Efficient radio resource management for wireless multimedia communications: a multidimensional QoS-based packet scheduler

Future wireless multimedia systems will support a variety of services with diverse range of capabilities and bit rates. For these systems, it is highly desired for real-time conversational and non-real-time services to efficiently share the available channels and bandwidth in an optimized way. The partitioned resource shaping with either fixed or a slow changing dynamic, proposed for conventional packet scheduling techniques, proves difficult and inefficient under fast-changing dynamics of radio channel and traffic. By taking into account almost all the aspects (dimensions) of quality-of-service (QoS) provisioning, the proposed unified fast dynamic multidimensional QoS-based packet scheduler (MQPS) in this paper elegantly and efficiently encapsulates features of many possible packet scheduling strategies. MQPS applies an optimization and tuning mechanism to packet scheduling weights to adopt the most appropriate packet scheduling and channel assignment strategy in response to the varying traffic and radio channel conditions. As an example, the technique is applied to a high-speed downlink packet access (HSDPA) system. It is shown that MQPS provides significantly better performance than existing techniques by satisfying all the requirements of a successful QoS provisioning to maximum possible level simultaneously.     

Joint radio resource management for heterogeneous wireless systems

Heterogeneous wireless systems are characterized by the physical coexistence of a variety of radio access technologies with different, but also complementary, technical characteristics and performance. A key aspect of heterogeneous systems is then the implementation of efficient joint radio resource management mechanisms. In this context, this paper presents and evaluates novel joint radio resource management techniques based on the CEA bankruptcy distribution rule. The proposed policies base their distribution decisions on the system conditions and the varying quality of service requirements present in multimedia scenarios. The obtained results demonstrate that the proposed policies can efficiently distribute the radio resources with a low computational cost.     

Energy efficient radio resource management for heterogeneous wireless network using CoMP

The coordinated multi point (CoMP) transmission technique is considered a key feature in future wireless network to improve both cell edge users throughput by exploiting interference. However, to provide CoMP transmission several BSs need to be active, which eventually increases network energy consumption. The simultaneous active multiple BSs with different transmission characteristics in heterogeneous environment cause interferences on each other. In this paper, we study the energy efficient radio resource management (EE-RRM) scheme for heterogeneous wireless networks to reduce interference. In particular, our aim is to allocate subcarrier power by optimizing EE metric and minimize interference with knowledge of channel state information between BSs and user equipment. The EE-RRM problem is a fractional programming problem. In order to solve, we use Charnes–Cooper transformation technique and transform it into an equivalent concave optimization problem. The numerical results of our work present the effect of different interference, rate and power thresholds on the EE metric.     

Future broadband radio access systems for integrated services withflexible resource management

The current challenge in radio networks is to provide integrated broadband services to everybody. The realization of this goal is dependent on both the development of products for the mass market and the improvement of the systems that support these products. New cellular mobile, fixed terrestrial, and satellite systems are being developed to provide broadband integrated services. The users of these new systems will not need, or even want, to know which particular systems are used to access the requested services. The users may negotiate terms of delivery, such as data rate and quality of service, but the actual system of delivery should be transparent. In order to both achieve transparent service delivery and ensure efficient use of the radio frequency spectrum, a flexible and scaleable resource management system is needed. This article highlights the development trends that will form the basis of future network systems and presents some suggestions for the management and control of these systems     

Cognitive radio: brain-empowered wireless communications

Cognitive radio is viewed as a novel approach for improving the utilization of a precious natural resource: the radio electromagnetic spectrum. The cognitive radio, built on a software-defined radio, is defined as an intelligent wireless communication system that is aware of its environment and uses the methodology of understanding-by-building to learn from the environment and adapt to statistical variations in the input stimuli, with two primary objectives in mind: /spl middot/ highly reliable communication whenever and wherever needed; /spl middot/ efficient utilization of the radio spectrum. Following the discussion of interference temperature as a new metric for the quantification and management of interference, the paper addresses three fundamental cognitive tasks. 1) Radio-scene analysis. 2) Channel-state estimation and predictive modeling. 3) Transmit-power control and dynamic spectrum management. This work also discusses the emergent behavior of cognitive radio.     

Fundamental limitations of power control and radio resource management in wireless networks

The ultimate resource in wireless networks is transmission power. The system stability and the resource sharing algorithms all rely on well functioning power control. To realistically address resource management algorithms, it is important to consider fundamental limitations of the radio resource and of power control. Exact and approximate capacity expressions are derived and related to Quality of Service (QoS) requirements of services. Power control is subject to limited update rate, limited feedback bandwidth, time delays, measurement errors, feedback errors and filtering effects which all affect the resulting performance. Simulations further illustrate the hampering effects and motivates models of power control inaccuracies. Copyright © 2004 John Wiley & Sons, Ltd.     

An enhanced radio resource management based MIH policies in heterogeneous wireless networks

The require of omnipresent wireless access and high data rate services are expected to increase extensively in the near future. In this context, heterogeneous networks, which are a mixture of different wireless technologies (LTE-advanced, LTE-advanced Pro, C-IoT (Cellular Internet of Thing), 5G WiFi, etc) are invited to enable important capabilities, such as high data rates, low latencies and efficient resource utilization in order to provide dedicated capacity to offices, homes, and urban hotspots. Mixing these technologies in the same system, with their complementary characteristics, to afford a complete coverage to users can cause various challenges such as seamless handover, resource management and call admission control. This article proposes a general radio resource management framework which can be supported by future network architectures. A combined call admission control, resource reservation algorithm and bandwidth adaptation based IEEE 802.21 MIH standard approach for heterogeneous wireless network is detailed in this framework. Our aims are to guarantee quality of service (QoS) requirements of all accepted calls, reduce new call blocking probability and handover call dropping probability, and maintain efficient resource utilization. Performance analysis shows that our proposed approach best guarantees QoS requirements.     

Cognitive radio networks for green wireless communications: an overview

As power consumption results in greenhouse gas emissions and energy costs for operators, analyzing power consumption in wireless networks and portable devices is of crutial importance. Due to environmental effects resulted from energy generation and exploitation as well as the cost of surging energy, energy-aware wireless systems attract unprecedented attention. Cognitive Radio (CR) is one of the optimal solutions that allows for energy savings on both the networks and devices. Thus, cognitive radio contributes to increase spectral and energy efficiency as well as reduction in power consumption. In addition, energy consumption of the CR technologies as intelligent technology should be considered to realize the green networks objective. In this article, we look into energy efficiency of the cognitive wireless network paradigms. Moreover, energy efficiency analysis and modelling in these systems are specifically focused on achieving green communications objectives. However, CRs by altering all elements of wireless data communications are considered in this paper, and the energy-efficient operation and energy efficiency enabler perspectives of CRs are also analyzed.

     

ROF在无线宽带移动通信中的应用

文章从光载无线通信(ROF)的基本原理出发,提出了ROF在未来无线宽带移动通信中的多种应用方式,包括ROF技术在多体制无线接入重载中的应用以及ROF在无线移动网络中实现基站与光网络节点设备的互联等.总结了ROF的技术优势,提出了有待解决的关键技术问题.     

Max-utility wireless resource management for best-effort traffic

Due to the characteristics of wireless channels, utility-based resource management in wireless networks requires a set of mechanisms that are different from those for wireline networks. This paper explores in detail why and how the requirements are different. In particular, we analyze the wireless network performance to find out the scheduling algorithm that maximizes total utility of the system. Unlike previous studies, this paper focuses on scenarios in which wireless networks are not fully loaded and all of the users are best-effort data users, i.e., there is no streaming user. Our first key conclusion is that Kleinrock's Conservation Law provides a valuable means to accurately capture the perceived rates of best-effort users in such systems. The queueing analysis further indicates that, within periods during which channel conditions are stable for each user, albeit differ from user to user, the max-utility scheduling algorithm can be derived using queueing theorem and can be readily implemented in actual systems for utility functions that are of exponential or log format. When further taking into account the time-variant nature of wireless channel conditions, our simulation results demonstrate that dynamic weighted fair queueing, with weights adjusted according to the channel conditions, can achieve highly desirable performance with great flexibility.     

Network-assisted resource management for wireless data networks

We propose a framework for network-assisted radio resource management in wireless data networks. This type of radio resource management techniques offer implementation and capacity benefits compared to conventional, interference-measurement based, dynamic channel assignment (DCA) algorithms. The basic idea is to use interbase signaling to shift most of the burden of the resource allocation from the air interface to the backbone infrastructure. By exchanging channel assignment as well as other relevant information in real time through the backbone network, each base can calculate the impact of a resource assignment on the system. As a result, rapid interference measurements, which are typically needed to implement DCA schemes, are replaced by a limited amount of path loss measurements and the computation of interference conditions by the base stations. This significantly reduces the measurement and over-the-air signaling requirements, and can also provide an opportunity for a better optimization of the system performance. We focus on two specific algorithms: network-assisted least-interference-based dynamic packet assignment (NA-LI-DPA) and network-assisted dynamic packet assignment with throughput optimization (NA-DPA). NA-LI-DPA closely resembles a least-interference-based dynamic channel assignment algorithm, and NA-DPA attempts to further improve the overall system throughput. The algorithms, as defined, are appropriate for a best-effort data service, where the primary goal is to provide a higher throughput. However, it will be clear from the discussion that it is also feasible to alter the algorithms to optimize performance metrics other than throughput, e.g., to ensure a certain quality of service. We show through simulation that, for a system like enhanced general packet radio service (EGPRS) system, NA-DPA can provide a throughput that is 50% higher than random packet assignment, and 25% higher than that obtained by conventional DCA algorithms     

未来无线资源管理

分析了未来异构多无线网络的特点和需求,介绍了未来无线资源管理涵盖的内容。重点分析了联合无线资源管理和传统无线资源管理的区别,以及未来联合无线资源管理可能采用的模式。     

Radio resource management in wireless LANs

Some chief information officers and information technology managers are reluctant to deploy wireless LANs. Among their concerns are reliability, availability, performance, and deployment. Each of these concerns can be directly addressed through the radio resource management techniques used in a new generation of wireless LAN equipment. The new capabilities include dynamic channel assignment, dynamic power control, and load sharing. Changing from the relatively static radio resource management techniques generally in use today to dynamic methods like those highlighted in this article helps to increase the capacity and improve the performance of large-scale wireless LANs.     

Vertical handover policies for common radio resource management

The 3G and Beyond 3G wireless networks introduce new technologies, and in many cases, new frequency bands. Integrated hierarchical network architectural studies suggest that by using a Common Radio Resource Manager to engineer traffic across these component networks, operators can achieve increased efficiency and flexibility in supporting changing traffic demands. This study demonstrates how vertical handovers can be used to optimize network performance, by adaptively rearranging traffic across network boundaries. We survey policy implementations that consider which services/sessions shall move, where they shall move, when they shall move, and whether they shall return. Copyright © 2005 John Wiley & Sons, Ltd.     

Cross-layer radio resource allocation in packet CDMA wireless mobile networks

An efficient radio resource allocation scheme is crucial for guaranteeing the quality of service (QoS) requirements and fully utilizing the scarce radio resources in wireless mobile networks. Most of previous studies of radio resource allocation in traditional wireless networks concentrates on network layer connection blocking probability QoS. In this paper, we show that physical layer techniques and QoS have significant impacts on network layer QoS. We use a concept of cross-layer effective bandwidth to measure the unified radio resource usage taking into account both physical layer linear minimum-mean square error (LMMSE) receivers and varying statistical characteristics of the packet traffic in code devision multiple access (CDMA) networks. We demonstrate the similarity between traditional circuit-switched networks and packet CDMA networks, which enables rich theories developed in traditional wireless mobile networks to be used in packet CDMA networks. Moreover, since both physical layer signal-to-interference ratio (SIR) QoS and network layer connection blocking probability QoS are considered simultaneously, we can explore the tradeoff between physical layer QoS and network layer QoS in packet CDMA networks. This work is supported by Natural Science and Engineering Research Council of Canada. Please address all correspondence to Professor Vikram Krishnamurthy at the above address. Fei Yu received the Ph.D. degree in electrical engineering from the University of British Columbia in 2003. From 2002 to 2004, he was with Ericsson (in Lund, Sweden), where he worked on the research and development of dual mode UMTS/GPRS handsets. From 2005, he has been working in Silicon Valley at a start-up, where he conducts research and development in the areas of advanced wireless communication technologies and new standards. After completing the PhD, he has been a research associate in the Department of Electrical and Computer Engineering at the University of British Columbia. His research interests include cross-layer optimization, QoS provisioning and security in wireless networks. Vikram Krishnamurthy (S’90-M’91-SM’99-F’05) was born in 1966. He received his bachelor’s degree from the University of Auckland, New Zealand in 1988, and Ph.D. from the Australian National University, Canberra, in 1992. Since 2002, he has been a professor and Canada Research Chair at the Department of Electrical Engineering, University of British Columbia, Vancouver, Canada. Prior to this he was a chaired professor at the Department of Electrical and Electronic Engineering, University of Melbourne, Australia. His research interests span several areas including ion channels and nanobiology, stochastic scheduling and control, statistical signal processing and wireless telecommunications. Dr. Krishnamurthy has served as associate editor for IEEE Transactions on Signal Processing, IEEE Transactions Aerospace and Electronic Systems, IEEE Transactions Nanobioscience, IEEE Transactions Circuits and Systems II, Systems and Control Letters and European Journal of Applied Signal Processing. He was guest editor of a special issue of IEEE Transactions on NanoBioScience, March 2005 on bio-nanotubes.     

Blockchain-enabled resource management and sharing for 6G communications

The sixth-generation (6G) network must provide better performance than previous generations to meet the requirements of emerging services and applications, such as multi-gigabit transmission rate, higher reliability, and sub-1 ​ms latency and ubiquitous connection for the Internet of Everything (IoE). However, with the scarcity of spectrum resources, efficient resource management and sharing are crucial to achieving all these ambitious requirements. One possible technology to achieve all this is the blockchain. Because of its inherent properties, the blockchain has recently gained an important position, which is of great significance to the 6G network and other networks. In particular, the integration of the blockchain in 6G will enable the network to monitor and manage resource utilization and sharing efficiently. Hence, in this paper, we discuss the potentials of the blockchain for resource management and sharing in 6G using multiple application scenarios, namely, Internet of things, device-to-device communications, network slicing, and inter-domain blockchain ecosystems.     

On the radio capacity of TDMA and CDMA for broadband wireless packet communications

Studies of the capacity of cellular systems, stated in terms of the admissible number of remote users, have generally been limited to voice telephony. We address the problem of comparing the interference-limited performance of code-division multiple-access (CDMA) and time-division multiple-access (TDMA) systems in a packet-switched environment. The objective is to determine whether the capacity advantages claimed for circuit-switched CDMA still apply in a packet-switched environment, where the natural time diversity of bursty transmission may be a significant factor. Under a set of specific assumptions about the wireless environment (including path loss, shadow fading, multipath delay spread, cochannel interference, power control, and coding), we evaluate the number of users that can be admitted to the system while maintaining some desired quality-of-service (QoS) level. Four different classes of users with different characteristics and requirements are considered. The system capacity is found to depend significantly on the QoS objectives, which might be stated in terms of availability of some specified signal-to-interference level, packet-loss rate, or mean tolerable delay. The main finding is that strict requirements imposed on the radio access level tend to favor CDMA, whereas if some form of packet recovery is allowed at the higher layers (implying a relaxed set of requirements on the radio interface), then a somewhat higher capacity may be achieved by TDMA.     

Measurements and models of radio frequency impulsive noise forindoor wireless communications

The authors present the results of average and impulsive noise measurements inside several office buildings and retail stores. The noise measurement system operated at 918 MHz, 2.44 GHz, and 4 GHz with a nominal 40-MHz, 3-dB RF bandwidth. Omnidirectional and directional antennas were used to investigate the characteristics and sources of RF noise in indoor channels. Statistical analyses of the measurements are presented in the form of peak amplitude probability distributions, pulse duration distributions, and interarrival time distributions. Simple first-order mathematical models for these statistical characterizations are also presented. These analyses indicate that photocopiers, printers (both line printers and cash register receipt printers), elevators, and microwave ovens are significant sources of impulse noise in office and retail environments