Abstract:
A method and system in which a Digital Subscriber Line Access Multiplexer (DSLAM) that is part of a DSL (Digital Subscriber Line) system is able to provide synchronous services to end user equipment connected to the DSLAM via a DSL link and Customer Premises Equipment (CPE). A sniffer device having direct or indirect access to a Primary Reference Clock (PRC) of the DSL system calculates the phase difference between the PRC and the DSLAM's Local Timing Reference (LTR). The phase difference is sent to the CPEs requiring accurate reference clock frequency. The CPEs are able to derive the PRC from the phase difference information transmitted by the sniffer device thus enabling synchronous end user equipment operation.
Abstract:
A frequency reference, comprising: an optical waveguide closed on itself so that a light pulse inserted into the waveguide circulates therein; a light source coupled to the waveguide and controllable to generate a light pulse that circulates in the waveguide; and a detector coupled to a region of the waveguide that generates an output pulse each time the circulating light pulse passes the region.
Abstract:
A method and system in which a Digital Subscriber Line Access Multiplexer (DSLAM) that is part of a DSL (Digital Subscriber Line) system is able to provide synchronous services to end user equipment connected to the DSLAM via a DSL link and Customer Premises Equipment (CPE). A sniffer device having direct or indirect access to a Primary Reference Clock (PRC) of the DSL system calculates the phase difference between the PRC and the DSLAM's Local Timing Reference (LTR). The phase difference is sent to the CPEs requiring accurate reference clock frequency. The CPEs are able to derive the PRC from the phase difference information transmitted by the sniffer device thus enabling synchronous end user equipment operation.
Abstract:
A system and method of compressing audio signals (110, 116, 130, 136, 140, 146) which simultaneously contain speech (110, 116), music (130, 136, 140, 146) and possibly other audio in such fashion as to reduce the required bandwidth or storage capacity. Audio (110, 116, 130, 136, 140, 146) is transmitted as simultaneous but separate streams of speech audio (110, 116) and music (or other non-speech) audio (130, 136, 140, 146), as well as other streams such as video (210, text (120, 220), computer graphics (230), etc. By keeping the music (130, 136, 140, 146) separate from the speech (110, 116), each can be maximally compressed. By synchronizing these streams (110, 116, 130, 136, 140, 146, 210, 216, 220, 230), the desired combination can be recreated at the receiver with the user being unaware of the separation. Instead of analog or digital mixing of the music or other non-speech audio (130, 136, 140, 146) with the speech audio (110, 116) to create a composite audio stream (110, 116, 130, 136, 140, 146), the streams are kept logically separate, and, thus, can be optimally compressed using existing technologies.