Abstract: An adapter which attaches Data Terminal Equipment (DTE) to a LAN includes a latch whose state is changed by conditions, such as a free token or a frame, on the LAN. The Output of the latch is used to calculate the bandwidth utilization of the LAN.

Abstract: A network interface card for attaching computers, work stations or the like to a Local Area Network (LAN) includes a device which indicates an address compare if selected bits in a first part of an address, in the address field of a received frame, matches bits stored in the network interface card and at least one bit of a code word stored at a particular address of an index RAM is set to a predetermined state. The particular address in the index RAM is identified by a second part of the address in the received frame. The range of address which can be recognized is further extended by a contents addressable memory (CAM) coupled to the device. The CAM makes a parallel compare between an input address and its contents and outputs a match signal if a match is found. A programmable control register is used to activate or deactivate the CAM or the device.

Abstract: An adapter which attaches Data Terminal Equipment (DTE) to a LAN includes a latch whose state is changed by conditions, such as a free token or a frame, on the LAN. The output of the latch is used to calculate the bandwidth utilization of the LAN.

Abstract: Dual detection paths containing speed recognition devices automatically determine the rate at which data is being transmitted on a multi-rate digital data communications network such as a token ring network. The multiple detection paths operate simultaneously with each detection path provided with a Phase Lock Loop (PLL) and a pattern recognition device. The PLL and its associated pattern recognition device are made to operate at one of the known ring speeds. The ring speed is determined by the detection path which is able to recognize a predetermined data pattern from the network.

Abstract: A system and method is provided for estimating the bit error rate of a data signal which has been reconstructed from a received data signal. The system comprises (i) logic for determining timing degradation and amplitude degradation of the received data signal; (ii) an actual bit error rate calculator for calculating the actual bit error rate of the reconstructed data signal; (iii) an instantaneous bit error rate calculator for estimating a bit error rate of the reconstructed signal using the timing degradation and the amplitude degradation; (iv) a first integrator for integrating the estimated bit error rate; (v) a comparator for comparing the integrated estimated bit error rate with the actual bit error rate and outputting an error signal which modifies the estimated bit error rate; and (vi) a second integrator for integrating the estimated bit error rate. The time constant associated with the second integrator is shorter than the time constant associated with the first integrator.

Abstract: Clock extraction and data regeneration logic is provided for a multiple rate digital data communications system such as a local area network (LAN). The logic is implemented in adapters which connect stations in the LAN to other stations in the LAN via transmission media such as wire or fiber optic cable. The clock extraction and data regeneration logic is adapted to quickly recognize the speed at which the token ring is operating, thereby preventing a station on the ring from sending data onto the ring at a rate which does not match the operating frequency of the ring. The logic also performs, at multiple speeds of operation, clock extraction and data reconstruction of a signal received from another station in the ring.

Abstract: An adaptive regeneration system is provided for reconstructing a signal received in the form of a multi-level composite data and clock signal which has been degraded with respect to amplitude and timing. The system includes a local clock circuit for outputting a plurality of phase-delayed local clock signals, and a clock recovery circuit for receiving the received multi-level signal and the plurality of phase-delayed clock signals and extracting a phase-delayed local clock signal which most accurately represents the phase shift between the received multi-level signal and the local clock signal. A threshold level selection circuit receives the extracted phase-delayed local clock signal and the received multi-level signal and outputs in real time a data amplitude reading and a plurality of multi-level threshold levels corresponding to the amplitude levels of the received multi-level signal.

Abstract: A multi-frame stripping method for use in a token ring network utilizing early token release with multiple frames transmitted by multiple stations circulating around the ring. The method recovers the ring with minimum loss of data after detection of an error condition resulting in frame corruption. The transmitting station is responsible for removing its own frames from the ring. With one or more of its frames corrupted, a station terminates frame removal after the transmitter has finished transmitting when a frame is received from another station without code violation errors in the frame header if the frame counter has returned to its initial value. The station terminates stripping when only a single frame is transmitted and then becomes corrupted if an isolated ending delimiter is detected at the station.

Abstract: A method and apparatus for enabling the transmitter to decide the number of variable length frames that can be trasmitted within the token holding timer (THT) window. The last frame decision algorithm enables the transmitter to set the intermediate frame bit in the ending delimiter to the right state to indicate the status of each frame in the transmitted frame sequence. A look-ahead technique is used to check the remaining transmit time available in the THT time window, therefor, no ring bandwidth is wasted on partially transmitted aborated frames, effectively optimizing the throughput of the network. Since key variables in the last frame decision algoritm are softwar programmable, the algorithm is independent of ring speed. The algorithm counts transmitted octets instead of measuring transmission time in deciding whether to transmit an additional frame. The algorithm can be applied to either signal frame or multi-frame transmit mode and to either normal or early token release.

Abstract: A frame stripping algorithm for use in a ring communication network utilizing early token release wherein multiple frames can exist on the ring at one time. The algorithm introduces two new strip terminating conditions which supplement two of the three conditions applicable to a normal token release scheme. The first of these conditions occurs when the source address in a received message is not the same as the receiving station's address and no code violation errors have been detected. The second condition occurs when the receiving station detects an isolated ending delimiter without a preceding starting delimiter.

Abstract: A method and apparatus for preparing a moving vehicle for impending impact with another vehicle or object which incorporates the extending of the air bag to fill in the space between an extendible bumper. A detection apparatus senses a dangerous speed of the vehicle or an approaching object in the path of the vehicle and extends the bumper forwardly or rearwardly from the body of the vehicle while at the same time filling the space between the body and bumper with an inflated air bag. Should the impact not take place, or the dangers facing the vehicle have decreased, the apparatus retracts to its initial inoperative condition. One form incorporates a first filled bag which is filled at all times, and then a second bag which is inflated when the bumper is extended.

Abstract: This invention is a method and apparatus for detecting the impending impact of a moving vehicle with another object whether the moving vehicle is approaching, or being approached by the vehicle containing the apparatus for such detection. It is further characterized by the placement of impact air bags between the body and the forward or rearward bumper of the vehicle and by an apparatus and method for partially filling such air bags so as to prepare such vehicle for impact with another object or vehicle. The actual impact between the vehicle and said other object further rapidly fills the air bag to its fullest capacity in order to allow the minimal damage to the two vehicles and the passengers therewithin.

Abstract: An air bag system to protect occupants of automobiles against injury in case of collision. An air bag is housed, when empty, in a tapered open container in the passenger compartment of the car. It is inflated by compressed air from an air tank in the vehicle. Inflation is controlled by solenoid valves actuated by switches responsive to excessive brake pedal pressure, harness tension, or force against the front bumper. The speed of inflation may vary. A manual switch controls a deflation pump which deflates the bag and also mechanically draws it back into its container. Normal repeated use of the brake pedal operates air pumping means to keep up the pressure in the air tank.

Abstract: An asymmetrically oriented, heat set, polymeric film is provided for use in laminated structures, such film having many desired mechanical and thermal properties, such as good dimensional and thermal stability and being frangible and further having improved optical properties, being substantially clear and haze free and free of distortion and being substantially free of color fringes upon viewing in partially polarized light. This film is particularly useful in glazing structures.For glazing applications, a two-ply laminated structure is provided comprising this specific film bonded to a layer of polyvinyl butyral or other tough elastomeric film; and, further provided is a three-ply laminated structure consisting of this two-ply laminated structure coated on its other surface with an abrasion-resistant material.

Abstract: A message actuating system for automobiles includes a key operated ignition switch which is movable between a first position and a second position, the automobile ignition system being operative when the ignition switch is in either the first or second position. A message device, such as a tape player with a prerecorded message, is activated when the switch is in the first position. The message device is selectively deactivated, and the tape rewound, when the switch is turned to the second position.