Abstract: A semiconductor waveguide includes a section containing free charge, either electrons or holes, which can be steered into or removed from the path of the beam under the control of electrical signals. The mobile charges come from a potential well which may be either filled or depleted under electrical control. When the well is filled, the charges speed the beam propagation, introducing a phase change. When the well is emptied the beam propagates with extra delay. The phase shifter allows very high speed modulation of the beam using low voltage and low power electronics. The device can be created using standard silicon processing techniques, and integrated with other optical components such as splitters and combiners to create amplitude modulators, attenuators and other optical devices.

Abstract: A tunable microlens uses at least two layers of electrodes and a droplet of conducting liquid. Such a droplet, which forms the optics of the microlens, moves toward an electrode with a higher voltage relative to other electrodes in the microlens. When calibration of the microlens is desired, an equal and constant voltage is passed over the first layer of electrodes and a different, constant voltage is passed over the second layer of electrodes such that the droplet of conducting fluid is adjusted to a calibrated position.

Abstract: A system and method for providing wireless time division multiplexed communications in which time is divided into a plurality of frames and each frame is divided into N data bursts, which has a first multiplexer defining a channel as a series of bursts that occur periodically every N bursts once per frame; a second multiplexer defining a sub-channel as every Mth burst of said channel; and a transmitter transmitting said channel and sub-channel from a first station to a second station. A new interleaving 0246/1357 method is used by the system which is just as good as the known 0123/4567 method when ideal frequency hopping is used, and 0246/1357 has better performance when non-ideal frequency hopping or no frequency hopping is used.

Abstract: A method and apparatus for the characterization of an optical pulse includes splitting an optical pulse into two replicas separated by a delay, modulating at least one of the two replicas with a linear temporal phase modulation, measuring a spectrum of the modulated replicas, and characterizing the optical pulse using the measured spectra. In one embodiment of the present invention a spectral phase difference between the replicas is obtained from the measured spectrum using Fourier Transform Spectral Interferometry.

Abstract: A method for reducing multiple dominant pilots in a CDMA transmission system comprises linking a transceiver element with a nearby base station for transporting signals between the transceiver element and the nearby base station. Transmitting from the transceiver element forward link signals of a nearby sector associated with the nearby base station. An apparatus is also described.

Abstract: A thermo-optic lens of the present invention includes a plurality of parallel heating elements having substantially constant center-to-center spacing and respective dimensions varying from the outermost heating elements to the innermost heating elements, and at least two conductive elements for providing a potential across the heating elements. The dimensions of the heating elements are varied such that a parabolic temperature distribution is generated within the thermo-optic lens. A dispersion compensator of the present invention includes a first and a second waveguide grating, each of the waveguide gratings having a first star coupler, an array of waveguides of increasing path lengths, a first end of each of the waveguides of the array of waveguides optically coupled to the first star coupler, and a second star coupler, a second end of each of the waveguides of the array of waveguides optically coupled to the second star coupler.

Abstract: A network management system and technique, implemented in hardware and software, automates certain aspects of a network element configuration in a network of routers that use the OSPF protocol. The network management system uses network wide configuration information to detect configuration deficiencies and configuration related intra-element dependencies, and to then configure the elements automatically. This includes automatically detecting and configuring OSPF virtual links under several different scenarios, including (a) either minimal or complete (redundant) configuration of a router that is newly added to an existing network, and (b) reconfiguring of the routers in an existing OSPF domain, when either minimal or complete configuration is required. Minimal configuration is attained when at least one area border router (ABR) in an area is guaranteed to be connected to a backbone. In a complete configuration, all ABR's in an area are guaranteed to be connected to the backbone.

Abstract: This invention is directed toward improving the subjective voice quality of a mobile to mobile phone call having tandem vocoder processing by modifying the spectrum of the voice signal before it is processed by the second vocoder to compensate for digital distortion which is generated by the second vocoder. An adaptive filter can be used to modify the spectrum of the voice signal. With this invention, the voice quality of a call from a first mobile phone to a second mobile phone has a quality that is substantially similar to the voice quality of a call from a mobile phone to a desk phone.

Abstract: A system and method is provided for measuring network round trip time by monitoring fast-response operations at one network endpoint, typically a client computer. A client computer of the system includes a network monitoring and analysis engine which monitors a sent packet for a fast-response operation. If a fast-response operation is detected, then the client computer assumes a server computer processed the packet substantially instantaneously. Thus, the processing time at the server computer is neglected as zero. The round trip time can then be approximated as the difference in time between when the client computer sent the packet and when the client computer received the response packet.

Abstract: A UNMTS (universal mobile telecommunications system) based system comprises a common control point, a number of base stations, K, and a mobile terminal. During a soft handoff involving the K base stations and the mobile terminal, the common control point receives individual user channel transmit powers from each of the K base stations. In addition, the common control point receives two parameters from the mobile terminal—the identity of that base station involved in the soft handoff that has the strongest received signal at the mobile terminal and, on an average, a value representing how much stronger the received SNR was in comparison to the SNR target maintained by the mobile terminal. The common control point then decides on a downlink reference user channel transmit power for each of the base stations as a function of the individual user channel transmit powers reported by each base station involved in the soft handoff and the information provided from the mobile terminal.

Abstract: A method is provided of informing mobile user terminals (12) camped on a cell of a base station (8) of a radio telecommunications network that a service is unavailable, such that a mobile user terminal (12) desirous of said service is handed over to another cell which provides said service. The method comprises informing the terminals (12) that selectably at least one of circuit-switched services (4) and packet-switched services (6) are unavailable.

Abstract: A liquid electrical switch is disclosed that uses a plurality of droplets of conducting liquid to form an electrical path. In a first embodiment, at least a first voltage differential is used to create a separation distance between two droplets. The droplets are illustratively contained within a housing and surrounded by an immiscible, insulating liquid. In this embodiment, the at least a first voltage differential draws at least a portion of at least one of the droplets away from a second droplet, thus preventing electrical current from flowing from the at least one droplet to the second droplet. In another embodiment, the at least a first voltage differential is changed in a way such that at least one liquid droplet is made to come into contact with a second droplet, thus creating an electrical path between the two droplets.

Abstract: In an ad-hoc mobile network, a geometry-based routing protocol (GRP) is used to route traffic from a source node to a destination node. In the GRP, each node maintains a location list, which comprises location information for a number of nodes of the ad-hoc mobile network. Periodically, each node transmits to its direct neighbors (i.e., those nodes with which it has a point-to-point link) (a) its location, and (b) its location list. Each node that receives a location list from an adjacent node merges the received location list into its own location list such that location information for existing nodes, and/or newly identified nodes, is current.

Abstract: A method and apparatus for assigning the data rate and/or power level to the mobile terminals without determining the highest theoretical system throughput, and without determining the highest weighted system throughput. An order is imposed on the terminals and the data rate and/or power covariance matrices are assigned such that the data rates of the terminals having a lower index in the order will not be decreased due to the presence of the terminals having a higher index in the order, and this is accomplished without changing the power covariance matrixes of the antennas involved in the communication with the lower index terminals. Thus, the assignment is made to the terminals based on the terminals requirements without regard to the interference introduced by the terminals with a higher index in the order since this interference will be compensated for by the compensation technique when the compensation technique process the terminals in accordance with the order.

Abstract: The scheduling of data transmissions for a CDMA system downlink or other type of communication network is implemented on a dynamic basis using a revenue-based policy. For a given transmission slot or other transmission interval, a maximum-rate user is identified from among a set of users requesting data transmissions, and a data transmission of the maximum-rate user is scheduled for the given interval. The maximum-rate user is identified based on application of coefficients of a revenue vector to corresponding feasible rates of the requesting users. The revenue vector is determined in an iterative manner using an adaptive algorithm which updates the revenue vector periodically to compensate for observed deviations between actual and target throughput, such that the deviations are reduced over time and the revenue vector converges to an optimal revenue vector.

Abstract: The invention comprises a system and method for transmitting and receiving between voice switches compressed multiplexed packets. The invention efficiently utilizes a Digital Signal Level Zero (DS0) to provide multiplexed voice traffic between two voice switches.

Abstract: An uplink and downlink channel structure supports a shared downlink data channel. The new structure accommodates advanced physical and Medium Access Control (MAC) layer techniques, such as incremental redundancy (IR), fast adaptation to channel conditions, and multiple input multiple output (MIMO) antenna configuration. The proposed changes are intended to lead to a downlink structure that achieves higher spectral efficiency for the packet oriented services over then shared downlink channel. Additionally, the new structure uses the base station transmit power information and of the channelization (OVSF) code space more efficiently.

Abstract: An HDLC formatter and a message processing core exchange messages over a high speed message exchange interface. The interface includes a memory shared by the HDLC formatter and the message processing core. A handshaking arrangement is used to coordinate message storage and retrieval in the shared memory by the HDLC formatter and the message processing core with minimal utilization of processing resources of the message processing core. This handshaking coordination, together with the use of a message buffer accessed by the HDLC formatter to buffer channelized messages exchanged with the message processing core, facilitates message processing on multiple serial links (e.g., 3) over multiple timeslots (e.g., 256).

Abstract: A spam filtering system and method are disclosed for filtering spam destined for a mobile communication device. In the spam filtering system, a processing system receives a message destined for a mobile communication device through an interface. The processing system processes the message based on first filtering criteria to make an initial determination whether the message is suspected of comprising spam. If the processing system determines that the message is not suspected of comprising spam, then the processing system transmits the message to a message center. If the processing system determines that the message is suspected of comprising spam, then the processing system processes the message based on second filtering criteria to make a final determination whether the message comprises spam. If the processing system determines that the message does comprise spam, then the processing system blocks the message.

Abstract: An echo canceling system, method of attenuating echo, and a bit pump and transceiver employing the system and method. The echo canceling system is couplable between a transmit and receive path of the bit pump and receives and attenuates the echo in a receive signal propagating along the receive path. In one embodiment, the echo canceling system includes a slave echo canceling stage that employs a filter coefficient to attenuate the echo. The echo canceling system also includes a separation circuit, coupled to the slave echo canceling stage, that generates data representing a residual echo substantially exclusive of the receive signal. The echo canceling system still further includes a master echo canceling stage, coupled to the separation circuit, that receives the data and modifies the filter coefficient based thereon.