This patent application is related to U.S. Non Provisional patent application Ser. No. 11/317,135 that is entitled “Dynamic Temporal Duration Optical Transmission Privacy”, that was filed Dec. 23, 2005 and U.S. patent application Ser. No. 11/343,094, which became U.S. Pat. No. 7,792,427, that is entitled “Optical Code Division Multiple Access Data Storage And Retrieval” and that was filed on Jan. 30, 2006, and the entire contents of which are incorporated by reference herein.
The present invention generally relates to the field of storing and retrieving data through an optical network and, more particularly, to storing data from optical data channels of an Optical Code Division Multiple Access (OCDMA) signal to data storage volumes such that the OCDMA signaling and formatting information are retained during storage and regenerated during retrieval. Additionally, the present invention provides for the encryption of the OCDMA signaling wavelengths during storage such that data privacy is enhanced.
Optical networks use optical signaling and formatting techniques, such as OCDMA, to support multiple data channels over a single fiber optic cable. The optical communications thereof are typically implemented by transmitting data through fiber-optic links because light is less prone to optical dispersion through fiber-optic links as opposed to other mediums, such as air. These optical communications use light to convey data to an intended receiver through the fiber-optic link, through “on-off keying” of the wavelength. For example, a binary signal (i.e., a signal of logical 1's and logical 0's) is transmitted through a fiber-optic link with the light switching on and off.
Demand on communications has dictated that optical fiber be shared among users. In this regard, a single optical fiber is often shared by multiple binary signals. One method of sharing involves assigning specific time periods to individual users and is called Time Division Multiplexing (“TDM”). During a period of time in TDM, a single user transmits data and other users wait for their time period. Another method of sharing involves assigning specific wavelengths of light to individual users and is called Wavelength Division Multiplexing (“WDM”). In WDM, each user has a specific wavelength of light and may transmit data on that wavelength at any time, but no other user may use that wavelength. Optical Code Division Multiple Access (“OCDMA”) is yet another method to share the optical fiber among a number of users. In OCDMA, each user is assigned a unique code that is composed of temporal and wavelength components. This unique OCDMA signature may be thought of as a unique identifier or thumbprint on a data stream. For a user to receive a data stream, the user must detect a data stream having an appropriate OCDMA signature.
To store such optical network communications, the data therein is typically decoded and converted to electronic data and stored in a storage element using a conventional disk block format. The optical to electronic conversion results in the removal of the original optical signaling and formatting information used to transfer the data over the network.
The systems and methods presented herein allow for OCDMA formatting information to be stored in a storage unit along with the user data. In this regard, the OCDMA formatting may be regenerated upon data retrieval. In one embodiment of the invention, the OCDMA signaling employs a two-dimensional coding technique allowing privatized individual channels of optical data and protection of the data while resident on the data storage system. Additionally, these systems and methods encrypt the OCDMA signaling by switching wavelengths to storage volumes during storage such that data privacy is enhanced.
In a first aspect, an OCDMA storage system includes an optical splitter optically interconnected with an optical network and a plurality of tunable filters optically interconnected with the optical splitter. The OCDMA storage system also includes a plurality of light detectors respectively optically coupled to the plurality of tunable filters and a plurality of storage volumes communicatively coupled to the plurality of light detectors, wherein each storage volume stores a generated electronic data stream associated with a plurality of tuned wavelengths of light.
The optical splitter may receive an OCDMA data stream from the optical network and divide the OCDMA data stream into a plurality of divided power OCDMA data streams. Each tunable filter may receive one divided power OCDMA data stream from the optical splitter and select one wavelength of light of the one divided power OCDMA data stream to filter at a time. Additionally, the OCDMA storage system may include a controller communicatively coupled to the plurality of tunable filters. The controller tunes the plurality of tunable filters such that each tunable filter selectively filters one wavelength of light.
In a second aspect, a method of encrypting an OCDMA data stream for storage includes steps of receiving the OCDMA data stream, dividing the OCDMA data stream to provide a plurality of optical signals, and transferring the plurality of optical signals to a plurality of tunable filters. The method also includes steps of tuning the plurality of tunable filters to filter wavelengths of light of the plurality of optical signals, converting each wavelength of light to an electronic data stream, and repeating the steps of tuning and converting.
The method may further include a step of storing each electronic data stream with a storage volume unit. In this regard, the storage volume unit includes a plurality of storage volumes, wherein each storage volume is communicatively coupled to one light detector used to execute the step of converting.
The step of tuning may include steps of receiving, with one of the plurality of tunable filters, one of the plurality of optical signals, and selectively filtering a wavelength of light from the one of the plurality of optical signals. Alternatively or additionally, the step of tuning may include a step of controlling the tunable filters to each filter a particular wavelength of light of a corresponding one of the plurality of optical signals. The step of repeating the step of tuning may include a step of randomly changing which wavelengths of light are filtered by the plurality of tunable filters.
In a third aspect, an OCDMA data retrieval system includes a storage volume unit includes a plurality of storage volumes, wherein each storage volume includes an electronic data stream. The OCDMA data retrieval system also includes a plurality of tunable light generators, wherein each of the plurality of tunable light generators is communicatively coupled to a corresponding storage volume of said plurality of storage volumes. The OCDMA data retrieval system further includes a controller communicatively coupled to each of the plurality of tunable light generators. The controller tunes each of the plurality of tunable light generators such that each light generator converts a corresponding electronic data stream to a plurality of optical data streams over time. Each optical data stream has a unique wavelength of light. Additionally, the OCDMA data retrieval system includes an optical coupler optically interconnected with the plurality of tunable light generators, wherein the optical coupler combines the optical data streams to provide an OCDMA data stream.
The optical coupler may further optically interconnect with an optical network for transferring the OCDMA data stream to the optical network. In this regard, the OCDMA data retrieval system may also include a fiber-optic link between the optical coupler and the optical network. The controller randomly tunes each of the plurality of tunable light generators such that all wavelengths of light of the OCDMA data stream are generated.
In a fourth aspect, a method of retrieving an OCDMA data stream from storage includes steps of retrieving information used to wavelength encrypt an OCDMA data stream during storage and transferring a plurality of electronic data streams from a plurality of storage volumes to a plurality of tunable light generators. Each storage volume is associated with one of the plurality of tunable light generators. The method also includes steps of tuning each of the tunable light generators using the information to generate a plurality of optical data streams and multiplexing the plurality of optical data streams to generate an OCDMA data stream.
The method may further include a step of decoding said OCDMA data stream to extract a data channel from said OCDMA data stream. The method may also include a step of splitting the OCDMA data stream into a plurality of divided power OCDMA data streams. The method may also include a step of repeating the step of tuning such that each tunable light generator switches to generate an optical data stream from a different wavelength of light. The step of tuning includes controlling the plurality of tunable light generators with a controller.
In a fifth aspect, a method of storing data includes steps of splitting a first optical signal into a plurality of divided power optical signals, wherein the step of splitting provides each divided power optical signal having less optical power than the first optical signal and filtering a plurality of optical data streams from the plurality of divided power optical signals. The method also includes a step of changeably associating each of the plurality of optical data streams with one or more of a plurality of storage volumes.
The method may further include a step of storing the plurality of optical data streams with the plurality of storage volumes. In this regard, each storage volume is communicatively coupled to one or more light detectors and each light detector is used to detect one of the plurality of optical data streams and generate a corresponding electronic data stream. The step of changeably associating each of the plurality of optical data streams may include a step of changing filter characteristics with the step of filtering to generate a respective optical data stream. Alternatively or additionally, the step of changeably associating each of the plurality of optical data streams may include a step of switching filtered optical data streams to the plurality of storage volumes.
Each data producer 302 is generally an electronic device capable of electronically generating data. For example, each data producer 302 may be an embedded computer system executing a software algorithm. In this regard, each data producer 302 may require that its output be stored to nonvolatile storage volume unit 106. As shown herein, each data producer 302 includes a corresponding OCDMA encoder 303 (e.g., data producer 3021 includes OCDMA encoder 3031, data producer 3022 includes OCDMA encoder 3032, etc.). However, data producers 3021 . . . k may each host multiple OCDMA encoder 303 units.
Each OCDMA encoder 303 converts the electronically generated data from its corresponding data producer 302 into an optical format (i.e., an OCDMA signal, such as OCDMA data stream 500 of
Optical coupler 305 is the common collection point for OCDMA encoders 3031 . . . k. Point-to-point fiber optic cable 301 optically connects a corresponding OCDMA encoder 303 to optical coupler 305 (e.g., point-to-point fiber optic cable 3011 optically connects OCDMA encoder 3031 to optical coupler 305, point-to-point fiber optic cable 3012 optically connects OCDMA encoder 3032 to optical coupler 305, etc.). Optical coupler 305 combines optical signals from the OCDMA encoders 3031 . . . k and generates a single OCDMA data stream 500.
Optical splitter 206 is configured for receiving OCDMA data stream 500 from a fiber optic network. For example, optical splitter 206 may couple to optical coupler 305 via fiber-optic cable 300 to receive OCDMA data stream 500. Upon receiving OCDMA data stream 500, optical splitter 206 may split the optical signal P0total(λ1 . . . λn) comprising OCDMA data stream 500 into a plurality of optical signals P01(λ1 . . . λn) . . . P01(λ1 . . . λn), with each typically having the same intensity. In this regard, each optical signal P0(λ1 . . . λn) maintains all wavelengths of light λ1 . . . λn of the optical signal P0total(λ1 . . . λn). Optical splitters, such as optical splitter 206, are readily understood devices by those skilled in the art.
Once split, each optical signal P0(λ1 . . . λn) is transferred to a corresponding tunable filter 103. For example, optical splitter 206 may optically couple to each tunable filter 103 to transfer an individual optical signal P0(λ1 . . . λn) to each tunable filter 103. In this regard, each tunable filter 103 may receive an individual optical signal P0(λ1 . . . λn) and, in turn, selectively filter one wavelength of light λ for a corresponding light detector 102. That is, each tunable filter 103 may provide a single wavelength of light λ of the plurality of wavelengths of light λ1 . . . λn that form optical signal P0total(λ1 . . . λn) to a light detector 102 at a given time. The wavelength of light λ that is provided to a light detector 102 is determined by controller 201.
Each light detector 102 may subsequently convert a received wavelength of light to a corresponding electronic data stream 112. Generally, the maximum number n of wavelengths of light λ for a given implementation of system 100 depends on the OCDMA coding scheme employed. That is, the OCDMA coding scheme may have an established number of wavelengths of light that determines the number of light detectors 102 to be used with system 100. The number n of wavelengths of light λ are exemplarily shown on the y-axis of OCDMA data stream 500 in
Upon conversion of the optical data stream 500 to electronic data streams 1121 . . . n, each electronic data stream 112 is transferred to a corresponding storage volume 107 within nonvolatile storage volume unit 106 (e.g., electronic data stream 1121 is stored with storage volume 1071, electronic data stream 1122 is stored with storage volume 1072, etc.). Timing information, as mentioned above, of a particular electronic data stream 112 is also stored with the corresponding storage volume 107. For example, data for a particular channel within OCDMA data stream 500 may be dispersed across a plurality of wavelengths because of the tuning of tunable filters 1031 . . . n. As such, each electronic data stream 112, being stored according to wavelength, may use timing information of the other electronic data streams such that data may be retrieved from nonvolatile storage volume unit 106 at a later date. That is, the timing information is used to extract the electronic data streams 112 from the storage volumes 107 in a manner that replicates the original OCDMA signal such that the individual data channels may thereafter be extracted therefrom.
In addition to the data privacy that is achieved through the storage of an OCDMA signal according to wavelength of light λ (e.g., as described in U.S. patent application Ser. No. 11/343,094, which became U.S. Pat. No. 7,792,427, hereinafter the “'427 patent”), data privacy, is enhanced because tunable filters 1031 . . . n variably tune to wavelengths of light λ1 . . . n. For example, tunable filter 1031 may tune to wavelength λ4 while tunable filter 1032 tunes to wavelength λ4 and tunable filter 1033 tunes to wavelength λ2, etc. Tuning of tunable filters 1031 . . . n may be a continual process throughout the entire transmission of OCDMA data stream 500. That is, tunable filters 1031 . . . n may continually tune through the range of wavelengths λ1 . . . n that form optical data stream 500 with each tunable filter 103 generally providing coverage of a single wavelength λ at any given time such that all wavelengths λ1 . . . n of optical data stream 500 are transferred to light detectors 1021 . . . n. Tuning operations of tunable filters 1031 . . . n are exemplarily illustrated below in
As stated, the wavelength of light λ that is provided to a light detector 102 is determined by controller 201. For example, controller 201 may be communicatively coupled to tunable filters 1031 . . . n such that controller 201 may control tunable filters 1031 . . . n. In this regard, controller 201 may generate control signal that determines a wavelength of light λ that a particular tunable filter 103 may pass to an associated light detector 102. Wavelength selection for tunable filters 1031 . . . n may be substantially random or performed according to a pattern such that data privacy is enhanced. For example, controller 201 may direct tunable filters 1031 . . . n to randomly switch between wavelengths during transmission of OCDMA data stream 500 while ensuring that each wavelength of light λ for OCDMA data stream 500 is received by a light detector 102.
Generally, the retrieval of data requires knowledge of the manner in which wavelengths of light λ for OCDMA data stream 500 are stored with nonvolatile storage volume unit 106. For example, controller 201 may use the pattern and associated timing used to control tunable filters 103 to retrieve the data from nonvolatile storage volume unit 106. Such is described below in
Each of electronic data streams 1141 . . . n are retrieved from nonvolatile storage volume unit 106 via corresponding tunable light generators 1081 . . . n. For example, electronic data streams 1141 . . . n are each associated with wavelengths of light λ1 . . . n. In this regard, the OCDMA signature codes of OCDMA data stream 500 may not be required to decode the data. Rather, tunable light generators 1081 . . . n may retrieve electronic data streams 1141 . . . n from associated storage volumes 1071 . . . n. Tunable light generators 1081 . . . n may then convert the electronic data streams 1141 . . . n to wavelengths of light λ (i.e., that form optical data streams f of optical data stream 500), when directed by data consumers 4021 . . . n and based on the manner in which wavelengths of light λ were stored with nonvolatile storage volume unit 106. That is, each storage volume 107 may have data stored that is associated with a plurality of wavelengths of light λ. Tunable light generators 1081 . . . n may tune to the wavelengths of light λ according to wavelengths of wavelengths of light λ which were used to store the data with nonvolatile storage volume unit 106. In this regard, tunable light generators 1081 . . . n may “undo” the wavelength tuning that was used to store the data as described in
As similarly described hereinabove, the maximum number n of wavelengths of light λ for a given implementation of system 200 generally depends on the OCDMA coding scheme employed. Again, the number n of wavelengths of light are shown on the y-axis of OCDMA data stream 500 in
Upon conversion of electronic data streams 1141 . . . n to optical data streams f E, optical coupler 109 combines the individual wavelengths of light λ of data streams f E generated by tunable light generators 1081 . . . n. In this regard, optical coupler 109 reconstructs the OCDMA data stream 500 for access by data consumers 4021 . . . n. Since the OCDMA coding scheme is generally retained with nonvolatile storage volume unit 106, optical coupler 109 may combine the generated individual wavelengths of light λ1 . . . n of OCDMA data stream 500 and thereby reconstruct the OCDMA data stream 500 for access by data consumers 4021 . . . n. As such, optical coupler 109 may couple to optical network 120 via fiber-optic cable 300 for access by data consumers 4021 . . . n. More specifically, optical coupler 109 may couple to optical splitter 405 via fiber-optic cable 300 for access by data consumers 4021 . . . n.
Similar to data producers 3021 . . . k and their corresponding OCDMA encoders 3031 . . . k of
Each OCDMA decoder 403 converts the optical data signal produced by optical splitter 405 into electrically formatted data available to the data consumer 402. For example, optical splitter 405 “splits” OCDMA data stream 500 into individual optical streams with one optical stream per OCDMA decoder 403 (i.e., each OCDMA decoder 403 receives all data of OCDMA data stream 500, generally in equal portions of the overall optical intensity of OCDMA data stream 500). Point-to-point fiber optic cables 401 optically connect optical splitter 405 to each OCDMA decoder 403 (e.g., point-to-point fiber optic cable 401, optically connects optical splitter 405 to OCDMA decoder 4031, point-to-point fiber optic cable 4012 optically connects optical splitter 405 to OCDMA decoder 4032, etc.). With the OCDMA decoders 403 optically interconnected with optical splitter 405, each data consumer 402 may thereby extract data from OCDMA data stream 500 via OCDMA decoder 403. Similar to system 100 of
The optical format of optical data stream 500 used with systems 100 and 200 are now described herein. Specifically,
Each OCDMA signature code is a 2-dimensional construct that uniquely identifies a data channel in an OCDMA network (e.g., OCDMA network 120). For example, OCDMA signature code 505 for a logical “1-bit” for Channel A is represented by spread pattern imposed on chips C0 . . . Cm (wherein m is an integer greater than 1) and wavelengths λ1 . . . n (i.e., optical data streams f E1 . . . n associated at those wavelengths). OCDMA signature code 506 for a logical “1-bit” of Channel B differs from OCDMA signature code 505 of Channel A with respect to chip and wavelength spread. Similarly, Channel C's OCDMA signature code 507 differs from OCDMA signature codes 506 and 505 with respect to chip and wavelength spread. This “distance” in coding (i.e., differences in chip occupations) allows for channel privatization such that only an OCDMA decoder 403 with knowledge of its proper OCDMA signature code can decode data from OCDMA data stream 500. For example, decoder 4031 may be designated as Channel A and therefore may have knowledge of OCDMA signature code 505. As such, decoder 4031 may use OCDMA signature code 505 to extract data from OCDMA data stream 500. Similarly, encoder 3031 may use OCDMA signature code 505 to encode data for coupling into OCDMA data stream 500 via optical coupler 305.
OCDMA data stream 500 also illustrates logical 0-bits interspersed with logical 1-bits. For example, when a logical 0-bit from a particular channel (e.g., channels A, B, or C) is transmitted via optical data stream 500, the bit comprises logical 0's (e.g., no light transmission) at all chips for that channel. However, those skilled in the art should readily recognize that the invention is not intended to be limited to logical 0-bits that include no light transmission for all chip/wavelength combinations for a particular bit. Rather, other embodiments may configure logical 0-bits with a particular code, such as described with respect to the logical 1-bits.
Additionally, those skilled in the art should readily recognize that OCDMA data stream 500 may in fact be a continuous data stream populated by more or less channels than those shown herein. For example, the maximum number n of wavelengths λ (y-axis) and the number of chips C0 . . . m per bit for a given implementation typically depends on the OCDMA coding scheme employed. As such, the chip/wavelength spread of a particular OCDMA coding scheme may dictate the number of wavelengths and chips per bit for a given OCDMA storage system and/or a given OCDMA retrieval system (e.g., system 100 and system 200, respectively).
To illustrate optical wavelength switching, at time increment 0, tunable filters 1031 . . . 4 are respectively filtering optical wavelengths λ1, λ2, λ3 and λ4 for storage in storage volumes 1041 . . . 4. At time increment 6, tunable filter 1031 may switch to optical wavelength λ4. At time increment 10, tunable filter 1034 may switch to optical wavelength λ1. Between the optical wavelength transitions of tunable filter 1031 and 1034 (i.e., between time increments 6 and 10), optical wavelength λ1 may be “picked up” by an auxiliary tunable filter 1035 which filters optical wavelength λ1 for storage with storage volume 1045 during time increments 2 through 13. Such switching may be continued for the remaining optical wavelengths at time increments as determined by controller 201.
Those skilled in the art should readily recognize that the invention is not intended to be limited to the embodiment shown herein. For example, while four optical wavelengths λ1 . . . 4 are exemplarily illustrated in
While the above embodiments have been shown and described in sufficient detail so as to enable one skilled in the art to make and use the invention, the invention is not intended to be limited to these embodiments. Those skilled in the art should readily recognize that certain features may be implemented in different ways. For example, certain steps may be implemented optically and/or electronically (e.g., such as with optoelectronic components). Additionally, such features may be controlled via firmware and/or software. Those skilled in the art are readily familiar with optoelectronics, software and firmware.
The foregoing description of the present invention has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit the invention to form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, and skill and knowledge of the relevant art, are within the scope of the present invention. The embodiments described hereinabove are further intended to explain best modes known as practicing the invention and to enable others skilled in the art to utilize the invention in such or other embodiments with various modifications required by the particular application(s) or use(s) of the present invention. It is intended that the appended claims, therefore, be construed to include alternative embodiments to the extent permitted by the prior art.
Number | Name | Date | Kind |
---|---|---|---|
4506387 | Walter | Mar 1985 | A |
4723310 | De Corlieu et al. | Feb 1988 | A |
4779266 | Chung et al. | Oct 1988 | A |
5005166 | Suzuki et al. | Apr 1991 | A |
5327276 | Shimosaka et al. | Jul 1994 | A |
5404240 | Nishio et al. | Apr 1995 | A |
5424543 | Dombrowski et al. | Jun 1995 | A |
5450224 | Johansson | Sep 1995 | A |
5594577 | Majima et al. | Jan 1997 | A |
5686722 | Dubois et al. | Nov 1997 | A |
5793907 | Jalali et al. | Aug 1998 | A |
5838437 | Miller et al. | Nov 1998 | A |
6014237 | Abeles et al. | Jan 2000 | A |
6025944 | Mendez et al. | Feb 2000 | A |
6038357 | Pan | Mar 2000 | A |
6233628 | Salmonsen et al. | May 2001 | B1 |
6292282 | Mossberg et al. | Sep 2001 | B1 |
6388782 | Stephens et al. | May 2002 | B1 |
6486984 | Baney et al. | Nov 2002 | B1 |
6532556 | Wong et al. | Mar 2003 | B1 |
6594050 | Jannson et al. | Jul 2003 | B2 |
6614950 | Huang et al. | Sep 2003 | B2 |
6628864 | Richardson et al. | Sep 2003 | B2 |
6690853 | Alaimo et al. | Feb 2004 | B1 |
6721306 | Farris et al. | Apr 2004 | B1 |
6728445 | Blomquist et al. | Apr 2004 | B2 |
6748083 | Hughes et al. | Jun 2004 | B2 |
6778102 | Grunnet-Jepsen et al. | Aug 2004 | B1 |
6831773 | Pfeiffer et al. | Dec 2004 | B2 |
6839521 | Davis | Jan 2005 | B2 |
6904239 | Chow et al. | Jun 2005 | B2 |
6915077 | Lo | Jul 2005 | B2 |
7035544 | Won | Apr 2006 | B1 |
7063260 | Mossberg et al. | Jun 2006 | B2 |
7110671 | Islam | Sep 2006 | B1 |
7113703 | Murata | Sep 2006 | B2 |
7200331 | Roorda et al. | Apr 2007 | B2 |
7200342 | Dafesh | Apr 2007 | B2 |
7239772 | Wang et al. | Jul 2007 | B2 |
7260655 | Islam | Aug 2007 | B1 |
7308197 | Zhong et al. | Dec 2007 | B1 |
7317698 | Jagger et al. | Jan 2008 | B2 |
7324753 | Kashima et al. | Jan 2008 | B2 |
7330660 | Duelk | Feb 2008 | B2 |
7340187 | Takeshita | Mar 2008 | B2 |
7341189 | Mossberg et al. | Mar 2008 | B2 |
7366426 | Kai et al. | Apr 2008 | B2 |
7369765 | Aoki et al. | May 2008 | B2 |
7406262 | Nakagawa et al. | Jul 2008 | B2 |
7415212 | Matsushita et al. | Aug 2008 | B2 |
7418209 | Salamon et al. | Aug 2008 | B2 |
7418212 | Bontu | Aug 2008 | B1 |
7433600 | Katagiri et al. | Oct 2008 | B2 |
7437080 | Schmidt et al. | Oct 2008 | B2 |
7450239 | Uehara et al. | Nov 2008 | B2 |
7474854 | Sekiya et al. | Jan 2009 | B2 |
7499652 | Zhong et al. | Mar 2009 | B2 |
7505597 | Stevens et al. | Mar 2009 | B2 |
7505687 | Jaggi et al. | Mar 2009 | B2 |
7580636 | Nogi | Aug 2009 | B2 |
7792427 | Uhlhorn et al. | Sep 2010 | B1 |
20020030868 | Salomaa | Mar 2002 | A1 |
20020067523 | Way | Jun 2002 | A1 |
20020067883 | Lo | Jun 2002 | A1 |
20020196541 | Cai | Dec 2002 | A1 |
20030123789 | Miyata et al. | Jul 2003 | A1 |
20030152393 | Khoury | Aug 2003 | A1 |
20030223687 | Blomquist et al. | Dec 2003 | A1 |
20040141499 | Kashima et al. | Jul 2004 | A1 |
20040184809 | Miyata et al. | Sep 2004 | A1 |
20040197099 | Kai et al. | Oct 2004 | A1 |
20040264965 | Kobayashi et al. | Dec 2004 | A1 |
20050019034 | Aoki et al. | Jan 2005 | A1 |
20050111376 | Raghothaman et al. | May 2005 | A1 |
20050147414 | Morrow et al. | Jul 2005 | A1 |
20050185959 | Kinoshita et al. | Aug 2005 | A1 |
20050219543 | Uehara et al. | Oct 2005 | A1 |
20050270999 | Schiff et al. | Dec 2005 | A1 |
20050281558 | Wang et al. | Dec 2005 | A1 |
20060098983 | Han et al. | May 2006 | A1 |
20060115210 | Nakagawa | Jun 2006 | A1 |
20060171719 | Schmidt et al. | Aug 2006 | A1 |
20060209739 | Kumar et al. | Sep 2006 | A1 |
20060210083 | Takemoto et al. | Sep 2006 | A1 |
20060257143 | Cavazzoni et al. | Nov 2006 | A1 |
20070036553 | Etamad et al. | Feb 2007 | A1 |
20070110442 | Peer | May 2007 | A1 |
20080002974 | Zhong et al. | Jan 2008 | A1 |
20090016726 | Suzuki et al. | Jan 2009 | A1 |