A dynamic file access control and management system and method in accordance with the present invention may be a proxy file management system (10) that includes one or more file system proxy servers that provide selective access and usage management to files available from one or more file systems or sources (210, 220). The present invention may embody a secure transport protocol that tunnels distributed file systems, application independent usage controls connected to files on end-user computers (150), dynamically merging secondary content to a requested file, and applying bandwidth management to any of the foregoing. Embodied in the various implementations of the present invention is enhanced file security. Preferably, the proxy file management system is transparent to an end-user. A dynamic content management system may also be included that selectively adds content to requested files.

Dynamic file access control and management

A device is configured for treating pathological narrowing of fluid-carrying conduits of the human body (such as blood vessels) in an area of a bifurcation (30). In particular, a stent delivery system (100) configured to carry one or more of a pair of dissimilar stents (12, 14). At least one of the stents (12, 14) is particularly suited for treating a widened portion of a blood vessel (46) immediately proximal to a bifurcation (30). The stent delivery system (100) can also include a handpiece (140) adapted to selectively deliver the stents.

Endoprosthesis deployment system for treating vascular bifurcations

A wireless communication system can comprise two or more antennas that interfere with one another via free space coupling, surface wave crosstalk, dielectric leakage, or other interference effect. The interference effect can produce an interference signal on one of the antennas. A cancellation device can suppress antenna interference by generating an estimate of the interference signal and subtracting the estimate from the interference signal. The cancellation device can generate the estimate based on sampling signals on an antenna that generates the interference or on an antenna that receives the interference. The cancellation device can comprise a model of the crosstalk effect. Transmitting test signals on the communication system can define or refine the model.

Method and system for antenna interference cancellation

This article provides a perspective on optical layer protection and restoration based on the services offered by carriers using the optical layer. This is different from other viewpoints that provide a taxonomy of protection techniques in a more abstract fashion for the purposes of standardization. The latter viewpoints are mostly based on the classification adopted in the SONET/SDH standards. In contrast, taking a services-based view provides a way to distinguish between protection schemes based on implementation costs and the associated services enabled by the protection scheme.

Optical layer survivability: a services perspective

Techniques for providing normal operation and service restoration capability in the event of failure of terminal equipment or transmission media in a heterogeneous network, such as a hybrid network containing single- and multi-wavelength lightwave communications systems. An optical switching node (OSN) is placed at each node in the ring network to provide the required connections between various fibers and terminal equipment, but having switch states that allow signals on the protection fibers to bypass the terminal equipment at that node. Ring-switched signals propagate around the ring on protection fibers without encountering the terminal equipment at the intervening nodes. To the extent that the protection fiber links between any given pair of nodes are incapable of supporting all the relevant communication regimes, such links are modified to provide such support.

Method and apparatus for operation, protection, and restoration of heterogeneous optical communication networks

An optical transmitter apparatus comprises a light source for optical signal transmission, an intensity modulator, a transmit signal generator and a signal generator. A transmit signal to be transmitted is supplied from the transmit signal generator to the intensity modulator, while a signal generated by the signal generator is supplied to the phase modulator. A light beam emitted from the light source passes through the intensity modulator and the phase modulator to be subsequently sent out as an optical signal for transmission with intensity thereof being modulated upon passing through the intensity modulator while spectrum thereof being spread by phase modulation which the optical signal undergoes upon passing through the phase modulator.

Optical intensity and phase modulators in an optical transmitter apparatus

A homodyne optical receiver equipment has a polarization beam splitter for dividing an optical signal into an optical signal with horizontal polariza-tion and an optical signal with vertical polarization; optical couplers for combining two optical signals of the two poalrized components with two optical local signals, which are almost matched therewith in the polarization, in a state where they are matched with each other in the phase, respectively; detectors for homodyne-detecting respective output optical signals of the optical couplers; two weighting circuits for giving output signals of the detectors weights approxi-mately proportinal to amplitudes thereof, respectively; and an adder, which adds output signals of said weighting circuits to each other.

Homodyne optical receiver equipment

An optical crossconnect apparatus which includes one terminal connected to a transmission path from one optical transmission terminal station and another terminal connected to a transmission path from another optical transmission terminal station, a first optical signal switch having “M1” ports and “N1” ports, through which the optical signal can pass, a second optical signal switch having “M2” ports and “N2” ports, through which the optical signal can pass, and “L” optical signal repeaters, one end connected to the “N1” ports of the first optical signal switch, and the other end connected to the “N2” ports of the second optical switch. The “N1” and the “N2” ports are equal to “L” optical signal repeaters. The “M1” ports of the first optical signal switch connected to the one terminal, and the “M2” ports of the second optical signal switch connected to the other terminal are larger than, or equal to 2.

Optical crossconnect apparatus and optical transmission system

An optical frequency division multiplexing transmitter is disclosed, which comprises a plurality of optical transmitters having different optical frequencies; an optical combiner multiplexing optical signals outputted by the different optical transmitters; and an optical filter having passbands, the frequency of each of which is approximately in accordance with the frequency of each of the signals, in which the signal thus multiplexed is inputted.

Optical frequency division multiplexing transmitter and optical frequency division multiplexing transmission apparatus

A method and system for information processing in a bidirectional information transmission system, particularly for transmitting information in accordance with a change in a transmission capacity of a transmission line. A system is provided which can change an information transmission rate in accordance with a room capacity of a transmission line. This information transmission system includes a plurality of information providers, a plurality of information receivers, an information storage and distribution unit connected to the information providers and receivers, and a plurality of information transmission lines for information transmission between the information providers and receivers and the information storage and distribution unit, wherein the information transmission rate of each information transmission line is changed.

Shigeki Kitajima

Papers

Optical intensity and phase modulators in an optical transmitter apparatus

Homodyne optical receiver equipment

Optical crossconnect apparatus and optical transmission system

Optical frequency division multiplexing transmitter and optical frequency division multiplexing transmission apparatus

Information transmission system with variable transmission rate