Location-based communications services are becoming more prevalent in connection with various devices, most notably mobile telephones, where a mobile telephone network is able to locate a given mobile telephone to within a predetermined degree of accuracy, possibly a few metres. Furthermore, modern electronic communications devices, including mobile telephones, are now equipped with non-network communications protocols, such as Bluetooth@ or similar, whereby the communications device is able to determine the local presence of other electronic communications devices.

While this ability to locate an electronic communications device has many advantages, there remains a need for managing privacy. For example, although users of such a device may be happy for their friends to know where they are, they may be less willing for this location information to be available to unknown third parties or the like. Furthermore, if a user is in the same locality as a close friend having a similar electronic communications device, they may both wish the electronic communications devices to indicate their proximity so that the user and his or her friend can meet. However, the user may not wish his or her presence to be indicated to another user who is not such a good friend.

It is apparent that there is a growing need to manage"levels"or"shells"of privacy, for example to indicate whether certain people fall into the class of"good friend"or "trusted associate"o-whether they are classified as people to whom the user does not want his or her presence to be indicated. This information could be updated

manually by the user, but this is cumbersome and the information is likely always to be out of date. An example of a method and system in which a user of a mobile communication unit (such as a mobile telephone) is alerted to the proximity of another user of a similar mobile communication unit, based on predetermined user- selected parameters, is described in WO 00/22860. However, because this method and system relies entirely on each user manually maintaining a contact or"buddy" list, including the user-selected parameters, it is relatively cumbersome to keep the contact list updated, especially in today's social and business environments where a person will come into contact with possibly hundreds of colleagues and co-workers in a single day.

According to a first aspect of the present invention, there is provided an electronic communications device adapted to be wirelessly linked to other electronic communications devices, the electronic communications devices each having a distinct identity and being individually locatable and identifiable by a network or identifiable by each other when in relative proximity, wherein the electronic communications device is adapted to access a memory adapted to store identity data relating to at least a predetermined number of the other electronic communications devices and to provide an indication of the identity of one or more of the other electronic communications devices determined to be within a predetermined distance of the electronic communications device, but only when : a) the one or more of the other electronic communications devices has been identified and determined to be in a location within a predetermined distance of a location of the electronic communications device more than a predetermined number of times, this being a first order relationship ; or b) the one or more of the other electronic communications devices is determined to have been identified and determined to have been in a location within a predetermined distance of an electronic communications device previously identified and determined to be within a predetermined distance of the electronic

communications device more than a predetermined number of times as defined in a) above, this being a second order relationship ; or c) the one or more of the other electronic communications devices is determined to have an nth order relationship with the electronic communications device, extrapolating from b) above.

According to a second aspect of the present invention, there is provided a method of identifying a uniquely-identifiable electronic communications device to another uniquely-identifiable electronic communications device, the electronic communications devices each having a distinct identity and being individually locatable and identifiable by a network or identifiable by each other when in relative proximity, wherein the electronic communications device accesses a memory adapted to store identity data relating to at least a predetermined number of the other electronic communications devices and provides an indication of the identity of one or more of the other electronic communications devices determined to be within a predetermined distance of the electronic communications device, but only when : a) the one or more of the other electronic communications devices has been identified and determined to be in a location within a predetermined distance of a location of the electronic communications device more than a predetermined number of times, this being a first order relationship ; or b) the one or more of the other electronic communications devices is determined to have been identified and determined to have been in a location within a predetermined distance of an electronic communications device previously identified and determined to be within the predetermined distance of the electronic communications device more than a predetermined number of times as defined in a) above, this being a second order relationship ; or

c) the one or more of the other electronic communications devices is determined to have an nth order relationship with the electronic communications device, extrapolating from b) above.

According to a third aspect of the present invention, there is provided an electronic communications device adapted to be wirelessly linked to other electronic communications devices, the electronic communications devices each having a distinct identity and being individually locatable and identifiable by a network or identifiable by each other when in relative proximity, wherein the electronic communications device is adapted automatically to build up a list in a memory of data relating to the identities of one or more of the other electronic communications devices which are determined to have been located within a predetermined distance of the electronic communications device at least a predetermined number of times, and to provide an indication when any of the one or more other electronic communications devices whose identity data have been stored in the memory is subsequently determined to be within a predetermined distance of the electronic communications device.

According to a fourth aspect of the present invention, there is provided a method of identifying a uniquely-identifiable electronic communications device to another uniquely-identifiable electronic communications device, the electronic communications devices each having a distinct identity and being individually locatable and identifiable by a network or identifiable by each other when in relative proximity, wherein the electronic communications device automatically builds up a list in a memory of data relating to the identities of one or more of the other electronic communications devices which are determined to have been located within a predetermined distance of the electronic communications device at least a predetermined number of times, and provides an indication when any of the one or more other electronic communications devices whose identity data have been stored in the memory is subsequently determined to be within a predetermined distance of the electronic communications device.

The predetermined distance may be 5m, 10m, 20m, 30m, 50m, 100m or more, depending on the nature of the electronic communications devices. In some embodiments, the predetermined distance may be defined as a maximum dimension of a room or building within which the electronic communications devices may be temporarily located.

An indication may be provided when the other electronic communications device is one which has been identified by the electronic communications device more than a predetermined number of times. In other words, the electronic communications device may only provide an indication of the proximity of one of the other electronic communications devices when that other electronic communications device has been previously identified to be proximate to the electronic communications device on more than a predetermined number of occasions. The number of times or occasions may be chosen appropriately by a user, and may be at least one, two, three, four, five, ten, twenty, fifty or any other number. In this way, an electronic communications device can build up a list of other electronic communications devices carried by other people with whom a person carrying the device is regularly in contact, such as friends or work colleagues. In a preferred embodiment, the presence of the electronic communications device is reciprocally indicated by the other electronic communications device, although it may be advantageous for this feature to be selectively operable. In this way, a user of an electronic communications device can be alerted to the presence of"friendly"associates who are carrying similarly- configured electronic communications devices.

The present invention can be thought of as providing a variation of a technique used by World-Wide Web search engines to identify and rank websites in order of likely importance and relevance by defining the importance of a website by the number of other websites to which it is linked to or by which are also defined as"important".

Although this definition of importance is somewhat circular, it is nevertheless a useful and powerful concept.

Preferably, the electronic communications device is adapted to allow a user to select which of the other electronic communications devices are identified to the user when in proximity thereto. For example, the presence of one of the other electronic communications devices may be indicated on a display, the display further providing identification information regarding a user of the other device. The user of the electronic communications device may then make a choice as to whether he wishes to be identified to the user of the other device, and if so, may press a key on his device or suchlike so as to set the identity of the other device in the memory with a flag indicating that the other device is one which is to be identified in future.

The memory to which the electronic communications device has access may be an on-board memory located on or in the electronic communications device, or may alternatively be a remote memory with which the electronic communications device communicates, possibly by way of a wireless network or by direct wireless communication such as BIuetooth0 or the like.

Where the memory is an on-board memory, it is to be appreciated that the memory will not contain identity details of any other individual electronic communications devices until the electronic communications device in question is first used. Upon first use, the device will start to build up a list of identity details relating to other devices which are determined by the device itself or by the network to which it is linked to be within the predetermined distance of its location. The identity details of the other devices may be transmitted directly from the other devices, for example as part of a repeatedly and automatically transmitted individual identity signal (which may be disabled by a user for privacy purposes), or may be delivered by way of the network (but preferably only when users of the other devices have positively selected automatic identification of their devices to others as an option from the network operator).

Alternatively, the memory may be a central memory or database or the like maintained by a network operator and to which the electronic communications device has access by way of the network. In this case, the central database may already contain details relating to each and every electronic communications device which has ever used the network, for example by way of a user registration process or automatically any time a device communicates by way of the network. This central database may allow many more identity details to be stored than an on-board memory, and may have superior searching facilities due to improved processing capability.

In a particularly preferred embodiment, there may be a combination of an on-board memory and a central database, with the on-board memory storing the identities of other devices which have already been determined to have been in proximity to the user's device more than a predetermined number of times, and the central database storing the identities of every device using the network and which the user's device has not yet identified to be in close proximity more than a predetermined number of times. This combination enables rapid processing of previously identified other devices without the need for a list of the identities of all possible other devices to be stored in the on-board memory.

It is to be appreciated that embodiments of the present invention provide a significant advantage over the system disclosed in WO 00/22860, which provides an electronic communications device adapted to indicate the proximity of other electronic communications devices, but only when the identities of the other electronic communications devices have been manually determined by a user and stored in a memory of the electronic communications device. By building up a memory list automatically on the basis of previous interactions with other electronic communications devices, the electronic communications device of embodiments of the present invention obviates the onerous requirement to update the memory list manually, thereby helping to keep the list up-to-date.

In a particularly preferred embodiment, the memory to which the electronic communications device has access and in which the identities of the other electronic communications devices and their associated users are stored may organise the identity data in a number of"shells"or subsets. For example, there may be different identity categories for personal friends, work colleagues, business associates and so forth. These"shells"or subsets may be constructed largely automatically, again based on location and time. For example, a given electronic communications device can automatically make users of other electronic communications devices members of"shells"or subsets such as"WORK"or"HOME"simply by detecting an unusual clustering of frequency time-and-space presences. The electronic communications device can then be operated by the user thereof so as to know that a given location is called"HOME", and another given location is called"WORK", for example, thus providing for an easy human-machine interface.

This concept may be extended to second and subsequent orders, in that if the electronic communications devices share data stored in their automatically-or- manually-determined"shells"or subsets (possibly via a communications network) then it is possible to define a selectable rule that members of the"shells"or subsets of a second electronic communications device can be made members of the"shells" or subsets of a first electronic communications device which includes the second electronic communications device in one of its own"shells"or subsets. It would then be possible for a user to sit in a room, for example, and to operate his or her electronic communications device to locate someone nearby carrying another electronic communications device and with whom he or she has a direct or indirect (location-based) relationship. The electronic communications device may be operable to explain the connection by displaying how the various members of the "shells"or subsets are linked, e. g."Person A is present. Ile used often to be at "WORK"with Person B, who is often at"WORK"with you now".

The user of the electronic communications device may selectively activate each of these"shells"or subsets depending on his personal circumstances. For example, the

user may be happy to identify and be identified by his work colleagues and business associates during working hours, but may prefer that only his personal friends are identified during the evenings and at weekends.

It is also possible to associate the memory with an electronic diary such as that provided by Microsoft@ as part of its Outlook@ software package. When entering details of future meetings and appointments, data identifying electronic communications devices carried by people who the user is to meet can also be entered. In this way, it is possible for the electronic communications device to indicate the proximity of another electronic communications device carried by a person with whom the user will be spending time in Mure. So, for example, the device may indicate that a person who the user will be meeting in two weeks'time at a conference is actually sitting in the same restaurant as the user before the meeting actually takes place.

The electronic communications device may be a mobile telephone, personal digital assistant, electronic pager, portable computer or other suchlike device. The electronic communications device may be adapted to be wirelessly linked to a network of other electronic communications devices and/or may be adapted to be wirelessly linked directly to other electronic communications devices, for example by way of the Bluetootht peer-to-peer communications protocol.

It will be appreciated that any processing carried out to identify the other electronic communications devices and to determine how many times, if at all, they have previously been determined to be proximate to the electronic communications device, as well as other matching or sorting algorithms and processes, may be carried out in the electronic communications device itself by way of an electronic processing unit, or remotely by a processor or server at a central location to which the electronic communications device has access by way of a network.