scispace - formally typeset
Search or ask a question
Author

Chatschik Bisdikian

Bio: Chatschik Bisdikian is an academic researcher from IBM. The author has contributed to research in topics: Asynchronous Transfer Mode & Wireless. The author has an hindex of 22, co-authored 40 publications receiving 2788 citations.

Papers
More filters
Journal ArticleDOI
Chatschik Bisdikian1
TL;DR: The Bluetooth/sup TM/ wireless technology is designed as a short-range connectivity solution for personal, portable, and handheld electronic devices.
Abstract: The Bluetooth/sup TM/ wireless technology is designed as a short-range connectivity solution for personal, portable, and handheld electronic devices. Since May 1998 the Bluetooth SIG has steered the development of the technology through the development of an open industry specification, including both protocols and application scenarios, and a qualification program designed to assure end-user value for Bluetooth products. This article highlights the Bluetooth wireless technology.

450 citations

Proceedings ArticleDOI
11 Nov 2001
TL;DR: It is shown through simulation that PARO is capable of outperforming traditional broadcast-based routing protocols (e.g., MANET routing protocols) due to its power conserving point-to-point on-demand design.
Abstract: This paper introduces PARO, a power-aware routing optimization that helps to minimize the transmission power needed to forward packets between wireless devices in ad hoc networks. Using PARO, one or more intermediate nodes called "redirectors" elects to forward packets on behalf of source-destination pairs thus reducing the aggregate transmission power consumed by wireless devices. PARO is applicable to a number of networking environments including sensor networks, home networks and mobile ad hoc networks. In this paper, we present the detailed design of PARO and evaluate the protocol using simulation and experimentation. We show through simulation that PARO is capable of outperforming traditional broadcast-based routing protocols (e.g., MANET routing protocols) due to its power conserving point-to-point on-demand design. We discuss some initial experiences from an early implementation of the protocol in an experimental wireless testbed using off-the-shelf radio technology.

359 citations

Journal ArticleDOI
TL;DR: It is shown through simulation that PARO is capable of outperforming traditional broadcast-based routing protocols (e.g., MANET routing protocols) due to its energy conserving point-to-point on-demand design.
Abstract: This paper introduces PARO, a dynamic power controlled routing scheme that helps to minimize the transmission power needed to forward packets between wireless devices in ad hoc networks. Using PARO, one or more intermediate nodes called "redirectors" elects to forward packets on behalf of source-destination pairs thus reducing the aggregate transmission power consumed by wireless devices. PARO is applicable to a number of networking environments including wireless sensor networks, home networks and mobile ad hoc networks. In this paper, we present the detailed design of PARO and evaluate the protocol using simulation and experimentation. We show through simulation that PARO is capable of outperforming traditional broadcast-based routing protocols (e.g., MANET routing protocols) due to its energy conserving point-to-point on-demand design. We discuss our experiences from an implementation of the protocol in an experimental wireless testbed using off-the-shelf radio technology. We also evaluate the impact of dynamic power controlled routing on traditional network performance metrics such as end-to-end delay and throughput.

220 citations

Patent
18 Aug 1997
TL;DR: In this paper, a method and apparatus for providing customized notification in response to a search query is presented, where a query is received from a user via a user interface and the user also selected a time and means of notification, such as for example, by fax at a specified time.
Abstract: A method and apparatus for providing customized notification in response to a search query. Moreover, with this invention, a query is received from a user via a user interface. The user also selected a time and means of notification, such as for example, by fax at a specified time. The system will also receive several notification choices from both the user and a supplier of information and match the choices so that a supplier can notify a user in accordance with a mutually selected time and means of notification.

209 citations

Patent
12 Nov 1999
TL;DR: In this paper, the authors present a method, apparatus and computer product for a mobile device to roam securely and seamlessly from one access point to another access point without disrupting an active PPP connection.
Abstract: The present invention provides a method, apparatus and computer product for a mobile device to roam securely and seamlessly from one access point to another access point without disrupting an active PPP connection. The method includes establishing, maintaining, and terminating a PPP connection between a mobile device and a PPP server via an access point, wherein the mobile device is equipped with a serial asynchronous communication interface. The PPP server is attached to a packet switched data network, and the access point is acting as a bridge between the serial communication interface and the packet switched communication interface. Also provided is a method to emulate a direct RS-232 cable connection between a mobile device and another computer located several hops away from the mobile device. It provides a method of keeping the RS-232 cable emulation between the mobile device an another computer system intact despite changes in mobile device's location in the network. It also provides a method of exchanging cookies between peers at the PPP connection establishment time and using them for fast reauthentication. This is a secure method of switching from one PPP proxy to another PPP proxy without disrupting the end to end PPP connection.

152 citations


Cited by
More filters
Journal ArticleDOI
01 Jul 2003
TL;DR: The important role that mobile ad hoc networks play in the evolution of future wireless technologies is explained and the latest research activities in these areas are reviewed, including a summary of MANETs characteristics, capabilities, applications, and design constraints.
Abstract: Mobile ad hoc networks (MANETs) represent complex distributed systems that comprise wireless mobile nodes that can freely and dynamically self-organize into arbitrary and temporary, ‘‘ad-hoc’’ network topologies, allowing people and devices to seamlessly internetwork in areas with no pre-existing communication infrastructure, e.g., disaster recovery environments. Ad hoc networking concept is not a new one, having been around in various forms for over 20 years. Traditionally, tactical networks have been the only communication networking application that followed the ad hoc paradigm. Recently, the introduction of new technologies such as the Bluetooth, IEEE 802.11 and Hyperlan are helping enable eventual commercial MANET deployments outside the military domain. These recent evolutions have been generating a renewed and growing interest in the research and development of MANET. This paper attempts to provide a comprehensive overview of this dynamic field. It first explains the important role that mobile ad hoc networks play in the evolution of future wireless technologies. Then, it reviews the latest research activities in these areas, including a summary of MANETs characteristics, capabilities, applications, and design constraints. The paper concludes by presenting a set of challenges and problems requiring further research in the future. � 2003 Elsevier B.V. All rights reserved.

1,430 citations

Journal ArticleDOI
TL;DR: A shortest cost path routing algorithm is proposed which uses link costs that reflect both the communication energy consumption rates and the residual energy levels at the two end nodes and is amenable to distributed implementation.
Abstract: A routing problem in static wireless ad hoc networks is considered as it arises in a rapidly deployed, sensor based, monitoring system known as the wireless sensor network. Information obtained by the monitoring nodes needs to be routed to a set of designated gateway nodes. In these networks, every node is capable of sensing, data processing, and communication, and operates on its limited amount of battery energy consumed mostly in transmission and reception at its radio transceiver. If we assume that the transmitter power level can be adjusted to use the minimum energy required to reach the intended next hop receiver then the energy consumption rate per unit information transmission depends on the choice of the next hop node, i.e., the routing decision. We formulate the routing problem as a linear programming problem, where the objective is to maximize the network lifetime, which is equivalent to the time until the network partition due to battery outage. Two different models are considered for the information-generation processes. One assumes constant rates and the other assumes an arbitrary process. A shortest cost path routing algorithm is proposed which uses link costs that reflect both the communication energy consumption rates and the residual energy levels at the two end nodes. The algorithm is amenable to distributed implementation. Simulation results with both information-generation process models show that the proposed algorithm can achieve network lifetime that is very close to the optimal network lifetime obtained by solving the linear programming problem.

1,375 citations

Journal ArticleDOI
TL;DR: A taxonomy of research in self-adaptive software is presented, based on concerns of adaptation, that is, how, what, when and where, towards providing a unified view of this emerging area.
Abstract: Software systems dealing with distributed applications in changing environments normally require human supervision to continue operation in all conditions. These (re-)configuring, troubleshooting, and in general maintenance tasks lead to costly and time-consuming procedures during the operating phase. These problems are primarily due to the open-loop structure often followed in software development. Therefore, there is a high demand for management complexity reduction, management automation, robustness, and achieving all of the desired quality requirements within a reasonable cost and time range during operation. Self-adaptive software is a response to these demands; it is a closed-loop system with a feedback loop aiming to adjust itself to changes during its operation. These changes may stem from the software system's self (internal causes, e.g., failure) or context (external events, e.g., increasing requests from users). Such a system is required to monitor itself and its context, detect significant changes, decide how to react, and act to execute such decisions. These processes depend on adaptation properties (called self-a properties), domain characteristics (context information or models), and preferences of stakeholders. Noting these requirements, it is widely believed that new models and frameworks are needed to design self-adaptive software. This survey article presents a taxonomy, based on concerns of adaptation, that is, how, what, when and where, towards providing a unified view of this emerging area. Moreover, as adaptive systems are encountered in many disciplines, it is imperative to learn from the theories and models developed in these other areas. This survey article presents a landscape of research in self-adaptive software by highlighting relevant disciplines and some prominent research projects. This landscape helps to identify the underlying research gaps and elaborates on the corresponding challenges.

1,349 citations

Patent
06 Jun 1996
TL;DR: In this article, an electronic program schedule system with access to both stored television program schedule information and data feeds containing status information for live programs such as sporting events is presented, where a video display generator is used to generate a display signal simultaneously comprising information from both the stored schedule and the received data feed.
Abstract: An electronic program schedule system with access to both stored television program schedule information and data feeds containing status information for live programs such as sporting events. The system includes a data processor for receiving program schedule information for a plurality of programs and data feeds containing status information for certain of the programs, and a video display generator for generating a display signal simultaneously comprising information from both the stored schedule information and the received data feed. The system is further provided with user control means such as a remote controller for generating user control commands and transmitting signals to the data processor in response thereto so as to control the content of the display signal. The display signal may be displayed on a display apparatus such as a television receiver. In addition, the program schedule system of the present invention utilizes category-specific user interfaces providing access to multiple services including television programs, received data feeds, home shopping services, and video games as well as the stored program schedule information.

1,116 citations