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US 5,477,362 AGranted
Optical switching system
AssigneeHitachi, Ltd.
InventorsManabu Okamoto, Kenichi Ohtsuki, Yoshito Sakurai
Life of this patent
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AssigneeHitachi, Ltd.
InventorsManabu Okamoto, Kenichi Ohtsuki, Yoshito Sakurai
Estimating the term…
An optical switching system to which a plurality of input transmission lines and output transmission lines for transmitting optical signals are arranged and connected, and in which fixed length cells transmitted from the input transmission lines are switched based on the routing information contained in the cells and the switched cells are outputted to the output transmission lines includes: optical cell synchronizer portions for detecting the fronts of the cells and synchronizing the fronts of the cells incoming from respective transmission lines; a switching portion for converting respective cells the fronts of which are synchronized to those of different wavelengths by input transmission lines and for switching them based on the routing information in the cells; multiplexer portions for wavelength division multiplexing the cells switched to different wavelengths by input transmission line with respect to respective output transmission lines; demultiplexer portions for splitting cells wavelength division multiplexed in the multiplexer portions by cell and aligning them in a time series, and wavelength converter portions for converting the cells split in the demultiplexer portions to cells having a predetermined single output wavelength.
An optical switching system having a plurality of input transmission lines and a plurality of output transmission lines for transmitting optical signals being aligned and connected to the system, and performing the switching of fixed length cells transmitted from said input transmission lines based on routing information contained in said cells and outputting the switched cells to said output transmission lines, comprising:
A synchronizer circuit being connected to a plurality of transmission lines for transmitting optical signals and for detecting the synchronization of optical signals being transmitted in respective transmission lines comprising:
A synchronizer circuit being connected to a plurality of transmission lines for transmitting optical signals and for detecting the synchronization of optical signals transmitted from respective transmission lines comprising:
A cell demultiplexer circuit for splitting wavelength division multiplexed cells comprising:
A cell demultiplexer circuit for splitting wavelength division multiplexed cells comprising:
An optical switching system in which a plurality of input transmission lines and output transmission lines for transmitting optical signals are connected, and the optical signals are switched based on routing information contained in fixed length cells transmitted from said input transmission lines, and outputted to the output transmission lines, comprising:
Dependencies are inferred from the claim text.
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No related US applications are recorded in the indexed filing history.
Packet switching systems: transfer mode dependent, e.g. ATM
Arrangements for synchronising receiver with transmitter: with photonic or optical means
ATM switching elements: using space switching, e.g. crossbar or matrix
ATM peripheral units, e.g. policing, insertion or extraction: header conversion, routing tables or routing tags
Term ended 9 Sep 2013 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
1. Field of the Invention
The present invention relates to a heat-sensitive recording sheet and more particularly, to a heat-sensitive recording sheet improved in color formability and sticking resistance and excellent in image stabilities such as plasticizer resistance and water resistance and in printability.
2. Related Art
FIG. 1 is a block diagram showing a constitution of an optical switching system as an embodiment of the present invention;
FIG. 2 is a diagram showing a cell structure in the embodiment;
FIG. 3A and FIG. 3B are diagrams showing data forms used in the embodiment;
An embodiment according to the present invention will be explained referring to FIG. 1. FIG. 1 shows the constitutional block diagram of an optical switching system in the present embodiment.
In FIG. 1, n incoming lines, 110 to 1n0, are optical transmission lines such as optical fibers being connected to optical cell synchronizer portions, 111 to 1n1, and from all incoming lines pieces of fixed length cell information arrive in the state of optical signals. In the optical cell synchronizer portions, 111 to 1n1, the front positions of cells from respective incoming lines are aligned and the fixed length cells (or fixed length packets) are synchronized and they are supplied to header converter portions, 112 to 1n2. In the header converter portions, 112 to 1n2, routing information contained in the header portions in the cells is taken out and the routing information together with the data portions of the cells are transmitted to the filter portions, 113 to 1n3, in the following stage. A switching portion 1123 is composed of the header converter portions and the filter portions. The switching portion 1123 converts synchronized cells to different wavelengths by input transmission lines, and performs switching based on the routing information in the cells. The filter portions, 113 to 1n3, are those for assigning the cells their respective output routes, and only the filter corresponding to an desired output route is controlled to be passed based on the routing information from the header converter portion. A filter portion is connected to n pieces of multiplexer portions, 114 to 1n4, so that n.times.n space sharing switches are constituted between a filter portion and multiplexer portions. In the multiplexer portions, 114 to 1n4, the cells which arrive from respective filter portions are multiplexed and the multiplexed data are transmitted to DMX portions (demultiplexing), 115 to 1n5. In the DMX portions, 115 to 1n5, respective cells are split from multiplexed data, and they are aligned in line by the time base. In the wavelength converter portions, 116 to 1n6, the cells having various wavelengths are converted to those having a single output wavelength.
Next, respective blocks will be explained in detail.