Telcordia Technologies

About: Telcordia Technologies is a based out in . It is known for research contribution in the topics: Network packet & Node (networking). The organization has 3097 authors who have published 4737 publications receiving 237882 citations.

Structural perfection of Y‐Ba‐Cu‐O thin films controlled by the growth mechanism

Abstract: For crystalline advanced materials, such as the high transition temperature oxide superconductors, the growth of defect‐free crystals is often the most sought after desideratum because it opens the doors to fundamental studies and the development of practical applications. We report the observation of YBa2Cu3O7−x(123) thin films having unprecedented structural perfection, at temperatures near 700 °C on [001] LaAlO3. The film’s c axis is in the surface plane, unlike films grown at higher temperatures. This orientation has important advantages for device applications and fundamental studies. The Tc,0 is only 70 K, presumably due to oxygen deficiency caused by thermal stresses; if so, it should be possible to raise the Tc,0 by relieving these stresses.

On the cover time of random walks on graphs

Abstract: This article deals with random walks on arbitrary graphs. We consider the cover time of finite graphs. That is, we study the expected time needed for a random walk on a finite graph to visit every vertex at least once. We establish an upper bound ofO(n 2) for the expectation of the cover time for regular (or nearly regular) graphs. We prove a lower bound of Ω(n logn) for the expected cover time for trees. We present examples showing all our bounds to be tight.

Design and analysis of low-power access protocols for wireless and mobile ATM networks

Abstract: This paper describes the design and analysis of a lowdpower medium access control lMACr protocol for wireless/mobile ATM networks. The protocol – denoted ECdMAC lenergy conserving medium access controlr – is designed to support different traffic types with qualitydofdservice lQoSr provisions. The network is based on the infrastructure model where a base station lBSr serves all the mobiles currently in its cell. A reservationdbased approach is proposed, with appropriate scheduling of the requests from the mobiles. This strategy is utilized to accomplish the dual goals of reduced energy consumption and quality of service provision over wireless links. A priority round robin with dynamic reservation update and error compensation scheduling algorithm is used to schedule the transmission requests of the mobiles. Discretedevent simulation has been used to study the performance of the protocol. A comparison of energy consumption of the ECdMAC to a number of other protocols is provided. This comparison indicates the ECdMAC has, in general, better energy consumption characteristics. Performance analysis of the proposed protocol with respect to different qualitydofdservice parameters using video, audio and data traffic models is provided.

Location based services for integrated cellular and LAN networks

Abstract: Determining the physical location of a WLAN client includes making a request to a core network of an integrated cellular—WLAN network. Using an HLR and WLAN client identifier, the WLAN network in which the client is located is determined. A location request is then made to a MSC/SGSN servicing that WLAN network, the MSC/SGSN then forwarding the request to a gateway that interfaces the WLAN network to the core network. Alternatively, the location request is directly forwarded to the gateway. Upon receiving the request, the gateway uses a positioning procedure(s) to determine the client's physical location. This location is then returned to the core network. According to one example positioning procedure, a database containing access point physical locations is maintained. Here, a determination is made as to which access point(s) the client can communicate. The location of the access point(s), as obtained through the database, then forms a basis for the client's location.

Thoth-II: hypertext with explicit semantics

Abstract: This paper describes a hypertext system — Thoth-II. This system provides a rich means for modeling semantic interconnections among texts. It allows a user to browse texts, exploring their relations with other texts. These relations are modeled by a directed graph. The texts are embedded in the graph. Connections among specified phrases in the text and the graph structure are automatically formed. In the browsing mode the user is presented with an interactive graphic display of the directed graph. In the text mode the user can use multiple windows to display and interact with the stored text.