In a distribution telecommunications system, channel data for performing equalisation on a channel between a central station and an outstation is determined from measurements on pairs of pulses transmitted from the outstation. Each pulse pair comprises a first in-phase pulse and a second quadrature pulse having a predetermined time/phase separation. Coefficients for an active filter provided at the outstation are calculated from the multipath transmissions of the pulses and from the received time/phase separation of those pulses. The filter is then used to pre distort signals transmitted from the outstation.

A method of determining the topology of a network comprising: transmitting a signal comprised of a sequence of bursts of packets formed of orthogonal signals, monitoring devices in the network including the destination device for reception of the signal, and defining a sequence of devices within the network by sensing a sequence of reception of the signal in the devices from the source device toward the destination device.

A system and method are provided to monitor informational resources, such as websites. A plurality of host units support one or more informational resources accessible over a network, such as the Internet. A plurality of monitoring units located on a distributed computer system are coordinated to access the network and monitor the informational resources to determine if they are accessible and to evaluate their performance. Preferably, a central control unit manages the monitoring units.

The present invention enables data communications between multiple devices over a single wire bus. This single-wire interface can be used for sensors, amplifiers, analog-to-digital converters (ADCs), or any other circuit which would normally have an electrical output. Advantages of the present invention include a reduction in device pin count, conservation of the limited number of I/O pins on the control device, and reduced board layout complexity. Speaking generally, each slave device coupled to the single wire bus interface is assigned a different response time window. This enables multiple slave devices to respond to an initial trigger signal generated by the master device without overlapping responses being generated on the single wire bus interface. A suitable slave electrical device includes application circuitry providing state information for the electrical device, an input/output pin suitable for making an electrical coupling external to the electrical device, and a single wire bus interface coupled to the input/output pin and the application circuitry. The single wire bus interface has conversion function circuitry defining a specific response time window for the electronic device. Further, the single wire bus interface is responsive to a start signal received on the input/output pin to generate a response signal within the specific response time window, the response signal indicative of the state information for the electrical device.

A reception indicator circuit is provided for use in an apparatus, wherein the apparatus enables a host system to receive information packets from a medium. The reception indicator circuit has a delay calculator, a byte count comparator and a signal asserter. The delay calculator selects and reads a reference delay value in one of N number of length-delay data storage elements. A reference length value contained in the one of N number of length-delay data storage elements corresponds to a length value of an information packet being received by the apparatus. The length value of the information packet is determined based on data in the information packet. The byte count comparator detects when the reference delay value number of bytes in the information packet have been received by the apparatus. The signal asserter asserts a reception indication signal when the byte count comparator detects that the reference delay value number of bytes in the information packet have been received by the apparatus. Alternatively, the reception indicator circuit may include a delay calculator that either calculates or selects an interrupt time. In such an alternate reception indicator circuit, the byte count comparator may be replaced by a delay comparator that determines when the interrupt time has elapsed. After the interrupt time has elapsed, the signal asserter asserts the reception indication signal. The apparatus may be a network peripheral, and the medium may be a communications network.