Abstract: A shared spanning tree protocol (SSTP) creates a plurality of spanning trees (i.e., loop-free paths) which are shared among one or more virtual local area network (VLAN) designations for data transmission within a computer network. Each shared spanning tree includes and is defined by a primary VLAN and may be associated with one or more secondary VLANs. In order to associate VLAN designation(s) with a single shared spanning tree, network devices exchange novel shared spanning tree protocol data units (SST-PDUs). Each SST-PDU corresponds to a given primary VLAN and preferably includes one or more fields which list the secondary VLAN designations associated with the given primary VLAN. The association of VLAN designations to shared spanning trees, moreover, preferably depends on which path traffic is to follow as well as the anticipated load characteristics of the various VLANs. The association of VLAN designations to shared spanning trees thus provides a degree of load balancing within the network.

Abstract: A port aggregation protocol (PAGP) dynamically aggregates redundant links between two neighboring devices in a computer network through the exchange of aggregation protocol data unit (AGPDU) frames between the two devices. Each AGPDU frame contains a unique identifier corresponding to the device sourcing the frame and a port number corresponding to the port through which the frame is forwarded. The exchange of AGPDU frames and the information contained therein allows the neighboring devices to identify those ports corresponding to the redundant links. Each device then dynamically aggregates its ports corresponding to the redundant links into a logical aggregation port (agport) which appears as a single, high-bandwidth port or interface to other processes executing on the device.

Abstract: There is disclosed a bit sync search and frame sync search system operative with a digital data signal as transmitted by a digital radio transmitter. The bit search is implemented by detecting a predetermined phasing signal which is incorporated in the digital signal and which has a repetitive bit pattern of ones and zeroes. The phasing signal is first detected by providing an in-phase and quadrature component signal and correlating those signals to provide an output signal indicative of the bit pattern in the phasing signal. After the phasing signal has been provided and an oscillator associated with a receiving apparatus is compensated according to the detected phasing signal, a tracking mode is entered, whereby a frame signal is captured and the system generates histograms of data bit transitions for producing an error signal indicative of the difference of the transmitted clock rate and the sampling portion of a received bit.

Abstract: There is disclosed a bit sync search and frame sync search system operative with a digital data signal as transmitted by a digital radio transmitter. The bit search is implemented by detecting a predetermined phasing signal which is incorporated in the digital signal and which has a repetitive bit pattern of ones and zeroes. The phasing signal is first detected by providing 94 in-phase and quadrature component signals and correlating those signals to provide an output signal indicative of the bit pattern in the phasing signal. After the phasing signal has been provided and an oscillator associated with a receiving apparatus is compensated according to the detected phasing signal, a tracking mode is entered, whereby a frame signal is captured and the system generates histograms of data bit transitions for producing an error signal indicative of the difference of the transmitted clock rate and the sampling portion of a received bit.

Abstract: A port aggregation protocol (PAGP) dynamically aggregates redundant links between two neighboring devices in a computer network through the exchange of aggregation protocol data unit (AGPDU) frames between the two devices. Each AGPDU frame contains a unique identifier corresponding to the device sourcing the frame and a port number corresponding to the port through which the frame is forwarded. The exchange of AGPDU frames and the information contained therein allows the neighboring devices to identify those ports corresponding to the redundant links. Each device then dynamically aggregates its ports corresponding to the redundant links into a logical aggregation port (agport) which appears as a single, high-bandwidth port or interface to other processes executing on the device.

Abstract: A signal management system is disclosed which integrates a patient switching box and an amplification unit into a single compact enclosure sufficiently small to reside by the patient table in an operating unit set up for electrophysiology procedures. The system includes a front panel designed to accept standard ECG leads, a plurality of intracardiac leads, including leads available for stimulation and/or lesion generation, and a plurality of pressure channels. The front panel also includes a touch screen display to allow quick assignments of labels to each of the ECG or intracardiac leads and the pressure channels. The system includes an onboard microprocessor which allows any operation performed on the System to be automatically updated on a remote computer processing unit if attached, and vice-versa. Digital signal processors are used in the system to perform switching operations on the electrical signals received, and to perform gain, limiting and/or filtering processes thereon.

Abstract: A versatile electrophysiology study monitoring system including an amplification system, a real time display monitor and a chart recorder as well as an optional data management and analysis system wherein the display monitor and chart recorder are controllable directly from the amplification system which may be positioned at the bedside of the patient to provide a portable system which may be used at the bedside of the patient or in the electrophysiology laboratory and which also includes a 32 channel display of physiological data and user settable filter settings for high and low pass filters.

Abstract: An integrated communications link in a communications network that is provided with apparatus which allows dynamic allocability of bandwidth among a plurality of channels. At least three different types of information can be carried on these channels, and the bandwidth of these channels are dynamic so that it can be changed according to a determinable scheme. The link also sends error control information with a message that informs the receiver how the bandwidth is to be allocated, this error control information providing an extremely high level of assurance that the receiver of the information will know how the received information is to be allocated.

Abstract: A method for maintaining a correct time in a distributed processing system involves clerk nodes maintaining their local clocks by requesting time intervals from server nodes, and server nodes maintaining their local clocks either by requesting time intervals from other server nodes or by receiving time information from an outside source. Server nodes also provide time intervals to requesting clerk nodes and requesting server nodes with such a method. System time is always increasing and monotonic and faulty servers are detected periodically.