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Showing papers on "Communications protocol published in 2003"


Proceedings ArticleDOI
19 May 2003
TL;DR: SPEED is a highly efficient and scalable protocol for sensor networks where the resources of each node are scarce, and specifically tailored to be a stateless, localized algorithm with minimal control overhead.
Abstract: In this paper, we present a real-time communication protocol for sensor networks, called SPEED. 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 soft real-time communication is achieved by maintaining a desired delivery speed across the sensor network through a novel combination of feedback control and non-deterministic geographic forwarding. SPEED is a highly efficient and scalable protocol for sensor networks where the resources of each node are scarce. Theoretical analysis, simulation experiments and a real implementation on Berkeley motes are provided to validate our claims.

1,347 citations


Proceedings ArticleDOI
25 Aug 2003
TL;DR: This paper examines the somewhat controversial subject of energy consumption of networking devices in the Internet, motivated by data collected by the U.S. Department of Commerce, and discusses the impact on network protocols of saving energy by putting network interfaces and other router & switch components to sleep.
Abstract: In this paper we examine the somewhat controversial subject of energy consumption of networking devices in the Internet, motivated by data collected by the U.S. Department of Commerce. We discuss the impact on network protocols of saving energy by putting network interfaces and other router & switch components to sleep. Using sample packet traces, we first show that it is indeed reasonable to do this and then we discuss the changes that may need to be made to current Internet protocols to support a more aggressive strategy for sleeping. Since this is a position paper, we do not present results but rather suggest interesting directions for core networking research. The impact of saving energy is huge, particularly in the developing world where energy is a precious resource whose scarcity hinders widespread Internet deployment.

963 citations


Journal ArticleDOI
29 Jan 2003
TL;DR: The architecture model of the TTA is presented, the design rationale is explained, the time-triggered communication protocols TTP/C andTTP/A are discussed, and how transparent fault tolerance can be implemented in the Tta is illustrated.
Abstract: The time-triggered architecture (TTA) provides a computing infrastructure for the design and implementation of dependable distributed embedded systems. A large real-time application is decomposed into nearly autonomous clusters and nodes, and a fault-tolerant global time base of known precision is generated at every node. In the TTA, this global time is used to precisely specify the interfaces among the nodes, to simplify the communication and agreement protocols, to perform prompt error detection, and to guarantee the timeliness of real-time applications. The TTA supports a two-phased design methodology, architecture design, and component design. During the architecture design phase, the interactions among the distributed components and the interfaces of the components are fully specified in the value domain and in the temporal domain. In the succeeding component implementation phase, the components are built, taking these interface specifications as constraints. This two-phased design methodology is a prerequisite for the composability of applications implemented in the TTA and for the reuse of prevalidated components within the TTA. This paper presents the architecture model of the TTA, explains the design rationale, discusses the time-triggered communication protocols TTP/C and TTP/A, and illustrates how transparent fault tolerance can be implemented in the TTA.

785 citations


Proceedings ArticleDOI
14 Sep 2003
TL;DR: Simulation results show that the use of obstacles and pathways has a significant impact on the performance of ad hoc network protocols.
Abstract: One of the most important methods for evaluating the characteristics of ad hoc networking protocols is through the use of simulation. Simulation provides researchers with a number of significant benefits, including repeatable scenarios, isolation of parameters, and exploration of a variety of metrics. The topology and movement of the nodes in the simulation are key factors in the performance of the network protocol under study. Once the nodes have been initially distributed, the mobility model dictates the movement of the nodes within the network. Because the mobility of the nodes directly impacts the performance of the protocols, simulation results obtained with unrealistic movement models may not correctly reflect the true performance of the protocols. The majority of existing mobility models for ad hoc networks do not provide realistic movement scenarios; they are limited to random walk models without any obstacles. In this paper, we propose to create more realistic movement models through the incorporation of obstacles. These obstacles are utilized to both restrict node movement as well as wireless transmissions. In addition to the inclusion of obstacles, we construct movement paths using the Voronoi diagram of obstacle vertices. Nodes can then be randomly distributed across the paths, and can use shortest path route computations to destinations at randomly chosen obstacles. Simulation results show that the use of obstacles and pathways has a significant impact on the performance of ad hoc network protocols.

663 citations


Journal Article
TL;DR: In this article, Stann et al. present RMST (Reliable Multi-Segment Transport), a new transport layer for Directed Diffusion, which provides guaranteed delivery and fragmentation/reassembly for applications that require them.
Abstract: Appearing in 1st IEEE International Workshop on Sensor Net Protocols and Applications (SNPA). Anchorage, Alaska, USA. May 11, 2003. RMST: Reliable Data Transport in Sensor Networks Fred Stann, John Heidemann Abstract – Reliable data transport in wireless sensor networks is a multifaceted problem influenced by the physical, MAC, network, and transport layers. Because sensor networks are subject to strict resource constraints and are deployed by single organizations, they encourage revisiting traditional layering and are less bound by standardized placement of services such as reliability. This paper presents analysis and experiments resulting in specific recommendations for implementing reliable data transport in sensor nets. To explore reliability at the transport layer, we present RMST (Reliable Multi- Segment Transport), a new transport layer for Directed Diffusion. RMST provides guaranteed delivery and fragmentation/reassembly for applications that require them. RMST is a selective NACK-based protocol that can be configured for in-network caching and repair. Second, these energy constraints, plus relatively low wireless bandwidths, make in-network processing both feasible and desirable [3]. Third, because nodes in sensor networks are usually collaborating towards a common task, rather than representing independent users, optimization of the shared network focuses on throughput rather than fairness. Finally, because sensor networks are often deployed by a single organization with inexpensive hardware, there is less need for interoperability with existing standards. For all of these reasons, sensor networks provide an environment that encourages rethinking the structure of traditional communications protocols. The main contribution is an evaluation of the placement of reliability for data transport at different levels of the protocol stack. We consider implementing reliability in the MAC, transport layer, application, and combinations of these. We conclude that reliability is important at the MAC layer and the transport layer. MAC-level reliability is important not just to provide hop-by-hop error recovery for the transport layer, but also because it is needed for route discovery and maintenance. (This conclusion differs from previous studies in reliability for sensor nets that did not simulate routing. [4]) Second, we have developed RMST (Reliable Multi-Segment Transport), a new transport layer, in order to understand the role of in- network processing for reliable data transfer. RMST benefits from diffusion routing, adding minimal additional control traffic. RMST guarantees delivery, even when multiple hops exhibit very high error rates. 1 Introduction Wireless sensor networks provide an economical, fully distributed, sensing and computing solution for environments where conventional networks are impractical. This paper explores the design decisions related to providing reliable data transport in sensor nets. The reliable data transport problem in sensor nets is multi-faceted. The emphasis on energy conservation in sensor nets implies that poor paths should not be artificially bolstered via mechanisms such as MAC layer ARQ during route discovery and path selection [1]. Path maintenance, on the other hand, benefits from well- engineered recovery either at the MAC layer or the transport layer, or both. Recovery should not be costly however, since many applications in sensor nets are impervious to occasional packet loss, relying on the regular delivery of coarse-grained event descriptions. Other applications require loss detection and repair. These aspects of reliable data transport include the provision of guaranteed delivery and fragmentation/ reassembly of data entities larger than the network MTU. Sensor networks have different constraints than traditional wired nets. First, energy constraints are paramount in sensor networks since nodes can often not be recharged, so any wasted energy shortens their useful lifetime [2]. This work was supported by DARPA under grant DABT63-99-1-0011 as part of the SCAADS project, and was also made possible in part due to support from Intel Corporation and Xerox Corporation. Fred Stann and John Heidemann are with USC/Information Sciences Institute, 4676 Admiralty Way, Marina Del Rey, CA, USA E-mail: fstann@usc.edu, johnh@isi.edu. 2 Architectural Choices There are a number of key areas to consider when engineering reliability for sensor nets. Many current sensor networks exhibit high loss rates compared to wired networks (2% to 30% to immediate neighbors)[1,5,6]. While error detection and correction at the physical layer are important, approaches at the MAC layer and higher adapt well to the very wide range of loss rates seen in sensor networks and are the focus of this paper. MAC layer protocols can ameliorate PHY layer unreliability, and transport layers can guarantee delivery. An important question for this paper is the trade off between implementation of reliability at the MAC layer (i.e. hop to hop) vs. the Transport layer, which has traditionally been concerned with end-to-end reliability. Because sensor net applications are distributed, we also considered implementing reliability at the application layer. Our goal is to minimize the cost of repair in terms of transmission.

650 citations


Journal ArticleDOI
01 Jul 2003
TL;DR: The emulation capabilities of NIST Net are described; the architecture of the tool is examined; and some of the implementation challenges encountered in building such a tool to operate at very high network data rates while imposing minimal processing overhead are discussed.
Abstract: Testing of network protocols and distributed applications has become increasingly complex, as the diversity of networks and underlying technologies increase, and the adaptive behavior of applications becomes more sophisticated. In this paper, we present NIST Net, a tool to facilitate testing and experimentation with network code through emulation. NIST Net enables experimenters to model and effect arbitrary performance dynamics (packet delay, jitter, bandwidth limitations, congestion, packet loss and duplication) on live IP packets passing through a commodity Linux-based PC router. We describe the emulation capabilities of NIST Net; examine its architecture; and discuss some of the implementation challenges encountered in building such a tool to operate at very high network data rates while imposing minimal processing overhead. Calibration results are provided to quantify the fidelity and performance of NIST Net over a wide range of offered loads (up to 1 Gbps), and a diverse set of emulated performance dynamics.

543 citations


01 Jan 2003
TL;DR: This thesis presents and operating system and three generations of a hardware platform designed to address the needs of wireless sensor networks and shows how the careful selection of the correct accelerators can lead to orders-of-magnitude improvements in efficiency without sacrificing flexibility.
Abstract: In this thesis we present and operating system and three generations of a hardware platform designed to address the needs of wireless sensor networks. Our operating system, called TinyOS uses an event based execution model to provide support for fine-grained concurrency and incorporates a highly efficient component model. TinyOS enables us to use a hardware architecture that has a single processor time shared between both application and protocol processing. We show how a virtual partitioning of computational resources not only leads to efficient resource utilization but allows for a rich interface between application and protocol processing. This rich interface, in turn, allows developers to exploit application specific communication protocols that significantly improve system performance. The hardware platforms we develop are used to validate a generalized architecture that is technology independent. Our general architecture contains a single central controller that performs both application and protocol-level processing. For flexibility, this controller is directly connected to the RF transceiver. For efficiency, the controller is supported by a collection of hardware accelerators that provide basic communication primitives that can be flexibility composed into application specific protocols. The three hardware platforms we present are instances of this general architecture with varying degrees of hardware sophistication. The Rene platform serves as a baseline and does not contain any hardware accelerators. It allows us to develop the TinyOS operating system concepts and refine its concurrency mechanisms. The Mica node incorporates hardware accelerators that improve communication rates and synchronization accuracy within the constraints of current microcontrollers. As an approximation of our general architecture, we use Mica to validate the underlying architectural principles. The Mica platform has become the foundation for hundreds of wireless sensor network research efforts around the world. It has been sold to more than 250 organizations. Spec is the most advanced node presented and represents the full realization of our general architecture. It is a 2.5 mm x 2.5 mm CMOS chip that includes processing, storage, wireless communications and hardware accelerators. We show how the careful selection of the correct accelerators can lead to orders-of-magnitude improvements in efficiency without sacrificing flexibility. In addition to performing a theoretical analysis on the strengths of our architecture, we demonstrate its capabilities through a collection of real-world application deployments.

474 citations


Proceedings ArticleDOI
03 Dec 2003
TL;DR: A mapping protocol for nodes that surround a jammer which allows network applications to reason about the region as an entity, rather than as a collection of broken links and congested nodes is described.
Abstract: Preventing denial-of-service attacks in wireless sensor networks is difficult primarily because of the limited resources available to network nodes and the ease with which attacks are perpetrated Rather than jeopardize design requirements which call for simple, inexpensive, mass-producible devices, we propose a coping strategy that detects and maps jammed regions We describe a mapping protocol for nodes that surround a jammer which allows network applications to reason about the region as an entity, rather than as a collection of broken links and congested nodes This solution is enabled by a set of design principles: loose group semantics, eager eavesdropping, supremacy of local information, robustness to packet loss and failure, and early use of results Performance results show that regions can be mapped in 1-5 seconds, fast enough for real-time response With a moderately connected network, the protocol is robust to failure rates as high as 25 percent

400 citations


Patent
05 Jun 2003
TL;DR: In this paper, the authors present a Gigabit Ethernet adapter that adapts to multiple communication protocols via a modular construction and design, and it provides a compact hardware solution to handling high network communication speeds.
Abstract: The invention is embodied in a gigabit Ethernet adapter. A system according to the invention provides a compact hardware solution to handling high network communication speeds. In addition, the invention adapts to multiple communication protocols via a modular construction and design.

352 citations


Patent
18 Jun 2003
TL;DR: In this paper, a communication interface and a common communication protocol allow data transfer between gaming machines and other network nodes such as gaming service servers, despite the presence of different proprietary gaming machine functions and proprietary communication protocols.
Abstract: Open architecture communication systems and methods are provided that allow flexible data transmission between gaming machines and other devices and nodes within a gaming machine network. The gaming machine and other devices employ a communication interface that sends and receives data via a common communication protocol and via common communication hardware. The communication interface and common communication protocol allow data transfer between gaming machines and other network nodes such as gaming service servers, despite the presence of different proprietary gaming machine functions and proprietary communication protocols and despite the presence of various proprietary hardware and proprietary communication protocols relied on by the servers.

300 citations


Journal ArticleDOI
01 Jan 2003
TL;DR: Non-layered approaches to the design and implementation of network protocols are investigated for greater flexibility and control with fewer feature interaction problems and a specific non-layering paradigm called role-based architecture is proposed.
Abstract: Questioning whether layering is still an adequate foundation for networking architectures, this paper investigates non-layered approaches to the design and implementation of network protocols. The goals are greater flexibility and control with fewer feature interaction problems. The paper further proposes a specific non-layered paradigm called role-based architecture.

Proceedings ArticleDOI
08 Mar 2003
TL;DR: An optimization method is proposed that can be used to tune parameters of the middleware services and applications to provide optimal performance, based on simulation, and is capable of handling 'noisy' error surfaces.
Abstract: 6 15-322-3 162 Abstr-act-The design of reliable, dynamic, fault-tolerant services in wireless sensor networks is a big challenge and a hot research topic. In this paper an optimization method is proposed that can be used to tune parameters of the middleware services and applications to provide optimal performance. The optimization method is based on simulation, and is capable of handling 'noisy' error surfaces. The proposed optimization algorithm is illustrated by a new spanning-tree formation algorithm, which can effectively operate even if links between nodes are asymmetrical. In the near future large-scale sensor networks will be the key elements of embedded systems used in space and aviationrelated challenges, e.g. monitoring and control of safety critical systems [l], Smart Surfaces, Smart Dust [2], or can be used to make everyday life more comfortable, e.g. Intelligent Spaces [3]. These sensor networks often use distributed operating system-like services (called middleware) over wireless communication protocols, which must be fault tolerant and adaptive because of the dynamic network topology and changing mission objectives. The design of such middleware services is not straightforward, since the sensors have limited resources, and thus the used protocols are usually very simple compared to ones used in wired communication schemes. The nondeterministic nature of the environment is another factor making the design more difficult. This paper presents a simulation-based optimization method that can be used to tune the algorithms used in the middleware layer. Also some results are presented that were gained by the proposed method. The hardware structure of the wireless sensors may vary greatly, but invariably each of the intelligent sensors is a compact device with its own power source, it contains a processing unit (a small microprocessor), a communication unit and the sensor itself. The widely used Berkeley fieldnodes (or motes) have similar structure containing an 8-bit microcontroller, a 916.5 MHz radio and several interchangeable sensors. These tiny units have a simple local operating system called TinyOS. Application-specific middleware services can be added to provide an interface between the application and the primitive services of the local operating system. The middleware can also be considered as a distributed operating system that establishes network-wide resources and functions that the applications can utilize, e.g. leader election, spanning tree formation, distributed consensus and mutual exclusion, distributed transactions, group communication services, clock synchronization, etc. Typical applications may include hundreds or thousands of motes with often unknown or random distribution (e.g. motes dropped from an airplane to a hostile environment). The communication services must be reliably established to achieve the overall goal of the distributed sensor system. During the operation of the sensor network different metrics for the quality of service (QoS) are required, a dynamic tradeoff is necessary between accuracy, response time, power consumption, and other qualities of interest. Thus, the middleware services must be prepared to adapt to the actual circumstances and the QoS metric. To design such middleware services, the highly random nature of the environment (wireless communication with possible disturbances, random layout, possibly damaged motes, etc.) must be taken into consideration. The proposed design method is a probabilistic simulationbased optimization that can help the designer choose the right algorithm with an optimal parameter set. The MATLAB-based simulator is capable of simulating the important aspects of the communication scheme: local OS services including the network protocol stack, and also the radio transmission phenomena (signal power vs. distance, fading, collision, disturbances). In the simulation

Journal ArticleDOI
TL;DR: Some of the ongoing work in the application of formal methods to cryptographic protocol analysis is described, as well as some of the new challenges and the ways in which they are being met.
Abstract: The history of the application of formal methods to cryptographic protocol analysis spans over 20 years and has been showing signs of new maturity and consolidation. Not only have a number of specialized tools been developed, and general-purpose ones been adapted, but people have begun applying these tools to realistic protocols, in many cases supplying feedback to designers that can be used to improve the protocol's security. In this paper, we describe some of the ongoing work in this area, as well as describe some of the new challenges and the ways in which they are being met.

Patent
18 Jul 2003
TL;DR: In this paper, a portable data collection terminal is described for use in mixed wireless and hardwired RF communication networks, wherein various radio transmitter modules and associated antennas may be selectively added to a base terminal unit to solve networking problems associated with specific types of business environments.
Abstract: Modular, portable data collection terminals are disclosed for use in mixed wireless and hard-wired RF communication networks, wherein various radio transmitter modules and associated antennas may be selectively added to a base terminal unit to solve networking problems associated with specific types of business environments. Modularity exists in both the hardware (splitting data collection and processing control circuitry from radio transceiver control circuitry) and software (splitting transceiver-specific, lower level communication protocol from generic, higher level communication protocol). The control circuitry, including associated microprocessors devices, interact to selectively activate communication circuits to perform necessary communication or data processing functions and enter and remain in a power-saving dormant state during other times. To support such dormant or “sleeping” states, a series of communication protocols provide for channel access to the communication network. The disclosed modular design also provides for automatic selection from a variety of available built-in and externally mounted antennas based on the particular type of radio transceiver(s) selected.

28 Jan 2003
TL;DR: Herbivore is described, a peer-to-peer, scalable, tamper-resilient communication system that provides provable anonymity and privacy and simultaneously provides high efficiency and scalability, distinguishing it from other anonymous communication protocols.
Abstract: Anonymity is increasingly important for networked applications amidst concerns over censorship and privacy. In this paper, we describe Herbivore, a peer-to-peer, scalable, tamper-resilient communication system that provides provable anonymity and privacy. Building on dining cryptographer networks, Herbivore scales by partitioning the network into anonymizing cliques. Adversaries able to monitor all network traffic cannot deduce the identity of a sender or receiver beyond an anonymizing clique. In addition to strong anonymity, Herbivore simultaneously provides high efficiency and scalability, distinguishing it from other anonymous communication protocols. Performance measurements from a prototype implementation show that the system can achieve high bandwidths and low latencies when deployed over the Internet.

Patent
06 Jan 2003
TL;DR: In this article, the authors propose an approach for secure application-to-application communication over the Internet using a combination of application message interception, centralized policy management, and generic secure data connectivity layer for applications.
Abstract: An approach for secure application-to-application communication over the Internet uses a combination of application message interception, centralized policy management, and generic secure data connectivity layer for applications. Intercepting messages at an application layer enables use of application-specific security policies prior to the messages for different applications merging at lower levels of a communication protocol stack, and enables securing of the application messages as early as possible in the path to a peer application. The centralized policy management enables enforcement of security policies on multiple computers, both within and outside and enterprise network and protects against circumvention of security features specified by the policies. Data is transported between applications executing on different computers using a generic connectivity layer, which enables communication through firewalls that limit to particular ports and protocols, for example, allowing only HTTP-based communication on standard IP ports. Optionally, the approach complements VPN solutions by passing application-specific control information to VPN endpoints to enable those endpoints to perform application-specific processing while maintaining confidentiality of the application messages themselves.

Proceedings ArticleDOI
01 Jun 2003
TL;DR: This paper introduces a set of efficient protocols and algorithms, DAM, EBAM, and EMLAM, for constructing and maintaining sensor aggregates that collectively monitor target activity in the environment.
Abstract: The development of lightweight sensing andcommunication protocols is a key requirement for designing resource constrained sensor networks. This paper introduces a set of efficient protocols and algorithms, DAM, EBAM, and EMLAM, for constructing and maintaining sensor aggregates that collectively monitor target activity in the environment. A sensor aggregate comprises those nodes in a network that satisfy a grouping predicate for a collaborative processing task. The parameters of the predicate depend on the task and its resource requirements. Since the foremost purpose of a sensor network is to selectively gather information about the environment, the formation of appropriate sensor aggregates is crucial for optimally allocating resources to sensing and communication tasks.This paper makes minimal assumptions about node onboard processing and communication capabilities so as to allow possible implementations on resource-constrained hardware. Factors affecting protocol performance are discussed. The paper presents simulation results showing how the protocol performance varies as key network and task parameters are varied. It also provides probabilistic analyses of network behavior consistent with the simulation results. The protocols have been experimentally validated on a sensor network testbed comprising 25 Berkeley MICA sensor motes.

Patent
07 Feb 2003
TL;DR: In this article, a structural definition of an enterprise facility in which devices are defined by personality modules and communicate with a system host in accordance with a protocol defined in a protocol module is presented.
Abstract: An environmental control system controls monitoring and operation of a multiplicity of disparate environmental control devices by determining an appropriate configuration for each control device and communicates corresponding monitoring and control commands to each device in accordance with its corresponding communication protocol over a selected I/O port. An operational instruction set includes a structural definition of an enterprise facility in which devices are defined by personality modules and communicate with a system host in accordance with a protocol defined in a protocol module. Facility implementation is defined by a node tree structure which collects suitable protocol nodes under a corresponding I/O interface port node. Device (personality) nodes are collected under corresponding protocol nodes, and data point nodes depend from their corresponding device nodes. Data points nodes are individually accessible by merely traversing the node tree using a URL-like notational structure, allowing off-site users to control and monitor environmental devices by issuing commands in the form of a URL.

Proceedings ArticleDOI
22 Apr 2003
TL;DR: A vehicle-vehicle location-based broadcast (LBB) communication protocol is designed to meet highway safety applications' communication requirements and the optimal relation between the performance and design parameters is obtained.
Abstract: We study the wireless communication among highway vehicles in the newly-assigned 5.9 GHz dedicated short range communication (DSRC) spectrum. A vehicle-vehicle location-based broadcast (LBB) communication protocol is designed to meet highway safety applications' communication requirements. The analytical expressions of the performance of the protocol in terms of probability of transmission failure and channel occupancy are derived with commonly satisfied assumptions. The optimal relation between the performance and design parameters is obtained from the expressions. The sensitivity of the protocol performance is tested for various communication conditions as well as highway traffic conditions. Feasible combinations of the communication and highway traffic parameters are found for certain requirements on protocol performance.

Journal ArticleDOI
TL;DR: The proposed solution is to model the traffic at the flow level by a Poisson shot-noise process, which provides a good approximation of the real traffic observed in the backbone and of its variation.
Abstract: Our goal is to design a traffic model for noncongested Internet backbone links, which is simple enough to be used in network operation, while being as general as possible. The proposed solution is to model the traffic at the flow level by a Poisson shot-noise process. In our model, a flow is a generic notion that must be able to capture the characteristics of any kind of data stream. We analyze the accuracy of the model with real traffic traces collected on the Sprint Internet protocol (IP) backbone network. Despite its simplicity, our model provides a good approximation of the real traffic observed in the backbone and of its variation. Finally, we discuss the application of our model to network design and dimensioning.

Patent
07 Apr 2003
TL;DR: A method for controlling an in-flight entertainment (IFE) system using network protocols, such as TCP/IP, HTTP, or FTP, is described in this paper, where the software for each line replaceable unit (LRU) may be designed, redesigned, or tested independently from other components within the IFE system.
Abstract: A method for controlling an in-flight entertainment (IFE) system using network protocols, such as TCP/IP, HTTP, or FTP. Control of a plurality of functions, including in-seat and broadcast audio and video, overhead reading light control, and flight attendant call, are implemented using a network client, a network server, and a network server program, each communicating with network protocols. The network client may be visible or invisible to a user of the in-flight entertainment system, depending on whether a web browser or a virtual web browser is used as a network client. The software for each line replaceable unit (LRU) may be designed, redesigned, or tested independently from other components within the IFE system. Particular functions of the IFE system can be made available only to particular parts of the IFE system, allowing different levels of access to the IFE system for different passenger classes.

Journal ArticleDOI
TL;DR: A baseband solution for an SDR system and a 2 Mb/s WCDMA design with GSM/GPRS and 802.11b capability that executes all physical layer processing completely in software are discussed.
Abstract: Software-defined radios offer a programmable and dynamically reconfigurable method of reusing hardware to implement the physical layer processing of multiple communications systems. An SDR can dynamically change protocols and update communications systems over the air as a service provider allows. In this article we discuss a baseband solution for an SDR system and describe a 2 Mb/s WCDMA design with GSM/GPRS and 802.11b capability that executes all physical layer processing completely in software. We describe the WCDMA communications protocols with a focus on latency reduction and unique implementation techniques. We also describe the underlying technology that enables software execution. Our solution is programmed in C and executed on a multithreaded processor in real time.

Patent
25 Jun 2003
TL;DR: In this article, a method and apparatus for communicating gaming machine settings is disclosed, and a universal configuration communication protocol is provided for retrieving or modifying, over a network, current gaming machine setting of a remotely located gaming machine.
Abstract: A method and apparatus for communicating gaming machine settings is disclosed. In one embodiment a universal configuration communication protocol is provided for retrieving or modifying, over a network, current gaming machine setting of a remotely located gaming machine. A translation table may be implemented with the communication protocol to achieve variable translation between different gaming machine platforms. In one embodiment the gaming machine status is requested prior to activating the communication protocol to prevent interruption of game play. In one embodiment activation of the communication protocol may result in the gaming machine momentarily entering an inactive status.

Journal ArticleDOI
TL;DR: The authors discuss several issues related to integrating the mobile Internet protocol with Manets, including how to incorporate the flexibility of mobile ad hoc networks into traditional IEEE 802.11-based access points.
Abstract: Extending traditional IEEE 802.11-based access points to incorporate the flexibility of mobile ad hoc networks would help make the dream of ubiquitous broadband wireless access a reality. The authors discuss several issues related to integrating the mobile Internet protocol with Manets.

Patent
19 Jun 2003
TL;DR: In this paper, a system, apparatus, and method are disclosed for providing quality of service (QoS) for a network data connection using a network protocol selectable from a plurality of network protocols.
Abstract: A system, apparatus, and method are disclosed for providing quality of service (QoS) for a network data connection The network data connection uses a network protocol selectable from a plurality of network protocols A QoS module can receive a request for a generic QoS and apply this to the network protocol using a specific QoS associated with the protocol The QoS module may include features for automatic management of QoS and a user interface for changing data connection parameters

Patent
11 Feb 2003
TL;DR: In this article, a system for communicating information includes a transceiver provided within a vehicle that is configured for wireless communication with a cellular phone and with a portable computing device using a Bluetooth communications protocol.
Abstract: A system for communicating information includes a transceiver provided within a vehicle that is configured for wireless communication with a cellular phone and with a portable computing device. The wireless communication between the transceiver and the cellular phone utilizes a Bluetooth communications protocol.

Patent
02 Sep 2003
TL;DR: In this paper, a computerized mobile robot with an onboard internet web server, and the capability of establishing a first connection to a remote web browser on the internet for robotic control purposes, and a capability to establish a second short range bi-directional digital radio connection to one or more nearby computerized digital radio equipped devices external to the robot.
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.

Patent
09 Dec 2003
TL;DR: In this article, a legacy device bridge for use in a network, such as a wired or wireless residential network, is provided, which performs protocol conversion to enable a network-attached entity that uses a packet-based communication protocol to communicate with and control legacy devices such as consumer electronics, that rely exclusively on IR or serial communication protocols.
Abstract: A legacy device bridge for use in a network, such as a wired or wireless residential network, is provided. The legacy device bridge performs protocol conversion to enable a network-attached entity that uses a packet-based communication protocol to communicate with and control legacy devices, such as consumer electronics, that rely exclusively on infrared (IR) or serial communication protocols. The legacy device bridge also performs a virtualization function that allows legacy devices to be advertised to the network as devices that comply with a packet-based discovery and control protocol, and to be controlled as such. The legacy device bridge is also adapted to probe, deduce and publish information relating to the state of a legacy device to other entities on the network.

Patent
29 Oct 2003
TL;DR: In this paper, a communication protocol over the serial bus allows a peripheral device to control the flow of data between a host computer and the peripheral device so as to maintain synchronization to a periodic reference signal.
Abstract: A communication protocol over the serial bus allows a peripheral device to control the flow of data between a host computer and the peripheral device so as to maintain synchronization to a periodic reference signal. The protocol involves transferring flow control messages between the peripheral device and the host computer, allowing the peripheral device to control how and when the host computer sends the uncompressed audio and video data.

Journal ArticleDOI
01 Jan 2003
TL;DR: This paper proposes a new paradigm called trajectory based forwarding (or TBF), which is a generalization of source based routing and Cartesian routing, and argues that TBF is an ideal technique for routing in dense ad-hoc networks.
Abstract: Relentless progress in hardware technology and recent advances in sensor technology, and wireless networking have made it feasible to deploy large scale, dense ad-hoc networks. These networks together with sensor technology can be considered as the enablers of emerging models of computing such as embedded computing, ubiquitous computing, or pervasive computing. In this paper, we propose a new paradigm called trajectory based forwarding (or TBF), which is a generalization of source based routing and Cartesian routing. We argue that TBF is an ideal technique for routing in dense ad-hoc networks. Trajectories are a natural namespace for describing route paths when the topology of the network matches the topography of the physical surroundings in which it is deployed which by very definition is embedded computing.We show how simple trajectories can be used in implementing important networking protocols such as flooding, discovery, and network management. Trajectory routing is very effective in implementing many networking functions in a quick and approximate way, as it needs very few support services. We discuss several research challenges in the design of network protocols that use specific trajectories for forwarding packets.