Showing papers on "Communications protocol published in 2002"

Energy-aware wireless microsensor networks

Abstract: This article describes architectural and algorithmic approaches that designers can use to enhance the energy awareness of wireless sensor networks. The article starts off with an analysis of the power consumption characteristics of typical sensor node architectures and identifies the various factors that affect system lifetime. We then present a suite of techniques that perform aggressive energy optimization while targeting all stages of sensor network design, from individual nodes to the entire network. Maximizing network lifetime requires the use of a well-structured design methodology, which enables energy-aware design and operation of all aspects of the sensor network, from the underlying hardware platform to the application software and network protocols. Adopting such a holistic approach ensures that energy awareness is incorporated not only into individual sensor nodes but also into groups of communicating nodes and the entire sensor network. By following an energy-aware design methodology based on techniques such as in this article, designers can enhance network lifetime by orders of magnitude.

A survey of rollback-recovery protocols in message-passing systems

Abstract: This survey covers rollback-recovery techniques that do not require special language constructs. In the first part of the survey we classify rollback-recovery protocols into checkpoint-based and log-based.Checkpoint-based protocols rely solely on checkpointing for system state restoration. Checkpointing can be coordinated, uncoordinated, or communication-induced. Log-based protocols combine checkpointing with logging of nondeterministic events, encoded in tuples called determinants. Depending on how determinants are logged, log-based protocols can be pessimistic, optimistic, or causal. Throughout the survey, we highlight the research issues that are at the core of rollback-recovery and present the solutions that currently address them. We also compare the performance of different rollback-recovery protocols with respect to a series of desirable properties and discuss the issues that arise in the practical implementations of these protocols.

Negotiation-based protocols for disseminating information in wireless sensor networks

Abstract: In this paper, we present a family of adaptive protocols, called SPIN (Sensor Protocols for Information via Negotiation), that efficiently disseminate information among sensors in an energy-constrained wireless sensor network. Nodes running a SPIN communication protocol name their data using high-level data descriptors, called meta-data. They use meta-data negotiations to eliminate the transmission of redundant data throughout the network. In addition, SPIN nodes can base their communication decisions both upon application-specific knowledge of the data and upon knowledge of the resources that are available to them. This allows the sensors to efficiently distribute data given a limited energy supply. We simulate and analyze the performance of four specific SPIN protocols: SPIN-PP and SPIN-EC, which are optimized for a point-to-point network, and SPIN-BC and SPIN-RL, which are optimized for a broadcast network. Comparing the SPIN protocols to other possible approaches, we find that the SPIN protocols can deliver 60% more data for a given amount of energy than conventional approaches in a point-to-point network and 80% more data for a given amount of energy in a broadcast network. We also find that, in terms of dissemination rate and energy usage, the SPIN protocols perform close to the theoretical optimum in both point-to-point and broadcast networks.

PFN/TRAC systemTM FAA upgrades for accountable remote and robotics control to stop the unauthorized use of aircraft and to improve equipment management and public safety in transportation

Abstract: This invention, a Protected Primary Focal Node PFN is a Trusted Remote Activity Controller TRAC and mobile communication router platform that provides accountable remote and robotics control to transportation vehicles by interfacing with the vehicles E/E systems. It connects each vehicle either on the earth's surface or near the earth's surface with application specific intranets for air, sea and land travel, via either host commercial servers or agency providers through wireless communication gateways and then further interfaces these vehicles in a larger machine messaging matrix via wireless and IP protocols to further coordinate movement assess and manage equipment use and impact on the world resources, societies infrastructure and the environment. This filing focuses directly on PFN/TRAC System use to augment and upgrade public safety and security in the Airline Industry and restrict any unauthorized use of an aircraft. Additionally, this application and related filings teaches the PFN/TRAC System™ use for all vehicle platforms to increase safety and security in a free society like the United State of America. The other related filings instruct in the technology's use for robust and accountable remote control for personal applications, stationary equipment and standalone functions, and coordinates them and interfaces them within the communication matrix. The TRAC controller also performs translation and repeating functions across a wide variety of communication protocols to complete a more mobile flexible matrix or web. This connected communication matrix of computers and humans provides an enhanced Human Machine Interfacing HMI scenario both locally and systemically in real-time for improve equipment management and world stability.

Network design consideration for distributed control systems

Abstract: This paper discusses the impact of network architecture on control performance in a class of distributed control systems called networked control systems (NCSs) and provides design considerations related to control quality of performance as well as network quality of service. The integrated network-control system changes the characteristics of time delays between application devices. This study first identifies several key components of the time delay through an analysis of network protocols and control dynamics. The analysis of network and control parameters is used to determine an acceptable working range of sampling periods in an NCS. A network-control simulator and an experimental networked a machine tool have been developed to help validate and demonstrate the performance analysis results and identify the special performance characteristics in an NCS. These performance characteristics are useful guidelines for choosing the network and control parameters when designing an NCS.

Service gateway for interactive television

Abstract: A service gateway provides a proxy between a client protocol and a plurality of standard communication protocols. The service gateway provides asymmetrical routing, data compression and encryption to optimize client processing power and communication link bandwidth. The service gateway enables content translation between clients and service providers. The service gateway keeps track of client available memory and sequence numbers in messages to generate error codes when applicable. A store and forward message capability is provided along with abstract session identifiers. The service gateway supports user datagram protocol.

Remote medical device access

Abstract: Systems, client computing devices, server computing devices, and methods are disclosed for accessing medical devices, providing remote access to medical devices and/or remotely accessing medical devices. In one exemplary embodiment, client computing devices utilize protocol components that may be obtained from a server computing device via a network to communicate with medical devices in a communications protocol supported by the medical device.

Gigabit Ethernet adapter

Abstract: An apparatus for decoding and encoding network protocols and processing data, consists of a network stack (101) for receiving and transmitting packets and for encoding and decoding the packets, and a plurality of dedicated hardwired logic protocol modules (102, 103 and 104), each being optimized for a spesific network protocol, wherein the protocol modules (102, 103 and 104) execute in parallel.

Method for switching protocols transparently in multi-user applications

Abstract: An application programming interface implements a method for transparently switching from one communication protocol to another and for restoring the state of a previous connection. The application programming interface executes on a local, client computer, as well as remote computers. It includes functions that multi-user application programs can call to communicate in a device independent manner with other applications executing on remote computers. To support communication on a variety of different computer communication protocols, the application programming interface accesses programs called service providers that implement the communication protocols and support the message passing model of the interface. The application programming interface can transparently switch the protocol on a remote computer by sending a system message to a compatible version of the interface on the remote computer that includes an identifier of the service provider for the new protocol. In response to the message, the application programming interface loads the new service provider and takes steps to set-up a new connection. The application programming interface can also restore the state of previous connection on a remote computer by sending a system message. In response to this message, the application programming interface on the remote computer retrieves the previous connection state from an MRU stack and loads the service provider for the previous connection.

Reliable peer-to-peer connections

Abstract: Embodiments of a system and method for establishing reliable connections between peers in a peer-to-peer networking environment. In one embodiment, a reliable communications channel may use transmit and receive windows, acknowledgement of received messages, and retransmission of messages not received to provide reliable delivery of messages between peers in the peer-to-peer environment. In one embodiment, each message may include a sequence number configured for use in maintaining ordering of received messages on a receiving peer. A communications channel may make multiple hops on a network, and different hops in the connection may use different underlying network protocols. Communications channels may also pass through one or more firewalls and/or one or more gateways on the network. A communications channel may also pass through one or more router (relay) peers on the network. The peers may adjust the sizes of the transmit and receive window based upon reliability of the connection.

Eliminating Steganography in Internet Traffic with Active Wardens

Abstract: Active wardens have been an area of postulation in the community for nearly two decades, but to date there have been no published implementations that can be used to stop steganography as it transits networks. In this paper we examine the techniques and challenges of a high-bandwidth, unattended, real-time, active warden in the context of a network firewall. In particular, we concentrate on structured carriers with objectively defined semantics, such as the TCP/IP protocol suite rather than on the subjective, or unstructured carriers such as images that dominate the information hiding literature. We introduce the concept of Minimal Requisite Fidelity (MRF) as a measure of the degree of signal fidelity that is both acceptable to end users and destructive to covert communications. For unstructured carriers, which lack objective semantics, wardens can use techniques such as adding noise to block subliminal information. However, these techniques can break the overt communications of structured carriers which have strict semantics. We therefore use a specification-based approach to determine MRF. We use MRF to reason about opportunities for embedding covert or subliminal information in network protocols and develop both software to exploit these channels, as well as an active warden implementation that stops them. For unstructured carriers, MRF is limited by human perception, but for structured carriers, well known semantics give us high assurance that a warden can completely eliminate certain subliminal or covert channels.

A digital television application protocol for interactive television

Abstract: A common communication language that can address all the applications running in a multitude of set top boxes (STBs) or client devices and application servers. The present invention, DATP protocol encapsulates a Meta language that provides a generic portable communication application programmer interface that requires light process or utilization and is well suited for a typical STB possessing limited processing power. DATP requires relatively few processing cycles compared to typical Internet communication protocols. DATP reduces the overhead of the communication protocol handler at the STB and makes the communication protocol handler common for all STBs applications. The preferred DATP protocol is portable for all STBs since it is written in a native language that interfaces with the underlying operating system of the STB. A SGW (SGW) performs as a DATP server. The SGW translate between DATP messages and standard communication protocols. SGW enables SP clients at STBs utilizing DATP to communicate with service applications using a variety of communication protocols. A content converter is provided to convert standard Web content into content suitable for display on a client-viewing device, e.g., a TV.

Method and apparatus for providing secure streaming data transmission facilities using unreliable protocols

Abstract: The invention provides a method and apparatus for transmitting data securely using an unreliable communication protocol, such as User Datagram Protocol. In one variation, the invention retains compatibility with conventional Secure Sockets Layer (SSL) and SOCKS protocols, such that secure UDP datagrams can be transmitted between a proxy server and a client computer in a manner analogous to conventional SOCKS processing. In contrast to conventional SSL processing, which relies on a guaranteed delivery service such as TCP and encrypts successive data records with reference to a previously-transmitted data record, encryption is performed using a nonce (504) that is embedded in each transmitted data record (507). This nonce acts both as an initialization vector for encryption/decryption of the record, and as a unique identifier to authenticate the record. Because decryption of any particular record does not rely on receipt of previously received data record, the scheme will operate over an unreliable communication protocol.

System and method for directing clients to optimal servers in computer networks

Abstract: A communication protocol includes one or more messages passed between Web routers over a reliable transmission protocol used for inter-Web router communication. These messages include information that allows the Web routers to dynamically update mappings of client addresses or address ranges to information object repository addresses based on client-to-server distance and server load. The mappings are preferably optimal mappings of the client addresses or address ranges to the information object repository addresses and the messages report updated distances from these information object repository addresses to the client addresses or address ranges. For example, the messages may report, for each updated distance, an associated client address or address range and/or an associated anchor address of a Web router co-located with an information object repository that is the subject of the message.

System, apparatus and methods for data communication between vehicle and remote data communication terminal, between portions of vehicle and other portions of vehicle, between two or more vehicles, and between vehicle and communications network

Abstract: A system, an apparatus, and methods are provided for data communications associated with a vehicle. The apparatus preferably includes at least one electronic subsystem associated with the vehicle and a plurality of electrical conductors connected to the at least one electronic subsystem and associated with the vehicle. A vehicle data communications protocol converter is preferably connected to the plurality of electrical conductors for converting a first data communications protocol associated with data communications along the plurality of electrical conductors to a second data communications protocol such as an infrared, an RF data, an Internet, or other network communications protocol. The apparatus also preferably includes a transceiver connected to the data communications protocol converter for transmitting the second data communications protocol from the vehicle and receiving the data communications protocol from another portion of the vehicle, a remote data communications terminal, another vehicle, or another communications network.

Adaptive multi-protocol communications system

Abstract: An adaptive multi-protocol communications system provides a plurality of single computer interface cards connected to a common backplane or interconnect. Each interface card sends and receives bit streams of a specific application protocol, exchanging data between possibly differing application protocols. The interface card feeds the incoming binary stream into a finite state machine dedicated to converting a specific application protocol bit stream into a multi-dimensional matrix representation for a particular communication protocol, e.g., EDI,XML, or the invention's intermediate translation representation. The invention uses finite state machines to convert from the initial communication protocol bit stream to the invention's intermediate representation. A finite s tate machine on a receiving interface card is used to convert the incoming bit stream into an intermediate language multi-dimensional matrix and passes the matrix to a destination interface card which has a finite state machine used to convert the intermediate language multi-dimensional matrix to an application protocol bit stream. The application protocol bit stream is then sent to a receiving computer system.

Tasking and reporting method and implementation for wireless appliance location systems

Abstract: A system and method for determining the location of a mobile appliance where the tasking of the system to determine the location of the mobile appliance utilizes a first communications protocol standard and the reporting of the location of the mobile appliance utilizes a second communications protocol standard, where the first and second communication protocol standards are not the same and can include any of the commonly used communication protocol standards including TIA defined standards, ETSI standards, and SMR/ESMR defined standards.

Mobile robotic with web server and digital radio links

Abstract: The invention is a computerized mobile robot with an onboard internet web server, and a capability of establishing a first connection to a remote web browser on the internet for robotic control purposes, and a capability of establishing a second short range bi-directional digital radio connection to one or more nearby computerized digital radio equipped devices external to the robot. The short-range bi-directional digital radio connection will typically have a maximum range of about 300 feet. In a preferred embodiment, this short-range wireless digital connection will use the 2.4 gHz band and digital protocols following the IEEE 802.11, 802.15, or other digital communications protocol. By employing the proper set of external short-range digital radio devices capable of interfacing with the robot (such as sensors, mechanical actuators, appliances, and the like), a remote user on the internet may direct the robot to move within range of the external devices, discover their functionality, and send and receive commands and data to the external devices through the CGI interface on the robot's onboard web server.

Decentralized sensor fusion with distributed particle filters

Abstract: This paper presents a scalable Bayesian technique for decentralized state estimation from multiple platforms in dynamic environments. As has long been recognized, centralized architectures impose severe scaling limitations for distributed systems due to the enormous communication overheads. We propose a strictly decentralized approach in which only nearby platforms exchange information. They do so through an interactive communication protocol aimed at maximizing information flow. Our approach is evaluated in the context of a distributed surveillance scenario that arises in a robotic system for playing the game of laser tag. Our results, both from simulation and using physical robots, illustrate an unprecedented scaling capability to large teams of vehicles.

Wireless identification system and protocol

Abstract: Monitoring systems and protocols (100) are disclosed that are flexible in mode operation and format depending on the environment in which they are used. Such monitoring systems and protocols are able to change their utilization automatically, or by received instruction to do so. A location detection system includes one or more low frequency transmitters (110, 120), one or more radio frequency monitoring tags (130) and one or more receiving devices. The low frequency transmitter location identification information, such as the transmitter ID, to a tag in the vicinity of the transmission. The tag relays the transmitter ID using a higher frequency transmission sent from the tag to the receiver. Communication protocols are disclosed that enable deciphering of multiple tag transmissions starting simultaneously.

Multi-protocol field device and communication method

Abstract: A multi-protocol smart field device uses a Fieldbus communication protocol to communicate process control information and uses a HART communication protocol to enable local configuration of the field device via a hand-held HART communicator. The multi-protocol smart field device includes a first communications interface communicatively coupled to a digital data bus that is adapted to process HART communications which are received from and which are sent to a HART hand-held communicator. The multi-protocol smart field device further includes a second communications interface communicatively coupled to the digital data bus that is adapted to process Fieldbus communications. Additionally, the multi-protocol smart field device includes a first filter coupled between the first communications interface and the digital data bus that substantially attenuates signals having frequencies associated with Fieldbus communications and a second filter coupled between the second communications interface and the digital data bus that substantially attenuates signals having frequencies associated with HART communications.

Common service platform and software

Abstract: The invention advantageously provides a mobile common service platform and software in telecommunications systems. A common service platform (CSP) according to the invention is an integrated platform that supports both wireless and landline mobile services and business transactions. A CSP system according to the invention includes a common service platform or CSP for integrating a plurality of applications into a single platform for multiple uses in a plurality of communications systems. The CSP is connected with the plurality of applications and a plurality of users. Multiple users in different communications systems having varied communications protocols can utilize generally the same application (as selected by the users) through the CSP. Requests for uses in different communications system are transferred to the CSP for conversion into generally the same format that is acceptable by a selected application. Outputs from the selected application are transferred into formats that are acceptable by the requesting user. The CSP system advantageously enables a communications system to be quickly offered to market in conjunction with value-added services through applications rendered by third party service providers.

System and method for enabling transactions between a web server and a smart card, telephone, or personal digital assistant over the internet

Abstract: An open network system for supporting input/output (I/O) operations for non-standard I/O devices are disclosed. The system includes a server coupled to a plurality of I/O devices through an open network and an extended open system protocol that supports communication with devices that are not personal computers (PCs). These devices include magnetic stripe readers, check readers, smart card readers, credit card terminals, screen phone terminals, PIN pads, printers, and the like. The extended open network protocol includes tags which identify device and input operations and attributes which identify the location, data exchange method, and data variable names for the retrieval, acquisition, and submission of data between the server and I/O devices. Preferably, the open network protocol is implemented in a Hyper Text Transport Protocol (HTTP).

Performance of collision avoidance protocols in single-channel ad hoc networks

Abstract: The paper presents the first analytical model to derive the saturation throughput of collision avoidance protocols in multi-hop ad hoc networks with nodes randomly placed according to a two-dimensional Poisson distribution. We show that the sender-initiated collision-avoidance scheme performs much better than the ideal CSMA scheme with a separate channel for acknowledgments. More importantly, we show that the collision-avoidance scheme can accommodate much fewer competing nodes within a region in a network infested with hidden terminals than in those cases without hidden terminals or with just a few, if reasonable throughput is to be maintained. Simulations of the popular IEEE 802.11 MAC protocol show that it cannot ensure collision-free transmission of data packets and thus throughput can degrade well below what is predicted by the analysis of a correct collision avoidance protocol. Based on these results, a number of improvements are proposed for the IEEE 802.11 MAC protocol.

Enhancements to multi-party authentication and other protocols

Abstract: Techniques are disclosed to increase the efficiency of multi-party authentication communications protocols. One technique includes a four party authentication method utilizing a general authenticator to store and provide a credit card authentication password and other payment information to an issuing bank and/or other parties involved in the transaction. Other techniques include the use of skeleton messages to minimize the forwarding of information through a forwarding party, the elimination of redundant communications exchanges, the use of a merchant appliance hardware solution to minimize system integration difficulties, and/or the imposition of credit card constraints. The techniques may be used singly or in combination.

SPEED: A Real-Time Routing Protocol for Sensor Networks

Abstract: : In this paper, we present a real-time communication protocol, called SPEED, for sensor networks. The protocol provides three types of real-time communication services, namely, real-time unicast, real-time area-multicast and real-time area-anycast. SPEED is specifically tailored to be a stateless, localized algorithm with minimal control overhead. End-to-end real-time communication guarantees are achieved using a novel combination of feedback control and non-deterministic QoS-aware geographic forwarding with a bounded hop count. SPEED is a highly efficient and scalable protocol for the sensor networks where node density is high while the resources of each node are scarce. Theoretical analysis and simulation experiments are provided to validate our claims.

Systems and methods for implementing host-based security in a computer network

Abstract: A network node is disclosed The network node includes a host processor The network node also includes an integrated circuit The integrated circuit includes a hardware portion configured to perform a first set of TCP acceleration tasks that require a first speed level The integrated circuit also includes a network protocol processor configured to perform a second set of TCP acceleration tasks that require a second speed level, which is lower than the first speed level The integrated circuit further includes an embedded processor configured to perform a third set of TCP acceleration tasks that require a third speed level, which is lower than the second speed level The network node further includes a plurality of data paths configured to couple the integrated circuit to the host processor, the plurality of data paths being implemented based on different protocols

System and method for high-performance delivery of Internet messages by selecting first and second specialized intermediate nodes to optimize a measure of communications performance between the source and the destination

Abstract: The invention uses a distributed network of specialized nodes of different types dispersed around the Internet. In operation, web client's requests are directed to a node of a first type chosen to be close to the client, and the client communicates with this node using a standard protocol such as HTTP. This first node receives the request, and locates a node of a second type, chosen to be an optimal initial relay on a path to the web server. The first node may communicates the request to the second node using a different, specialized, protocol that has been designed for improved performance and specifically to reduce traffic volume and to reduce latency. The second node receives communication from the first node using this specialized protocol, and relays it to an optimally chosen third node using the same, or possibly different internode communication protocol. This process may repeat over additional internode hops until finally, the last node receives the request from the previous network node, converts it back to a standard protocol such as HTTP, and forwards the request to the server. Responses from server to client can take the same or similar reverse route, and can also be carried over specialized protocols between the network nodes. In addition, these nodes can employ other techniques such as web caches that avoid or improve some communication steps.

Verisim: formal analysis of network simulations

Abstract: Network protocols are often analyzed using simulations. We demonstrate how to extend such simulations to check propositions expressing safety properties of network event traces in an extended form of linear temporal logic. Our technique uses the INS simulator together with a component of the MaC system to provide a uniform framework. We demonstrate its effectiveness by analyzing simulations of the ad hoc on-demand distance vector (AODV) routing protocol for packet radio networks. Our analysis finds violations of significant properties and we discuss the faults that cause them. Novel aspects of our approach include modest integration costs with other simulation objectives such as performance evaluation, greatly increased flexibility in specifying properties to be checked and techniques for analyzing complex traces of alarms raised by the monitoring software.