Microsoft Technology Licensing, LLC

Gerald Cermak

John R Douceur

Atul Adya

William J Bolosky

Galen Clyde Hunt

Robert J Stets, Jr

Marvin Michael Theimer

Roger Wattenhofer

Eric J Horvitz

John Charles Krumm

Edward C Miller

Adel Amin AbdelAzim Youssef

Gideon Andreas Yuval

Davide Massarenti

R Donald Thompson, Iii

Cosmin A Corbea

A serverless distributed file system manages the storage of files and directories using one or more directory groups. The directories may be managed using Byzantine-fault-tolerant groups, whereas files are managed without using Byzantine-fault-tolerant groups. Additionally, the file system may employ a hierarchical namespace to store files. Furthermore, the directory group may employ a plurality of locks to control access to objects (e.g., files and directories) in each directory.

Serverless distributed file system

Serialized data from broadcast services is provided to a broadcast server for transmitting to one or more client devices. The serialized data may correspond to shared data, private data, or control data. Data is scheduled for transmission based on weighted priorities including quality of service metrics. The transmission frame is arranged according to a frame protocol that includes provisions for a table of contents indexing system for the shared data. Packets of shared data are formatted based on criteria that is known by the particular broadcast service and corresponding application that is resident on the client device. The client device receives the table of contents at the transport layer, and notifies applications of data that will be available in the next frame. Applications submit prioritized requests to the transport layer, requesting data in the next frame. Data is retrieved by the transport layer, and deserialized by handlers for each application.

Frame protocol and scheduling system

Methods of factoring operating system functions into one or more groups of functions are described. Factorization permits operating systems that are not configured to support computing in an object-oriented environment to be used in an object oriented environment. This promotes distributed computing by enabling operating system resources to be instantiated and used across process and machine boundaries. In one embodiment, criteria are defined that govern how functions of an operating system are to be factored into one or more groups. Based on the defined criteria, the functions are factors into groups and groups of functions are then associated with programming objects that have data and methods, wherein the methods correspond to the operating system functions. Applications can call methods on the programming objects either directly or indirectly that, in turn, call operating system functions.

Methods of factoring operating system functions, methods of converting operating systems, and related apparatus

Methods of factoring operating system functions into one or more groups of functions are described. Factorization permits operating systems that are not configured to support computing in an object-oriented environment to be used in an object oriented environment. This promotes distributed computing by enabling operating system resources to be instantiated and used across process and machine boundaries. In one embodiment, criteria are defined that govern how functions of an operating system are to be factored into one or more groups. Based on the defined criteria, the functions are factors into groups and groups of functions are when associated with programming objects that have data and methods, wherein the methods correspond to the operating system functions. Applications can call methods on the programming objects either directly or indirectly that, in turn, call operating system functions.

The present invention leverages changes in the sensed strength of radio signals at different locations to determine a device's location. In one instance of the present invention, inference procedures are used to process ambient commercial radio signals, to estimate a location or a probability distribution over the locations of a device. In another instance of the present invention, a system utilizes learning and inference methods that are applied to rank vector of signal strength vectors. Moving to such rank orderings leads to systems that bypass consideration of absolute signal strengths in location calculations. The present invention facilitates approximations for locating a device by providing a system that does not require a substantial number of available ambient signal strengths while still providing useful location inferences in determining locations.

Systems for determining the approximate location of a device from ambient signals

A file format for a serverless distributed file system is composed of two parts: a primary data stream and a metadata stream. The data stream contains a file that is divided into multiple blocks. Each block is encrypted using a hash of the block as the encryption key. The metadata stream contains a header, a structure for indexing the encrypted blocks in the primary data stream, and some user information. The indexing structure defines leaf nodes for each of the blocks. Each leaf node consists of an access value used for decryption of the associated block and a verification value used to verify the encrypted block independently of other blocks. In one implementation, the access value is formed by hashing the file block and encrypting the resultant hash value using a randomly generated key. The key is then encrypted using the user's key as the encryption key. The verification value is formed by hashing the associated encrypted block using a one-way hash function. The file format supports verification of individual file blocks without knowledge of the randomly generated key or any user keys. To verify a block of the file, the file system traverses the tree to the appropriate leaf node associated with a target block to be verified. The file system hashes the target block and if the hash matches the access value contained in the leaf node, the block is authentic.

On-disk file format for a serverless distributed file system

Operating system functions are defined as objects that are collections of data and methods. The objects represent operating system resources. The resource objects can be instantiated and used across process and machine boundaries. Each object has an associated handle that is stored in its private state. When an application requests a resource, it is given a second handle or pseudo handle that corresponds with the handle in the object's private state. The second handle is valid across process and machine boundaries and all access to the object takes place through the second handle. This greatly facilitates remote computing. In preferred embodiments, the objects are COM objects and remote computing is facilitated through the use of Distributed COM (DCOM) techniques. Other embodiments of the invention provide legacy and versioning support by identifying each resource, rather than the overall operating system, with a unique identifier that can specified by an application. Different versions of the same resource have different identifiers. This ensures that applications that need a specific version of a resource can receive that version. This also ensures that an application can specifically request a particular version of a resource by using its unique identifier, and be assured of receiving that resource. Other embodiments of the invention provide legacy support by intercepting calls for operating system functions and transforming those calls into object calls that can be understood by the resource objects. This is accomplished in preferred embodiments by injecting a level of indirection between an application and an operating system.

Operating system application programming interfaces and methods of using operating systems

The present invention leverages changes in the sensed strength of radio signals at different locations to determine a device's location. In one instance of the invention, inference procedures are used to process ambient commercial radio signals, to estimate a location or a probability distribution over the locations of a device. In an instance of the invention, learning and inference methods are applied to rank vector of signal strength vectors. Moving to such rank orderings leads to methods that bypass consideration of absolute signal strengths in location calculations. The invention facilitates approximations for locating a device by providing a method that does not require a substantial number of available ambient signal strengths while still providing useful location inferences in determining locations.

Methods for determining the approximate location of a device from ambient signals

The present invention employs approximate device locations determined from changes in the sensed strength of radio signals at different locations. In one instance of the invention, the approximate device locations are based on inference procedures that are used to process ambient commercial radio signals, to estimate a location or a probability distribution over the locations of a device. In another instance of the invention, approximate device locations derived from learning and inference methods that are applied to rank vector of signal strength vectors are utilized. Moving to such rank orderings leads to methods that bypass consideration of absolute signal strengths in location calculations. The invention utilizes approximations for a device location that is based on a method that does not require a substantial number of available ambient signal strengths while still providing useful location inferences in determining locations. Several location-centric services are supported, including receipt of location-specific information such as traffic reports, emergency information, transmission about device location, and time-sensitive promotions such as discounts offered by businesses for load balancing the provision of services.

Growing community of inventors

Bothell, WA, United States of America

Gerald Cermak