Adtran Gmbh

Bruce Edward Mitchell

Paul Graves McElroy

Ayman Ghobrial

Phillip Stone Herron

Richard Lee Goodson

Darrin L Gieger

James M Glass, Iii

Jerry Lynn Greer

Christopher A Otto

Sanjai Kumar Pandey

A time-division multiplexed (TDM) communication system has a dynamic bandwidth allocation (DBA) controller that is configured to reduce demand overestimation so that more optimal bandwidth allocation is achieved. Upon receiving load information from a transceiver, the DBA controller is configured to estimate an amount of change to the transceiver's reported load based on previous allocations of bandwidth to the transceiver for frames that occur during a reporting delay (e.g., the delay from the time that the load information is transmitted until it is received and processed). That is, the estimated load is reduced in an effort to account for transmissions made by the transceiver during the reporting delay, thereby preventing or reducing the amount of demand overestimation that would otherwise occur. Thus, the transceiver may be allocated less bandwidth according to a desired DBA algorithm so that more network bandwidth is available for other transceivers.

Time-division multiplexed systems and methods for reducing overestimation of bandwidth demand

A dual PHY-based integrated access device (IAD) platform employs a highly integrated time division multiplexed (TDM), a synchronous transfer mode (ATM) cell based architecture, to provide enhanced interfacing flexibility for multiple and diverse signaling protocols, effectively reducing the cost and constraints as to choice of host processor used in conventional digital signal processor (DSP)-based IADs. With the signaling transport speed of the dual PHY based path being an order of magnitude greater than that of any of the plurality of communication paths with which the IAD is interfaced, the IAD of the invention provides effectively real time support for different communication requirements, including TDM, ATM, HDLC, and the like.

Dual-PHY based integrated access device

For diagnostic and trouble-shooting purposes, an audio/voice signal capture mechanism is adapted to be interfaced with a time division multiplexed (TDM) transport path-cascaded echo canceler and compression arrangement for an integrated access device (IAD). The audio/voice signal capture mechanism captures a 'snapshot' of the audio/voice signals by storing a prescribed number of seconds of audio/voice path signals transmitted in both directions through the IAD, and time stamping the captured audio/voice signals and associated signaling events of interest. In this way, the invention operates as a 'virtual' oscilloscope, as it is able to capture pertinent data for any voice call problem along with an associated time stamp event log.

Full duplex voice path capture buffer with time stamp

A cascaded signal processing arrangement processes digitally encoded voice samples transported over a time division multiplex (TDM) communication path for application to a processor-controlled digital communication device, in particular an integrated access device. Processed voice samples are packetized in accordance with an encapsulating protocol and transmitted as a packetized voice output stream to a destination receiver device. The arrangement includes an echo canceller coupled to the TDM communication path and performing echo cancellation processing on the digitally encoded voice samples. The echo cancellation-processed voice sample signals are compressed by a data compression operator and applied to a packet encapsulating host processor via the TDM communication path. This obviates the necessity of the host processor having to use data bus cycles to download processed digitized voice samples.

Echo canceller and compression operators cascaded in time division multiplex voice communication path of integrated access device for decreasing latency and processor overhead

A voice path direct memory access (DMA)-based packet generation mechanism writes digitally encoded voice samples directly into prescribed subportions of a preallocated portion of random access memory, to avoid interrupting a main processor for the purpose. A pointer to a respective buffer space subportion is presented to a protocol stack, so that one or more overhead bytes for the stored voice samples can be generated and written into adjacent address space of the preallocated portion of random access memory. The contents of the preallocated memory space are then serialized out for transmission to a destination receiver.

Mechanism for utilizing voice path DMA in packetized voice communication system to decrease latency and processor overhead

Adaptive clock recovery for the receiving entity of a communication system transporting constant bit-rate (CBR) services over an asynchronous transfer mode (ATM) or ATM-like network is performed by a digital phase locked loop (DPLL). The recovered clock is based on the DPLL's phase detector's count of high frequency service clock cycles between transitions in an input signal representative of instances of receipt of ATM cells subject to cell delay variations through the network, and a reference clock signal whose frequency is a prescribed fraction of that of the output clock. The DPLL's VCO function is an increment/decrement of the service clock frequency, which avoids constraining the operation of a high performance modem (such as a V.90 modem).

Method and apparatus for providing reliable voice and voice-band data transmission over asynchronous transfer mode (ATM) network

A universal digital communication device includes a first digital communications interface for a first type of digital communication signals (such as basic rate 2B1Q ISDN signals), and a second digital communications interface for a second type of digital communication signals (such as extended range 3B1O ISDN signals) having a digital transport range over a telecommunications network greater than that of the first type of digital communication signals. A processor-controlled multiplexer unit determines which of the two types of digital communication signals is required for providing digital communication connectivity between local and remote communications equipment. It then couples the terminal equipment to the telecommunications network by way the digital communications interface that is capable of interfacing the required digital communication signals with the telecommunication network.

Self-configuring universal communication device for interfacing communication signals having different properties with repeaterless two-wire telephone link

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Madison, AL, United States of America

Bruce Edward Mitchell