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Internet 0 is a low-speed physical layer designed to route 'IP over anything'.[ citation needed ] It was developed at MIT's Center for Bits and Atoms by Neil Gershenfeld, Raffi Krikorian, and Danny Cohen. When it was invented, a number of other proposals were being labelled as "internet 2". The name was chosen to emphasize that this was designed to be a slow, but very inexpensive internetworking system, and forestall "high-performance" comparison questions such as "how fast is it?"
Effectively, it would enable a platform for pervasive computing -- everything in a building could be on the same network to share data gathering and actuation. A light switch could turn on a light bulb by sending a packet to it, they can be linked together by the user.
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Internet 0 was originally a minor, expedient bit of engineering support for other MIT projects. It was intended to network buildings, improve efficiency, and gather data through the control of HVAC systems (heating, ventilation, and air conditioning).
The protocol works pretty well in a wide variety of media. The wide utility and multiple media of the protocol interested network theorists. It awakened a burst of academic papers, and started some commercial interest.
The simple, inexpensive implementation still appeals to hobbyists and students, where most of the new implementations were found as of 2011. Modern implementations are mostly software on small microcontrollers, usually with a transistor to transmit, and capacitors to isolate the transmitter and receiver. The connector literally becomes the major expense of the communication system. Such a simple, inexpensive system can be embedded into many devices to allow data retrieval or control via the Internet -- these small devices can be used to form an Internet of Things.
The current largest deployment of Internet 0 was at the Venice Biennale Architecture Exhibition, in the year 2008, by a group led by the Institute of Advanced Architecture of Catalonia, directed by the architect Vicente Guallart.
The idea behind Internet 0 is to provide a general-purpose physical layer that operates well in many media. As such, it is very similar to morse code: a general-purpose layer 1 for the Internet. Logically, this is a recursive application of the internet principle (a ubiquitous protocol) to layer 1 of the network. The pulse-position modulation of Internet 0 operates best over a segregated wire, but it works in many media. It has been tested over radio frequency (RF), infrared (IR), ultrasonics, optical, DC and AC power wiring, and even physical representations such as printed bar codes and engraving on a key.
One of the main advantages of this approach is that routers become very simple. They are just a sensor, pulse reshaper and a transmitter.
Coupling the reusable physical layer to the internet protocols enables a network with very inexpensive nodes that is also addressable from the global Internet.
The design intent is to provide a simple, very inexpensive system that can transmit data slowly over many types of media, and yet still connect devices to the internet. Connecting to the internet is a crucial part of the design, because much of the value of a networked device is provided by easy, wide access to it. The higher layers of an Internet 0 network are usually Serial Line Internet Protocol (SLIP), Internet Protocol (IP), and above that, usually User Datagram Protocol (UDP) or more rarely Transmission Control Protocol (TCP).
The protocol layers are chosen to need a minimum of code, to keep the expense of the computer low. Internet 0 has been implemented in small AVR microcontrollers. In most existing implementations, the layers are not distinct, because small code is more important than elegant design.
A small translation device normally attaches a local network of Internet 0 devices to the serial port of a PC that acts as a gateway and firewall to the Internet.
Devices can talk directly to each other without requiring a server. The distributed architecture ensures that there is no central point of failure.
Address assignment and cryptographic key initialization is sometimes performed by closing a contact on the device while having a master controller broadcast an assignment message. Security is via a simplified encryption system.
Internet 0 is similar to a serial port running at 9600 baud except it sends data by pulse-position modulation, and accepts up to 30% timing deviations. The medium is broadcast, and half duplex. Software in the receiving devices examines the IP address of each packet, rejecting unwanted packets.
A zero bit is a one-microsecond pulse in the center of the first half of a bit time, and a one is a pulse in the second half of a bit time. Data is sent as 8 bit bytes. A byte is preceded by a bit time that has two pulses (at both 1 and 0 times), and ends with a bit time that has another two pulses. In some variations, the stop bit-time is optional, and the dual-pulse bit times are treated as byte separators.
The dual-pulse start and stop bit times permit a receiver to synchronize with the beginnings of bytes, and also measure the baud rate of a sender. Synchronizing on 8-bit bytes permits a 9600 baud internet-0 connection to easily translate to a standard, low-speed 19,200 baud TCP/IP serial port. The baud rate measurement permits senders and receivers to use inexpensive low-precision oscillators such as ceramic resonators or resistor-capacitor oscillators.
The most common interface uses the power supply wiring to the device. The circuit is a small surface mounted capacitor between an AC mains wire or a DC power wire and a single digital pin of a small microcontroller that switches a high-power transistor briefly on, then off. The pulses are normally generated by having software toggle a digital I/O pin on the microcontroller. They are received through another capacitor, by a microcontroller with a pin configured as an interrupt, or as a hardware timer's gate.
While Internet 0 works in many media, for any given transmission medium there are usually competing, preexisting physical layers that are more reliable, higher speed or lower power, such as Homeplug, or G.hn for power-line networking, or LIN for vehicles. While they are usually not as flexible, and rarely as inexpensive, they are less surprising.
In the early exploration of the concept, Sun Microsystems, Cisco Systems and Schneider Electric were interested in commercial deployment. Schneider eventually decided to deploy Zigbee, a low-powered radio protocol.
Internetwork Packet Exchange (IPX) is the network layer protocol in the IPX/SPX protocol suite. IPX is derived from Xerox Network Systems' IDP. It also has the ability to act as a transport layer protocol.
Internet Protocol version 4 (IPv4) is the fourth version of the Internet Protocol (IP). It is one of the core protocols of standards-based internetworking methods in the Internet and other packet-switched networks. IPv4 was the first version deployed for production on SATNET in 1982 and on the ARPANET in January 1983. It is still used to route most Internet traffic today, even with the ongoing deployment of Internet Protocol version 6 (IPv6), its successor.
The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the set of communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the suite are the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and the Internet Protocol (IP). Early versions of this networking model were known as the Department of Defense (DoD) model because the research and development were funded by the United States Department of Defense through DARPA.
In computer networking, the maximum transmission unit (MTU) is the size of the largest protocol data unit (PDU) that can be communicated in a single network layer transaction. The MTU relates to, but is not identical to the maximum frame size that can be transported on the data link layer, e.g., Ethernet frame.
The Open Systems Interconnection model is a reference model from the International Organization for Standardization (ISO) that "provides a common basis for the coordination of standards development for the purpose of systems interconnection." In the OSI reference model, the communications between systems are split into seven different abstraction layers: Physical, Data Link, Network, Transport, Session, Presentation, and Application.
In computer networking, Point-to-Point Protocol (PPP) is a data link layer communication protocol between two routers directly without any host or any other networking in between. It can provide loop detection, authentication, transmission encryption, and data compression.
A router is a computer and a networking device that forwards data packets between computer networks. Routers perform the traffic directing functions between networks and on the global Internet. Data sent through a network, such as a web page or email, is in the form of data packets. A packet is typically forwarded from one router to another router through the networks that constitute an internetwork until it reaches its destination node.
Xerox Network Systems (XNS) is a computer networking protocol suite developed by Xerox within the Xerox Network Systems Architecture. It provided general purpose network communications, internetwork routing and packet delivery, and higher level functions such as a reliable stream, and remote procedure calls. XNS predated and influenced the development of the Open Systems Interconnection (OSI) networking model, and was very influential in local area networking designs during the 1980s.
The Address Resolution Protocol (ARP) is a communication protocol used for discovering the link layer address, such as a MAC address, associated with a given internet layer address, typically an IPv4 address. This mapping is a critical function in the Internet protocol suite. ARP was defined in 1982 by RFC 826, which is Internet Standard STD 37.
In the seven-layer OSI model of computer networking, the physical layer or layer 1 is the first and lowest layer: the layer most closely associated with the physical connection between devices. The physical layer provides an electrical, mechanical, and procedural interface to the transmission medium. The shapes and properties of the electrical connectors, the frequencies to transmit on, the line code to use and similar low-level parameters, are specified by the physical layer.
The Serial Line Internet Protocol (SLIP) is an encapsulation of the Internet Protocol designed to work over serial ports and router connections. It is documented in RFC 1055. On personal computers, SLIP has largely been replaced by the Point-to-Point Protocol (PPP), which is better engineered, has more features, and does not require its IP address configuration to be set before it is established. On microcontrollers, however, SLIP is still the preferred way of encapsulating IP packets, due to its very small overhead.
The data link layer, or layer 2, is the second layer of the seven-layer OSI model of computer networking. This layer is the protocol layer that transfers data between nodes on a network segment across the physical layer. The data link layer provides the functional and procedural means to transfer data between network entities and may also provide the means to detect and possibly correct errors that can occur in the physical layer.
AX.25 is a data link layer protocol originally derived from layer 2 of the X.25 protocol suite and designed for use by amateur radio operators. It is used extensively on amateur packet radio networks.
1-Wire is a wired half-duplex serial bus designed by Dallas Semiconductor that provides low-speed (16.3 kbit/s) data communication and supply voltage over a single conductor.
The Parallel Line Internet Protocol (PLIP) is a computer networking protocol for direct computer-to-computer communications using the parallel port normally used for connections to a printer.
LIN is a network protocol used for communication between components in modern vehicles. It is a low-cost single-wire serial protocol that supports communications up to 19.2 Kbit/s with a maximum bus length of 40 metres (131.2 ft).
The System Packet Interface (SPI) family of Interoperability Agreements from the Optical Internetworking Forum specify chip-to-chip, channelized, packet interfaces commonly used in synchronous optical networking and Ethernet applications. A typical application of such a packet level interface is between a framer or a MAC and a network processor. Another application of this interface might be between a packet processor ASIC and a traffic manager device.
The PARC Universal Packet was one of the two earliest internetworking 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.
A computer network is a set of computers sharing resources located on or provided by network nodes. Computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are made up of telecommunication network technologies based on physically wired, optical, and wireless radio-frequency methods that may be arranged in a variety of network topologies.
DeviceNet is a network protocol used in the automation industry to interconnect control devices for data exchange. It utilizes the Common Industrial Protocol over a Controller Area Network media layer and defines an application layer to cover a range of device profiles. Typical applications include information exchange, safety devices, and large I/O control networks.