International Business Machines Corporation

Times N Systems, Inc.

T.n.s. Holdings, Inc.

Lynn P West

Theodore G Scardamalia

Harold G Markey

Harold B Pearce

Joseph A Alvarez, Iii

Donald C Flemming

Mark A Einkauf

Bruce D Gobioff

Karlon K West

Brian E Parker

Ralph J Metz

Systems and methods are described for a load/store micropacket handling system. A method includes interconnecting a compute node with a shared memory node; translating a processor instruction into an interconnect command; transforming the interconnect command into a direct memory access interconnect command; transmitting the direct memory access interconnect command via a link medium; and performing an operation defined by the direct memory access interconnect command. An apparatus includes a computer network, including: a compute node, having: a compute node interconnect interface unit; and a compute node interconnect adapter; a link medium, coupled to the compute node; and a shared memory node, coupled to the link medium, having: a shared memory node interconnect interface unit; and a shared memory node interconnect adapter.

Load/store micropacket handling system

A method and apparatus for using a memory adapter may allow a system to access the memory adapter. The memory adapter may comprise a list of entries for data within the memory adapter. Each entry may include an adapter memory segment offset, a segment length, a segment status, and a corresponding system memory address. The adapter memory segment offset may be the location of the offset within the memory adapter. A processor may access the adapter memory segment offsets through the system address space. The method and apparatus may be used to perform functions, such as read adapter memory, write adapter memory, insert adapter memory segment, remove an adapter memory segment, scan for an adapter memory segment, scan for a removable adapter memory segment, and potentially other functions.

Method and apparatus for demand usable adapter memory access management

A memory alias adapter, coupled to a processor's memory bus, monitors processor memory accesses. Whenever a memory access corresponds to shared memory, rather than memory local to the processor, the adapter constructs a memory request message, and transmits the message over a network link to a shared memory unit. The shared memory unit performs the shared memory access and issues a response message over the network link. The memory alias adapter accepts the response message, and completes processor's memory access on the memory bus. As a result, it is transparent to the processor whether its memory access is to the local memory or to the shared memory.

Shared memory apparatus and method for multiprocessor systems

A memory alias adapter, coupled to a processors memory bus, monitors processor memory accesses. Whenever a memory access corresponds to shared memory, rather than memory local to the processor, the adapter constructs a memory request message, and transmits the message over a network link to a shared memory unit. The shared memory unit performs the shared memory access and issues a response message over the network link. The memory alias adapter accepts the response message, and completes processor's memory access on the memory bus. As a result, it is transparent to the processor whether its memory access is to the local memory or to the shared memory,

Automatic gain control in a digital signal processor. An incoming electrical signal is sampled and multiplied by a gain factor with the resulting product compared to a constantly changing maximum value. If the magnitude of the changing maximum value lies outside a predetermined range of values, then the gain factor is adjusted proportionally to the error calculated by the amount the maximum value is outside the threshold range. In an alternative embodiment, the gain is adjusted according to whether or not one of the resulting products lies outside such upper and lower threshold range. The running maximum value decays with time in order to allow the automatic gain control to rack a signal which slowly weakens in strength. A time dependent factor enables the gain to be adjusted much more radically when a signal is first received.

Proportional automatic gain control

This invention enables voice energy to be distinguished from energy due to other sources such as telephone call progress signals. A portion of the audio spectrum is divided into a high and into a low frequency band and the energy content of these bands is examined. The audio energy of a signal is passed through a set of filters and compared. A frequency boundary crossing of an input signal subsequent to filtering is used to signify the receipt of a voice signal. By operating in this manner, voice, whose predominant frequency switches in a random fashion from being greater than to less than a cutoff frequency, can be distinguished from other signals either below or above the cutoff frequencies of the filters. The detection of voice energy is not begun until a predetermined threshold of energy has been received for a specified period of time. This specified period of time need not be continuous after a ringback signal is received. Subsequent to the receipt of a ringback signal, the voice detection mechanism will proceed as long as the total time above the threshold exceeds the specified time.

Method and apparatus for voice detection having adaptive sensitivity

Automatic gain control (AGC) is provided in a digital signal processor environment. A predetermined threshold value, a predetermined automatic gain control value, and a predetermined count threshold value are established and stored in a data memory associated with a signal processor. Each incoming signal sample that is received is multiplied by the AGC value with the product being temporarily stored in the data memory. The absolute value of the resulting product is taken and added to the predetermined threshold value. If the result of this operation results in a signal processor overflow, then the AGC value is reduced and stored back into the data memory. The adjustment period of the AGC value is chosen to be well under the allowable distortion time for speech, dual tone multi-frequency reception, and modem operation.

Automatic gain control in a digital signal processor

A method and apparatus are described for phase and frequency locking a reference oscillator to an incoming modulated signal. The method and apparatus enable the carrier recovery of the incoming modulated signal. Phase and frequency locking devices are connected in feedback loops with a coherent detector that determine the amount of phase and frequency error between the reference oscillator of the coherent detector and the incoming modulated signal. The feedback loops correct such frequency and phase error so as to enable the reference oscillator to be in phase and frequency step with the modulated signal.

Carrier recovery of modulated signals

A filter suppresses energy at time varying or ensemble varying frequencies. The filter comprises multiplier sections having sets of values which are dynamically varied during the receipt of time varying or ensemble varying energy. The variation of the values of the multiplier sections provides the suppression of energy at the time varying or ensemble varying frequencies. The sets of values for the multiplier sections are chosen such that the poles of such values lie within the unit circle of the z-plane locus. The location of the poles within the unit circle guarantees that the filter remain stable even though the multipliers may be located in a feedback path. In the preferred embodiment, the dynamically varying filter is used in a dual tone multi-frequency (DTMF) receiver.

Adaptive stop-notch filter

A starloop communication network for intraestablishment communication in a multiterminal processing system includes a digital switch as its central terminal. In the basic mode, the switch is configured so that the input from each terminal is switched back to the next terminal forming a loop network. A central processor in the network need only service the output of the first terminal on the loop and the input from the last terminal. The digital switch includes a port connected to monitor activity on the loop. In the event of a failure, the monitor can determine the failing terminal in the loop by use of a binary search around the loop. The failing terminal will be detected by the monitor and automatically isolated from the loop by the digital switch. The communication network may also be configured to include a plurality of terminal devices of equal performance and intelligence, i.e. a plurality of central processors.

Starloop communication network and control system therefor

In a time division multiple access (TDMA) system, for 'multi-path' data communication via satellite repeater, the form of transmitted data is varied adaptively to maintain error-free transmission under varying noise conditions. Adjustments are made on a path selective and channel selective basis to protect only the most vulnerable data in specific transmission paths experiencing noise deterioration. Accordingly any multi-channel burst may contain channels of data in both protected and unprotected forms. A predetermined portion of each channel containing data in unprotected format is used explicitly to designate the destination of the accompanying data and implicitly to distinguish the data format as unprotected. In protected format data including error protective coding is transmitted in two contiguous channels along with information in the first channel explicitly distinguishing the protected format. This format-distinguishing information occupies the space allotted in the unprotected format for designating the data destination. The destination of protectively encoded data is explicitly designated in a separate predetermined space in the associated double-channel slot.

Adaptive error encoding in multiple access systems

Modular digital exchange terminals linked in a network by earth satellite provide coordinated multiplex switching and activity compression between line circuits and satellite time division channels. The line circuits carry digital data and digitalized voice telephone information into and out of the network. Nodal access modules (NAU's) interface to the satellite radio equipment. Branch exchange modules (NCU's) link line circuits switchably to a nodal access module through time division channels of subsidiary digital communication links. In transit up-link (to satellite time division channels) information is switched between lines and NCU buffer stores (virtual channels), selectively assigned by activity compression to time channels on associated digital links (each link accommodating only a fraction of the virtual traffic capacity of the associated stores), and transmitted to the NAU. In the NAU the activity compressed composite is time-concentrated with traffic of other digital links (in NAU buffer storage), and passed out on demand assigned satellite time division (traffic burst) channels. In downlink distribution to outlet line circuits the receiving NAU picks out from the interleaved network composite only the information channels destined for its outlet line circuits. These are stored, reordered in space/time associations with digital link time channels and activity compressed into associated digital link channels. The receiving NCU buffers and switches the information through associated internal (virtual) channels to respective outlet line circuits (destinations).

Distributional activity compression

Modular digital exchanges linked by earth satellite provide coordinated time division switching and time compressed communication services relative to externally attached telephone and data (user) trunks. Branch exchange modules (NCU's) perform call switching, buffer storage, time compression and activity selective channel assignment handling between individual external user trunks and multi-bit channels of external time division highways (digital links). The latter are linked pyramidally to time division multiple access nodes of the satellite through Network (Nodal) Access Unit modules (NAU's) which perform further time compression handling and adaptive assignment of satellite channels based upon nodal distribution of demand. The NCU modules also provide 'local' switching between user trunks and 'tandem' linkage directly between NCU's (without NAU and satellite handling). The modules have individual common control processors which inter-communicate via reserved signaling channels on the digital links and satellite. The modularity is in increments suitable for adaptive deployment of connection equipment relative to satellite access nodes (e.g. to adapt to shifts in user populations and/or plant facilities).

Modular branch exchange and nodal access units for multiple access

Digital exchange stations linked by earth satellite operate in a coordinately controllable time division switching and communication network system relative to externally attached telephone and data trunks. Modular switching equipment operating in coordination with satellite frames establishes and releases connection paths to trunk stores which interface with time and space domain channels of the system. Circuits through the system utilizing these paths are termed virtual connections because in different frames a circuit may be completed through different channels or even blocked under certain conditions. Telephone speech is converted between analog and digital forms relative to modular groups of 96 ports. Digital switching (slot interchange) equipment serving up to four groups (and cycling in coordination with satellite time division frames) cyclically completes local (intra-station) connections between ports and segments of toll (inter-station) connections between ports and locations in the trunk stores. The trunk stores comprise separate sections for system traffic bound to and from ports of the respective station. A duplicate arrangement of subsections in each section is alternately filled and emptied in successive frames; enabling the station to maintain continuity of communication relative to the system in successive frames. The 192 bit spaces of each location are filled in one frame and emptied in the next frame. Groups of 96 outbound locations are 'virtually' associated for transmission with groups of 48 time division transmission channels of said facilities. The association operates by a process of selection termed voice activity compression (abbreviated VAC) based upon activity information developed at the port interface and carried through the switching equipment in positional association with trunk locations. The VAC process assigns only locations (virtual channels) containing activity to up to 46 of the 48 time channels, eliminating any excess of active virtual channels (over 46) in a selective order of priority. VAC mask information transmitted in a separate one of the 48 time channels indicates the virtual-to-real (96-to-46) assignment for the respective group in the respective frame. A bit in the mask for each virtual channel of the group indicates the assignment or elimination of the respective virtual channel. Assigned channels are transmitted in the time order of respective mask bits. Establishment of virtual connections is restricted system-wide by tables stored in the stations. These tables are subject to external modification and may contain path exclusion information enabling the system to remain effectively operational with inoperative elements.

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Austin, TX, United States of America

Lynn P West