Abstract: The present invention describes a system of multiple devices and multiple users, wherein the identity and location of each device and user may be known to the system. A method is described for establishing media connections between at least a first user and a second user based on the context of the system and the environment of the particular device, computing devices, or users. The system receives a media connection request from the first user, including information indicating the first user preferences for media, and identifies the intended recipient user or users. The location and media devices in proximity to each of the users is determined, and the preset profiles and policies of the users involved are determined. Each user may specify acceptable media connections and contextual attributes. When the contextual attributes and acceptable media connections for each user are consistent, media device communications paths are established.

Abstract: A system for transferring digital information to spatially localizable portable electronic devices has a plurality of portable electronic devices, with each portable electronic device supporting wireless communication. A spatial localizing module determines spatial location with submeter precision for each of the plurality of electronic devices, and a communication module is connected to the spatial localizing module for mediating wireless communication between the portable electronic devices. A user can define electronic data transfers between portable electronic devices in user determined spatial locations with submeter precision. Data transfers are possible to adjacent electronic devices, electronic devices within a defined radius, electronic devices along a defined bearing or having specific orientations, or even located within a defined set of regions or rooms.

Abstract: Write operations for weakly consistent replicated database systems have application-specific embedded dependency queries and related descriptions of the results that are expected to be returned when the respective dependency queries are run against the database. The dependency queries are arbitrary queries that are provided by the application to satisfy the requirements of the application. Write operations that conflict with the current state of any given instance of such a database are detected by comparing (a) the results that are returned when the dependency queries for those writes are run against the given instance of the database with (b) the results that are expected to be returned.

Abstract: A method in which access control programs (ACPs) permit controlled delegation of access rights from clients to untrusted intermediaries. ACPs are programs that encode arbitrary specifications of delegated access rights. In the method, a client creates an ACP and associates it with a request to a server, the request being made through one or more intermediaries. When processing a request received from an intermediary, the server executes the access control program to determine whether or not to grant the request.

Abstract: In a freight tracking and routing system, each individual package is provided with a tag physically attached thereto. The tag includes a radio or infrared transceiver, and a microprocessor. At important nodes at geographical locations within the distribution system, location transceivers broadcast signals representative of their locations. The microprocessor, in response to receiving a desired destination signal, emits a signal commanding external equipment to take the package so that it remains at the desired location. The tags are also capable of being electronically queried, or alternately can emit distress signals when they do not reach a particular location at a particular time.

Abstract: The present invention describes a method for superimposing prespecified locational, environmental, and contextual controls on user interactions, including interactions of mobile users, with computational resources. A system is described for electronically monitoring contextual information concerning users and machines, including state and locational information including proximity. Interaction policies, including user specified interaction policies, may be registered on an identifiable address path. Methods are described for detecting, selecting and controlling computercontrolled devices, based on the proximity of the device to the user, the current context of the user, the location of other nearby users and devices, and the current state of the devices. Temporary transfer of control, including exclusive control, of particular computers and computer controlled devices to individual users based on the context and environment in proximity to those computing devices is also described.

Abstract: The present invention describes a method for superimposing prespecified locational, environmental, and contextual controls on user interactions, including interactions of mobile users, with computational resources. A system is described for electronically monitoring contextual information concerning users and machines, including state and locational information including proximity. Interaction policies, including user specified interaction policies, may be registered on an identifiable address path. Methods are described for detecting, selecting and controlling computercontrolled devices, based on the proximity of the device to the user, the current context of the user, the location of other nearby users and devices, and the current state of the devices. Temporary transfer of control, including exclusive control, of particular computers and computer controlled devices to individual users based on the context and environment in proximity to those computing devices is also described.

Abstract: Write operations for weakly consistent replicated database systems have embedded application-specific merge procedures that are invoked for resolving conflicts whenever it is found that the related write operation conflicts with the current state of a given instance of such a database. The effect of executing such a merge procedure is deterministic for any state of the given instance of the database happens to be in when the merge procedure is executed.

Abstract: Write operations for weakly consistent replicated database systems have embedded conflict detection and conflict resolution procedures for identifying and resolving, respectively conflicts between such write operations and the current state of any given instance of such a database. These write operations are committed to a firm execution order by the host for one instance of such a database, and this execution order propagates to the other instances of the database. Accordingly, a write log distinguishes between the writes that are known to be committed to a firm execution order (the "tentative writes") is maintained for each instance of the database, thereby enabling the user to explicitly identifying the stable data and the potentially unstable data in any given instance of the database. Furthermore, provision is made for enabling users to select from a set of predefined consistency guarantees across all instances of such a database for any given session.

Abstract: The present invention provides client-selected consistency guarantees to clients of a weakly consistent replicated database on a per "session" basis. The clients have access to utilities which allow the clients to, individually or collectively, define a "session" over which the selected guarantees are enforced. A "session" is broadly defined as a sequence of logically related Reads and Writes to the database. Sessions are initiated and terminated substantially independently of other sessions which may exist concurrently. Clients are allowed, however, to clone sessions and/or merge sessions with other clients. Clients select a minimum relevant subset of guarantees from among a set of pre-defined consistency guarantees, where "relevancy" is a client determined factor. At any given time, the system may be enforcing a number of different combinations of consistency guarantees.

Abstract: A write log that distinguishes between write operations that are known to be in a stable write order ("committed writes") and write operations that still are in a potentially unstable write order ("tentative writes") are maintained for each instance of a weakly consistent replicated database so that the stable and the potentially unstable data in any given instance of such a database can be explicitly identified.

Abstract: The present invention describes a method for superimposing prespecified locational, environmental, and contextual controls on user interactions, including interactions of mobile users, with computational resources. A system is described for electronically monitoring contextual information concerning users and machines, including state and locational information including proximity. Interaction policies, including user specified interaction policies, may be registered on an identifiable address path. Methods are described for detecting, selecting and controlling computercontrolled devices, based on the proximity of the device to the user, the current context of the user, the location of other nearby users and devices, and the current state of the devices. Temporary transfer of control, including exclusive control, of particular computers and computer controlled devices to individual users based on the context and environment in proximity to those computing devices is also described.

Abstract: The present invention describes a method for superimposing prespecified locational, environmental, and contextual controls on user interactions, including interactions of mobile users, with computational resources. A system is described for electronically monitoring contextual information concerning users and machines, including state and locational information including proximity. Interaction policies, including user specified interaction policies, may be registered on an identifiable address path. Methods are described for detecting, selecting and controlling computercontrolled devices, based on the proximity of the device to the user, the current context of the user, the location of other nearby users and devices, and the current state of the devices. Temporary transfer of control, including exclusive control, of particular computers and computer controlled devices to individual users based on the context and environment in proximity to those computing devices is also described.

Abstract: The present invention describes a method for selectively delivering electronic messages to an identified user or users in a system of mobile and fixed devices, including multiple display devices and multiple users, based on the context of the system and the environment of the identified user. Electronic messages intended for an identified user or users may be given a level of privacy and a level priority, and contextual attributes for its delivery may be specified. The system perceives contextual attributes for the recipient user or users, including display devices in close proximity to the identified users, and determines a display property for said electronic message based on the contextual attributes, the user profile properties of each user, and the level of privacy and level of priority of the electronic message.

Abstract: A system is provided for servicing requests by a mobile controller to utilize stationary or mobile resources present within a partitioned communication cell such as an office or room in a building. The mobile controller has a control signal mechanism for generating control request signals to modify behavior of the stationary or mobile resource, with the range of the control request signals substantially limited to the partitioned communication cell. A room agent receives and acts upon the control request signals after dynamically determining availability of both mobile resources entering and exiting the partitioned communication cell and stationary resources already present in the partitioned communication cell.