Abstract: In a battery pack made up of battery cells encased within a housing made up of a stronger outer housing portion and a weaker inner housing portion, the battery cells are secured to the stronger outer housing portion. Advantageously, the relative motion between the battery cells and the stronger of the housing portions that results when prior art battery packs are dropped, and which causes catastrophic failure of the prior art battery packs, is prevented. The battery cells may be secured to the stronger outer housing portion, for example, by gluing the battery cells to the stronger housing portion, attaching the battery cells to the stronger housing portion by using double-sided sticky tape, molding features into the stronger housing portion that immobilize the battery cells adjacent to the stronger housing portion, or providing screw holes through the stronger housing portion so that screws may engage the battery cell or an appendage thereto.

Abstract: Power control for a laser is performed on at least a per-packet basis, rather than a per-pulse basis, and that end-of-life detection may similarly be performed. This is achieved by accumulating the current generated by a photodiode in response to the light signal generated by the laser, subtracting therefrom a preset threshold current which is similarly modulated in response to the data signal used to drive the laser, and comparing the resulting difference to the value prior to having begun accumulating and subtracting. The result of the comparison, which may be filtered, is used to control the driver of the laser or as an indicator, e.g., for use in end-of-life detection.

Abstract: A limitation of a three dimensional world in which objects in the distance may be represented in only two dimensions as a video on a screen is that when an object within the field represented by the video undergoes a trajectory that takes it to a location in the world that is not represented by the video but instead is a location which is represented by computer graphics, namely, any portion of the object that is no longer on the video screen disappears. To overcome this limitation, when an object within the field represented by the video undergoes a trajectory that takes it to a location in the world that is not represented by the video on the video screen as currently configured, i.e., shaped and sized, the configuration of the screen is changed so that the object can continue to be displayed as video. The size and/or shape of the video screen is changed.

Abstract: Enhanced Internet service is provided over an ISDN line by eliminating from the D-channel any packets that will introduce unacceptable delay in packets transmitted over the B-channel. The enhancement is achieved by segregating the packets between the B-channels and the D-channel based on the stream to which the packets belong. Furthermore, instead of bonding together both B-channels and the D-channel, only the B-channels may be bonded to each other, while the D-channel is kept independent. To do so, instead of using MLPPP over the combination of both B-channels and the D-channel, as in the prior art, MLPPP is used over only both B-channels, while data that is separately directed to the D-channel employs another protocol, e.g., PPP. Advantageously, the number of protocols used to transmit the information over the D-channel may be reduced, resulting in a higher bandwidth for applications.

Abstract: Power control for a laser used for bust mode communication as well as end-of-life detection for the laser are performed in a combined manner, resulting in a savings in both cost and power consumption. This is achieved by employing a peak comparator which is supplied with an indication of the magnitude of a the laser signal, and supplying to the peak comparator in a time multiplexed manner with different thresholds, such as a first threshold which is used for performing power control and a second threshold which is used for performing end of life detection, on an alternative packet-by-packet basis. Thus, the first threshold is supplied for the duration of a first packet and the second threshold is used for the duration of a second packet. Additional thresholds and packets may be employed for other functions as desired by an implementor.

Abstract: A user on a data call, e.g., to the Internet, is prevented from establishing a data call immediately after an emergency interrupt has been initiated, and the fact that the emergency interrupt took place is brought to his attention. This is necessary because otherwise the emergency interrupt is likely to be perceived by a user connected to the Internet as simply a dropped line, in response thereto the user is likely to simply originate a new call to the ISP, and so may never become aware that there has been an attempt to bring to his attention, via the emergency interrupts, an extraordinary circumstance. The invention achieves this by transmitting from the telephone network a signal which is recognizable by the user's modem and which indicates that an emergency interrupt took place. Such an emergency-interrupt-occurred signal may be transmitted upon the occurrence of the emergency interrupt or after the line next goes off-hook. Such a signal may be in addition to or in lieu of dial tone.

Abstract: A bipolar peak detector that maintains the charge on its capacitor longer than prior art peak detectors can due to the discharging thereof that occurs during long periods of reception of only a single value in the received signal, e.g. a long string of zeros, by substantially exactly duplicating, i.e., duplicating to within manufacturing tolerances, the current that is leaking out of the capacitor and injecting the duplicate current into the capacitor.

Abstract: A high density read only memory structure is arranged to have the decoders and selectors which are used to access the read only memory arrays in a layer which is above and/or below the read only memory array layers. Note that by layer it is meant a substantially planar structure with some thickness in which the circuitry that makes up particular functionality resides. Thus, the inefficient two-dimensional structure of the prior art is folded over to create a compact read only memory device with a three-dimensional structure. Connection of the decoders to the rows is not limited to the ends of the rows, but instead may be made at any point along the rows. Similarly, connection of the selectors to the columns is not limited to the ends of the columns, but instead may be made at any point along the columns. Advantageously, additional circuitry is not required on the periphery of the memory array, so that a smaller overall memory device is achieved.

Abstract: A verification of the protocol between the various communicating elements of a concurrent system may be performed directly using the actual code that implements the element when it is actually operating. This is achieved by combining stateless search techniques with partial order methods, namely, persistent set and sleep set methods. In particular, the code of each element of a system is exercised by a scheduler in such a way that global states of the system are visited according to a stateless search, which is a search that does not use an explicit representation of the global states. A global state is a state in which the next operation to be executed by every element of the system is a visible operation. The set of visible operations includes at least those operations related to communication between the elements.

Abstract: Enhanced Internet service is provided over an ISDN line by eliminating from the D-channel any packets that will introduce unacceptable delay in packets transmitted over the B-channel. The enhancement is achieved by segregating the packets between the B-channels and the D-channel based on the stream to which the packets belong. Furthermore, instead of bonding together both B-channels and the D-channel, only the B-channels may be bonded to each other, while the D-channel is kept independent. To do so, instead of using MLPPP over the combination of both B-channels and the D-channel, as in the prior art, MLPPP is used over only both B-channels, while data that is separately directed to the D-channel employs another protocol, e.g., PPP. Advantageously, the number of protocols used to transmit the information over the D-channel may be reduced, resulting in a higher bandwidth for applications. The bandwidth of the D-channel can be dynamically throttled by an access server.

Abstract: Information can be communicated back from a receiver to a transmitter over a serial link designed for communication to be essentially only in one direction without requiring a separate feedback path with an extra wire. This is achieved by changing at least one characteristic of the receiver input. For example, the receiver input impedance, the receiver input voltage, or both, may be altered. The change in a characteristic of the receiver input can be detected by an appropriately designed transmitter, and such detection can be used to trigger a change in the behavior of the transmitter. Advantageously, only simple alterations are required in conventional serial link circuits to provide a low bandwidth reverse communication path over the same wires. Such a change in a receiver input characteristic can also be employed to inform a transmitter of the existence of a receiver that is on a card that is hot-plugged into system.

Abstract: A mix of computer graphics and video is employed to display images, and more particularly, the ratio of computer graphics to video is adjusted as a function of the available processing and transport capacity. The function for adjusting the ratio of computer graphics to video may also be dependent on the motion of the viewer's viewpoint.

Abstract: An image sensor circuit which employs a photodiode in conjunction with a charge transfer mechanism. By employing the photodiode, at least a portion of the light sensed does not pass through a layer of polysilicon, and so is not prevented from reaching the sensing area by the polysilicon. The image sensor circuit of the invention is made up of device structures readily available in standard CMOS process technologies Advantageously, image sensors embodying the invention show substantially improved quantum efficiency for short wavelength light over the prior art sensors. In addition, image sensors embodying the invention display improved dark current uniformity, thus improving yield.

Abstract: The NEG output of the Booth encoding circuit and the multiplicand input are gated so as to minimize switching activity in the multiplier without adding any delay to the critical path thereof. Advantageously, power consumption in the multiplier is significantly reduced, e.g., on the order of 90%, when multiplication is in fact not being performed. Additionally, by changing the structure of the last XOR gate of the partial product generation circuit, the need to gate the multiplicand input can be eliminated. Advantageously, this eliminates the extra circuitry which would otherwise be required to gate the multiplicand input, thus reducing cost. Furthermore, additional power savings may be achieved by efficiently resynchronizing the multiplicand input with the Booth encoded input to the partial product circuit.

Abstract: A DC coupled burst mode optical receiver circuit having improved sensitivity and improved dynamic range. The output of the receiver's photodiode is single endedly amplified by a main preamplifier and the main preamplifier's output is then converted, using an operational amplifier, e.g., with a gain of 1, to a differential signal which swings symmetrically around a threshold level. More specifically, the output of the main preamplifier is connected to one input of the operational amplifier. The output of a tracking preamplifier, which is identical to the main preamplifier, is coupled to the other input of the operational amplifier. The output of the tracking preamplifier is used to match the DC voltage of the main preamplifier, e.g., by being noise-free and by tracking changes in supply voltage, temperature, and the like. It is used to set the DC reference voltage for the standard operational amplifier functions.

Abstract: The length of the tail which results in an optical output from a laser diode after the laser diode is no longer being driven is reduced or eliminated by a laser diode driver with a tail eliminator. More specifically, the laser diode driver includes an energy drainage path that is activated when packet communication is over. In one embodiment of invention, the terminals of the laser diode are short-circuited to provide the energy drainage path. In another embodiment of the invention, the laser diode is reverse biased, so that charges stored in the laser diode are combined with charges which are provided thereto. Advantageously, the tail emission is substantially eliminated.

Abstract: The amount of jitter that results in a serial receiver having a parallel architecture Can is reduced by insuring that the edges specifically introduced by the code are actually received by the phase detector. In particular, the code is designed to increase the probability that the edges it introduces are actually received by the phase detector. In a preferred embodiment of the invention, all the edges introduced by the code are actually received by the phase detector. This is achieved by guaranteeing that the edges introduced by the code are evenly spaced in the data stream at a rate corresponding to the phase detector sampling rate. For example, if the receiver consists of N data samplers, e.g., N=5, and one phase detector, the edges introduced by the code are arranged to be N symbols apart. This may be done by inserting as the Nth symbol an overall symbol that has a dummy component so that an edge results between the N-1 symbol and the overall Nth symbol.

Abstract: A DC coupled burst mode optical receiver circuit having improved sensitivity and improved dynamic range. The output of the receiver's photodiode is single endedly amplified by a main preamplifier and the main preamplifier's output is then converted, using an operational amplifier, e.g., with a gain of 1, to a differential signal which swings symmetrically around a threshold level. More specifically, the output of the main preamplifier is connected to one input of the operational amplifier. The output of a tracking preamplifier, which is identical to the main preamplifier, is coupled to the other input of the operational amplifier. The output of the tracking preamplifier is used to match the DC voltage of the main preamplifier, e.g., by being noise-free and by tracking changes in supply voltage, temperature, and the like. It is used to set the DC reference voltage for the standard operational amplifier functions.

Abstract: An enhanced call waiting (ECW) feature is provided by a switch serving a called subscriber who, while still on a first telephone call, receives a subsequent telephone call.

Abstract: When a user has a portable telephone near the absolute end of its available battery power, the user can be caused to behave in a manner that more likely results in the preservation of some battery power for subsequent high priority high priority calls by conveying the illusion that the battery will soon be, or is, depleted even though there actually remains sufficient power in the battery to power the portable telephone for an additional period of time. To this end, at a predetermined time, e.g., two minutes, prior to a projected time at which the battery is expected to have power for only a particular additional amount of time, e.g., eight minutes, the user is signaled with an almost-out-of-power warning. This warning indicates that there remains in the battery enough power to operate the portable telephone only until the projected time, notwithstanding that there actually remains in the battery sufficient power to operate the portable telephone for the additional time beyond the projected time.