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Remote control of CNC machines using the CyberOPC communication system over public networks

TORRISI, Nunzio M.; OLIVEIRA, Joao F. G.
Fonte: SPRINGER LONDON LTD Publicador: SPRINGER LONDON LTD
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
35.91%
During the last few years, the evolution of fieldbus and computers networks allowed the integration of different communication systems involving both production single cells and production cells, as well as other systems for business intelligence, supervision and control. Several well-adopted communication technologies exist today for public and non-public networks. Since most of the industrial applications are time-critical, the requirements of communication systems for remote control differ from common applications for computer networks accessing the Internet, such as Web, e-mail and file transfer. The solution proposed and outlined in this work is called CyberOPC. It includes the study and the implementation of a new open communication system for remote control of industrial CNC machines, making the transmission delay for time-critical control data shorter than other OPC-based solutions, and fulfilling cyber security requirements.; FAPESP; ZEMA Industrial Grinders; GE Fanuc

Um estudo sobre redes de comunicacao de dados

Tarouco, Liane Margarida Rockenbach
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Dissertação Formato: application/pdf
Português
Relevância na Pesquisa
35.88%
A implantação de grandes redes de comunicação de dados, como instrumento de disseminação da utilização da computação, e o surgimento, no Brasil, das primeiras ideias e experiências com redes de comunicação de dados, inspiraram a presente dissertação, abordando os conceitos básicos, algumas experiências e as dificuldades encontradas no uso do teleprocessamento. O trabalho e dirigido aos que pretendem criar redes de comunicação de dados bem como, aos alunos de cursos voltados para o teleprocessamento. Descreve-se, no texto a organização das redes de comunicação de dados e salienta-se os problemas ,inerentes á transmissão ao sinal. Finalmente, são descritas algumas formas de aplicações, utilizando-se o sistema Burroughs B-6700.; The implementation of large data communications networks as an ever growing tool of computer use, added to the appearance, in Brazil, of the first ideas and experiences concerning data communication networks, motivated this discus sion of basic concepts, some experiences and difficulties arisen in teleprocessing. The dissertation is addressed to all those involved in creating data communication networks, as well as to students enrolled in teleprocessing courses. It describes the organization of the data communication networks and points out to some inherent problems related to signal transmission. Finally...

Implementação da biblioteca de comunicação DECK sobre o padrão de protocolo de comunicação em nível de usuário VIA; DECK communication library implementation over the standard user-level communication protocol VIA

Silva, Leonardo Alves de Paula e
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Dissertação Formato: application/pdf
Português
Relevância na Pesquisa
35.86%
O uso de técnicas de cópia-zero e desvio do sistema operacional permitem a diminuição da latência de comunicação e o aumento da largura de banda. Menores latências e maiores larguras de banda contribuem para que o desempenho das aplicações paralelas seja mais alto, bem como torna-as mais escaláveis. Protocolos de comunicação que utilizam-se destas técnicas são conhecidos como protocolos de comunicação em nível de usuário. Baseado nas experiências de outros grupos de pesquisa na implementação de bibliotecas de comunicação e bibliotecas de programação paralelas sobre VIA e na experiência do GPPD na implementação da biblioteca DECK, este texto apresenta a implementação das primitivas DECK sobre o padrão VIA, o qual é classificado como sendo um protocolo de nível de usuário. O objetivo desta dissertação é implementar o DECK sobre VIA evitando qualquer cópia intermediária na comunicação de uma mensagem, atingindo assim cópia-zero. Dentre as bibliotecas de comunicação sobre VIA, DECK/VIA foi a única biblioteca que teve o compromisso ser totalmente livre de cópias intermediárias, embora houvesse que forçar um sincronismo na comunicação para manter este compromisso. Para a implementação do DECK/VIA...

Efficient aggregate computations in large-scale dense wireless sensor networks

Pereira, Nuno Alexandre Magalhães
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Tese de Doutorado
Publicado em 10/09/2010 Português
Relevância na Pesquisa
35.87%
Tese de doutoramento em Informática; Assuming a world where we can be surrounded by hundreds or even thousands of inexpensive computing nodes densely deployed, each one with sensing and wireless communication capabilities, the problem of efficiently dealing with the enormous amount of information generated by those nodes emerges as a major challenge. The research in this dissertation addresses this challenge. This research work proves that it is possible to obtain aggregate quantities with a timecomplexity that is independent of the number of nodes, or grows very slowly as the number of nodes increases. This is achieved by co-designing the distributed algorithms for obtaining aggregate quantities and the underlying communication system. This work describes (i) the design and implementation of a prioritized medium access control (MAC) protocol which enforces strict priorities over wireless channels and (ii) the algorithms that allow exploiting this MAC protocol to obtain the minimum (MIN), maximum (MAX) and interpolation of sensor values with a time-complexity that is independent of the number of nodes deployed, whereas other state-of-the-art approaches have a time-complexity that is dependent on the number of nodes. These techniques also enable to efficiently obtain estimates of the number of nodes (COUNT) and the median of the sensor values (MEDIAN). The novel approach proposed to efficiently obtain aggregate quantities in large-scale...

Network interfaces flying over IP networks

Brito, Alexandre; Aguiar, Rui L; Barraca, João Paulo
Fonte: IEEE Publicador: IEEE
Tipo: Conferência ou Objeto de Conferência
Português
Relevância na Pesquisa
35.89%
We propose a novel method to export both interface control and data planes across different hosts, effectively enabling hardware specific control of network interfaces over the Internet, or from a host to its virtualized guests. Our solution is a major step towards distributed environments of heterogeneous communication systems, particularly relevant in the scope of custom system composition, remote development and testing, and is especially relevant when considering embedded or geographically constrained devices. Results obtained by our prototype implementation validate the effectiveness of the solution. We present a preliminary characterization of its impact, when considering traffic generation applications, when applied over an IEEE 802.11g communication medium.

Energy-efficient data gathering and aggregation for wireless sensor networks.

Wang, Yuexian
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2011 Português
Relevância na Pesquisa
35.87%
Wireless sensor networks, when compared with other traditional wireless communication systems, possess two unique characteristics: (i) the limited battery power supply of sensor nodes, and (ii) the redundant data which are correlated among different nodes. These two are associated with energy consumption and data traffic control. The research in this thesis aims at designing an energy efficient routing scheme with data aggregation in wireless sensor networks. In this thesis, we developed an energy-efficient routing scheme consisting of the setup phase, the routing tree optimisation phase and the data gathering phase. The setup phase is to build initial routing trees by the ant colony optimisation algorithm which is executed between the base station and all sensor nodes. A key to our routing scheme is the routing tree optimisation phase. The routing tree optimisation is performed by the base station using the particle swarm optimisation algorithm. We propose a modified particle swarm optimisation algorithm that is capable of jointly exploring the data traffic and communication structure to provide the optimal strategy for data gathering. Once the routing tree optimisation has been accomplished, it comes to the data gathering phase. Data flows to the aggregator node...

Distributed Cooperative Communications in Wireless Networks

Khojastepour, Mohammad; Khojastepour, Mohammad
Fonte: Universidade Rice Publicador: Universidade Rice
Tipo: Thesis; Text
Português
Relevância na Pesquisa
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PhD Thesis; The primary challenge in communication over wireless networks, unlike wireline networks, is the existence of interference and channel variations (fading). Having more users at higher data rates means that current point-to-point networks will not scale. To engineer a scalable network, we introduce a new paradigm that exploits different network characteristics. We show that cooperation between users in the net- work, network coding, not only reduces existing (destructive) interferences from other users but it can also generate constructive interference, transforming the destructive interference into useful information. In this thesis, we explore the problem of source and channel coding over wireless networks, ranging from information theoretical analysis to code design and practical implementation issues. We show that significant gains in throughput can be achieved through network coding. Despite the importance of the problem and the work done on wireless networks, little is known about network coding and the effective use of the relaying function and cooperative strategy at the intermediate nodes. A notable example is the lack of an optimal coding scheme over the relay channel, the simplest form of a network...

Modeling and design for future wireless cellular networks: coverage, rate, and security

Wang, He
Fonte: Universidade Nacional da Austrália Publicador: Universidade Nacional da Austrália
Tipo: Thesis (PhD); Doctor of Philosophy (PhD)
Português
Relevância na Pesquisa
35.86%
Accompanied by the wide penetration of smartphones and other personal mobile devices in recent years, the foremost demand for cellular communications has been transformed from offering subscribers a way to communicate through low data rate voice call connections initially, into providing connectivity with good coverage, high data rate, as well as strong security for sensitive data transmission. To satisfy the demands for improved coverage and data rate, the cellular network is undergoing a significant transition from conventional macrocell-only deployment to heterogeneous network (HetNet), in which a multitude of radio access technologies can be co-deployed intelligently and flexibly. However, the small cells newly introduced in HetNet, such as picocells and femtocells, have complicated the network topology and the interference environment, thus presenting new challenges in network modeling and design. In recent studies, performance analyses were carried out accurately and tractably with the help of Poisson point process (PPP)-based base station (BS) model. This PPP-based model is extended in this work with the impact of directional antennas taken into account. The significance of this extension is emphasized by the wide usage of directional antennas in sectorized macrocell cells. Moreover...

Connecting to Work : How Information and Communication Technologies Could Help Expand Employment Opportunities

Raja, Siddhartha; Imaizumi, Saori; Kelly, Tim; Narimatsu, Junko; Paradi-Guilford, Cecilia
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Publications & Research :: Working Paper; Publications & Research
Português
Relevância na Pesquisa
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Information and communication technology (ICT) has grown as a sector and now employs millions of people worldwide. The proliferation of ICTs has also helped digitize how people find and do work. The world will need to create over 600 million jobs by 2030 for unemployment to remain at current levels. ICT-enabled employment may help address some of this problem both by creating jobs in the ICT sector and by helping to make labor markets more inclusive, innovative, flexible, and transparent. What can governments do to prepare for these changes and maximize employment opportunities? This paper is a first step in an effort by the World Bank to understand how ICTs are shaping, changing, and transforming labor markets. It explores how governments and other stakeholders might respond to leverage the growth of ICTs to help increase employment opportunities. This paper is structured as follows: section 1 serves as an introduction; section 2 defines the scope, focusing on the types of employment opportunities due to ICT as a sector and as a tool; section 3 considers the impact of the ICT sector on software programming...

Uma nova arquitetura para provisão de QoS utilizando enxame de partículas em redes WiMAX fixas

Dosciatti, Eden Ricardo
Fonte: Curitiba Publicador: Curitiba
Tipo: Tese de Doutorado
Português
Relevância na Pesquisa
35.89%
Technological advances in recent years have led to a growth in the user base using communication networks, especially with multimedia services such as IPTV, video conferencing and VoIP. As these services require more resources and generate a great demand on the network infrastructure, each user must have their applications dealt with in accordance with certain priorities, to provide an acceptable level of service. Under this assumption, the communication networks for wireless broadband, based on the IEEE 802.16 standard, also known as WiMAX, can meet the various demands of end users, the need for access to data at all times and in any place and the connectivity efficient broadband, offering excellent tredeoff for the end user by enabling high data transmission capacity at a relatively low cost of deployment. The provision of quality services is a very important factor for the performance of communication networks for that, the scheduling mechanisms, admission control connections and traffic policing, must be present. However, the IEEE 802.16 standard specifies only policies of how these mechanisms should be implemented, but does not define how to implement them. This research aims to present a new architecture for uplink traffic, the WiMAX network base stations...

Reduzindo o consumo de potência em redes intra-chip através de esquemas de codificação de dados.; Reducing the power consumption in networks-on-chip through data coding schemes

Palma, José Carlos Sant'Anna
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Tese de Doutorado Formato: application/pdf
Português
Relevância na Pesquisa
35.86%
O consumo de potência em uma Rede Intra-Chip (em inglês, Network-on-Chip – NoC) cresce linearmente com a quantidade de transições de sinais nos pacotes transmitidos através da infra-estrutura de interconexão. Uma forma de minimizar o consumo de potência em um sistema baseado em NoC é reduzir a atividade de transição de sinais nas portas de entrada dos módulos que constituem a NoC. Esta redução pode ser obtida através da utilização de esquemas de codificação de dados. Vários esquemas de codificação foram propostos no final dos anos 90, porém direcionados a arquiteturas de comunicação baseadas em barramentos. Este trabalho investiga a utilização destes esquemas de codificação em sistemas baseados em Networks-on-Chip. Dentre os esquemas encontrados na literatura, quatro foram implementados e avaliados neste trabalho. Este trabalho também apresenta como contribuição original um novo esquema de codificação de dados adequado a NoCs. A estimativa do consumo de potência da NoC é calculada com base em macromodelos que reproduzem a potência consumida em cada módulo interno da NoC, de acordo com a atividade de transição de sinais no tráfego recebido. Estes macromodelos são aqui caracterizados através da simulação elétrica de cada módulo da NoC e dos esquemas de codificação. Para permitir a análise de consumo com tráfegos de aplicações reais...

Successive structuring of source coding algorithms for data fusion, buffering, and distribution in networks

Draper, Stark Christiaan
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 165 p.; 6835571 bytes; 6835377 bytes; application/pdf; application/pdf
Português
Relevância na Pesquisa
35.92%
Numerous opportunities to improve network performance present themselves when we make communication networks aware of the characteristics of the data content they are handling. In this thesis, we design such content-aware algorithms that span traditional network layers and are successively structured, focusing on problems of data fusion, buffering, and distribution. The successive structuring of these algorithms provides the flexibility needed to deal with the distributed processing, the heterogeneous sources of information, and the uncertain operating conditions that typify many networks. We investigate the broad interactions between estimation and communication in the context of data fusion in tree-structured sensor networks. We show how to decompose any general tree into serial (pipeline) and parallel (hub-and-spoke) networks. We develop successive coding strategies for these prototype sensor networks based on generalized Wyner-Ziv coding. We extend Wyner-Ziv source coding with side information to "noisy" encoder observations and develop the associated rate-distortion function. We show how to approach the serial and parallel network configurations as cascades of noisy Wyner-Ziv stages. This approach leads to convenient iterative (achievable) distortion-rate expressions for quadratic-Gaussian scenarios. Under a sum-rate constraint...

Reducing Cascading Failure Risk by Increasing Infrastructure Network Interdependency

Korkali, Mert; Veneman, Jason G.; Tivnan, Brian F.; Hines, Paul D. H.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
35.88%
Increased coupling between critical infrastructure networks, such as power and communication systems, will have important implications for the reliability and security of these systems. To understand the effects of power-communication coupling, several have studied interdependent network models and reported that increased coupling can increase system vulnerability. However, these results come from models that have substantially different mechanisms of cascading, relative to those found in actual power and communication networks. This paper reports on two sets of experiments that compare the network vulnerability implications resulting from simple topological models and models that more accurately capture the dynamics of cascading in power systems. First, we compare a simple model of topological contagion to a model of cascading in power systems and find that the power grid shows a much higher level of vulnerability, relative to the contagion model. Second, we compare a model of topological cascades in coupled networks to three different physics-based models of power grids coupled to communication networks. Again, the more accurate models suggest very different conclusions. In all but the most extreme case, the physics-based power grid models indicate that increased power-communication coupling decreases vulnerability. This is opposite from what one would conclude from the coupled topological model...

Detecting criminal organizations in mobile phone networks

Ferrara, Emilio; De Meo, Pasquale; Catanese, Salvatore; Fiumara, Giacomo
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 03/04/2014 Português
Relevância na Pesquisa
35.88%
The study of criminal networks using traces from heterogeneous communication media is acquiring increasing importance in nowadays society. The usage of communication media such as phone calls and online social networks leaves digital traces in the form of metadata that can be used for this type of analysis. The goal of this work is twofold: first we provide a theoretical framework for the problem of detecting and characterizing criminal organizations in networks reconstructed from phone call records. Then, we introduce an expert system to support law enforcement agencies in the task of unveiling the underlying structure of criminal networks hidden in communication data. This platform allows for statistical network analysis, community detection and visual exploration of mobile phone network data. It allows forensic investigators to deeply understand hierarchies within criminal organizations, discovering members who play central role and provide connection among sub-groups. Our work concludes illustrating the adoption of our computational framework for a real-word criminal investigation.; Comment: http://www.sciencedirect.com/science/article/pii/S0957417414001614. Expert Systems with Applications, 2014

Disaster-Resilient Control Plane Design and Mapping in Software-Defined Networks

Savas, S. Sedef; Tornatore, Massimo; Habib, M. Farhan; Chowdhury, Pulak; Mukherjee, Biswanath
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 01/09/2015 Português
Relevância na Pesquisa
35.88%
Communication networks, such as core optical networks, heavily depend on their physical infrastructure, and hence they are vulnerable to man-made disasters, such as Electromagnetic Pulse (EMP) or Weapons of Mass Destruction (WMD) attacks, as well as to natural disasters. Large-scale disasters may cause huge data loss and connectivity disruption in these networks. As our dependence on network services increases, the need for novel survivability methods to mitigate the effects of disasters on communication networks becomes a major concern. Software-Defined Networking (SDN), by centralizing control logic and separating it from physical equipment, facilitates network programmability and opens up new ways to design disaster-resilient networks. On the other hand, to fully exploit the potential of SDN, along with data-plane survivability, we also need to design the control plane to be resilient enough to survive network failures caused by disasters. Several distributed SDN controller architectures have been proposed to mitigate the risks of overload and failure, but they are optimized for limited faults without addressing the extent of large-scale disaster failures. For disaster resiliency of the control plane, we propose to design it as a virtual network...

Network Coded Gossip with Correlated Data

Haeupler, Bernhard; Cohen, Asaf; Avin, Chen; Médard, Muriel
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 08/02/2012 Português
Relevância na Pesquisa
35.9%
We design and analyze gossip algorithms for networks with correlated data. In these networks, either the data to be distributed, the data already available at the nodes, or both, are correlated. This model is applicable for a variety of modern networks, such as sensor, peer-to-peer and content distribution networks. Although coding schemes for correlated data have been studied extensively, the focus has been on characterizing the rate region in static memory-free networks. In a gossip-based scheme, however, nodes communicate among each other by continuously exchanging packets according to some underlying communication model. The main figure of merit in this setting is the stopping time -- the time required until nodes can successfully decode. While Gossip schemes are practical, distributed and scalable, they have only been studied for uncorrelated data. We wish to close this gap by providing techniques to analyze network coded gossip in (dynamic) networks with correlated data. We give a clean framework for oblivious network models that applies to a multitude of network and communication scenarios, specify a general setting for distributed correlated data, and give tight bounds on the stopping times of network coded protocols in this wide range of scenarios.

Close Communication and 2-Clubs in Corporate Networks: Europe 2010

Mokken, Robert J.; Laan, Steven
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
35.92%
Corporate networks, as induced by interlocking directorates between corporations, provide structures of personal communication at the level of their boards. This paper studies such networks from a perspective of close communication in sub-networks, where each pair of nodes (boards of a corporation) are either neighbours, or have a common neighbour. These correspond to subgraphs of diameter at most 2, designated by us earlier as 2-clubs, with three types (coteries, social circles and hamlets) as degrees of close communication in social networks, within the concept of boroughs of a network. Boroughs are maximal areas and containers of close communication between nodes of a network. This framework is applied in this paper to an analysis of corporate board interlocks between the top 300 European corporations 2010, as studied by Heemkerk (2013), with data provided by him for that purpose. The paper gives results for several perspectives of close communication in the European corporate network of 2010, a year close to the global crash of 2008, as a further elaboration of those given in Heemskerk (2013).; Comment: Keywords: social networks, corporate networks, interlocking directorates, close communication, 2-clubs, social circle, hamlet...

Inside all-optical networks

Tariq, Sana
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
Português
Relevância na Pesquisa
35.87%
Imagine a world where lightning speed Internet is as common as telephones today. Imagine when light, the fastest moving thing in the universe, is the signal-carrying transport medium. Imagine when bandwidth no more remains a constraint for any application. Imagine when imagination is the only limit! This all can be made possible with only one technology and that is optical communication. Optical networks have thus far provided a realization to a greater extent to the unlimited bandwidth dreams of this era, but as the demands are increasing, the electro-optic conversions seem to become bottlenecks in blended optical networks. The only answer to this is a complete migration to `All-Optical Networks' (AONs) which promise an end-to-end optical transmission. This thesis will investigate various aspects of all-optical networks and prove that AONs perform better than currently existing electro-optical networks. In today's' electro-optical networks, routing and switching is performed in electronic domain. Performance analysis of electro-optical and all-optical networks would include node utilization, link utilization and percentage of traffic routed. It will be shown through Opnet Transport Planner simulations that AONs work better under various traffic conditions. The coming decade will see a great boom in demands on telecommunications networks. The development in bandwidth-hungry applications like real-time video transmission...

Are low cost accountability, communications, and management systems for emergency first responders using 3G and 4G cellular technologies feasible?

Coleman, Kenneth
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
Português
Relevância na Pesquisa
35.92%
Reliable, easily deployed communication networks are a necessity for emergency responders as the coordination of their efforts and their safety depend on it. As a volunteer firefighter, this researcher is aware of the shortcomings of the current communication technologies presently deployed, and the risks it poses to firefighters. Some studies have proposed deployment of sophisticated hybrid, mesh networks and mobile ad hoc networks that allow for location tracking, environment and personnel vital signs monitoring, and data communications. Unfortunately the cost of these systems and required training in use of the equipment inhibits their adoption and wide scale deployment across the nation's emergency responder agencies. We are surrounded by secure, reliable cellular network technologies that meet our voice and data communication needs, yet current studies focus on building network infrastructures from the ground up and discussing how to address the security and performance issues of their proposed networks. This study proposes the use of the existing cellular network architecture already in place across the nation as a foundation to explore the feasibility of a low cost communication, management and accountability system utilizing 3G and 4G technologies and architecture.

Cooperation and resource optimization in wireless networks

Guan, Yang
Fonte: University of Delaware Publicador: University of Delaware
Tipo: Tese de Doutorado
Português
Relevância na Pesquisa
35.9%
Shen, Chien-Chung; Wireless technologies have been widely used to provide the communication functionality to various networking applications. However, the resources available to these applications are typically limited due to the fact that network devices are constrained by battery power, storage capacity and/or computational capabilities, and the fact that neighboring network devices share the common wireless spectrum with limited bandwidth. As a result, enabling cooperation among distributed network devices, and jointly optimizing the use of available resources become critical to wireless networks. In this dissertation, we study cooperation and resource optimization in various wireless networking scenarios including: ad hoc networks, underwater acoustic networks, wireless sensor networks and cellular networks. We aim to design efficient cooperation and resource optimization strategies to optimize system resource usage, and to maximize network performance. For ad hoc networks, we study the use of cooperative communications to combat various fading effects in wireless channels. We design the Cooperative Source Routing (CSR) protocol to translate the physical-layer gain of cooperative communications into improved network-level performance. By cooperatively transmitting both route-request and route-reply control protocol data units (PDUs)...