Abstract: A bidirectional amplifier that compensates for signal attenuation in a transmission medium uses a first diplex filter for directing a first signal including a pilot signal and propagating in a first direction along a first section of the transmission medium onto a first path of the amplifier. A second diplex filter directs a second signal in a different frequency band than the first signal that is propagating in a second direction opposite to the first signal along a second section of the transmission medium onto a second path of the amplifier. The first and second paths interconnect separate sections of the first and second diplex filters. A compensating device is disposed in the first and second paths wherein a pilot detection circuit detects the pilot signal in the first signal and generates therefrom separate control signals to first and second Bode Slope Equalizers in the first and second paths, respectively.

Abstract: An improved method for solving collisions in an Ethernet network. In one embodiment, the invention is implemented using circuitry that senses when the system cable is active. When a station on the network involved in a collision is implementing its collision backoff algorithm and the system cable becomes active, a Stop Backoff Logic comprising an AND gate provides a signal to stop the collision backoff algorithm counter until the system cable is again quiet.

Abstract: A method determines the signal usability of an adjacent channel in a multi-cell communication system without the aid of synchronization symbols. In general, a three step search is used to arrive at the adjacent channel signal quality. The first step is a coarse timing phase search. This is accomplished through a signal quality estimates (606). The second step arrives at the optimum time phase by first interpolating (608) the received signal around the time phase selected in the first step to generate additional samples. After the interpolation (608), signal quality estimates are calculated (610) for the time phases immediately surrounding the time phase found in the first step. The optimum time phase corresponds to the maximum of these quality estimates. Finally, in the third step, the signal quality estimate is calculated for the optimum time phase. This provides the adjacent channel signal quality estimate desired.

Abstract: A computer-implemented method and system for browsing encoded images. According to a preferred embodiment, at least one image is encoded with an encoding system to provide at least one encoded image. The encoding includes transforming images of the at least one image in accordance with a transform to provide a plurality of transform coefficients. A subset of the plurality of transform coefficients corresponding to a selected image is transmitted to a remote computer system, wherein the subset of the plurality of transform coefficients corresponds to a low quality version of the selected image.

Abstract: System (10) and methods (100) assign satellite link access bandwidth upon demand as requested by a number of subscriber units (30). After receiving the connection request, a number of time slots being requested is determined. Next, if the maximum number of available time slots is greater than or equal to the number of time slots being requested plus the number of time slots already in use, the connection request is accepted and the number of requested time slots are allocated before communication begins. Otherwise the connection request is rejected and the subscriber unit (30) must try later.

Abstract: When data is transferred by using a plurality of time slots, the transferring period is shortened by adopting priority to assign the required number of slots. The base station BS which accepted packet P1 generates a "BUSY" signal and an echo at the final portion of the first time slot TS which begins at time t4. The base station BS, recognizing that there is a packet following the packet P1, generates a "RESERVED" signal at the final portion of the time slot TS which begins at time t5. The mobile station MS-A learns that the first time slot is assigned by recognizing the "BUSY" signal and the echo, and that the second time slot is also assigned by recognizing the "RESERVED" signal. Therefore, the first and second time slots are used successively for fast transferring.

Abstract: A data link control procedure for wireless ATM access channels based on a dynamic TDMA/TDD framework provides integrated ATM services including available bit-rate (ABR) data and constant/variable bit-rate (CBR/VBR) voice or video through the addition of wireless-specific medium access control and data link control protocol layers between the physical and ATM network layers. Generally, a data link control is used to insulate the ATM network layer from wireless channel impairments by selective retransmission of erroneous or lost cells before they are released to the ATM layer. The data link control methods disclosed use the on-demand ABR burst transmission capability of the dynamic TDMA channel to retransmit unacknowledged cells in available slots not allocated to service data. Specific error recovery procedures for both (asynchronous) ABR and (isochronous) CBR services are provided.

Abstract: The method of providing a frame clock for data signals in a communications network includes determining phase positions (P1, P2, . . . ) of respective frame clock information (RT1, RT2, . . . ) of incoming data signals with respect to frame clock information (RTN) available at a switching point in at least one switching device (NK1, NK2, . . . ); storing in a memory device (SPN) in the at least one switching device (NK1, NK2, . . .

Abstract: The invention provides a method of suppressing a background noise signal in a sampled noisy voice signal. The method comprises the following steps: digital frequency-domain processing of the noisy voice signal to produce time-domain filtering coefficients, and digital time-domain processing of the noisy voice signal in accordance with the filter coefficients to produce a voice signal in which the background noise signal is substantially suppressed.

Abstract: In an inter-PBX routing apparatus, calls from channels of different service categories to a destination are normally carried by a first route. A controller determines the available bandwidth remaining in the first route, classifies the channels as a first or a second category if they cannot or can tolerate delays when establishing an alternate route, respectively, or a third category if they do not require the second route when the first route is overflowed. A second route is established on a pre-assigned basis when the bandwidth of at least one idle channel of the first category is greater than the available bandwidth and on a demand-assigned basis in response to a request from a channel of the second category having a bandwidth greater than the available bandwidth.

Abstract: A method is disclosed for rate allocation within the individual switches of a communications network implementing a rate-based congestion control approach for best-effort traffic. The methodology of the invention centers on a new rate allocation algorithm which performs its allocation functions independently of the number of connections sharing a network link and therefore performs an allocation in .THETA.(1) complexity. With that implementation simplicity, the algorithm is particularly advantageous for implementation in ATM switches carrying a large number of virtual channels. The algorithm operates on bandwidth information supplied from the source of a connection in special cells or packet headers, such as ATM Resource Management cells. By storing parameter values for other connections sharing a network link, the algorithm requires a constant number of simple computations for each request from a connection for a bandwidth allocation.

Abstract: A communication system including a switching system which comprises a switching unit and a control circuit. The control circuit comprises a transmitting-side signalling handler procedure (ASH) for managing the connection and for exchanging messages with other procedures, and a receiving-side signalling handler procedure (BSH) for managing the connection and for exchanging messages with other procedures. For providing optional external services, the switching unit is coupled to a service control system. Furthermore, the control circuit comprises an additional procedure (ZUSA) for exclusively exchanging messages with the transmitting-side and the receiving-side signalling handler procedures (ASH, BSH).

Abstract: One, or more, ISDN interfaces have their reach extended without violating ISDN interface standards by a method which converts ISDN coded information which is to be delivered over an extended channel into binary coded data prior to transmission, transmitting the binary coded information to a receiver at an extended location and there, after storage, and assembly, converting the binary coded data into ISDN specific coded data for delivery to an ISDN interface.

Abstract: A network node and a method of dynamically allocating bandwidth for intranodal and internodal telecommunications sessions include monitoring resource utilization at both a line shelf level and a system-wide level. In one embodiment, the dynamic allocation of bandwidth is applied to multimedia conferencing between subscribers of the same private branch exchange (PBX). If resource utilization at one or both of the line shelves that are involved in the intranodal session reaches or exceeds a preselected maximum threshold, bandwidth reallocation is triggered. In like manner, if a switching fabric of the PBX has reached a resource utilization maximum threshold that threatens system-wide blocking of any additional sessions, resources are reallocated for the system in order to free bandwidth. Utilization thresholds preferably adaptively vary on an hour-to-hour basis and/or a day-to-day basis.

Abstract: A TDMA communication system having a selectable synchronization code receive window is described. To eliminate any false detections of a synchronization code, a selectable window is created during which the synchronization code is expected to appear. The size of the window is reduced once the synchronization code is detected. In one embodiment, the size of the window is based on the elapsed time since the last synchronization of the TDMA system.

Abstract: An ATM switching system has a receiving unit for receiving an ATM cell, reassembling it into a frame and temporarily storing a buffer memory with this frame. When the receiving unit receives the cell, there is discriminated whether the cell is a continuous in-receipt cell or a last cell. A cell-to-cell receiving time or a receiving time between a head cell and the last cell is monitored. When this receiving time exceeds a set time, a determination is that the cell loss is detected. Invalid holding of a buffer memory is restrained by releasing the buffer memory.

Abstract: A shared-disk cluster system includes a cluster membership manager framework which coordinates the joining or leaving among all nodes in a cluster including taking the multiple layers of involved subsystems through transitions. Subsystems are notified of transitions in particular order depending upon the transition, and all nodes' subsystems receiving a notification must process that notification prior to another layer of subsystems being notified. One of the subsystems registered for notification is an event manager in user space. The event manager carries out transfers of client services, including user applications, resulting from nodes joining and leaving the cluster. This includes a registration and launch service which registers a node, or multiple nodes, in a cluster which claims, or is assigned, responsibility for the service and provides an optional launching function which initiates the client service upon successful registration.

Abstract: A frame based traffic policing system that determines if incoming data cells are conforming or non-conforming according to the a traffic contract. The frame based traffic policing system first detects a cell at the beginning or end of a frame and determines if the frame conforms with a traffic contract. If the cell does not exceed the parameters of the traffic contract, then the frame based traffic policing system deems the cell as conforming. If the cell was the first cell of a frame, then frame based traffic policing system treats all the remaining cells in the frame as conforming or non-conforming depending upon if the first data cell was conforming or non-conforming. If the cell was the last cell of a frame, then frame based traffic policing system treats all the cells of the following frame as conforming or non-conforming depending upon if the last cell of a previous frame was conforming or non-conforming.

Abstract: A method and system for controlling admission to a packet switched radio channel (PRCH) is provided. A PRCH admission control function evaluates admission requests for users requesting admission to a PRCH. The admission requests each contain a priority value and an estimated data traffic for the requesting user. If the estimated data traffic from one or more packet calls currently using the PRCH and having a priority equal to or higher than the priority of the requesting user, plus the estimated data traffic required by the requesting packet call are less than a maximum tolerable traffic level, the packet call is granted admission.

Abstract: The frame timing control of TDMA signals in cellular systems is implemented in mobile stations and/or base stations according to the invention so that the functions are divided between the frame timing control unit (1) and the microcontroller (2). In this way, the frame timing can be controlled in a flexible manner, for instance when moving from one TDMA cell type to another, without breaking the speech or data communication.