Abstract: A system and method are provided for reducing data slow-down that occurs over an asymmetric communication link, particularly where the size ratio between message packets and acknowledgment packets is greater than the asymmetry ratio of the bandwidth of the communication link. Specifically, the invention resides at an intermediate system node, wherein the intermediate node is disposed to communicate across an asymmetric communication link on one side, and communicating across a high-speed symmetric bandwidth communication link on the other side. The broad aspect of the invention is that the intermediate node monitors acknowledgments being transmitted from the high-speed symmetric link, through the intermediate node, in the upstream direction of the asymmetric link. If an acknowledgment is received at a time when a prior received acknowledgment is being transmitted to the upstream node, the later received acknowledgment(s) is/are stored in a memory storage area.

Abstract: A cellular modem couples a data terminal equipment (DTE) to a portable mobile telephone that includes a cellular transceiver. The cellular modem monitors the activity of a circuit-switched analog cellular data connection between the DTE and a far-end data endpoint, e.g., a computer, through a cellular modem pool in the network. If the circuit-switched analog cellular data connection is idle for a predetermined amount of time, the cellular modem initiates a power-down sequence. For example, the cellular modem uses a protocol, e.g., a predefined tone, to indicate to the cellular modem pool that a power-down is occurring and that the circuit-switched analog data connection is to be put on hold.

Abstract: A modem apparatus and method to allow a single central site modem with a low processing power DSP to handle numerous DSL lines. More particularly, the modem apparatus and method take advantage of the bursty nature of Internet data traffic to allow the low processing power DSP equipped modem to handle multiple lines simultaneously. The multiple lines can be serviced via a round robin routine or via a quality of service routine, in which the data traffic on the line is analyzed for real time activity, such analysis using UDP transport layer protocol to determine real time activity. The quality of service routine also constantly monitors the data communications lines during periods of data communication to determine if a data line should be entered into the high priority queue.

Abstract: A digital subscriber line (DSL) remote terminal unit (RTU) using a plurality of forwarding policies and a management information base (MIB) allows the implicit support of IP subnetworks by creating dynamically, the routing tables necessary for IP subnetwork addressing. By using a constructed enterprise DSL ipInjection MIB to define a plurality of objects that describe the creation and management of a plurality of IP subnetworks the present invention allows the creation and support of both contiguous IP subnetworks and discontiguous IP subnetworks.

Abstract: A transmitting Mu-law modem creates a probe signal by modifying the 7th bit of each of a number of PCM samples during the "hand-shaking" phase of a data connection. Furthermore, the transmitting Mu-law modem only makes this modification on those PCM samples that fall into the range of segment 1 as defined in CCITT Recommendation G.711. Similarly, a receiving Mu-law modem searches for this known pattern. Upon detection of this pattern, the receiving Mu-law modem provides an acknowledgment signal and both modems subsequently switch to a digital-mode of operation. On the other hand, if, in fact, there is a least one analog link in the data connection, the probe signal becomes distorted and, since the receiving Mu-law modem does not detect the probe signal, handshaking is completed in the standard fashion.

Abstract: A transceiver capable of transmitting and receiving current-driven communication signals is implemented within a communication system, for example a subscriber loop associated with the public-switched-telephone-network (PSTN). By utilizing current drivers having high source impedance the load across a communication connection servicing the transceiver is significantly reduced such that additional transceivers may be bridged to the communication connection without substantially affecting the quality of the communication signals.

Abstract: A noncooperative feedback system is provided for a compensation system associated with, for example, a transmitter or codec, for enabling the compensation system to improve the accuracy of digital signals transmitted to a, digital network. The noncooperative feedback system is particularly suited for providing feedback to a compensation system for correcting distortion resulting from rob bit signaling (RBS), digital loss, or other types of digital signal degradation. The noncooperative feedback system includes a compensation selector in a transmitter (e.g., digital modem, analog modem, codec, etc.) that combines different compensations with frames of digital data by way of an addition mechanism to produce modified digital data frames. The transmitter is configured to transmit the modified digital data frames into the digital network. A receiver (e.g., digital modem, analog modem, etc.

Abstract: A method and apparatus are provided for communicating data across a communication link, in a manner that senses and dynamically adapts to the simultaneous transmission of voice information across the local loop. In accordance with one aspect of the invention, a method is provided for dynamically communicating data over a local loop using a modem comprising the steps of transmitting data in a full-band transmission state, sensing a band-limiting condition, and adjusting the transmission of data from the full-band transmission state to a bandlimited transmission state, in response to the sensing step. In accordance with the method, data may be transmitted by the modem across the local loop at the same time that voice information is communicated via telephone across the same local loop. A significant aspect of the present invention is the dynamic allocation of the data transmission bandwidth, whereby the invention senses a condition indicative of whether voice information is being communicated.

Abstract: A cellular modem pool provides call progress information to a calling party during call setup. In particular, the cellular modem pool includes a coupling means, which communicates any signals between the cellular-side of the cellular data connection and the PSTN-side of the cellular data connection during call setup. This allows the calling party to hear the call progress on the called party side of the data call. In addition, the cellular modem pool monitors the signals for a data signal provided by the called party, e.g., a predefined answer tone. Once the answer tone is detected, the cellular modem pool opens the connection provided by the coupling means and processes the respective signals on the cellular-side and the PSTN-side of the cellular modem pool.

Abstract: A user-configurable frame relay network system is provided. In accordance with one aspect of the invention, the system is designed around a service provided frame relay network. More specifically, a plurality of frame relay user equipment are configured to intercommunication via one or more primary communication links that pass through a service provided frame relay network. At least one frame relay access unit is interposed between the service provided frame relay network and each frame relay user equipment. In this way, communications between the various frame relay user equipment pass through the frame relay access units. At least one secondary communication link extends from a first access unit of the plurality of access units to a second access unit of the plurality of access units, the at least one communication link being outside the service provided frame relay network.

Abstract: Apparatus and method for generating user warning signal during data transmission suspension or degradation, that allows an user to identify that parallel operation of plain old telephone system (POTS) and digital data communications equipment is either occurring, or being attempted. More particularly, the user signal warning indicates the impact to the operation of a multiple channel data communications device as a result of the parallel operation with the POTS equipment. A multiple variable signal alerts the user to the parallel operation, the amount of degradation, the elapsed time of the degradation to data communications, and which user site is causing the degradation by the direction of the data traffic being impacted.

Abstract: A plurality of distributed POTS filters (DPF) are associated with a respective plurality of POTS communications devices and decouple a POTS channel from a telephone connection, while permitting and not interfering with a second communications channel (e.g., DSL, ADSL, SDSL, RADSL, VADSL, etc.) on the telephone connection that is utilized by a modem, and permit the passage of additional signals, such as caller ID signals, to the plurality POTS communications devices. In architecture, the DPF system includes a plurality of POTS communications devices, such as telephones, and a plurality of the DPFs corresponding respectively with and connecting each of the POTS communications devices to the telephone connection. Each of the DPFs comprise an automatic control mechanism, which includes circuitry configured to allow the passage of additional signals, such as caller ID signals, to the plurality of POTS communications devices and a POTS filter.

Abstract: An improvement to a half duplex multipoint communication environment enables the full duplex communication of information between a control modem and any one of a plurality of remote modems at any given time. This is accomplished by providing a system for echo cancellation in a multipoint communication environment whereby a first modem having a first echo canceler for canceling the echo on a transmission line and a plurality of additional modems each having an echo canceler are connected to the same copper wire pair. The presence of an echo canceler in each modem connected to the transmission path enables the full duplex exchange of information between the control modem and one of the remote modems at any given time.

Abstract: Apparatus and method are provided for qualifying POTS devices for optimum operation that involve measurements and analysis of the POTS device's impedance over the modem spectrum, noise emanations, and non-linear distortion. The apparatus includes a test port that analyzes the POTS device measurements that could impact the data communication device performance over the POTS line into the user premises. Testing for line monitoring of the entire premises while the data communication device is in an operating state is also possible. Operating state testing measures the minimum and maximum data rate achievable by the data communication device while each POTS device is in an on-hook or off-hook state. The data communications device is configured to provide notice if a less than desirable data rate occurs. This notice indicates that there is a device connected within the user premises that is limiting the overall data rate and that testing of each individual POTS device is needed.

Abstract: An improvement to a half duplex multipoint communication environment wherein a digital subscriber line (DSL) receiver employs an adaptive comb filter and a decision feedback equalizer (DFE) to efficiently suppress or eliminate low frequency periodic impulse noise and crosstalk generated in the vicinity of the device receiver.

Abstract: A Mobile Switching Center (MSC) includes a cellular modem pool that comprises a number of pairs of modems in which the data terminal equipment (DTE) ports of each modem pair are cross-connected in a "back-to-back" fashion. This allows the two modems of each pair to interchange data via their DTE ports and thereby isolate that portion of the cellular fax call over the cellular communications channel from that portion of the cellular fax call through the public-switched telephone network (PSTN). Fax information is transmitted over both the PSTN-portion of the cellular fax call and the cellular portion of the cellular fax call using standard fax modulation techniques. The cellular-side modem of each modem pair is adapted to recover fax handshaking and data signaling from the received--fax modulated--signal and translate the recovered fax information into "AT-type commands" for application to the corresponding PSTN-side modem of the modem pair.

Abstract: A method and apparatus for actively simulating an apparent termination input impedance to a current driven data communication equipment (DCE) device is disclosed. The DCE device utilizes several components to implement the apparent termination impedance. A first component is a current driver for providing a source of current within the DCE device. The current source is configured to actively drive an input-output signal line within a communication link. The current driven DCE also includes a mechanism for sensing an input-output signal line voltage, a mechanism for converting the sensed voltage to a feed back current and an active termination for simulating an apparent termination impedance. The converting mechanism is coupled to a summation node which sums current provided from the current driver and current from the converting mechanism to force the desired termination impedance in the DCE device, whilst performing DCE current drive function.

Abstract: The present invention provides a method and apparatus for multi-protocol, point-to-point communications which allocates processing tasks between a processor of an end point device and a processor of a communication device. The processor of the end point device performs all higher level protocol processing and the processor of the communication device performs lower level protocol processing. Internet service providers usually have several modems connected to each host computer for providing simultaneous point-to-point communication with a plurality of end users. The modems normally are located on cards which reside inside of the host computer, which may be a personal computer. To prevent the host processor from having to perform all of the protocol processing tasks for each session, the present invention provides for off-loading at least a portion of the Point-to-Point Protocol processing onto the modem processors. The host and the communication device or devices are interfaced via a shared memory device.

Abstract: A synchronous clock regeneration system is implemented in a modem to enable the generation of a clock waveform at the same frequency as that of the transmitting device. The synchronous clock regeneration system receives an error signal indicating the timing difference in the receiving modem and the remote modem. The value in the error signal is added to a value in an offset integrator which integrates all of the error signals produced in a given transmission. The data is then relayed to a modulo subtractor which subtracts a predetermined value from the data if the value of the data is greater than the predetermined value. The data is then introduced to the offset integrator for integration and to a waveform generator. The waveform generator uses the data to offset a supply waveform an appropriate amount to match the frequency of the remote modem. As a result, the waveform generator produces a waveform that synchronously and smoothly tracks the clock waveform generated by the remote modem.

Abstract: A virtual ethernet interface interconnects a first computer at a customer premise with an ethernet local area network (LAN) at a central office that is connected to the customer premise via a digital subscriber line (DSL). The virtual ethernet interface comprises a virtual interface card connected to the first computer and a physical interface card connected to a second computer that is in communication with the ethernet hub. On start up, the central office computer sends the MAC address associated with the ethernet interface of the physical interface card back to the virtual interface card of the first computer. Thus, the virtual ethernet interface allows the first computer to form ethernet frames using the MAC address of the physical interface card so that it appear as though they were originated from the second computer. Further, the first computer can receive frames taken from the ethernet LAN by the physical interface card and transmitted to the virtual interface card over the DSL link.