Abstract: The present invention is a transmitter device and related system and method for use in high speed optical transmission systems. In one exemplary embodiment of the present invention, light from a laser diode output is split into two branches of orthogonal polarization (Eox, and Eoy) of substantially equal power. Polarization selectors coupled thereto are operable to select a specific polarization to be output to a corresponding external optical polarization modulator. A first polarization modulator, receives light from the polarization selector, for example, Eox, and modulates URZ data from a URZ coder thereon. A second polarization modulator receives light from the second polarization selector, for example, Eoy, and modulates delayed data (URZd) representative of the URZ data from the URZ coder thereon. The URZ data and the delayed URZd data may be combined at the transmitter, fiber channel or receiver for transmission over a single optical medium, for example, a fiber optic cable.

Abstract: Message retrieval methods and devices allow for the remote retrieval of caller identity delivery (“CID”) information or messages stored in telephones, telephone answering devices (“TAD”) and the like through the use of dual-tone, multi-frequency (“DTMF”) signals.

Abstract: Systems and methods utilize cradle contacts for completing diagnostic tests of rechargeable devices, such as cordless telephones. A cordless telephone handset or base is placed into a test fixture. Once the handset or base is cradled, diagnostic message signals are transmitted through cradle contacts in the test fixture and handset/base. The message signals may be made up of ASK signals. The beginning and end of each test may be identified by a code or codes embedded in a message signal. The use of cradle contacts to complete diagnostic tests alleviates problems associated with use of internal test access ports to carry out such tests.

Abstract: Methods and devices are provided for overcoming interference which occurs when one or more cordless devices seek to communicate over the same range of narrow band channels. Any one of a number of algorithms not based on channel clarity may be utilized to order groups of available channels which surround a cordless device. The device then selects a channel from within the ordered group of channels to assure clear communications between a cordless telephone handset and base. The algorithm may be randomly selected from among a number of algorithms or may be selected by other means.

Abstract: Methods and devices are provided for quickly producing all possible linear polarization states of light at the output of a length of optical fiber. Linearly polarized light is input and is transmitted through a fiber. Due to the birefringence of the fiber, light at the output of the fiber is elliptically polarized irrespective of the input polarization. The elliptically polarized states of light at the output are generated as an arbitrary circle on an output Poincare sphere. This arbitrary circle is then manipulated to produce a final circle substantially coinciding with the equator of the Poincare sphere. This final circle represents all possible linear polarization states at the output of the fiber. The invention eliminates the need for determining transformation matrices and performing point-by-point calculations in order to obtain input polarization settings for polarization-based, passive optical network (“PON”) testing.

Abstract: A microcomputer incorporates a pair of DMA controllers that are co-dependently operated to read and write common data blocks to two peripheral devices. In an exemplary embodiment of the invention, one of the DMA controllers is designated to read a data block from memory, store the data, and then write the data in a single write cycle to each of the two peripheral devices. This DMA controller provides the address and control signals necessary for writing the data to a first of the two peripheral devices, while the other DMA controller provides the address and control signals necessary for writing the data block to a second of the two peripheral devices. As a result, only one read and one write command are required for the data to be written to the two peripheral devices.

Abstract: A facility is provided for interfacing the Internet with a telecommunications network and vice versa so that a user who does not have access to the Internet may, nevertheless, provide a Web page and update the Web page via the telecommunications network and so that a user may access the telecommunications network via the Internet.

Abstract: Intelligent memory devices allow for the transfer of data between two or more electronic devices, such as digital signal processors and microcontrollers. The memory devices may be designed as dual port memory devices capable of sending/receiving synchronous, serial data. The use of serial data reduces the pin count of the memory devices and those connected to it. The memory devices also utilize a dedicated pair of data bits and memory pointers to carry out management of the memory and data transfers allowing connected devices to reduce the amount of processing time spent on such matters.