Soma Networks, Inc.

Yscope Inc.

University of Toronto

Huawei Technologies Canada Co., Ltd.

Quietus Systems Inc.

Oanda Corporation

Other

Wireless Systems Technologies, Inc.

Michael Stumm

William Martin Snelgrove

Xu Gang Zhao

Yu Luo

Ding Yuan

Mauricio De Simone

Livio B Soares

Richard B Olsen

David Lion

Chung-Man Abelard Chow

Sari Sultan

Muhammad Faizanullah

Ming Chen

Kia Shakiba

Yongle Zhang

Albert Lee

Bruno Richard Preiss

Mark J Frazer

Martin Snelgrove

Kirk Rodrigues

Kenneth C Sevcik

Trevor Moat

Yatish Pathak

Bruno R Preisa

Stergios V Anastasiadis

For a given application, increasing the size of a cache is beneficial up to a certain point and the number of hits does not increase significantly with a greater cache size. This disclosure provides a method to determine a miss ratio curve, for a cache having data blocks with a time-to-live. A hashed value of a data block's key address can be used to generate a 2D HLL counter for storing expiry times of the data blocks. The 2D HLL counter can be converted to a 1D array, from which a stack distance can be calculated. A frequency distribution of stack distances can then be converted into a miss ratio curve, from which an appropriate cache size can be selected.

Systems and methods to generate a cache miss ratio curve where cache data has a time-to-live

A method to obtain a cache miss ratio curve where a memory blocks of a cache have variable block sizes. By stacking sets of counters, each set being for a different block size, a stack distance for variable block sizes can be obtained and used to determine a miss ratio curve. Such curve can then be used to select a cache size that is appropriate for an application without requiring excessive memory. Methods can be used for batches of request, can apply limits to block sizes, and rounding for intermediary block sizes, they can be used with pruning, and their space complexity can be held constant.

Systems and methods to generate a miss ratio curve for a cache with variable-sized data blocks

A log of execution of an executable program is obtained. Log messages contained in the log are parsed to generate object identifiers representative of instances of programmatic elements in the executable program. Relationships among the object identifiers are identified. A representation of identified relationships is constructed and outputted as, for example, a visual representation.

Log processing and analysis

Existing program code, which is executable on one or more computers forming part of a distributed computer system, is analyzed. The analysis identifies log output instructions present in the program code. Log output instructions are those statements or other code that generate log messages related to service requests processed by the program code. A log model is generated using the analysis. The log model is representative of causal relationships among service requests defined by the program code. The log model can then be applied to logs containing log messages generated by execution of the program code, during its normal operation, to group log messages for improved analysis, including visualization, of the performance and behaviour of the distributed computer system.

Systems and processes for computer log analysis

Existing program code, which is executable on one or more computers forming part of a distributed computer system, is analyzed. The analysis identifies log output instructions present in the program code. Log output instructions are those statements or other code that generate log messages related to service requests processed by the program code. A log model is generated using the analysis. The log model is representative of causal relationships among service requests defined by the program code. The log model can then be applied to logs containing log messages generated by execution of the program code, during its normal operation, to group log messages for improved analysis, including visualization, of the performance and behavior of the distributed computer system.

A method and system is disclosed which alters the performance of computer systems to make exception-less system calls, thus avoiding or reducing the direct and indirect overheads associated with making an exception-based system call. The invention can be employed with single core processor systems and with multi-core processor systems.

Method and system method and system for exception-less system calls for event driven programs

A method and system is disclosed which can enhance the performance of computer systems by altering the operation of the operating system of those computer systems. The invention provides a system and method for making exception-less system calls, decoupling the invocation and execution of system calls, thus avoiding or reducing the direct and indirect overheads associated with making a conventional exception-based system call. The invention can be employed with single core processor systems and with multi-core processor systems, both affording improved temporal execution locality and the later also providing improved spatial execution locality. The system and method can be employed in a wide range of operating systems.

Method and system for exception-less system calls in an operating system

In one aspect, the present invention comprises a system for trading currencies over a computer network. A preferred embodiment comprises: (a) a server front-end; (b) at least one database; (c) a transaction server; (d) a rate server; (e) a pricing engine; (f) an interest rate manager; (g) a trade manager; (h) a value at risk server; (i) a margin control manager; (j) a trading system monitor; and (k) a hedging engine. In another aspect, the present invention comprises methods for trading currency over a computer network. In another aspect, the present invention comprises software for currency trading over a computer network.

Currency trading system, methods, and software

A telecommunication system and method for communicating between at least two end users over a telecommunication network, where the communication is defined by a set of parameters. At least two entities, such as one or both of the end users and/or the service providers negotiate an agreed set of values for said parameters that define the desired communication. The entities also negotiate a warranty agreement with the network service provider defining at least one of the agreed parameters to be warranted including a compensation method to be applied should said at least one monitored parameter fail to meet the corresponding one of said agreed values. The agreed warranted parameters are monitored once the communication is established and, in the event of a failure of the monitored parameters to meet agreed values, at least one of the entities is compensated in accordance with the agreed compensation method. When more than two entities are involved in a communication, the compensation from an entity can be divided amongst the other entities according to an agreed scheme.

Method and system of teleconferencing

The present invention provides a novel telecommunication architecture. The architecture includes a subscriber agent for each subscriber within a telecommunication network. The subscriber agent includes the subscriber's telephone number and calling features. The network also includes terminal agents which are directly associated with one or more terminals such as telephones. The subscriber agent can be associated with one or more terminal agents within the network, so that the subscriber's telephone number and set of calling features can be carried to any terminal within the network. A wide variety of calling features and terminals are supported by the architecture.

Telecommunication architecture

A media server having at least one of a stride-based storage device space allocation scheme, stride-based method of striping data across multiple storage devices for continuous media streaming, server-based smoothing of variable bit-rate streams, distributed architecture, and fault tolerance.

Streaming server

A subscriber station operable to communicate with a base station and provide telephony and data services to users. The subscriber station connects to telephony and data devices and preferably communicates with the base station using a wireless modem.

Subscriber stations

A wireless local loop system manages radio data transmission capacity and network resources shared by a plurality of subscriber stations by considering the type of connections desired to be created to the subscriber stations and the radio data transmission capacity, and in some cases QoS parameters, and network resources required for those connections. The subscriber stations include data and telephony ports and can include a subscriber utilization client (SUC) to assist in the management process. The SUC in each subscriber station communicates with a network utilization manager (NUM) to request network resources from the base station. The NUM determines the requirements, in data transmission capacity and/or QoS levels, for the desired connection and considers the utilization of the network resources at the base station, or sector of the base station, in determining whether to establish the desired connection. The NUM can consider the required level and a desired level of data transmission capacity and/or QoS levels and allocate resources for the connection according to either level, or therebetween. The SUC and NUM can prioritize the establishment of connections on an appropriate basis, including the type of connection, the parties to the connection, the revenue potential of the connection and the port for the connection at the subscriber station, etc.

Wireless local loop

The present invention relates generally to telecommunications, and more specifically to a method and system of providing telecommunication services that is flexible and efficient. Existing Public Switched Telephone Network systems suffer from a number of problems including system complexity, access being proprietary and services being implemented on fixed hardware. As a result, new services are complex and costly to develop, so telcos only provide services that appeal very broadly. The invention provides an open and flexible system by describing communications in terms of graph packets which contain pointers to blocks of software code, rather than containing large blocks of executable code. In the preferred embodiment, these graphs identify software filters which are dedicated to particular tasks, and are based on a standard API. This allows third parties to create new filters and make them available, allowing new services to be provided quickly and easily.

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Toronto, Canada

Michael Stumm