of every cell. It also provides satisfactory probability of successful packet transmission. In addition, a simple control mechanism can be applied in the method to improve performance for harsh radio environments     

Optimal resource allocation for wireless video over CDMA networks

We present a multiple-channel video transmission scheme in wireless CDMA networks over multipath fading channels. We map an embedded video bitstream, which is encoded into multiple independently decodable layers by 3D-ESCOT video coding technique, to multiple CDMA channels. One video source layer is transmitted over one CDMA channel. Each video source layer is protected by a product channel code structure. A product channel code is obtained by the combination of a row code based on rate compatible punctured convolutional code (RCPC) with cyclic redundancy check (CRC) error detection and a source-channel column code, i.e., systematic rate-compatible Reed-Solomon (RS) style erasure code. For a given budget on the available bandwidth and total transmit power, the transmitter determines the optimal power allocations and the optimal transmission rates among multiple CDMA channels, as well as the optimal product channel code rate allocation, i.e., the optimal unequal Reed-Solomon code source/parity rate allocations and the optimal RCPC rate protection for each channel. In formulating such an optimization problem, we make use of results on the large-system CDMA performance for various multiuser receivers in multipath fading channels. The channel is modeled as the concatenation of wireless BER channel and a wireline packet erasure channel with a fixed packet loss probability. By solving the optimization problem, we obtain the optimal power level allocation and the optimal transmission rate allocation over multiple CDMA channels. For each CDMA channel, we also employ a fast joint source-channel coding algorithm to obtain the optimal product channel code structure. Simulation results show that the proposed framework allows the video quality to degrade gracefully as the fading worsens or the bandwidth decreases, and it offers improved video quality at the receiver.     

Time-based resource allocation for downlink in heterogeneous wireless cellular networks

Telecommunication Systems - Heterogeneous Wireless Cellular Networks (HWCNs) are an essential part of current and future cellular networks as a result of several benefits they offer regarding the...     

Radio resource allocation algorithms for multi-service OFDMA networks: the uniform power loading scenario

Adaptive Radio Resource Allocation is essential for guaranteeing high bandwidth and power utilization as well as satisfying heterogeneous Quality-of-Service requests regarding next generation broadband multicarrier wireless access networks like LTE and Mobile WiMAX. A downlink OFDMA single-cell scenario is considered where heterogeneous Constant-Bit-Rate and Best-Effort QoS profiles coexist and the power is uniformly spread over the system bandwidth utilizing a Uniform Power Loading (UPL) scenario. We express this particular QoS provision scenario in mathematical terms, as a variation of the well-known generalized assignment problem answered in the combinatorial optimization field. Based on this concept, we propose two heuristic search algorithms for dynamically allocating subchannels to the competing QoS classes and users which are executed under polynomially-bounded cost. We also propose an Integer Linear Programming model for optimally solving and acquiring a performance upper bound for the same problem at reasonable yet high execution times. Through extensive simulation results we show that the proposed algorithms exhibit high close-to-optimal performance, thus comprising attractive candidates for implementation in modern OFDMA-based systems.     

一种多业务交换机的分区资源分配方法

文章首先介绍了多业务交换机的多个国际标准化组织提出的参考模型,并在此基础上针对各模型中的主要问题之一即交换机的分区问题阐述了其实现模型.文章最后针对分区中最为复杂的分区方式即动态分区,提出了一种算法和实现方案。     

Underwater optical wireless sensor networks using resource allocation

Telecommunication Systems - Optical wireless communications is an energy efficient and cost-effective solution for high speed and high secure wireless connections. In this paper, we propose an...     

A framework for the multicast lifetime maximization problem in energy-constrained wireless ad-hoc networks

We consider the problem of maximizing the lifetime of a given multicast connection in wireless networks that use directional antennas and have limited energy resources. We provide a globally optimal solution to this problem for a special case of using omni-directional antennas. This graph theoretic approach provides us insights into more general case of using directional antennas, and inspires us to produce a group of heuristic algorithms. Experimental results show that our algorithms outperform other energy-aware multicast algorithms significantly in terms of multicast lifetime.

Prediction-based resource allocation for multimedia traffic over high-speed wireless networks

Both call admission control (CAC) and efficient scheduling are of great importance in next generation wireless networks, which are expected to handle various types of highly demanding multimedia users. In this paper, we present and evaluate a new mechanism which combines CAC with bandwidth allocation in a high-speed downlink time division multiple access (TDMA) wireless channel with errors; our mechanism incorporates predictions of the wireless channel condition in its decision making and our results show that, with the use of the feedback between the scheduler and the admission controller, system performance is significantly enhanced (in terms of voice-WAP-SMS-H.263 video QoS) compared to a scheme without prediction on the channel condition.     

Dynamic resource allocation schemes during handoff for mobilemultimedia wireless networks

User mobility management is one of the important components of mobile multimedia systems. In a cell-based network, a mobile should be able to seamlessly obtain transmission resources after handoff to a new base station. This is essential for both service continuity and quality of service assurance. In this paper, we present strategies for accommodating continuous service to mobile users through estimating resource requirements of potential handoff connections. A diverse mix of heterogeneous traffic with diverse resource requirements is considered. The investigate static and dynamic resource allocation schemes. The dynamic scheme probabilistically estimates the potential number of connections that will be handed off from neighboring cells, for each class of traffic. The performance of these strategies in terms of connection blocking probabilities for handoff and local new connection requests are evaluated. The performance is also compared to a scheme previously proposed by Yu and Leung (see IEEE J. Select. Areas Commun., vol.15, p.1208-25, 1997). The results indicate that using dynamic estimation and allocation, we can significantly reduce the dropping probability for handoff connections     

Multiuser cross-layer resource allocation for video transmission over wireless networks

With the advancement of video-compression technology and the wide deployment of wireless networks, there is an increasing demand for wireless video communication services, and many design challenges remain to be overcome. In this article, we discuss how to dynamically allocate resources according to the changing environments and requirements, so as to improve the overall system performance and ensure individual quality of service (QoS). Specifically, we consider two aspects with regard to design issues: cross-layer design, which jointly optimizes resource utilization from the physical layer to the application layer, and multiuser diversity, which explores source and channel heterogeneity for different users. We study how to efficiently transmit multiple video streams, encoded by current and future video codecs, over resource-limited wireless networks such as 3G/4G cellular system and future wireless local/metropolitan area networks (WLANs/WMANs).     

A separation principle for resource allocation in industrial wireless sensor networks

Industrial production lines have been used to assemble a wide range of commercial goods such as metallurgy, automobile, and electronic devices. Since these production lines create tens of trillions of dollars annually, their production efficiency, cost, and safety are critical for global economy. This paper uses industrial wireless sensor networks (IWSNs) to monitor multi-stage production lines. Unlike traditional surveillance WSNs, IWSNs feature a unique cascaded network topology, which can be leveraged to optimize network performance (e.g., end-to-end delay). To our best knowledge, research along this direction is lacking. Specifically, considering the physical characteristics and functional requirements of production lines, we introduce the cascaded FieldNets where each FieldNet is a field sub-net corresponding to one process stage. In particular, the end-to-end minimization oriented resource allocation problem is concerned. It is a nonlinear mixed integer programming problem formulated by both (1) channel allocation among FieldNets and (2) multichannel transmission scheduling within each FieldNet. To solve it, a separation principle is proposed, by which we prove that the resource allocation within each FieldNet can be determined independently from the channels allocation among FieldNets. Performance evaluation demonstrates that the proposed resource allocation approach provides a \(10{\times }\) larger region of schedulability and achieves as low as 10 % of end-to-end delay compared with the scheduling approach in WirelessHART, and only consumes half of the energy based on some existing MACs such as Y-MAC and EM-MAC under high-traffic condition.     

A comprehensive resource management framework for next generation wireless networks

We propose an integrated resource management approach that can be implemented in next generation wireless networks that support multimedia services (data, voice, video, etc.). Specifically, we combine the use of position-assisted and mobility predictive advanced bandwidth reservation with a call admission control and bandwidth reconfiguration strategy to support flexible QoS management. We also introduce a mobile agent based framework that can be used to carry out the functions of geolocation and of the proposed resource management in wireless networks. A model is also developed to obtain the optimal location information update interval in order to minimize the total cost of the system operation. The comparison of the achievable performance results of our proposed scheme with the corresponding results of a conventional system that supports advanced bandwidth reservation only, as means of supporting the QoS requirements, demonstrate that our integrated scheme can alleviate the problem of overreservation, support seamless operation throughout the wireless network, and increase significantly the system capacity.     

Adaptive subcarrier allocation schemes for wireless ofdma systems in wimax networks

WiMAX is one of the most important technologies for providing a Broadband Wireless Access (BWA) in a metropolitan area. The use of OFDM transmissions has been proposed to reduce the effect of multipath fading in wireless communications. Moreover, multiple access is achieved by resorting to the OFDMA scheme. Adaptive subcarrier allocation techniques have been selected to exploit the multiuser diversity, leading to an improvement of performance by assigning subchannels to the users accordingly with their channel conditions. A method to allocate subcarriers is to assign almost an equal bandwidth to all users (fair allocation). However, it is well known that this method limits the bandwidth efficiency of the system. In order to lower this drawback, in this paper, two different adaptive subcarrier allocation algorithms are proposed and analyzed. Their aim is to share the network bandwidth among users on the basis of specific channel conditions without loosing bandwidth efficiency and fairness. Performance comparisons with the static and the fair allocation approaches are presented in terms of bit error rate and throughput to highlight the better behavior of the proposed schemes in particular when users have different distances from the BS.     

Energy‐efficient resource allocation for lifetime maximization in M2M networks

Machine‐to‐machine (M2M) communications is one of the major enabling technologies for the realization of the Internet of Things (IoT). Most machine‐type communication devices (MTCDs) are battery powered, and the battery lifetime of these devices significantly affects the overall performance of the network and the quality of service (QoS) of the M2M applications. This paper proposes a lifetime‐aware resource allocation algorithm as a convex optimization problem for M2M communications in the uplink of a single carrier frequency division multiple access (SC‐FDMA)‐based heterogeneous network. A K‐means clustering is introduced to reduce energy consumption in the network and mitigate interference from MTCDs in neighbouring clusters. The maximum number of clusters is determined using the elbow method. The lifetime maximization problem is formulated as a joint power and resource block maximization problem, which is then solved using Lagrangian dual method. Finally, numerical simulations in MATLAB are performed to evaluate the performance of the proposed algorithm, and the results are compared to existing heuristic algorithm and inbuilt MATLAB optimal algorithm. The simulation results show that the proposed algorithm outperforms the heuristic algorithm and closely model the optimal algorithm with an acceptable level of complexity. The proposed algorithm offers significant improvements in the energy efficiency and network lifetime, as well as a faster convergence and lower computational complexity.     

Adaptive resource allocation for prioritized call admission over anATM-based wireless PCN

In future personal communications networks (PCNs) supporting network-wide handoffs, new and handoff requests will compete for connection resources in both the mobile and backbone networks. Forced call terminations due to handoff call blocking are generally more objectionable than new call blocking. The previously proposed guard channel scheme for radio channel allocation in cellular networks reduces handoff call blocking probability substantially at the expense of slight increases in new call blocking probability by giving resource access priority to handoff calls over new calls in call admission control. While the effectiveness of a fixed number of guard channels has been demonstrated under stationary traffic conditions, with nonstationary call arrival rates in a practical system, the achieved handoff call blocking probability may deviate significantly from the desired objective. We propose a novel dynamic guard channel scheme which adapts the number of guard channels in each cell according to the current estimate of the handoff call arrival rate derived from the current number of ongoing calls in neighboring cells and the mobility pattern, so as to keep the handoff call blocking probability close to the targeted objective while constraining the new call blocking probability to be below a given level. The proposed scheme is applicable to channel allocation over cellular mobile networks, and is extended to bandwidth allocation over the backbone network to enable a unified approach to prioritized call admission control over the ATM-based PCN     

Adaptive proportional fairness resource allocation for OFDM-based cognitive radio networks

In this paper, we study the resource allocation problem in multiuser Orthogonal Frequency Division Multiplexing (OFDM)-based cognitive radio networks. The interference introduced to Primary Users (PUs) is fully considered, as well as a set of proportional rate constraints to ensure fairness among Secondary Users (SUs). Since it is extremely computationally complex to obtain the optimal solution because of integer constraints, we adopt a two-step method to address the formulated problem. Firstly, a heuristic subchannel assignment is developed based on the normalized capacity of each OFDM subchannel by jointly considering channel gain and the interference to PUs, which approaches a rough proportional fairness and removes the intractable integer constraints. Secondly, for a given subchannel assignment, we derive a fast optimal power distribution algorithm that has a complexity of O(L ² N) by exploiting the problem’s structure, which is much lower than standard convex optimization techniques that generally have a complexity of O((N + K)³), where N, L and K are the number of subchannels, PUs and SUs, respectively. We also develop a simple power distribution algorithm with complexity of only O(L + N), while achieving above 90 % sum capacity of the upper bound. Experiments show that our proposed algorithms work quite well in practical wireless scenarios. A significant capacity gain is obtained and the proportional fairness is satisfied perfectly.     

无线频谱资源分配在5G网络中的进展分析

随着现代网络技术的高速发展,现代移动通信的触角已经开始逐步延伸到5G时代,无线频谱也相应的得到了更深层次的应用和发展,尤其是在资源分配方面.由于频谱资源分配受多种因素的影响,因此在实际运用过程中必须对其做进一步的研究.对此,本文将系统的分析和探讨无线频谱资源分配在5G网络中的发展.     

A prioritized resource allocation algorithm for multiple wireless body area networks

This paper presents a prioritized resource allocation algorithm to share the limited communication channel resource among multiple wireless body area networks. The proposed algorithm is designed based on an active superframe interleaving scheme, one of the coexistence mechanisms in the IEEE 802.15.6 standard. It is the first study to consider the resource allocation method among wireless body area networks within a communication range. The traffic source of each wireless body area network is parameterized using the traffic specification, and required service rate for each wireless body area networks can be derived. The prioritized resource allocation algorithm employs this information to allocate the channel resource based on the wireless body area networks’ service priority. The simulation results verified that the traffic specification and the wireless body area network service priority based resource allocation are able to increase quality of service satisfaction, particularly for health and medical services.