Showing papers by "Telcordia Technologies published in 2002"

Universally composable two-party and multi-party secure computation

Abstract: We show how to securely realize any multi-party functionality in a universally composable way, regardless of the number of corrupted participants. That is, we consider a multi-party network with open communication and an adversary that can adaptively corrupt as many parties as it wishes. In this setting, our protocols allow any subset of the parties (with pairs of parties being a special case) to securely realize any desired functionality of their local inputs, and be guaranteed that security is preserved regardless of the activity in the rest of the network. This implies that security is preserved under concurrent composition of an unbounded number of protocol executions, it implies non-malleability with respect to arbitrary protocols, and more. Our constructions are in the common reference string model and make general intractability assumptions.

AMRoute: ad hoc multicast routing protocol

Abstract: The Ad hoc Multicast Routing protocol (AMRoute) presents a novel approach for robust IP Multicast in mobile ad hoc networks by exploiting user-multicast trees and dynamic logical cores. It creates a bidirectional, shared tree for data distribution using only group senders and receivers as tree nodes. Unicast tunnels are used as tree links to connect neighbors on the user-multicast tree. Thus, AMRoute does not need to be supported by network nodes that are not interested/capable of multicast, and group state cost is incurred only by group senders and receivers. Also, the use of tunnels as tree links implies that tree structure does not need to change even in case of a dynamic network topology, which reduces the signaling traffic and packet loss. Thus AMRoute does not need to track network dynamics; the underlying unicast protocol is solely responsible for this function. AMRoute does not require a specific unicast routing protocol; therefore, it can operate seamlessly over separate domains with different unicast protocols. Certain tree nodes are designated by AMRoute as logical cores, and are responsible for initiating and managing the signaling component of AMRoute, such as detection of group members and tree setup. Logical cores differ significantly from those in CBT and PIM-SM, since they are not a central point for data distribution and can migrate dynamically among member nodes. Simulation results (using ns-2) demonstrate that AMRoute signaling traffic remains at relatively low level for typical group sizes. The results also indicate that group members receive a high proportion of data multicast by senders, even in the case of a highly dynamic network.

Optimization of Insertion Compounds Such as LiMn2 O 4 for Li-Ion Batteries

Abstract: The spinel LiMn 2 O 4 , whose electrochemical activity with Li was discovered in the early 1980s, was put forth in the early 1990s as a possible alternative to LiCoO 2 as a positive electrode material for Li-ion batteries. Ten years later, the Li-ion LiMn 2 O 4 /C cells are on the verge of entering the portable electronics and electric/hybrid vehicle market. This paper retraces the key steps of this decade that were necessary to master the intimate physical/electrochemical relationship of LiMn 2 O 4 , and that led to the development of rechargeable Li-ion LiMn 2 O 4 /C technology. During the long development period, the early supremacy of LiMn 2 O 4 as the only alternative to LiCoO 2 diminished with the development of positive electrode materials that present abundance and cost advantages. Despite the uncertainty of the future of the spinel, successfully translating a fundamental success into a commercial one, we stress that the long learning experience will benefit the scientific battery community aiming at rapidly optimizing the electrochemical performance of alternative materials, such as LiFePO 4 .

Device and service discovery in home networks with OSGi

Abstract: We present an overview of the Open Services Gateway Initiative (OSGi/spl trade/) technology and its associated mechanisms for accessing devices. A technical description of work currently underway to map various industry device and service discovery protocols to OSGi is presented, followed by an illustrative usage case for a home networking environment. Finally, the authors describe the benefits OSGi discovery technology offers in home networking and discuss potential future work in this area.

The Electrochemistry of Zn3 N 2 and LiZnN A Lithium Reaction Mechanism for Metal Nitride Electrodes

Abstract: LiZnN has been isolated by way of an electrochemical conversion reaction of Zn 3 N 2 with Li. We show that Zn 3 N 2 reversibly reacts with lithium electrochemically, exhibiting a large reduction capacity of 1325 mAh/g corresponding to the insertion of 3.7 Li per Zn. Of this initial capacity, 555 mAh/g were found to be reversible. Through the use of extensive in situ and ex situ X-ray diffraction, the reaction mechanism with lithium was identified as a conversion reaction of Zn 3 N 2 into LiZn and a matrix of βLi 3 N, the high pressure form of Li 3 N. Upon oxidation, LiZn transformed into metallic Zn, while βLi 3 N contributed to the transformation into LiZnN. This is the first identification of a reversible Li 3 N conversion mechanism. The formation of LiZnN as the new end member of the electrochemical reaction with lithium was identified as the cause of the irreversible loss observed during the first cycle. The βLi 3 N and LiZn oxidation into LiZnN was found to be reversible upon subsequent cycles. Poor cycle life was mainly attributed to the electromechanical grinding of the Li-Zn alloying reaction. Cu 3 N is also introduced as a material utilizing a similar conversion reaction but exhibiting improved cycle life.

Efficient piconet formation and maintenance in a Bluetooth wireless network

Abstract: The invention is addressing the problem of efficient formation and maintenance of piconets with assistance from the master of an already existing piconet. The master of an existing piconet initiates the formation of a new helper piconet by at least two of its slaves. One of the slaves of the existing piconet becomes the master of the newly formed helper piconet and the other slave becomes a slave of the helper piconet. This process can be used to expand the number of Bluetooth devices that can use an Internet access point. It can also be used to permit two slave devices to communicate directly with one another so as not to unnecessarily use bandwidth available through the master. Finally, the method and system could be used to provide a method of efficient hand-off from one piconet to another.

Efficient flooding with Passive Clustering (PC) in ad hoc networks

Abstract: An ad hoc network is a fast deployable self-configuring wireless network characterized by node mobility, dynamic topology structure, unreliable media and limited power supply. Nodes in an ad hoc network must cooperate and carry out a distributed routing protocol in order to make multi-hop communications possible. On Demand Routing is one of the most popular routing styles in ad hoc networks. In On Demand Routing, "flooding" is used to find a feasible route from source to destination. The function of flooding is to deliver a packet from one source to every other node in the system. Conventional flooding can be very costly in On Demand networks in terms of network throughput efficiency as well as node energy consumption. The main reason is that the same packet is rebroadcast unnecessarily several times (redundant rebroadcast). Indeed, the penalty of redundant rebroadcast increases when the size of network grows and the density of network increases. In this paper we introduce a novel clustering scheme, call Passive Clustering that can reduce the redundant rebroadcast effect in flooding. We demonstrate the efficiency of the proposed scheme in the AODV (Ad hoc, On demand Distance Vector) routing scheme.

Faster approximation schemes for fractional multicommodity flow problems

Abstract: We present fully polynomial approximation schemes for concurrent multicommodity flow problems that run in time independent of the number of commodities k. We show that by modifying the algorithms by Garg & Konemann [5] and Fleischer [3] we can reduce their running time to a logarithmic dependence on k, and essentially match the running time of [3] for the maximum multicommodity flow problem.

Methods and systems for reducing interference across coverage cells

Abstract: Methods and systems are provided for reducing interference across coverage cells using base stations interconnected by a packet network. A wireless device monitors the channel signal strength of its serving cell and its neighboring cell (902). The serving cell collects measurements from the wireless devices within its cell (904, 906) and informs its neighboring cell when one of the wireless devices may be causing significant interference to the neighboring cell (910). The neighboring cell collects this information (912) and executes a multi-user detection and cancellation algorithm on a subset of these interfering wireless devices.

Metal oxides as negative electrode materials in Li-ion cells

Abstract: The electrochemical performance of 3d metal oxide (MO) electrode materials for Li-ion batteries was studied in the form of Li/CoO(Co 3 O 4 ) half-cells. Reversible capacity in the 750-1000 mAh/g range was achieved and sustained over numerous charge-discharge cycles both at room temperature and at 55°C. The studied oxides were then used as negative-electrode active materials to assemble larger plastic MO/LiCoO 2 Li-ion cells, which exhibited an average output voltage of 2 V and a stable reversible specific energy of 120 Wh/kg during extended cycling at ambient and elevated temperatures. This value can be compared to 180 Wh/kg obtained for similar C/LiCoO 2 Li-ion cells. Based on modeling, several scenarios involving material considerations present the optimum method for boosting the energy density of such MO/LiCoO 2 Li-ion systems.

IDMP-based fast handoffs and paging in IP-based 4G mobile networks

Abstract: We consider the use of our previously proposed Intra-Domain Mobility Management Protocol (IDMP) in fourth-generation mobile networks. On evaluating the heterogeneous access technologies, cellular layouts, and application characteristics of 4G environments, we realize a need to reduce both handoff latency and the frequency of mobility-related signaling. We first present IDMP's fast intradomain handoff mechanism that uses a duration-limited proactive packet multicasting solution. We quantify the expected buffering requirements of our proposed multicasting scheme for typical 4G network characteristics and compare it with alternative IP-based fast handoff solutions. We also present a paging scheme under IDMP that replicates the current cellular paging structure. Our paging mechanism supports generic paging strategies and can significantly reduce the mobility-related IP signaling load.

A Nonaqueous Asymmetric Hybrid Li4Ti5 O 12 / Poly(fluorophenylthiophene) Energy Storage Device

Abstract: An asymmetric hybrid energy storage device has been built using a lithium titanate intercalation anode and the pseudocapacitive electronically conducting polymer poly(fluorophenythiophene). Results show that the device operates in the power range of electrochemical double-layer capacitors, while having three to four times their energy density, and a voltage profile and self-discharge characteristics typical of a battery. The cycle life is also intermediate between that of a battery and a supercapacitor, in the range of several thousands of cycles.

IDMP: an intradomain mobility management protocol for next-generation wireless networks

Abstract: This article describes a lightweight intradomain mobility management protocol (IDMP) for managing mobility within a domain, commonly known as micromobility management, for next-generation wireless networks. IDMP is modular and simple because it leverages existing protocols, such as Mobile IP or SIP as global mobility management, for locating roaming nodes. Unlike other proposed intradomain mobility management schemes, IDMP uses two dynamically auto-configured care-of addresses for routing the packets destined to mobile nodes. The global care-of address is relatively stable and identifies the mobile node's attachment to the current domain, while the local care-of address changes every time the mobile changes subnets and identifies the mobile's attachment to the subnet level granularity. After describing the lightweight base protocol, we discuss possible enhancements to reduce the latency of intradomain updates during handoffs, which are critical for real-time applications both for wide area cellular networks and enterprise wireless LANs. We also discuss mechanisms to incorporate paging support in IDMP and hence reduce the mobility-related signaling load on a mobile node. Detailed implementation and performance results from experiments on our testbed are also presented.

System and method for out-sourcing the functionality of session initiation protocol (sip) user agents to proxies

Abstract: Session Initiation Protocol (SIP) is used to communicate with Network-capable appliances (340). In a system employing SIP, a remote user agent client (UAC) sends a message over the Internet via a Proxy server (320) to a user agent server at the location of the appliances (340), e.g., the client's home. This communications channel allows the client to control the appliances and to determine their status. The Proxy server (320) between the UAC and a plurality of UAS processors has the address mapping, authentication, authorization and/or translation functions out-sourced from the UAS processors to the Proxy server (320) connected to them.

Method for distributing and conditioning traffic for mobile networks based on differentiated services

Abstract: A method for distributing and conditioning IP traffic for mobile networks based on differentiated services, wherein edge/border routers are only required to maintain QoS profiles for related mobile stations. A new IP address or a new service level subscription or service level agreement of an mobile station is only sent to related edge/border routers. As a result, unnecessary IP traffic is significantly reduced. The routers in accordance with methods of the invention disregard the contents of an IP payload and therefore all of the IP addresses that a mobile station may posse. A mobile station is permitted to enter into a domain and obtain a desired quality of service (e.g., Gold or Standard service) without the need to maintain the service while moving through the domain.

Loop makeup identification via single ended testing: beyond mere loop qualification

Abstract: Digital subscriber lines (DSLs) offer carriers the possibility of exploiting the existing loop plant to deliver high-speed data and voice services. However, before deploying DSL, local loops must be tested in order to see whether they can support service, and at what level. In fact, there are many impairments that could disqualify a loop for supporting DSL services: load coils, excessive loop length, bridged taps, and wideband noise. Single-ended automatic qualification is essential for achieving low-cost deployment of DSL, since it allows loops to be qualified in bulk and does not involve any human intervention at the customer's location. An even more ambitious challenge is to fully characterize a loop, i.e., to identify its loop makeup. If it is feasible to perform loop makeup identification via single-ended measurements with sufficient accuracy, then operators will benefit substantially because, besides qualifying a loop for DSL service, this capability will allow the updating of telephone company loop-records. These records can in turn be accessed to support engineering, provisioning and maintenance operations. Despite its potential importance, the possibility of achieving loop makeup identification via single-ended measurements is not widely addressed in the current literature. In the present contribution the feasibility of loop makeup identification via single-ended measurements is presented.

Advances in the management and control of optical Internet

Abstract: Given the ever increasing demand for network bandwidth, and the phenomenal advances in optical wavelength division multiplexing (WDM) networking technologies, a major component of the next generation Internet will be an Internet protocol (IP)-based optical WDM network. As IP over WDM networking technologies mature, a number of important architectural, management and control issues have surfaced. These issues need to be addressed before a true next generation optical Internet can emerge. We enumerate some of the key architectural, management and control issues and discuss corresponding approaches and advances made toward addressing these issues. We first review the different IP/WDM networking architectural models and their tradeoffs. We outline and discuss several management and control issues and corresponding approaches related to the configuration, fault, and performance management of IP over dynamic WDM networks. We present an analysis and supporting simulation results demonstrating the potential benefits of dynamic IP over WDM networks. We then discuss the issues related to IP/WDM traffic engineering in more detail, and present the approach taken in the NGI SuperNet Network Control and Management Project funded by DARPA. In particular, we motivate and present an innovative integrated traffic-engineering framework for reconfigurable IP/WDM networks. It builds on the strength of multiprotocol label switching for fine-grain IP load balancing, and on the strength of reconfigurable WDM networking for reducing the IP network's weighted-hop-distance, and for expanding the bottleneck bandwidth.

Determining and provisioning paths within a network of communication elements

Abstract: A graph of a network is created by efficiently modeling the network elements, and the network links and virtual trunks that interconnect these elements. The network elements are model as one or more routing nodes wherein each routing node represents part of an element or a set of one or more elements, and has the characteristic that any ingress and egress ports of the network element or network elements associated with the routing node can be interconnected. The network links and virtual trunks are both modeled as routing links, wherein routing links interconnect the routing nodes to create the graph of the network. The graph is subsequently used for determining routing paths through the network for the provisioning of virtual trunks and circuits.

Service performance correlation and analysis

Abstract: Methods and apparatus are provided to determine performance of a network. A first measurement relating to a first layer of communications in the network and a second measurement relating to a second layer of communications in the network are provided. Based on the first and second measurements, a set of parameters is generated. The performance of the network is then determined based on the generated set of parameters.

MarconiNet supporting streaming media over localized wireless multicast

Abstract: Flexible multi-media streaming such as advertisment insertion, location based services, mobility and wireless access are vital components that make existing Internet Radio and TV networks more attractive for the roaming users. All of these applications also provide added value to telematics, and military usage including coordination, education, situation awareness, distributed simulation, battlefield communication and multi-player games. While content distribution over a wired network can be realized by instituting proxies and gateways at several parts of the access network, providing mobility over heterogeneous wireless access need to consider many operational issues such as handoff, join and leave latency and desired level of quality of service for the mobile clients. This paper discusses some novel application layer techniques that provide a platform for Mobile E-Commerce with a multi-tiered payment and security scheme that supports a business model for a global streaming network. The proposed streaming network called MarconiNet is based on standard IETF protocols such as SIP, SAP and SDP for signaling, RTSP for stream control and RTP/RTCP for media delivery and feedback control.

Ultralow noise and supermode suppression in an actively mode-locked external-cavity semiconductor diode ring laser.

Abstract: We report what is to our knowledge the lowest phase and amplitude noise characteristics achieved to date in a 10-GHz pulse train produced by the active harmonic mode locking of an external-cavity semiconductor diode laser. Supermode noise has also been suppressed below -140 dBc/Hz by use of a high-finesse fiber Fabry–Perot etalon as an intracavity filter. Novel noise sideband measurements that extend to the Nyquist offset frequency suggest a significant advantage in using harmonic (rather than fundamental) mode locking to produce ultralow-noise pulse trains, owing to the relationship between the noise roll-off frequency and the fundamental cavity frequency.

Polynomial-time approximation schemes for geometric min-sum median clustering

Abstract: The Johnson--Lindenstrauss lemma states that n points in a high-dimensional Hilbert space can be embedded with small distortion of the distances into an O(log n) dimensional space by applying a random linear transformation. We show that similar (though weaker) properties hold for certain random linear transformations over the Hamming cube. We use these transformations to solve NP-hard clustering problems in the cube as well as in geometric settings.More specifically, we address the following clustering problem. Given n points in a larger set (e.g., ℝd) endowed with a distance function (e.g., L2 distance), we would like to partition the data set into k disjoint clusters, each with a "cluster center," so as to minimize the sum over all data points of the distance between the point and the center of the cluster containing the point. The problem is provably NP-hard in some high-dimensional geometric settings, even for k = 2. We give polynomial-time approximation schemes for this problem in several settings, including the binary cube {0,1}d with Hamming distance, and ℝd either with L1 distance, or with L2 distance, or with the square of L2 distance. In all these settings, the best previous results were constant factor approximation guarantees.We note that our problem is similar in flavor to the k-median problem (and the related facility location problem), which has been considered in graph-theoretic and fixed dimensional geometric settings, where it becomes hard when k is part of the input. In contrast, we study the problem when k is fixed, but the dimension is part of the input.

Designing Regulatory Policy with Limited Information

Abstract: Examines policy design when the policy maker in imperfectly informed, focusing on cases where the regulated firm possesses better information about its technology than the regulator.

Location aware services infrastructure

Abstract: Entity identity information and location identity information are sensed and made available to subscriber applications through a secure location-aware services infrastructure, thereby allowing for the creation of location-based services. Information detected by a sensor is passed to an interface aggregator for conversion to a standardized format and then forwarded to location registers for the domain of the sensors. Subscriber applications query the registers to determine which entities are in a particular location and to determine the location of entities. By unifying diverse sensing technologies, location information can be simultaneously obtained on varying degrees of granularity. In addition, the system is scalable to large scenarios by using a plurality of sensors, interface aggregators, and registers.

Dynamic bandwidth reallocation

Abstract: Bandwidth allocated between the traffic classes of a network path is dynamically reallocated when one or more traffic classes have insufficient available bandwidth to support a service request for the traffic classes, wherein the reallocation occurs without modifying the traffic class bandwidth allocations enforced by router mechanisms. A provisioning system maintains an available bandwidth indication for each traffic class, which indications are decremented as a service request is admitted to the path. If a requested traffic class has insufficient available bandwidth to support a request, one or more other traffic classes can loan bandwidth to the requested traffic class by decrementing the available bandwidth indicators for the one or more other traffic classes in the amount of the insufficiency, thereby indicating that less bandwidth is available in these classes for future requests. The provisioning system also maintains an indication of the amount of bandwidth each traffic class loans to the other traffic classes.

Method and system for spectrally compatible remote terminal ADSL deployment

Abstract: An ADSL spectral compatibility system provides for computer (200) having a processor (210) in communication with a memory (220) and input/output (I/O) unit (230). I/O unit (230) is adapted to receive data from a broadband test head (BBTH) (240) and/or a database (250) of network configuration data. The ADSL system and a method are for deploying remote-terminal (RT)-based ADSL in a manner that is compatible with central office (CO)-based ADSL so as to maximize both the upstream and downstream data transmission rates while maintaining compliance with spectrum management guidelines.

A sampling-based estimator for top-k selection query

Abstract: Top-k queries arise naturally in many database applications that require searching for records whose attribute values are close to those specified in a query. We study the problem of processing a top-k query by translating it into an approximate range query that can be efficiently processed by traditional relational DBMSs. We propose a sampling-based approach, along with various query mapping strategies, to determine a range query that yields high recall with low access cost. Our experiments on real-world datasets show that, given the same memory budgets, our sampling-based estimator outperforms a previous histogram-based method in terms of access cost, while achieving the same level of recall. Furthermore, unlike the histogram-based approach, our sampling-based query mapping scheme scales well for high dimensional data and is easy to implement with low maintenance cost.

Next generation service creation using XML scripting languages

Abstract: The next generation of scripting languages for creating value-added services in converged networks will be based upon XML. Industry forums, like Parlay, JAIN and OSA, have developed open standard application program interfaces (APIs) to enable service creation in converged next generation networks (NGN). While services can be developed in traditional programming languages (e.g. Java or C++) using these APIs, XML-based scripting languages offer some advantages. While not as flexible or powerful as a programming language, scripting languages are typically easier to learn, and are language and platform independent. We describe the architecture and framework (creation, deployment and execution) of XML-based service scripts in NGN. We focus on the service control markup language (SCML) being developed by the JAIN forum for call control scripts that is closely tied to the JAIN Java call control (JCC) API. SCML is intended to be part of a family of NGN service scripting languages that include facilities for user interaction, mobility, and other open NGN API functions. We compare SCML to the call processing language (CPL) defined by the IETF and note that SCML offers several advantages. We also briefly compare it to the requirements that are being developed by the W3C voice browser working group.