Hewlett-packard Development Company, L.P.

Hewlett-packard Company

Michael P Spratt

Alan R Albrecht

Simon Edwin Crouch

Steven H Goody

John Deryk Waters

James Thomas Edward McDonnell

Joseph A Curcio

Andrew D Thomas

Daniel J Dove

Robert Francis Squibbs

Lawrence Wilcock

Patricia Ann Thaler

Rycharde Jeffery Hawkes

Jonathan Jedwab

Oran Sharon

Jayant Kadambi

Gregory C Watson

Andrew Thomas

Location data about a mobile entity () is provided in encrypted form by a location server () to a recipient that is one of the mobile entity () or a service system () usable by the mobile entity. The location data (P) is encrypted such that it can only to be decrypted using a secret available to a decryption entity () that is not under the control of the recipient. This permits location data (P) to be provided in a confidential manner to service systems () and also protects billing relationships between participants. A mechanism is also described for limiting the accuracy of decrypted location data (L) made available to a service system ().

Providing location data about a mobile entity

Location data about a mobile entity () is periodically provided to a location-sensitive application, for example, a route-tracking application. The location data is updated at a frequency that is adaptively varied in dependence on the provision of location data about the mobile entity from other sources (). The update frequency can also be made dependent on further factors such as: the motion of the mobile entity('V'), the current environment of the mobile entity ('E'), and the progress of the location-sensitive application (&#x201c;Z&#x201d;).

Obtaining location updates about a mobile entity for use in a location-sensitive application

A method is provided for augmenting a set of image recordings in which, in addition to making image recordings (), location data () is recorded for locations for which the user desires an, or a further, image recording. This desired-image-recording location data is subsequently used to retrieve one or more corresponding image recordings from a service system ().

Augmentation of sets of image recordings

A message is carried towards a target receiver (T) at a known location by one or more mobile entities (L,Q) that receive and pass on the message by short-range communication. The message includes an indication of the location of the target receiver (T). Before a mobile entity (L,Q) is used to carry the message, a determination is made as to whether the direction of travel of the mobile entity concerned is generally towards either the target receiver (T) or an intermediate staging post suitable for progressing the message towards the target receiver.

Message passing to a known location

A location discovery method using location data items that originate at known locations (X,Y) and are passed to, and diffused between, entities (A,B) by short-range communication. Each location data item received by an entity (A,B) indicates a maximum distance of the entity from one of the known locations (X,Y). Each entity (A,B) prior to using a location data item for location determination or transferring it to another entity, is operative to increase the maximum distance indicated by the location data item to take account of movement of the mobile entity since receiving that item. A mobile entity (A) effects location determination by finding locations () simultaneously consistent with the maximum distances () it knows of and any applicable route constraints for how the location data items passed to the mobile entity.

Location data diffusion and location discovery

A static but movable device has a short-range wireless transceiver by which it can receive location data items. These items are usable by a location-data processing arrangement of the device to derive an estimate of the current location of the device. If the device is moved to another location, this estimate will cease to be valid. Accordingly, the device is provided with a move detection arrangement for detecting indications that the device may have been moved, these indications being used by a location-validity supervisor to determine whether or not the current location estimate is to be treated as still valid.

Location data validation by static entities receiving location data items by short-range communication

Information with local relevance is diffused locally using mobile devices equipped with non-wired short-range communication means, the information being propagated from an originating point in messages passed from device to device in an unstructured way. The devices implement measures for limiting message propagation including controlling propagation of a message from a particular originating point (OP) in dependence on the prominence of the occurrence of that originating point in a set of most recently received messages.

Limiting message diffusion between mobile devices

A location determination method uses location data items that originate at known locations and are passed to, and diffused between, entities by short-range communication. Each location data item received by an entity specifies its originating location and a time value dependent on when it originated from that location. An entity derives its location from received location data items by effecting a weighted combination of the known locations specified in the received location data items, the weighting of the known location specified in each received location data item being dependent on the associated time value.

Location determination using location data items received by short-range communication

Information with local relevance is diffused locally using mobile devices () equipped with non-wired short-range communication means, the information being propagated from an originating point () in messages passed from device to device in an unstructured way. To encourage users of the mobile devices () to participate in the propagation method, the presentation of a message received at a device to the device user is inhibited unless the device is enabled to propagate on the message.

Message diffusion between mobile devices

Information with local relevance is diffused locally using mobile devices equipped with non-wired short-range communication means, the information being propagated from an originating point in messages passed from device to device in an unstructured way. The devices implement measures for limiting message propagation. For a device that is arranged to propagate a received message multiple times, these measures include increasing (75) the interval between retransmissions in dependence on how many times the same message has been received by the device either in total or during a recent period.

A method and device is provided for obscuring the location of a mobile entity to a specified accuracy level. Available location data that has a known accuracy greater than the specified accuracy has its accuracy decreased (85) by combining with the components of the available location data, additional components randomized over a range set by the difference between the known accuracy of the available location data and the specified accuracy level.

A mobile entity ( ) provides accuracy limit data (Q) that indicates a desired accuracy of location data (L) about the mobile entity. This data (Q) is passed, either directly or indirectly from the mobile entity ( ), to a location handling system ( ) which provides location data (L) about the corresponding mobile entity limited to the desired accuracy. In one embodiment, the location handling system is a location server. In another embodiment the location handling system is a decryption entity ( ) for decrypting encrypted location data.

A position-discovery method is provided for a mobile device equipped with non-wired short-range communication means for receiving locally-transmitted messages. At least some of the messages include position data concerning the originating point of the message. The device determines its position as being that of the most common originating point for messages in a set of most recently received messages.

Position discovery using short range mobile devices

A location determination method uses location data items that originate at known locations and are passed to, and diffused between, entities by short-range communication. Each location data item received by an entity includes a displacement value indicative of the displacement of the item since leaving a specified known location. This displacement value of a location data item has been updated to reflect movement of entities temporarily hosting the item and/or the range of the transmission hops made by the item. An entity derives its location from received location data items by effecting a weighted combination of the known locations specified in the received location data items, the weighting of the known location specified in each received location data item being dependent on the associated displacement value.

In order to reduce power consumption of battery-powered devices to which location data is to be dissemination by short range communication, the devices are arranged to wake-up to listen for location data at known times as judged against a reference time standard. This time standard is also available to the transmitters of location data which accordingly transmit their location data at the known times.

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Bristol, United Kingdom

Michael P Spratt