38 results about "Bridge tap" patented technology

Estimates of a communication system configuration, such as a DSL system, are based on operational data collected from a network element management system, protocol, users and/or the like. The operational data collected from the system can include performance-characterizing operational data that typically is available in an ADSL system via element-management-system protocols. Generated estimates and/or approximations can be used in evaluating system performance and directly or indirectly dictating/requiring changes or recommending improvements in operation by transmitters and/or other parts of the communication system. Data and/or other information may be collected using “internal” means or may be obtained from system elements and components via email and/or other “external” means. The likelihood of a model's accuracy can be based on various data, information and/or indicators of system performance, such as observed normal operational data, test data and/or prompted operational data that shows operating performance based on stimulation signals. One example of such prompted data uses frequency carrier masks to approximate the Hlog of a given channel, including information regarding bridged taps, attenuation, etc.

An active terminating device (30) for an electrical transmission line with optional line-receiving and line-driving capabilities. The basic device is a two-terminal unit, denoted as a Signal Canceling Unit (SCU), which sensesthe signal available at its terminals (34a, 34b), and applies negative feedback in order to cancel and absorb the signal. When applied to the end of a transmission line (15a, 15b) as part of wired communication network, the SCU functions as a terminator. When connected in the middle of such wired transmission line, the SCU splits the transmission line into two separate and isolated segments. In such a configuration, the SCU can be used to isolate a portion of a network from signal degradation due to noise or bridge-tap. Furthermore, the two isolated segments may each employ independent communications, such that no interference exists between the segments. In another embodiment, line receiver functionality is integrated into the SCU, designated as a Signal Canceling and Receiving Unit (SCRU) (90). The SCRU can perform all the SCU functions, and also serves as a line receiver in the communication network. In yet another embodiment, line driver functionality is integrated into the SCRU, designated as a Signal Canceling, Receiving and Transmitting Unit (SCRTU) (120). The SCRTU can perform all the SCRU functions, and also serves as a line driver in the communication network. Upon connecting multiple SCRTU's to a continuous transmission line, terminated independent point-to-point communication segments are formed.

The present invention provides a method and apparatus for performing line qualification tests, and binning the results of such testing. The lines are tested to determine or estimate various characteristics of the line. Physical characteristics of the line may be estimated (e.g. line length, line gauge, insertion loss). The presence of devices on the line such as load coils, bridged taps, terminations and the like may also be determined. A prediction of the data rate the loop can support is made from the measured and estimated line conditions. The results are binned according to certain criteria and to provide an easily discernable status of the line. The binning can be performed by a computer using software designed specifically for this purpose. The binned results may include a first category indicating the line cannot support a certain level of high speed access. The binned results may also include a second category indicating the line can support a certain level of high speed access. The results may also include a third category indicating the line cannot currently support a certain level of high speed access but would be able to upon removal of an impediment. A fourth category indicating the characteristics of the selected line fall outside the area of coverage of the test system may also be included. Each category may be assigned a respective color in order to make the status of the line easily discernable. The testing and binning may be performed for a variety of different high speed access levels. Customers can be charged different rates dependent upon the level of service made available to them.

Through the use of a least squares minimization concept, the loop length, the number of bridged taps and length of the bridged taps on a transmission line can be determined from readily available modem data. In particular, the loop length, the number of bridge taps and the length of bridged taps can be estimated by comparing a measured frequency domain channel impulse response of the transmission line to a model of a loop that is comprised of multiple sections and multiple bridge taps.

A method and apparatus for measuring data rates is disclosed. An apparatus that incorporates teachings of the present disclosure may include, for example, a diagnostic system having a Time Domain Reflectometer (TDR) element that submits a signal over a cable and determines from its reflection in the cable a length of the cable and a length of a bridged tap, and a diagnostic element that determines downstream and upstream bit rates for the cable according to the length of the cable and the length of the bridged tap. Additional embodiments are disclosed.

A method and apparatus for service multiplexing over telephone networks which employ bridged tap construction to allow the simultaneous delivery of different services to physically separated subscribers over a shared single pair of wires. Service is provided to one or more subscribers by connecting them to an open-circuited branch or directly with the working portion of the shared line. Service filters are used at appropriate locations in the network topology to couple or isolate the different communication channels. The wire pairs are used to simultaneously carry different services to physically separated subscribers, i.e., a portion of a common line carries one service to one location and a second service to another location. Telecommunication services are partitioned to occupy separate frequency bands in the spectrum of the transmission line using frequency division multiplexing (FDM) techniques. The location of the terminating point for each service is different and flexible as facilitated by the use of bridged taps, service drop connections and appropriate filtering. Inverse multiplexing, a method of combining multiple physical links (e.g., telephone lines) into a single, virtual communication link, is used to increase transmission bandwidth. The simultaneous delivery of different telecommunication services over a common line to physically separated subscribers may be used in conjunction with inverse multiplexing to increase and/or vary the transmission bandwidth to individual subscribers.

Methods, systems, and devices are described for wired communication. In one aspect, a method relates to detecting cable impairments with reflectometry. The method includes transmitting a test signal and receiving one or more reflected signals in response to the test signal. The method also includes applying a first asymmetric windowing function to the one or more reflected signals to generate frequency domain data. Additionally, the method includes transforming the frequency domain data from a frequency-domain representation to a time-domain representation to generate a time domain reflectometry (TDR) signal. The method can detect and locate a bridge tap, line cut, and/or termination condition on the transmission line.

The invention provides a system and method for testing a telephone or communications line to determine if the line qualifies for a particular type or class of communications service, for example DSL service. In accordance with one embodiment, a potential customer can download a software program. The program first performs a DSL distance qualification calculation. If the customer' line passes this step, the program determines whether the line coupled between the customer and a central office servicing that customer is electrically qualified for DSL communications. A series of tests to measure signal levels, noise, and other characteristics are performed by a test server, which generally include local loop tests to determine the presence of bridged taps, load coils, and subscriber line concentrators. After the tests are completed, the customer can receive the results, order completion and other instructions.

Methods and apparatus for protecting quality of service during a process involving bridge tap in a communications system are described. Bridge tap may occur during system construction, central office re-concentration, replacement projects, upgrade projects, expansion projects, and installation of back-up cables, etc. Cables, with one end connected to a point in the system, and the other end left unterminated, result in bridge tap. In the bridge tap moderator of the present invention, a plurality of termination networks are attached to a modular connector such that a separate termination load is placed across each connector terminal pair for each corresponding wire pair of the cable. Communication lines can be easily attached to the moderator thereby easily, quickly, and efficiently eliminating bridge tap on a large number of wire pairs. The bridge tap modulator apparatus and method of use also minimize the amount of time bridge tap exists during cable and/or communication device installation. The use of bridge tap moderator results in improved overall system performance reflected in an improvement in attainable sync rate and increase in allowable loop length.

A method and system for managing a line topology is provided by the embodiments of the disclosure. The method for managing a line topology includes obtaining an actual transfer function of the line according to the actual transfer function of the line and a transfer function of the bridge tap model, estimating a diameter and length of the bridge tap of the line and a diameter and length of the trunk line of the line according to the estimated diameter and length of the bridge tap and the diameter and length of the trunk line, obtaining a transfer function of the line model that includes the location parameter of the bridge tap by comparing the error between the actual transfer function and the transfer function of the line model which includes the location parameter of the bridge tap, estimating the position of the bridge tap according to the estimated diameter and length of the trunk line and the diameter and length of the bridge tap and the location of the bridge tap, and generating a topology of the line. By applying the embodiment of the disclosure to maintain and manage the line topology, the location of the bridge tap can be estimated effectively, and the line topology can be obtained.

The present invention establishes a communications link between a central office (CO) modem and a customer premise equipment (CPE) modem. The CO modem then evaluates the performance of the communications link. Impairments on the communications link are identified based on the evaluation results. Next, adjustment parameters for improving the performance of the communications link are determined. The CPE modem is then modified in accordance with the determined adjustment parameters to establish an adjusted communications link between the CO modem and the CPE modem. In this way, impairments such as bridged taps and cross-talk can be avoided.

Briefly, techniques that may be used to provide characteristics of a signal propagation medium. Based on test signals transmitted into the medium, the techniques may be used to construct a mosaic waveform with multiple time segments. Each time segment may be based on a gain enhanced received reflected signal and each time segment may have an applied gain that is at a highest level without causing saturation. The techniques may further remove unwanted bridge tap reflection.