query: who is credited with the initial research on packet switching theory

pos: Packet switching Packet switching Packet switching is a method of grouping data that is transmitted over a digital network into "packets". Packets are made of a header and a payload. Data in the header are used by networking hardware to direct the packet to its destination where the payload is extracted and used by application software. Packet switching is the primary basis for data communications in computer networks worldwide. In the early 1960s, American computer scientist Paul Baran developed the concept "Distributed Adaptive Message Block Switching" with the goal to provide a fault-tolerant, efficient routing method for telecommunication messages as part of

pos: Leonard Kleinrock the Internet. His initial contribution to this field was his doctoral thesis at the Massachusetts Institute of Technology in 1962, published in book form in 1964; he later published several of the standard works on the subject. He described this work as: Basically, what I did for my PhD research in 1961–1962 was to establish a mathematical theory of packet networks ... In 2001 he received the Draper Prize "for the development of the Internet". However, Kleinrock's contribution to packet switching is disputed by some, including Robert Taylor, Paul Baran and Donald Davies. His theoretical work on hierarchical routing in

pos: History of the Internet network would be divided into what he called "message blocks". Independently, Donald Davies (National Physical Laboratory, UK), proposed and was the first to put into practice a local area network based on what he called packet switching, the term that would ultimately be adopted. Larry Roberts applied Davies' concepts of packet switching for the ARPANET wide area network, and sought input from Paul Baran and Leonard Kleinrock. Kleinrock subsequently developed the mathematical theory behind the performance of this technology building on his earlier work on queueing theory. Packet switching is a rapid store and forward networking design that divides messages

pos: Paul Baran through existing wiring. Baran extended his work in packet switching to wireless-spectrum theory, developing what he called "kindergarten rules" for the use of wireless spectrum. In addition to his innovation in networking products, he is also credited with inventing the first doorway gun detector. He received an honorary doctorate when he gave the commencement speech at Drexel in 1997. Baran died in Palo Alto, California, at the age of 84 on March 26, 2011 from complications caused by lung cancer. Upon his death, RAND President James Thomson, stated, "Our world is a better place for the technologies Paul Baran invented

pos: ARPANET the network rather than the large mainframes that would be the nodes of the ARPANET. Roberts modified the ARPANET plan to incorporate Clark's suggestion. The plan was presented at the ACM Symposium in Gatlinburg, Tennessee, in October 1967. Donald Davies' work on packet switching and the NPL network, presented by a colleague (Roger Scantlebury), came to the attention of ARPANET developers at this conference. Roberts applied Davies' concept of packet switching for the ARPANET, and sought input from Paul Baran and Leonard Kleinrock. Building on his earlier work on queueing theory, Kleinrock modelled the performance of packet-switched networks, which underpinned

pos: Lawrence Roberts (scientist) ARPA Information Processing Techniques Office (IPTO) to become the program manager for the ARPANET. Wesley A. Clark suggested the use of a dedicated computer, called the Interface Message Processor at each node of the network instead of centralized control. Shortly afterwards, at the 1967 ACM Symposium on Operating System Principles, Roberts met a member of Donald Davies' team (Roger Scantlebury) who presented their research on packet switching and suggested it for use in the ARPANET. Roberts applied Davies' concepts of packet switching for the ARPANET, and sought input from Paul Baran and Leonard Kleinrock. Subsequently, Roberts developed the plan for

pos: ARPANET passwords in the VMS operating system and is still being used for this purpose. ARPANET The Advanced Research Projects Agency Network (ARPANET) was an early packet-switching network and the first network to implement the protocol suite TCP/IP. Both technologies became the technical foundation of the Internet. The ARPANET was initially funded by the Advanced Research Projects Agency (ARPA) of the United States Department of Defense. The packet-switching methodology employed in the ARPANET was based on concepts and designs by Leonard Kleinrock and Paul Baran, British scientist Donald Davies, and Lawrence Roberts. The TCP/IP communications protocols were developed for the ARPANET

pos: ARPANET ARPANET The Advanced Research Projects Agency Network (ARPANET) was an early packet-switching network and the first network to implement the protocol suite TCP/IP. Both technologies became the technical foundation of the Internet. The ARPANET was initially funded by the Advanced Research Projects Agency (ARPA) of the United States Department of Defense. The packet-switching methodology employed in the ARPANET was based on concepts and designs by Leonard Kleinrock and Paul Baran, British scientist Donald Davies, and Lawrence Roberts. The TCP/IP communications protocols were developed for the ARPANET by computer scientists Robert Kahn and Vint Cerf, and incorporated concepts from the French

pos: Timeline of United States inventions (1946–91) that are linked by copper wires, fiber-optic cables, wireless connections, and other technologies. The concept of packet switching of a network was first explored by Paul Baran in the early 1960s, and the mathematical formulations behind packet switching were later devised by Leonard Kleinrock. On October 29, 1969, the world's first electronic computer network, the ARPANET, was established between nodes at Leonard Kleinrock's lab at UCLA and Douglas Engelbart's lab at the Stanford Research Institute (now SRI International). Another milestone occurred in 1973 when Bob Kahn and Vinton Cerf co-invented Internet Protocol and Transmission Control Protocol while working on ARPANET

pos: Donald Davies Donald Davies Donald Watts Davies, (7 June 1924 – 28 May 2000) was a Welsh computer scientist who was employed at the UK National Physical Laboratory (NPL). In 1965 he developed the concept of packet switching, which is today the dominant basis for data communications in computer networks worldwide, and implemented it in the NPL network. This was independent of the work of Paul Baran in the United States who had a similar idea in the early 1960s. The ARPANET project, a precursor to the Internet, credited Davies for his influence. Davies was born in Treorchy in the Rhondda Valley,

pos: Internet comparison, Hypertext Transfer Protocol, or HTTP, is the language used on the Web for information transfer, yet it is just one of many languages or protocols that can be used for communication on the Internet. The term "Interweb" is a portmanteau of "Internet" and "World Wide Web" typically used sarcastically to parody a technically unsavvy user. Research into packet switching, one of the fundamental Internet technologies started in the early 1960s in the work of Paul Baran, and packet switched networks such as the NPL network by Donald Davies, ARPANET, Tymnet, the Merit Network, Telenet, and CYCLADES, were developed in

pos: Paul Baran technology, records Paul Baran and Donald Davies as the inventors of digital packet switching. In 1969, when the US Advanced Research Projects Agency (ARPA) started developing the idea of an internetworked set of terminals to share computing resources, the reference materials that they considered included Baran and the RAND Corporation's "On Distributed Communications" volumes. The resiliency of a packet-switched network that uses link-state routing protocols, which are used on the Internet, stems in some part from the research to develop a network that could survive a nuclear attack. In 1968, Baran was a founder of the Institute for the Future

pos: Packet switching of digital message switching (without packets) in 1961. The concept of switching small blocks of data was first explored independently by Paul Baran at the RAND Corporation starting in the late 1950s in the US and subsequently by Donald Davies at the National Physical Laboratory (NPL) in the UK. Baran developed the concept of "distributed adaptive message block switching" during his research at the RAND Corporation for the US Air Force into communications networks that could survive nuclear wars. The concept was first presented to the Air Force in the summer of 1961 as briefing B-265, later published as RAND

pos: South East England Britain's early computers, and invented packet switching in the late 1960s at the National Physical Laboratory in Teddington. Packet-switching was taken up by the Americans to form the ARPANET; the first computer network was built by Lawrence Roberts and three others at the MIT Lincoln Laboratory (IBM and AT&T took no interest in the project), built by BBN with Bob Taylor and Paul Baran (who chose the design of packets and nodes) with Interface Message Processors; TCP was invented in 1973 and adopted as standard in 1981. The IBM 360/195 at RHEL was the first machine outside of the US

pos: Donald Davies by some, including Robert Taylor, Baran and Davies. The U.S. National Inventors Hall of Fame, which recognizes inventors who hold a U.S. patent of highly significant technology, records Donald Davies and Paul Baran as the inventors of digital packet switching. Davies relinquished his management responsibilities in 1979 to return to research. He became particularly interested in computer network security. He retired from the NPL in 1984, becoming a leading consultant on data security to the banking industry. Together with David O. Clayden, they designed the Message Authenticator Algorithm (MAA), an early Message Authentication Code that was adopted as international standard

neg: Packet switching a research program at the RAND Corporation, funded by the US Department of Defense. This concept contrasted and contradicted then-established principles of pre-allocation of network bandwidth, largely fortified by the development of telecommunications in the Bell System. The new concept found little resonance among network implementers until the independent work of British computer scientist Donald Davies at the National Physical Laboratory (United Kingdom) in 1965. Davies is credited with coining the modern term "packet switching" and inspiring numerous packet switching networks in the decade following, including the incorporation of the concept in the early ARPANET in the United States. A

neg: Packet switching switching is characterized by a fee per unit of connection time, even when no data is transferred, while packet switching may be characterized by a fee per unit of information transmitted, such as characters, packets, or messages. In the late 1950s, the US Air Force established a wide area network for the Semi-Automatic Ground Environment (SAGE) radar defense system. They sought a system that might survive a nuclear attack to enable a response, thus diminishing the attractiveness of the first strike advantage by enemies. Leonard Kleinrock conducted early research in queueing theory and published a book in the related field

neg: TRAME In year 1974, packet switching was a technology known only in research circles. The concept started by year 1968 associated to the USA's Advanced Research Projects Agency (ARPA) research project ARPAnet. The idea of applying the packet switching concept to electric utilities control communication networks first appeared in 1974 when the Swedish Power Utility Vattenfall started to create its TIDAS packet switching network and it was followed by the Spanish electric utility ENHER, which was targeting to telecontrol and automate its high voltage power network. With that goal ENHER created a specific team of people for developing both the packet

neg: Packet processing used for voice communications. The concept of packet switching was introduced to create a communications network that would continue to function in spite of equipment failures throughout the network. In this paradigm shift, networks are viewed as collections of systems that transmit data in small packets that work their way from origin to destination by any number of routes. Initial packet processing functions supported the routing of packets through the network, transmission error detection and correction and other network management functions. Packet switching with its supporting packet processing functions has several practical benefits over traditional circuit-switched networks: A network packet

neg: Packet Assembler/Disassembler (Interactive Terminal Protocol) was an early PAD protocol for use over X.25 developed in the 1970s for use with UK GPO's EPSS (Experimental Packet Switching System, the predecessor of PSS). ITP predated Triple-X, and is a completely different protocol. Science and Engineering Research Council (SERC) also used ITP on SERCnet and continued developing ITP after EPSS, although it eventually gave way to Triple-X. Packet Assembler/Disassembler A packet assembler/disassembler, abbreviated PAD is a communications device which provides multiple asynchronous terminal connectivity to an X.25 (packet-switching) network or host computer. It collects data from a group of terminals and places the data

neg: DARPA Multics system, developed by a cooperation among Bell Labs, General Electric and MIT, which DARPA supported by funding Project MAC at MIT with an initial two-million-dollar grant). DARPA supported the evolution of the ARPANET (the first wide-area packet switching network), Packet Radio Network, Packet Satellite Network and ultimately, the Internet and research in the artificial intelligence fields of speech recognition and signal processing, including parts of Shakey the robot. DARPA also funded the development of the Douglas Engelbart's NLS computer system and The Mother of All Demos; and the Aspen Movie Map, which was probably the first hypermedia system and

neg: Packet switching a bulk storage system. Philips Research Laboratories in Redhill, Surrey developed a packet switching network for internal use. It was a datagram network with a single switching node. PARC Universal Packet (PUP or Pup) was one of the two earliest internetwork protocol suites; it was created by researchers at Xerox PARC in the mid-1970s. The entire suite provided routing and packet delivery, as well as higher level functions such as a reliable byte stream, along with numerous applications. Further developments led to Xerox Network Systems (XNS). RCP was an experimental network created by the French PTT. It was used to

neg: Packet switching February 1999 and went on to upgrade the entire backbone to OC-48c. In June 1999 MCI WorldCom introduced vBNS+ which allowed attachments to the vBNS network by organizations that were not approved by or receiving support from NSF. After the expiration of the NSF agreement, the vBNS largely transitioned to providing service to the government. Most universities and research centers migrated to the Internet2 educational backbone. In January 2006, when MCI and Verizon merged, vBNS+ became a service of Verizon Business. Packet switching Packet switching is a method of grouping data that is transmitted over a digital network into "packets".

neg: Packet switching a progenitor network of the Internet and the first network to run the TCP/IP suite using packet switching technologies. BNRNET was a network which Bell Northern Research developed for internal use. It initially had only one host but was designed to support many hosts. BNR later made major contributions to the CCITT X.25 project. The CYCLADES packet switching network was a French research network designed and directed by Louis Pouzin. First demonstrated in 1973, it was developed to explore alternatives to the early ARPANET design and to support network research generally. It was the first network to make the hosts

neg: Internet science failure. An initial listing of datasets, analytic tools and e-Infrastructures is available in a dedicated Internet science evidence base.There is ongoing activity on the development of Internet Science curricula, initially on a postgraduate level. 1934: The first person who imagined a 'Radiated Library' in 1934 was Paul Otlet. 1965: Two different computers started to communicate at MIT Lincoln Lab by using a packet-switching technology. 1968: Beranek and Newman have discovered an effectiveness and final version of the Interface Message Processor (IMP) specifications. 1969: The nodes were installed by UCLA’s Network Measurement Centre, Stanford Research Institute (SRI), University of California-Santa Barbara

neg: Packet switching pilot experiment in 1967, the NPL Data Communications Network entered service in 1969. Building on his earlier work on queueing theory, Leonard Kleinrock subsequently carried out theoretical work to model the performance of packet-switched networks, which underpinned the development of the ARPANET. The NPL team also carried out simulation work on packet networks. In 1974, Vint Cerf and Bob Kahn published the specifications for Transmission Control Protocol (TCP), an internetworking protocol for sharing resources using packet-switching among the nodes (this monolithic protocol was later layered as "TCP" atop the Internet Protocol, or "IP"). The French CYCLADES network, designed by Louis

neg: Packet switching Ethernet and Frame Relay are common. Newer mobile phone technologies (e.g., GPRS, i-mode) also use packet switching. X.25 is a notable use of packet switching in that, despite being based on packet switching methods, it provides virtual circuits to the user. These virtual circuits carry variable-length packets. In 1978, X.25 provided the first international and commercial packet switching network, the International Packet Switched Service (IPSS). Asynchronous Transfer Mode (ATM) also is a virtual circuit technology, which uses fixed-length cell relay connection oriented packet switching. Datagram packet switching is also called connectionless networking because no connections are established. Technologies such as

neg: W. David Sincoskie District Manager of the Computer Communications Research group for the first few years. During this time, Dr. Sincoskie worked on Internet telephony and as a result developed what is now known today as the VLAN. From 1986 to 1990, he managed the Packet Communications Research Department, which spearheaded the telecommunications transition from circuit-switching to packet-switching, a key factor in the successful commercialization of the Internet. Dr. Sincoskie also co-authored the first specifications for Local ATM, which were later adopted by the ATM Forum. From 1990 to 1996, Dr. Sincoskie was Executive Director of the Computer Networking Research Department at Telcordia.

neg: History of the Internet 1973, it was developed to explore alternatives to the early ARPANET design and to support network research generally. It was the first network to make the hosts responsible for reliable delivery of data, rather than the network itself, using unreliable datagrams and associated end-to-end protocol mechanisms. Concepts of this network influenced later ARPANET architecture. Based on ARPA's research, packet switching network standards were developed by the International Telecommunication Union (ITU) in the form of X.25 and related standards. While using packet switching, X.25 is built on the concept of virtual circuits emulating traditional telephone connections. In 1974, X.25 formed the

neg: W. David Sincoskie and received the IEEE's Fred W. Ellersick Prize (2003) for his paper, “Broadband Packet Switching: A Personal Perspective,” which detailed his research contributions over two decades to the development of today's broadband Internet. He was a member of Tau Beta Pi and Eta Kappa Nu. Dr. Sincoskie is also credited with many patents and numerous papers. He was elected to the UD Alumni Wall of Fame in 2006. W. David Sincoskie Walter David "Dave" Sincoskie (December 21, 1954 – October 20, 2010) was an American computer engineer. Sincoskie installed the first ethernet local area network at Bellcore, and helped invent

neg: Circuit switching two telephones, for as long as the call lasts. Circuit switching contrasts with packet switching, which divides the data to be transmitted into packets transmitted through the network independently. In packet switching, instead of being dedicated to one communication session at a time, network links are shared by packets from multiple competing communication sessions, resulting in the loss of the quality of service guarantees that are provided by circuit switching. In circuit switching, the bit delay is constant during a connection, as opposed to packet switching, where packet queues may cause varying and potentially indefinitely long packet transfer delays. No

neg: Donald Davies at a conference in Gatlinburg, Tennessee, in October 1967. In Scantlebury's report following the conference, he noted "It would appear that the ideas in the NPL paper at the moment are more advanced than any proposed in the USA". Larry Roberts of the Advanced Research Projects Agency in the United States applied Davies' concepts of packet switching in the late 1960s for the ARPANET, which went on to become a predecessor to the Internet. Davies first presented his own ideas on packet switching at a conference in Edinburgh on 5 August 1968. At NPL Davies helped build a packet-switched network

neg: ARPANET the IMPs performed store-and-forward packet switching functions, and were interconnected with leased lines via telecommunication data sets (modems), with initial data rates of . The host computers were connected to the IMPs via custom serial communication interfaces. The system, including the hardware and the packet switching software, was designed and installed in nine months. The BBN team continued to interact with the NPL team. The first-generation IMPs were built by BBN Technologies using a rugged computer version of the Honeywell DDP-516 computer configured with of expandable magnetic-core memory, and a 16-channel Direct Multiplex Control (DMC) direct memory access unit. The

neg: Keith Uncapher on the technology of packet switching, in which digital messages are broken into small packets, sent over a network and reassembled at their destination. Due to this methods inherent reliability and robustness it attracted a great deal of interest at the Department of Defense Advanced Projects Research Agency. He helped officials see the technology's vast potential for facilitating a revolution in computer communications. Uncapher also designed the first time-sharing computer system for mathematicians. He also led the RAND Tablet Project, a computer system for recognizing hand printed characters using a tablet and stylus. Packet switching research and development led first

neg: Circuit switching nonetheless each channel on the multiplexed link was either dedicated to one call at a time, or it was idle between calls. In circuit switching, a route and its associated bandwidth is reserved from source to destination, making circuit switching relatively inefficient since capacity is reserved whether or not the connection is in continuous use. In contrast, packet switching is the process of segmenting data to be transmitted into several smaller packets. Each packet is labeled with its destination and a sequence number for ordering related packets, precluding the need for a dedicated path to help the packet find its

neg: Packet switching later) were open standards with published specifications, and several implementations were developed outside DEC, including one for Linux. This was an experimental network from Nippon PTT. It mixed circuit switching and packet switching. It was succeeded by DDX-2. European Informatics Network was a project to link several national networks. It became operational in 1976. The Experimental Packet Switching System (EPSS) was an experiment of the UK Post Office. It was the first public packet switching network when it began operating in 1977, based on protocols defined by the UK academic community in 1975. Ferranti supplied the hardware and software. The

neg: Matter wave that one finds: . The frequency is to be measured, of course, in the rest frame of the energy packet. This hypothesis is the basis of our theory." De Broglie followed his initial hypothesis of a periodic phenomenon, with frequency , associated with the energy packet. He used the special theory of relativity to find, in the frame of the observer of the electron energy packet that is moving with velocity formula_12, that its frequency was apparently reduced to Then using the same notation as above. The quantity formula_32 is the velocity of what de Broglie called the "phase y

neg: Internet in the United Kingdom funded by the United States. Beginning in the mid-1960s, Donald Davies and his team at the National Physical Laboratory pioneered packet switching, now the dominant basis for data communications in computer networks worldwide. They developed and implemented the concept in a local area network, the NPL network, which operated from 1969 to 1986, and carried out work to analyse and simulate the performance of packet switching networks. Their research and practice was adopted by the ARPANET in the United States, the forerunner of the Internet, and influenced other researchers in the UK and Europe. Peter T. Kirstein's research group at

neg: Packet switching Pouzin in the early 1970s, was the first to make the hosts responsible for the reliable delivery of data, rather than this being a centralized service of the network itself. Packet switching may be classified into connectionless packet switching, also known as datagram switching, and connection-oriented packet switching, also known as virtual circuit switching. Examples of connectionless protocols are Ethernet, Internet Protocol (IP), and the User Datagram Protocol (UDP). Connection-oriented protocols include X.25, Frame Relay, Multiprotocol Label Switching (MPLS), and the Transmission Control Protocol (TCP). In connectionless mode each packet includes complete addressing information. The packets are routed individually, sometimes

neg: Message switching example of a delay system or a queuing system. Message switching is still used for telegraph traffic and a modified form of it, known as packet switching, is used extensively for data communications. The advantages to message switching are: Message switching In telecommunications, message switching was the precursor of packet switching, where messages were routed in their entirety, one hop at a time. It was first built by Collins Radio Company, Newport Beach, California, during the period 1959–1963 for sale to large airlines, banks and railroads. Message switching systems are nowadays mostly implemented over packet-switched or circuit-switched data networks. Each

neg: Wormhole switching route the packet. If the address (the first byte) of an incoming SpaceWire packet is in the range 32 to 255, the SpaceWire switch uses that value as an index into an internal routing table that indicates which port(s) to send the packet and whether to delete or retain that first byte. Address 0 is used to communicate directly with the switch, and may be used to set the routing table entries for that switch. Wormhole switching Wormhole flow control, also called wormhole switching or wormhole routing, is a system of simple flow control in computer networking based on known

neg: Packet switching and the OSI model, the X.25 era when many postal, telephone, and telegraph companies introduced networks with X.25 interfaces, and the Internet era. Research into packet switching at the National Physical Laboratory (NPL) began with a proposal for a wide-area network in 1965, and a local-area network in 1966. ARPANET funding was secured in 1966 by Bob Taylor, and planning began in 1967 when he hired Larry Roberts. The NPL network, ARPANET, and SITA HLN became operational in 1969. Before the introduction of X.25 in 1973, about twenty different network technologies had been developed. Two fundamental differences involved the division

neg: Circuit switching way to its destination. Each packet is dispatched independently and each may be routed via a different path. At the destination, the original message is reordered based on the packet number to reproduce the original message. As a result, datagram packet switching networks do not require a circuit to be established and allow many pairs of nodes to communicate concurrently over the same channel. Circuit switching Circuit switching is a method of implementing a telecommunications network in which two network nodes establish a dedicated communications channel (circuit) through the network before the nodes may communicate. The circuit guarantees the full

neg: Public switched data network Public switched data network A public switched data network (PSDN) is a network for providing data services via a system of multiple wide-area networks, similar in concept to the public switched telephone network (PSTN). A PSDN may use a variety of switching technologies, including packet switching, circuit switching, and message switching. A packet-switched PSDN may also be called a packet-switched data network. Originally the term PSDN referred only to Packet Switch Stream (PSS), an X.25-based packet-switched network, mostly used to provide leased-line connections between local area networks and the Internet using permanent virtual circuits (PVCs). Today, the term may refer

neg: National Physical Laboratory (United Kingdom) Davies designed and proposed a national data network based on packet switching in his 1965 "Proposal for the Development of a National Communications Service for On-line Data Processing". Subsequently, the NPL team (Davies, Derek Barber, Roger Scantlebury, Peter Wilkinson, Keith Bartlett, and Brian Aldous) developed the concept into a local area network which operated from 1969 to 1986, and carried out work to analyse and simulate the performance of packet switching networks. Their research and practice influenced the ARPANET in the United States, the forerunner of the Internet, and other researchers in the UK and Europe. Directors of NPL include

neg: Packet switching the nodes adjacent to the sending and receiving terminals. Switched virtual calls were not supported, but through the use of "logical ports" an originating terminal could have a menu of pre-defined destination terminals. Iberpac is the Spanish public packet-switched network, providing X.25 services. Iberpac is run by Telefonica. JANET was the UK academic and research network, linking all universities, higher education establishments, publicly funded research laboratories. The X.25 network was based mainly on GEC 4000 series switches, and run X.25 links at up to 8 Mbit/s in its final phase before being converted to an IP based network. The JANET

neg: Cut-through switching Cut-through switching In computer networking, cut-through switching, also called cut-through forwarding is a method for packet switching systems, wherein the switch starts forwarding a frame (or packet) before the whole frame has been received, normally as soon as the destination address is processed. Compared to store and forward, this technique reduces latency through the switch and relies on the destination devices for error handling. Pure cut-through switching is only possible when the speed of the outgoing interface is equal to or greater than the incoming interface speed. Adaptive switching dynamically selects between cut-through and store and forward behaviors based on

neg: Donald Davies ("Mark I NPL network"). It was replaced with the "Mark II" in 1973, and remained in operation until 1986, influencing other research in the UK and Europe. Baran was happy to acknowledge that Davies had come up with the same idea as him independently. In an e-mail to Davies he wrote Leonard Kleinrock, a contemporary working on analysing data flow, also reached similar conclusions when he developed a theoretical basis for the operation of packet networks in his proposal for a PhD thesis in 1961. He published his ideas in that year. However, Kleinrock's contribution to packet switching is disputed

neg: Packet switching network, Tymnet.) The design was hierarchical with redundant communication links. IPSANET was a semi-private network constructed by I. P. Sharp Associates to serve their time-sharing customers. It became operational in May 1976. The Internetwork Packet Exchange (IPX) and Sequenced Packet Exchange (SPX) are Novell networking protocols derived from Xerox Network Systems' IDP and SPP protocols, respectively. They were used primarily on networks using the Novell NetWare operating systems. Merit Network, Inc., an independent non-profit 501(c)(3) corporation governed by Michigan's public universities, was formed in 1966 as the Michigan Educational Research Information Triad to explore computer networking between three of Michigan's

neg: Network packet Network packet A network packet is a formatted unit of data carried by a packet-switched network. A packet consists of control information and user data, which is also known as the payload. Control information provides data for delivering the payload, for example: source and destination network addresses, error detection codes, and sequencing information. Typically, control information is found in packet headers and trailers. In packet switching, the bandwidth of the communication medium is shared between multiple communication sessions, in contrast to circuit switching, in which circuits are preallocated for the duration of one session and data is typically transmitted as

neg: University of Utah College of Engineering was ranked second for its undergraduate program and fourth for its graduate program by the Princeton Review. The University of Utah was one of the original four nodes of ARPANET, the world's first packet-switching computer network and embryo of the current worldwide Internet. In late 1969, the U's computer graphics department was linked into the node at Stanford Research Institute in Menlo Park, California to complete the initial four-node network. The School of Computing has made important contributions to computer graphics and computer animation. These contributions include: Gouraud shading, the Phong reflection model, the Phong shading method, and the rendering

neg: Label switching Label switching Label switching is a technique of network relaying to overcome the problems perceived by traditional IP-table switching (also known as traditional layer 3 hop-by-hop routing). Here, the switching of network packets occurs at a lower level, namely the data link layer rather than the traditional network layer. Each packet is assigned a label number and the switching takes place after examination of the label assigned to each packet. The switching is much faster than IP-routing. New technologies such as Multiprotocol Label Switching (MPLS) use label switching. The established ATM protocol also uses label switching at its core. According

neg: Multilayer switch 2 switching uses the media access control address (MAC address) from the host's network interface cards (NICs) to decide where to forward frames. Layer 2 switching is hardware-based, which means switches use application-specific integrated circuit (ASICs) to build and maintain filter tables (also known as MAC address tables or CAM tables). One way to think of a layer 2 switch is as multiport bridge. Layer 2 switching provides the following Layer 2 switching is highly efficient because there is no modification to the data packet and the frame, encapsulation of the packet changes only when the data packet is passing

neg: NPL network of being translated into languages other than English without compromise. Packet switching was used to produce an experimental network using a Honeywell 516 node. According to "Zakon", NPL under Davies was the earliest organisation that created a packet switching network. Following a pilot experiment during 1967, Davies gave the first public demonstration of packet switching on 5 August 1968. Elements of the first version of the network, Mark I, became operational during 1969 then fully operational in 1970, and the Mark II version operated from 1973. The NPL team also carried out simulation work on the performance of packet networks.

neg: Packet switching simple definition of packet switching is: Packet switching allows delivery of variable bit rate data streams, realized as sequences of packets, over a computer network which allocates transmission resources as needed using statistical multiplexing or dynamic bandwidth allocation techniques. As they traverse networking hardware, such as switches and routers, packets are received, buffered, queued, and retransmitted (stored and forwarded), resulting in variable latency and throughput depending on the link capacity and the traffic load on the network. Packets are normally forwarded by intermediate network nodes asynchronously using first-in, first-out buffering, but may be forwarded according to some scheduling discipline for

neg: Packet switching in dial up connections. When Internet connectivity was made available to anyone who could pay for an ISP subscription, the distinctions between national networks blurred. The user no longer saw network identifiers such as the DNIC. Some older technologies such as circuit switching have resurfaced with new names such as fast packet switching. Researchers have created some experimental networks to complement the existing Internet. The Computer Science Network (CSNET) was a computer network funded by the U.S. National Science Foundation (NSF) that began operation in 1981. Its purpose was to extend networking benefits, for computer science departments at academic and

neg: Message switching Message switching In telecommunications, message switching was the precursor of packet switching, where messages were routed in their entirety, one hop at a time. It was first built by Collins Radio Company, Newport Beach, California, during the period 1959–1963 for sale to large airlines, banks and railroads. Message switching systems are nowadays mostly implemented over packet-switched or circuit-switched data networks. Each message is treated as a separate entity. Each message contains addressing information, and at each switch this information is read and the transfer path to the next switch is decided. Depending on network conditions, a conversation of several messages

neg: History of the Internet Institute (SRI). Packet switching networks such as the NPL network, ARPANET, Tymnet, Merit Network, CYCLADES, and Telenet, were developed in the late 1960s and early 1970s using a variety of communications protocols. Donald Davies first demonstrated packet switching in 1967 at the National Physics Laboratory (NPL) in the UK, which became a testbed for UK research for almost two decades. The ARPANET project led to the development of protocols for internetworking, in which multiple separate networks could be joined into a network of networks. The Internet protocol suite (TCP/IP) was developed by Robert E. Kahn and Vint Cerf in the

neg: ARPANET the United States from research and education organizations. The ARPANET was decommissioned in 1990. Historically, voice and data communications were based on methods of circuit switching, as exemplified in the traditional telephone network, wherein each telephone call is allocated a dedicated, end to end, electronic connection between the two communicating stations. Such stations might be telephones or computers. The temporarily dedicated line typically comprises many intermediary lines which are assembled into a chain that reaches from the originating station to the destination station. With packet switching, a network could share a single communication link for communication between multiple pairs of

neg: Packet Switch Stream saw X.25 packet switching as a core offering BT's then senior management regarded packet switching as a passing phase until the telecommunications nirvana of ISDN's 64 kbit/s for everyone arrived. Even in its recent history BT's senior management stated that the Internet was "not fit for purpose". PSS suffered from inconsistent investment during its early years. Sometimes not enough and sometimes too much but mostly for the wrong reasons. Investments in value added network services (VANS) and BT's own access level packet switching hardware delayed operating profit. This in turn dented PSS's low credibility with BT's management still further. Despite

neg: Turing switch and then that application specific logic should be implemented using optical components. The work is not actually based on Turing's research. A Turing switch consists of a switched fabric, one or more ingress interfaces (also referred to as sources), one or more egress interfaces (sinks), and a decision procedure to determine an egress interface given an ingress interface. Interfaces are sometimes referred to as ports. A packet (cell or switched unit) arrives at an ingress interface, the appropriate egress interface is determined by the decision procedure, and the packet is then transported across the switching fabric to the egress interface.

neg: Packet switching small, as it only needs to contain this code and any information, such as length, timestamp, or sequence number, which is different for different packets. Packet switching is used to optimize the use of the channel capacity available in digital telecommunication networks, such as computer networks, and minimize the transmission latency (the time it takes for data to pass across the network), and to increase robustness of communication. The best-known use of packet switching is the Internet and most local area networks. The Internet is implemented by the Internet Protocol Suite using a variety of Link Layer technologies. For example,

neg: Pål Spilling the then proposed Transmission Control Protocol conducting the first TCP tests between different implementations. During the next few years Spilling also participated in the development of the Internet Protocol and other early computer network protocols. He was visiting scientist at SRI International at Stanford University in 1979/80, where he worked on the Packet Radio program. Spilling left NDRE in August 1982 to join the former Research Department of the Norwegian Telecommunications Administration (NTA-RD), also at Kjeller. The NDRE ARPANET node followed Spilling to NTA-RD, and became a dooropener to packet switching and real time international communications for Norwegian research and

neg: Packet switching public universities as a means to help the state's educational and economic development. With initial support from the State of Michigan and the National Science Foundation (NSF), the packet-switched network was first demonstrated in December 1971 when an interactive host-to-host connection was made between the IBM mainframe computer systems at the University of Michigan in Ann Arbor and Wayne State University in Detroit. In October 1972, connections to the CDC mainframe at Michigan State University in East Lansing completed the triad. Over the next several years, in addition to host-to-host interactive connections, the network was enhanced to support terminal-to-host connections,

neg: Multistage interconnection networks Multistage interconnection networks Multistage interconnection networks (MINs) are a class of high-speed computer networks usually composed of processing elements (PEs) on one end of the network and memory elements (MEs) on the other end, connected by switching elements (SEs). The switching elements themselves are usually connected to each other in stages, hence the name. MINs are typically used in high-performance or parallel computing as a low-latency interconnection (as opposed to traditional packet switching networks), though they could be implemented on top of a packet switching network. Though the network is typically used for routing purposes, it could also be used

neg: Packet Switch Stream old telcos style companies around the world. Now BT appears to be inheriting a dominating position in the Global Network Services market, based on packet switching, as CSC and Reuters sell up their networks to BT. As the commodity price of IP services based in their core 21st century MPLS network to carry voice and data finally gives them the real cost efficiencies that packet switching always promised. Packet Switch Stream In the United Kingdom, Packet Switch Stream (PSS) was an X.25-based packet-switched network, provided by the British Post Office Telecommunications and then British Telecommunications starting in 1980. After a

neg: Traffic flow (computer networking) tag switching. Packet flow can be represented as a path in a network to model network performance. For example, a water flow network can be used to conceptualize packet flow. Channels can be thought of as pipes, with the pipe capacity corresponding to bandwidth and flows corresponding to data throughput. This visualization can help to understand bottlenecks, queuing, and help understand the unique requirements of tailored systems. Traffic flow (computer networking) In packet switching networks, traffic flow, packet flow or "network flow" is a sequence of packets from a source computer to a destination, which may be another host, a

neg: Packet Assembler/Disassembler Packet Assembler/Disassembler A packet assembler/disassembler, abbreviated PAD is a communications device which provides multiple asynchronous terminal connectivity to an X.25 (packet-switching) network or host computer. It collects data from a group of terminals and places the data into X.25 packets (assembly). A PAD also does the reverse, it takes data packets from packet-switching network or host computer and returns them into a character stream that can be sent to the terminals (disassembly). A Frame Relay Assembler/Disassembler (FRAD) is a similar device for accessing Frame Relay networks. The structure of a PAD is defined by the ITU-T in recommendations X.3, X.28,

neg: Packet switching fair queuing, traffic shaping, or for differentiated or guaranteed quality of service, such as weighted fair queuing or leaky bucket. Packet-based communication may be implemented with or without intermediate forwarding nodes (switches and routers). In case of a shared physical medium (such as radio or 10BASE5), the packets may be delivered according to a multiple access scheme. Packet switching contrasts with another principal networking paradigm, circuit switching, a method which pre-allocates dedicated network bandwidth specifically for each communication session, each having a constant bit rate and latency between nodes. In cases of billable services, such as cellular communication services, circuit

neg: Multiprotocol Label Switching this is done through the use of EtherType values 0x8847 and 0x8848, for unicast and multicast connections respectively. An MPLS router that performs routing based only on the label is called a label switch router (LSR) or transit router. This is a type of router located in the middle of an MPLS network. It is responsible for switching the labels used to route packets. When an LSR receives a packet, it uses the label included in the packet header as an index to determine the next hop on the label-switched path (LSP) and a corresponding label for the packet from

neg: OpenComRTOS on the use of prioritised Packet switching with communication and routing being part of the underlying system services. One of the results is that the source code of the Tasks is independent of the mapping of Tasks and Hubs to the processing nodes in the target system. The initial purpose for developing OpenComRTOS was to provide a software runtime environment supporting a coherent and unified systems engineering methodology based on Interacting Entities. This was originally developed by Open License Society since 2005, and since 2008 further developed and commercialised by Altreonic. A previously developed RTOS called Virtuoso served as a

neg: Packet switching address information and are negotiated between endpoints so that they are delivered in order and with error checking. Address information is only transferred to each node during the connection set-up phase, when the route to the destination is discovered and an entry is added to the switching table in each network node through which the connection passes. The signaling protocols used allow the application to specify its requirements and discover link parameters. Acceptable values for service parameters may be negotiated. Routing a packet requires the node to look up the connection id in a table. The packet header can be

neg: Turing switch Turing switch In theoretical network science, the Turing switch is a logical construction modeling the operation of the network switch, just as in theoretical computer science a Turing machine models the operation of a computer. Both are named in honor of the English logician Alan Turing, although the research in Turing switches is not based on Turing's research. Some introductory research on the Turing switch was started at the University of Cambridge by Jon Crowcroft (Homepage). In essence, Crowcroft suggests that instead of using general-purpose computers to do packet switching, the required operations should be reduced to application specific logic

neg: Dynamic Packet Transport Ethernet, and others. As aforementioned, DPT is composed of two rings for fault tolerance and increased throughput. The method for switching between these two rings in the event of a failure is called Intelligent Protection Switching, or IPS. This ensures that a fiber cut or link failure (layer 1 error) will be rectified and IP traffic will be resumed within 50 ms. DPT also contains a "plug and play" feature which dynamically fetches the MAC addresses of neighboring devices which provides for very simple configuration with little to no setup prior to functional data transfer. Dynamic Packet Transport Dynamic packet

neg: Fractional lambda switching Fractional lambda switching Fractional lambda switching (FλS) leverages on time-driven switching (TDS) to realize sub-lambda switching in highly scalable dynamic optical networking, which requires minimum (possibly optical) buffers. Fractional lambda switching implies switching fractions of optical channels as opposed to whole lambda switching where whole optical channels are the switching unit. In this context, TDS has the same general objectives as optical burst switching and optical packet switching: realizing all-optical networks with high wavelength utilization. TDS operation is based on time frames (TFs) that can be viewed as virtual containers for multiple IP packets that are switched at every TDS

neg: Packet Switch Stream introduced based on a low speed PAD interface. The network was initially based upon a dedicated modular packet switch using DCC's TP 4000 communication processor hardware. The operating system and the packet switching software was developed by Telenet (later on GTE Telenet). At the time of PSS's launch this was in advance of both Telenet's own network and most others that used general purpose mini-computers as packet switches. BT bought Telenet's system via Plessey Controls of Poole, Dorset who also sold Telex and Traffic light systems. Later on BT used Telematics packet switches for the Vascom network to support the

neg: NPL network NPL network was designed and directed by Donald Davies. In 1965, Donald Davies, who was later was appointed to head of the NPL Division of Computer Science, proposed a national data network based on packet switching in "Proposal for the Development of a National Communications Service for On-line Data Processing". After the proposal was not taken up nationally, during 1966 he headed a team which produced a design for a local network to serve the needs of NPL and prove the feasibility of packet switching. The design was the first to describe the concept of an "Interface computer", today known

neg: History of the Internet feasibility of packet switched networks. By 1969 he had begun building the Mark I packet-switched network to meet the needs of the multidisciplinary laboratory and prove the technology under operational conditions. In 1976, 12 computers and 75 terminal devices were attached, and more were added until the network was replaced in 1986. NPL, followed by ARPANET, were the first two networks in the world to use packet switching, and were interconnected in the early 1970s. Robert Taylor was promoted to the head of the information processing office at Defense Advanced Research Projects Agency (DARPA) in June 1966. He intended to

neg: Packet radio Packet radio Packet radio is a form of packet switching technology used to transmit digital data via wireless communications. Packet radio uses the same concepts of data transmission using datagrams that are fundamental to communications on the Internet, as opposed to older techniques used by dedicated or switched circuits. Packet radio can be used over long distances without the need for a physical connection between stations. Packet radio can also be used for mobile communications. Packet radio is a digital radio communications mode. Earlier digital modes were telegraphy (Morse code), teleprinter (Baudot code) and facsimile. It is possible for any

neg: Packet switching resulting in different paths and out-of-order delivery. Each packet is labeled with a destination address, source address, and port numbers. It may also be labeled with the sequence number of the packet. This precludes the need for a dedicated path to help the packet find its way to its destination, but means that much more information is needed in the packet header, which is therefore larger, and this information needs to be looked up in power-hungry content-addressable memory. Each packet is dispatched and may go via different routes; potentially, the system has to do as much work for every packet

neg: Internet in the United Kingdom University College London was one of the first international connections on the ARPANET in 1973, alongside Norwegian Seismic Array (NORSAR) and Sweden's Tanum Earth Station. Kirstein co-authored (with Vint Cerf) one of the most significant early technical papers on the internetworking concept. His research group at UCL adopted TCP/IP in 1982, a year ahead of ARPANET, and played a significant role in the very earliest experimental Internet work. Kirstein's group included Sylvia Wilbur who programmed the computer used as the local node for the network. Post Office Telecommunications developed the first public packet switching network EPSS in 1977 based on

neg: Network packet Making the NICAM bitstream look more like white noise is important because this reduces signal patterning on adjacent TV channels. Network packet A network packet is a formatted unit of data carried by a packet-switched network. A packet consists of control information and user data, which is also known as the payload. Control information provides data for delivering the payload, for example: source and destination network addresses, error detection codes, and sequencing information. Typically, control information is found in packet headers and trailers. In packet switching, the bandwidth of the communication medium is shared between multiple communication sessions, in contrast

neg: IEEE 1355 routing, housekeeping and protocol management. Software is not needed for these tasks. When there is an error, the two ends of a link exchange an interval of silence or a reset, and then restart the protocol as if from power-up. A switching node reads the first few bytes of a packet as an address, and then forwards the rest of the packet to the next link without reading or changing it. This is called "wormhole switching" in an annex to the standard. Wormhole switching requires no software to implement a switching fabric. Simple hardware logic can arrange fail-overs to redundant

neg: Packet switching lines. It was the first transcontinental 10 Gigabit Ethernet network. It operates with high aggregate capacity of up to 1.6 Tbit/s and a high 40 Gbit/s bitrate, with plans for 100 Gbit/s. The upgrade never took place and NLR ceased operations in March 2014. TransPAC2 and TransPAC3, continuations of the TransPAC project, a high-speed international Internet service connecting research and education networks in the Asia-Pacific region to those in the US. TransPAC is part of the NSF’s International Research Network Connections (IRNC) program. The Very high-speed Backbone Network Service (vBNS) came on line in April 1995 as part of a

neg: Packet switching research institutions that could not be directly connected to ARPANET, due to funding or authorization limitations. It played a significant role in spreading awareness of, and access to, national networking and was a major milestone on the path to development of the global Internet. Internet2 is a not-for-profit United States computer networking consortium led by members from the research and education communities, industry, and government. The Internet2 community, in partnership with Qwest, built the first Internet2 Network, called Abilene, in 1998 and was a prime investor in the National LambdaRail (NLR) project. In 2006, Internet2 announced a partnership with Level

neg: Platform switching Platform switching In dentistry, platform switching is a method used to preserve alveolar bone levels around dental implants. The concept refers to placing screwed or friction fit restorative abutments of narrower diameter on implants of wider diameter, rather than placing abutments of similar diameters, referred to as "platform matching". Discovered by accident in the late 1980s, the benefits of platform switching have become the focus of implant-related research with increasing frequency. Numerous peer-reviewed articles and recent systematic reviews have revealed that platform switching can be considered a means of preventing initial peri-implant bone loss. After being placed in a surgical

neg: Lawrence Roberts (scientist) Lawrence Roberts (scientist) Lawrence G. Roberts (born December 21, 1937 in Connecticut) is an American scientist who received the Draper Prize in 2001 "for the development of the Internet", and the Principe de Asturias Award in 2002. As a program manager and office director at the Advanced Research Projects Agency, Roberts and his team created the ARPANET using packet switching techniques invented by British computer scientist Donald Davies. The ARPANET was a predecessor to the modern Internet. Lawrence (Larry) Roberts grew up in Westport, Connecticut as the son of Elliott and Elizabeth Roberts, who both had earned their doctorates in

neg: Packet switching gain experience with packet switching technology before the specification of Transpac was frozen. RCP was a virtual-circuit network in contrast to CYCLADES which was based on datagrams. RCP emphasised terminal-to-host and terminal-to-terminal connection; CYCLADES was concerned with host-to-host communication. TRANSPAC was introduced as an X.25 network. RCP influenced the specification of X.25 Red Especial de Transmisión de Datos was a network developed by Compañía Telefónica Nacional de España. It became operational in 1972 and thus was the first public network. "The experimental packet-switched Nordic telecommunication network SCANNET was implemented in Nordic technical libraries in the 1970s, and it included first

neg: Time-driven priority Time-driven priority Time-driven priority (TDP) is a synchronous packet scheduling technique that implements UTC-based pipeline forwarding and can be combined with conventional IP routing to achieve the higher flexibility than another pipeline forwarding implementation known as time-driven switching (TDS) or fractional lambda switching (FλS). Packets entering a switch from the same input port during the same [time frame] (TF) can be sent out from different output ports, according to the rules that drive IP packet routing. Operation in accordance to pipeline forwarding principles ensures deterministic quality of service and low complexity packet scheduling. Specifically, packets scheduled for transmission during a

neg: Pål Spilling Kjeller in Norway, and in 1974 started working on computer networks under the leadership of Yngvar Lundh at NDRE in collaboration with the DARPA-funded research program on packet switching and Internet technology in the US. The first ARPANET node outside the US was established at Kjeller, Norway in June 1973 for the NDRE researchers, and by the end of July 1973, an ARPANET node was also set up in the U.K. at the University College London. Spilling visited Professor Peter Kirstein's research group at UCL in 1974 and worked with Vint Cerf, then junior assistant professor at Stanford University, on

neg: Circuit switching result was a physical electrical connection between the two subscribers' telephones for the duration of the call. The copper wire used for the connection could not be used to carry other calls at the same time, even if the subscribers were in fact not talking and the line was silent. Circuit switching contrasts with packet switching which divides the data to be transmitted into small units, called packets, transmitted through the network independently. Packet switching shares available network bandwidth between multiple communication sessions. Multiplexing multiple telecommunications connections over the same physical conductor has been possible for a long time, but

neg: Packet switching of ISDN's layer two protocol, LAPD and LAPB. As such, its integrity operations pertain only between nodes on a link, not end-to-end. Any retransmissions must be carried out by higher layer protocols. The X.25 UNI protocol is part of the X.25 protocol suite, which consists of the lower three layers of the OSI Model. It was widely used at the UNI for packet switching networks during the 1980s and early 1990s, to provide a standardized interface into and out of packet networks. Some implementations used X.25 within the network as well, but its connection-oriented features made this setup cumbersome and

neg: Deflection routing packets (because, for instance, those links do not yield shortest paths). Depending on the rate of incoming packets and the capacity of the outgoing links, deflection routing can work without any packet buffering. Of course, it is always possible to simply drop packets in a network with a best effort delivery strategy. Deflection routing Deflection routing is a routing strategy for networks based on packet switching which can reduce the need of buffering packets. Every packet has preferred outputs along which it wants to leave the router, and when possible a packet is sent along one of these outputs. However,

neg: Wormhole switching switching, each buffer is either idle, or allocated to one packet. A header flit can be forwarded to a buffer if this buffer is idle. This allocates the buffer to the packet. A body or trailer flit can be forwarded to a buffer if this buffer is allocated to its packet and is not full. The last flit frees the buffer. If the header flit is blocked in the network, the buffer fills up, and once full, no more flits can be sent: this effect is called "back-pressure" and can be propagated back to the source. The name "wormhole" plays

neg: Flit (computer networking) responsibility of the switching strategy. There are basically two types of switching strategies, a circuit switched network is a network where a path is reserved and blocked off from other messages, till the message is delivered to its destination node. A famous example of circuit switched network is the telephone services, which establish a circuit through many switches for a call. The alternative approach is the packet switched network where messages are broken down into smaller compact entities called packets. Each packet contains a part of data in addition to a sequence number. This implies that each packet can now

neg: Packet switching report P-2626 in 1962, and finally in report RM 3420 in 1964. Report P-2626 described a general architecture for a large-scale, distributed, survivable communications network. The work focuses on three key ideas: use of a decentralized network with multiple paths between any two points, dividing user messages into "message blocks", and delivery of these messages by store and forward switching. Donald Davies at the National Physical Laboratory (UK) developed a similar message routing concept in 1965. He called it "packet switching", a more accessible name than Baran's terminology, and proposed building a nationwide network in the UK. He gave a

neg: Predictive control of switching power converters the converter. Receding Horizon Optimum Predictive Control Predictive control of switching power converters Predictive Control of Switching Power Converters. Predictive controllers rely on optimum control systems theory and aim to solve a cost functional minimization problem. Predictive controllers are relatively easy to numerically implement but electronic power converters are non-linear time varying dynamic systems, so a different approach to predictive must be taken. The first step to design a predictive controller is to derive a detailed direct dynamic model (including non-linearities) of the switching power converter. This model must contain enough detail of the converter dynamics to allow, from initial

neg: Predictive control of switching power converters Predictive control of switching power converters Predictive Control of Switching Power Converters. Predictive controllers rely on optimum control systems theory and aim to solve a cost functional minimization problem. Predictive controllers are relatively easy to numerically implement but electronic power converters are non-linear time varying dynamic systems, so a different approach to predictive must be taken. The first step to design a predictive controller is to derive a detailed direct dynamic model (including non-linearities) of the switching power converter. This model must contain enough detail of the converter dynamics to allow, from initial conditions, a forecast in real time and

neg: Interlanguage strategies (i.e., circumlocution), and overgeneralization of L2 language patterns. Interlanguage is based on the theory that there is a dormant psychological framework in the human brain that is activated when one attempts to learn a second language. Interlanguage theory is often credited to Larry Selinker, who coined the terms "interlanguage" and "fossilization." Uriel Weinreich is credited with providing the foundational information that was the basis of Selinker's research. Selinker (1972) noted that in a given situation, the utterances produced by a learner are different from those native speakers would produce had they attempted to convey the same meaning. This comparison

neg: Multilayer switch datagram (see layer 4 switching later on this page for the difference). The difference between a layer 3 switch and a router is the way the device is making the routing decision. Traditionally, routers use microprocessors to make forwarding decisions in software, while the switch performs only hardware-based packet switching (by specialized ASIC with the help of content-addressable memory). However, some traditional routers can have advanced hardware functions as well in some of the higher-end models. The main advantage of layer 3 switches is the potential for lower network latency as a packet can be routed without making extra network