Will the New Wi-Fi Fly?

Since the approval of the original IEEE 802.11 standard and the increased use of the resulting Wi-Fi technology over the years, interest in wireless networking has grown rapidly. As is the case with other networking technologies, Wi-Fi users have sought faster IEEE 802.11 versions with longer transmission ranges. Because of this, users have eagerly awaited IEEE 802.11n, which promises higher speeds and longer ranges than earlier Wi-Fi versions. However, the technology has had a rocky standardization process. As is so often the case, two groups of vendors squared off over whose 802.11n approach would become the standard and thereby yield revenue and potential market dominance to the winner. Recently, though, the two sides have moved toward a compromise. However, there are still some unresolved issues, and the IEEE 802.11 Wireless Local Area Networks (WLAN) Working Group still hasn't approved the new technology as a standard     

New interpretation of laser gyro drifts

Discuss and develop some contents which are relevant to the IEEE Std 647TM-2006 in this paper. The IEEE Std only involves Allan variance, and decomposes it into five primary noise terms, in which, however, the noise nature of the so called rate random walk noise and the rate ramp is doubted by the IEEE Std editors. Here we use a mathematical identity to entirely affirm the first query and partially the second query as mentioned above. Besides, we argue that only the classical variance can be used in navigat...     

New year, New Challenges [Editor's Remarks]

It is a great honor and privilege for me to serve as the Editor-in-Chief of IEEE Computational Intelligence Magazine (CIM). I would like to take this opportunity to thank the Administrative Committee (ADCOM) and the Executive Committee (EXCOM) of IEEE Computational Intelligence Society (CIS), particularly David B. Fogel and Xin Yao, for supporting my appointment. My deep appreciation also goes to the founding Editor-in-Chief of CIM, Gary G. Yen, for his unconditional support during the period of transition. I look forward to his continued contributions to the magazine in his new capacity as the IEEE CIS President.     

Classifier design for static security assessment using particle swarm optimization

Security is recognized as an important problem in planning, design and operation stages of electric power systems. Power system security assessment deals with the system’s ability to continue to provide service in the event of an unforeseen contingency. This paper proposes a particle swarm optimization (PSO) based classification for static security evaluation in power systems. A straightforward and quick procedure is used to select a small number of variables as features from a large set of variables which are normally available in power systems. A simple first order security function is designed using the selected features for classification. The training of weights in the classifier function (security function) is carried out by PSO technique. The PSO algorithm has minimized the error rate in classification. The procedure to determine the security function (classifier) is discussed. The performance of the algorithm is tested on IEEE 14 Bus, IEEE 57 Bus and IEEE 118 Bus systems. Simulation results show that the PSO classifier gives a fairly high classification accuracy and less misclassification rate.     

Revised standard addresses design requirements for computers usedin nuclear power-plant safety systems

The IEEE Nuclear Engineering Committee has standards that address hardware issues. The IEEE Computer Society has standards addressing software. The P-7-4.3.2, IEEE standard criteria for digital computers in safety systems of nuclear power generating stations, which brings together standards from both groups to address the integration of computer hardware and software with noncomputer hardware, is discussed. P-7-4.3.2 is being developed to show the interrelationship of software and hardware requirements as they apply throughout the development process. The influence of system design development on system quality, system qualification, and system integrity, are described     

Evaluating transport protocol performance over a wireless mesh backbone

IEEE 802.11n wireless physical layer technology increases the deployment of high throughput wireless indoor mesh backbones for ubiquitous Internet connectivity at the urban and metropolitan areas. Most of the network traffic flows in today’s Internet use ‘Transmission Control Protocol’ (TCP) as the transport layer protocol. There has been extensive works that deal with TCP issues over wireless mesh networks as well as noisy wireless channels. Further, IEEE 802.11n is well known for its susceptibility to increased channel losses during high data rate communication. This paper investigates the dynamics of an end-to-end transport layer protocol like TCP in the presence of burst and correlated losses during IEEE 802.11n high data rate communication, while maintaining fairness among all the end-to-end flows. For this purpose, we evaluate four TCP variants-Loss Tolerant TCP (LT-TCP), Network Coded TCP (TCP/NC), TCP-Horizon and Wireless Control Protocol (WCP), where the first two protocols are known to perform very well in extreme lossy networks, and the last two are specifically designed for mesh networks. Our evaluation shows that WCP performs better in a IEEE 802.11n supported mesh networks compared to other three variants. However, WCP also results in negative impact at high data rates, where end-to-end goodput drops with the increase in physical data rate. The analysis of the results reveals that explicit loss notifications and flow balancing are not sufficient to improve transport protocol performance in an IEEE 802.11n supported mesh backbone, rather a specific mechanism is required to synchronize the transport queue management with lower layer scheduling that depends on IEEE 802.11n features, like channel bonding and frame aggregation. The findings of this paper give the direction to design a new transport protocol that can utilize the full capacity of IEEE 802.11n mesh backbone.     

On the performances of IEEE 802.16(d) mesh CDS-mode networks using Single-Switched-Beam Antennas

The IEEE 802.16(d) mesh coordinated distributed scheduling (CDS) mode is a novel technology for future fixed wireless backbone networks and designed for the use of omnidirectional antennas. The use of Single-Switched-Beam Antennas (SSBAs) may have great potential to increase network capacity due to the antenna directivity. However, a network designed for omnidirectional antennas usually cannot operate well or achieve good performance with the presence of antenna directivity.In this paper, we review the designs of the IEEE 802.16 mesh CDS-mode network, study the issues of this network with the use of Single-Switched-Beam Antennas (SSBAs), and propose a complete solution to solve these issues. The performances of our proposed scheme is evaluated using simulations. The simulation results show that our proposed scheme can effectively solve the issues of using SSBAs in the IEEE 802.16 mesh CDS-mode network and greatly increase its network capacity.     

Relay technologies and technical issues in IEEE 802.16j Mobile Multi-hop Relay (MMR) networks

An amendment to the 802.16e standard namely IEEE 802.16j specifying relay station (RS) and multi-hop relay base station (MR-BS) was approved in year 2006 supports Mobile Multi-hop Relay networks. (MMR). It provides coverage extension to isolated area and throughput enhancement by specifying relay stations. The physical (PHY) layer of WiMAX IEEE 802.16j standard is based on the IEEE 802.16-2004 and IEEE 802.16e-2005 standards and was designed from IEEE 802.11a. This paper reviews the Relay technologies and technical issues in the physical and MAC layer of IEEE 802.16j such as Data forwarding schemes frame structure, Link adaptation, modulation and coding, these issues belongs to physical layer, QoS scheduling services, Bandwidth allocation and request, Network planning, MAC handover procedures, connection management, path management, interference management, all these issues belongs to MAC layer.     

New software-quality metrics methodology standard fills measurementneed

The IEEE 1061, IEEE standard for a software-quality metrics methodology, which is the first IEEE-issued standard that deals with quality metrics, is discussed. The philosophy behind the standard, the scope of the standard, and the standard's intended audience are described. Several aspects of the standard, including the methodology of metrics and validity criteria, are reviewed     

Embedded boundary scan

As boundary scan technology continues to mature, engineers continue to find innovative ways of using the IEEE Std. 1149.1 facilities throughout the life cycle of a board. Lucent Technologies is at the forefront of this development, and the authors here describe how they have expanded the use and reuse of the IEEE 1149.1 board tests into a variety of additional test environments.     

Design and implementation of a vehicle interface protocol using an IEEE 1394 network

A wide variety of in-vehicle devices such as camera sensors, navigation systems, telematics and communication equipments have been incorporated into a vehicle to realize Intelligent Transport Systems (ITS) applications. Because an efficient standardized network is required, ITS Data Bus (IDB) has been discussed to carry high-speed multimedia data for audio, video and other real-time ITS applications. For connecting devices in a standardized manner, the IDB network has architecture with a gateway called vehicle interface which is located between automaker’s proprietary network and the standardized IDB network. IEEE 1394 (also known as iLink or FireWire), which can transport multimedia data for consumer electronics, is a good candidate for IDB network. In this paper, we analyze the issues for existing AV/C protocol (application layer protocol over IEEE 1394) to comprise the IDB network. In addition, we designed and implemented the vehicle interface protocol as a higher layer of IEEE 1394 to address the AV/C protocol issues for realizing the whole IDB network architecture.     

IEEE 1394: status and growth path

In December 1995, the final public review of the High Performance Serial Bus draft standard concluded, and the IEEE ratified it as IEEE Std 1394-1995. As 1394 working-group chair, I extend my appreciation to all those who took the time to review vote, and comment upon the draft standard. It is also gratifying to the entire working group to observe the various computer and digital audiovisual (AV) products now incorporating support for the 1394 interface. This column's purpose is to review technical issues raised by the IEEE study group exploring the development of a second-generation standard based on 1394. This second-generation activity is likely to consist of several 1394-related working groups. Each expanding a different attribute or capability of the standard. To set a proper foundation for the discussion of 1394's future. I first summarize the concepts and facilities of the present standard and review its current status in the computer and digital AV industries     

QoS provisioning in IEEE 802.11-compliant networks: Past,present, and future

Proliferation of portable, wireless-enabled laptop computers and PDAs, cost-effective deployment of access points, and availability of the license-exempt bands and appropriate networking standards contribute to the conspicuous success of IEEE 802.11 WLANs. In the article, we provide a comprehensive overview of techniques for capacity improvement and QoS provisioning in the IEEE 802.11 protocol family. These techniques represent the R&D efforts both in the research community and the IEEE 802.11 Working Groups. Specifically, we summarize the operations of IEEE 802.11 legacy as well as its extension, introduce several protocol modeling techniques, and categorize the various approaches to improve protocol capacity, to provide QoS (by either devising new MAC protocol components or fine-tuning protocol parameters in IEEE 802.11), and to judiciously arbitrate radio resources (e.g., transmission rate and power). To demonstrate how to adapt QoS provisioning in newly emerging areas, we use the wireless mesh network as an example, discuss the role IEEE 802.11 plays in such a network, and outline research issues that arise.     

The growing role of IT in transportation

The automobile and railway industries have grown more reliant on IT, but future intelligent transportation systems must also address potential security breaches. This article focuses on the security issues that ITSs must address before a full-blown implementation becomes feasible. The broad spectrum of our transportation-related articles is simply the tip of the iceberg. On 25 August 2003, the Altamont Commuter Express train that serves the San Francisco bay are became one of the first commuter rail systems in the US to serve as a mobile IEEE 802.11 hot spot for commuters. IEEE 802.11 is a family of specifications that the IEEE developed for wireless LAN (local area network) technology. Now, for better or for worse, commuters can maintain nearly door-to-door broadband connectivity between their homes and their offices. Even in automobiles, phones based on Bluetooth - an open standard for short-range digital transmissions - and personal digital assistants are likely to become integrated with fully wired onboard dashes. Meanwhile, government agencies are continuously enhancing traffic-monitoring systems to better route highway resources and increase public safety.     

Energy-Efficient Localized Topology Control Algorithms in IEEE 802.15.4-Based Sensor Networks

Sensor networks have emerged as a promising technology with various applications, where power efficiency is one of the critical requirements. The recent IEEE 802.15.4 standard offers a promising platform for wireless sensor networks. Since each node can act as a coordinator or a device in the IEEE 802.15.4 standard, 802.15.4-based sensor networks have various possible network topologies. To reduce power consumption, in this paper, we try to construct network topologies with a small number of coordinators while still maintaining network connectivity. By reducing the number of coordinators, the average duty cycle is reduced and the battery life is prolonged. Three topology control algorithms are proposed in this paper. Self-pruning (SP) is the simplest one with O(1) running time and provides the shortest path to the sink node. Ordinal pruning (OP) can significantly improve SP in terms of power saving with O(n) running time. Layered pruning (LP) is a trade off between the first two pruning algorithms with O(radicn) running time and has a slightly higher power consumption than OP. Furthermore, all three algorithms are independent of the physical radio propagation characteristics. Extensive simulations have been performed to verify the effectiveness of the proposed topology control schemes     

Streamlining the standards development process

The technical quality of an IEEE standard and its expeditious delivery to the user community are the responsibility of highly competent professionals, working in committees, to achieve those results. In a way, these goals are compelling forces. Rushing a standard by sacrificing quality is unacceptable, yet it is equally unacceptable to miss a market niche by delivering a standard too late. That is why the IEEE, as the best equipped standards developer in the electrotechnology field, must continue to strive for process improvements. Authors of documents should be the ones creating the ultimate electronic product     

An energy-efficient MAC protocol with downlink traffic scheduling strategy in IEEE 802.11 infrastructure WLANs

To support mobility, mobile devices are powered by batteries with limited energy. Thus, the good design of energy efficiency becomes one of the most important issues in wireless networks. A well-designed energy-efficient MAC protocols can be realized with both minimum energy consumption as well as maximum data throughput and can be easily implemented in products with de facto standards. Based on IEEE 802.11 infrastructure WLANs, we propose an energy-efficient MAC protocol which employs a novel approach to schedule those to-be-transmitted frames for saving energy by reducing the total waiting time and the collisions of the frames. Fault tolerance issues are also considered in the proposed protocol because frames are transmitted in fading interference wireless environment. Through analyses and simulations, we demonstrate that our protocol presents a better performance than IEEE 802.11 and other protocols not only in energy efficiency but also in aggregate throughput and frame transmission delay.     

Panel Summaries

"IEEE 1500: Embedded core-based test standard—Why should I adopt it?" The IEEE standards committee has now developed a new standard, IEEE 1500, which defines an isolation mechanism for IPs (cores) whereby an IEEE 1500 wrapper can isolate cores for test and debug on a SoC. A panel session at the 23rd IEEE VLSI Test Symposium debated how and why the industry should adopt this new standard. The 11th IEEE International On-Line Testing Symposium (IOLTS 05) held a special panel session on the topic, "Online Testing for Secure Implementations: Design and Validation." The panelists discussed how online testing techniques can improve security and how to evaluate, at different stages in the design flow, the achieved level of security. The panelists raised such issues as fault-based and side-channel attacks, the need for secure and efficient DFT methodologies, and the need to better evaluate a given implementation's level of robustness.     

Optimal location and parametric settings of FACTS devices based on JAYA blended moth flame optimization for transmission loss minimization in power systems

This paper presents a novel hybrid algorithm that includes the superior properties of strong algorithms which have been developed in recent past. The study involves minimization of transmission loss in IEEE networks through the efficient placement of flexible alternating current transmission system (FACTS) devices. In this work two types of devices namely thyristor controlled series compensator (TCSC) and static VAR compensator (SVC) are used in IEEE 14 bus and IEEE 30 bus systems. The main objective of active power loss reduction is achieved through the minimization of installation cost of these devices which is considered as the fitness function for the optimization algorithms. In this paper Moth flame optimization (MFO) in its natural form as well as in hybrid form called JAYA blended MFO (JMFO) is applied for the study. The results obtained are compared with existing technique like particle swarm optimization (PSO).

     

Differentiation, QoS guarantee, and optimization for real-time traffic over one-hop ad hoc networks

Nodes having a self-centrically broadcasting nature of communication form a wireless ad hoc network. Many issues are involved to provide quality of service (QoS) for ad hoc networks, including routing, medium access, resource reservation, mobility management, etc. Previous work mostly focuses on QoS routing with an assumption that the medium access control (MAC) layer can support QoS very well. However, contention-based MAC protocols are adopted in most ad hoc networks since there is no centralized control. QoS support in contention-based MAC layer is a very challenging issue. Carefully designed distributed medium access techniques must be used as foundations for most ad hoc networks. In this paper, we study and enhance distributed medium access techniques for real-time transmissions in the IEEE 802.11 single-hop ad hoc wireless networks. In the IEEE 802.11 MAC, error control adopts positive acknowledgement and retransmission to improve transmission reliability in the wireless medium (WM). However, for real-time multimedia traffic with sensitive delay requirements, retransmitted frames may be too late to be useful due to the fact that the delay of competing the WM is unpredictable. In this paper, we address several MAC issues and QoS issues for delay-sensitive real-time traffic. First, a priority scheme is proposed to differentiate the delay sensitive real-time traffic from the best-effort traffic. In the proposed priority scheme, retransmission is not used for the real-time traffic, and a smaller backoff window size is adopted. Second, we propose several schemes to guarantee QoS requirements. The first scheme is to guarantee frame-dropping probability for the real-time traffic. The second scheme is to guarantee throughput and delay. The last scheme is to guarantee throughput, delay, and frame-dropping probability simultaneously. Finally, we propose adaptive window backoff schemes to optimize throughput with and without QoS constraints.