WO2003030455A1

WO2003030455A1 - Improvements in and relating to communication systems and methods

Info

Publication number: WO2003030455A1
Application number: PCT/GB2002/004327
Authority: WO
Inventors: David Last
Original assignee: University Of Wales, Bangor
Priority date: 2001-09-29
Filing date: 2002-09-24
Publication date: 2003-04-10
Also published as: GB0123498D0

Abstract

There is disclosed a communication system (2) comprising a wireless local area network (6, 8 10,12) for receiving identification signals communicated from mobile objects (4) and means (15, 17, 19, 21) for transmitting a location signal of the mobile object externally of the receiving wireless local area network regardless of whether the mobile object is an authorised client of the receiving wireless local area network. A corresponding method is also disclosed.

Description

Improvements In and Relating to Communication Systems and

Methods

Field of the Invention

The present invention relates to communication systems and methods for tracking mobile objects, and to such systems and methods for determining the location of a mobile object .

Background to the Invention

There are many systems available for tracking objects, in particular vehicles, all of which embody the principle of determining the location of the mobile object and communicating that information to a tracking centre. One such system in common use is the satellite Global Positioning_. System (GPS) for determining location, together with cellular telephony or private mobile radio for the communication of location. Several alternative location systems are available. One such is a cellular identification system in which the base station with which a mobile phone is communicating is used to locate the phone to within a given cell. Typically this will locate an object to within a few hundred metres. Another such system is the enhanced observed time delay (EOTD) system in which the distance of a mobile phone from a base station is determined by measuring the delays between transmitted and received signals. A location can be determined approximately if two or more such readings are obtained. If the mobile object is within a building, such as a dwelling or offices, the location technologies referred to above require radio signals to penetrate the building from the outside. Low frequency signals do this poorly; ultra high frequency (UHF) and microwave signals are a little better, but no technology can reliably penetrate more deeply than one room into a structure. So, for instance in a large office complex as the mobile object moves deeper within the building, the signals are generally lost or at least degraded and the location function fails.

Wireless local area networks enable mobile objects to remain in contact with a network. In such a wireless local area network an access point is a node physically connected to the network and a client is in a mobile object and which can be an authorised client of the network and a node thereof .

It is an aim of preferred embodiments of the present invention to obviate or overcome a disadvantage of the prior art, whether referred to herein or otherwise.

Summary of the Invention

According to the present invention in a first aspect, there is provided a communication system comprising a wireless local area network for receiving identification signals communicated from mobile objects and means for transmitting a location signal of the mobile object externally of the receiving wireless local area network regardless of whether the mobile object is an authorised client of the receiving wireless local area network. Suitably, the identification signal comprises a reference signal from a mobile object to identify the mobile object. Typically this will be by the transponder having a unique reference code. Suitably, the reference signal is a media access control ("MAC") address.

Suitably, the location signal transmitted by the wireless local area network (which may be by a node thereof) is the received identification signal, though this need not be the case.

Suitably, the location signal includes an object identifier. Suitably, the location signal comprises a location identifier, which location identifier identifies the wireless local area network having received the identification signal from the mobile object. Suitably, the location signal comprises a location identifier, which location identifier identifies the access point node having received the identification signal from the mobile object. Suitably, the local area network communicates the reference signal and an access point node identifier signal .

Suitably, the wireless local area network comprises a personal computer.

Suitably, the system further comprises a location server for receiving the location signal from the wireless local area network.

Preferably, the location signal is transmitted to a predetermined web-site URL. Suitably, the system comprises a database relating object location signals to physical locations. Suitably, the physical location is provided for the mobile object at the web-site .

Suitably, the system uses any of BLUETOOTH (trade mark) , Home RF, hyperlan or IEEE 802.11 communication protocols.

Suitably, the system further comprises a mobile object comprising a communication means for communicating a mobile object identification signal.

Suitably, the communication means comprises a short range communication device. Suitably, the communication means comprises a radio transmitter.

Suitably, the communication means comprises a transponder. Suitably, the transponder is a network interface card or a bridge .

Suitably, the system is configured whereby the wireless local area network communicates with the mobile object using the frequency band of the wireless local area network .

The object can be an item, a person, a package, a vehicle etc.

Suitably, the system is suitable for locating the mobile object to within 100m, more suitably to within 50m, even more suitably to within 25m and preferably to within 10m. Suitably, the mobile object comprises a mobile communication device which may be a wireless telephone such as a cellular telephone.

Suitably, there is a plurality of such wireless local area networks in the communication system.

According to the present invention in a second aspect, there is provided a communication method for a communication system comprising wireless local area network, a mobile object capable of communication to the wireless area network, the method comprising the steps of the wireless local area network receiving an identification signal from a mobile object, and the wireless local area network transmitting a location signal for the mobile object externally of the wireless local area network regardless of whether the mobile object is an authorised client of the wireless local area network.

Suitably, the location signal transmitted by the wireless local area network (which may be by a node thereof) is the received identification signal, though this need not be the case .

Suitably, the identification signal comprises a reference signal from the mobile object to identify the mobile object. Typically this will be by the transponder having a unique reference code. Suitably, the reference signal is a media access control address.

Suitably, the location signal includes an object identifier. Suitably, the location signal comprises a location identifier, which location identifier identifies the wireless local area network having received the identification signal from the mobile object. Suitably, the location signal comprises a location identifier, which location identifier identifies the node having received the identification signal from the mobile object. Suitably, the local area network communicates the reference signal and a node identifier signal.

Suitably, the local area network is a computer network comprising a plurality of networked computer nodes.

Suitably, a networked computer node is a personal computer.

Suitably, there are a plurality of wireless local area networks capable of receiving mobile object identification signals and transmitting location signals externally thereof .

Preferably, the location signal is transmitted to a predetermined web-site URL.

Suitably, the system comprises a database relating node location signals to physical locations. Suitably, the physical location is provided for the mobile object at the web-site.

Suitably, the mobile object comprises communication means including a short range communication device. Suitably, the communication means comprises a radio transmitter.

Suitably, the communication means comprises a transponder. Suitably, the transponder is a network interface card or a bridge . Suitably, the system uses any of BLUETOOTH (trade mark) , Home RF, Hyperlan, ETSI 300.328 or IEEE 802.11 communication protocols.

Suitably, the wireless local area network communicates with the mobile object using the frequency band of the wireless local area network

The object can be an item, a person, a package, a vehicle etc.

Suitably, the system is suitable for locating the mobile object to within 100m, more suitably to within 50m, even more suitably to within 25m and preferably to within 10m.

Suitably, a payment is made (which may be any form of consideration) to the local area network party for providing location information.

Suitably, the mobile object comprises a mobile communication device which may be a wireless telephone such as a cellular telephone.

Brief Description of the Drawings

The present invention will now be described, by way of example only, with reference to the drawings that follow; in which:

Figure 1 is a schematic illustration of a system according to the present invention . Figure 2 is a schematic illustration of communications used in the system of Figure 1.

Figure 3 is a functional diagram illustrating a method according to the present invention.

Description of the Preferred Embodiments

Referring to Figure 1 of the drawings that follow, there is shown a communication system 2 comprising a wireless communication object, such as a mobile phone device 4 and a plurality of wireless local area networks (LANs) 6, 8, 10 and 12. Each wireless LAN 6-12 has a variety of devices or nodes (indicated schematically at 14, 16, 18 and 20) as authorised clients thereof. The authorised client nodes in the LAN may be computers, printers, scanners, computer peripherals etc.

Each LAN 6-12 is linked to a distributed electronic network, here the internet, indicated schematically at 22 and includes respective means, generally a LAN controller, 15, 17, 19, 21 for transmitting location/identification data externally of the respective LAN 6-12. A specific internet web-site (having a given universal resource locator (URL) ) for use with the present embodiment is indicated at 24, which has access to a locations database 25.

The mobile phone 4 comprises a handset 26 in which is located an IEEE 802.11 transponder 28.

Each wireless LAN 6-12 employs short range wireless communication, typically radio communication, to link LAN nodes. The LAN nodes serve devices such as computers, printers or scanners .

The wireless LANs 6-12 may use any short range wireless communication technology, such as BLUETOOTH (trade mark) , Home RF, Hyperlan, ETSI 300.328 or members of the IEEE 802 family. Embodiments of the present invention are described according to the IEEE 802 implementation.

The transponder 28 is a network interface card or it may be a bridge. Alternatively, it may simply be an identification signal transmitter. The mobile phone 4 does not initially share a Service Set Identification

(SSID) with any of the LANs 6-12, but the LANs 6-12 are configured to monitor for identification signals (such as Media Access Control (MAC) addresses) from transponders such as transponder 28 (as is known in the art) . If there is to be two way communications, the mobile phone 4 adopts the SSID broadcast by an access point node of a LAN 6, 8, 10 or 12. It sends this SSID back to the access point node, together with its own MAC address. If its MAC address (and, possibly, higher level credentials such as a user name and password) are accepted, the mobile phone 4 becomes an authorised client of the LAN. It is only those devices that are acceptable to the relevant wireless LAN that can become authorised clients thereof. The transponder 28, and therefore mobile phone 4, are thus configured to be detectable by each of the LANs 6-12. The transponder 28 is characterised by a unique object reference code, to identify it from other objects and transponders using the system. Each LAN 6-12 is also uniquely identified and has a unique node reference code. For simplicity the MAC address for each device is used as the unique object reference code and unique node reference code respectively. The MAC address is a 12 character hexadecimal . Alternatively another dedicated reference code can be established.

Referring to Figures 2 and 3 of the drawings that follow, the communications used in the system of Figure 1 are illustrated schematically in Figure 2 as, in Figure 3, is a method of communication according to the present invention. Transponder 28 is configured to emit its MAC address as an OBJECT IDENT signal 30 (step 100) , an identification signal. Each network access point node 14, 16, 18, 20 of each LAN 6-12 is configured whereby upon receipt (step 102) of an OBJECT IDENT signal 30 from transponder 28 a combined OBJECT IDENT and NODE IDENT signal 32 (a location signal) is communicated (step 104) automatically as a location signal to web-site 24 at a predetermined uniform resource locator (URL) via the internet 22. The NODE IDENT signal is the MAC address at the access point node as referred to above. The OBJECT IDENT signal 30 may include handshaking signals to permit 2 -way communication between the mobile object and the specific LAN 6-12 which has received its OBJECT IDENT signal 30. Thus, the combined OBJECT IDENT and NODE IDENT signal 32 includes the object reference code (ie its MAC address) and the access point node reference code (ie its MAC address) .

Thus a user 34, such as a third party or object owner wishing to track the mobile phone 4 can access web-site 24

(step 106), enter details of the object they wish to track

(e.g. the MAC address or a simpler cross-referenced code which may correspond to the MAC address in a look-up table) and, if authorised to receive it, may be provided (step 108) information on the LAN 6, 8, 10 or 12 and/or specific LAN access point node 14, 16, 18 or 20 near the mobile phone 4. This is an indication of the proximity of the mobile object to the LAN and/or LAN access point node and thus an indication of its physical location. Information about the LAN or LAN access point node can be at various levels. At the simplest it may be the MAC address of an access point node, but generally a better indication of a physical location is given. The system can use location database 25 correlating LAN access point node reference codes to physical locations. Alternatively in a closed environment the user may simply be informed of the most recent location information in relation to a specific network access point node without being told specifically where that network access point node is located.

Depending upon the configuration of each LAN 6-12, the combined OBJECT IDENT and access point NODE IDENT signal

32 may be transmitted externally of the relevant LAN 6-12 by the LAN access point node 14, 16, 18, 20 receiving the

OBJECT IDENT signal or via the LAN controller. The LAN controller may optionally be configured to monitor for transponder signals. One or more devices of each LAN

(here in particular the LAN controller) can be configured to map each LAN in order to determine if one or more access point nodes in the LAN has detected or is in communication with a mobile object's transponder. Detection may be achieved from any attempted association, whether successful or not. The transponder 28 may be switched off at the user's discretion or be deactivated if a subscribed service.

An OBJECT IDENT and LOCATION signal 32 may, alternatively be transmitted (eg via e-mail, wireless communication etc) to user 34. The signal 32 may be transmitted automatically each time a new access point node locates the object, at predetermined intervals or when requested by the user 34.

Normally when a network access point node receives an identification communication from a mobile object, the wireless LAN will only do anything with the received signal if it recognises the mobile object, by its identification communication, as an authorised client of the wireless LAN. According to the present invention, however, the received signal is acted upon regardless of whether the mobile object is an authorised client. That is, all received identification signals are onward transmitted as location signals. A device does not need to be an authorised client of the respective wireless LAN receiving its identification signal to have that signal communicated externally of the receiving wireless LAN. Thus any wireless LAN can be used to track the mobile object.

Embodiments of the present invention can be used to track a wide variety of objects, including electronic devices, cargo, people (for instance, lone workers, children, hospital patients, high value items, etc) . For instance, in a factory a pallet carrying an item to be manufactured can be tracked by a transponder in the pallet or a component, or personnel can be tracked in a building. In some of these embodiments location information may be used in the LAN itself.

It will be appreciated that location of the mobile object is not exact. Rather the proximity of the object to a LAN access point node can be determined on a proximity tracking basis.

If a communication device such as a mobile phone 4 comprises a network interface card for digital communication with the wireless LAN 14, location specific information can automatically be transmitted to the phone

4 by each LAN access point node. Typically, this will give longitude/latitude and height information, street location etc. Accordingly, the phone 4 can display location information to its user. Alternatively if the phone 4 is internet enabled, the user can access web-site

18 for location information. Whether for location or tracking a payment can be made to the LAN party (eg owner or controller of the LAN 14) for providing the location information. Other location-based interactive services can be provided.

Although embodiments of the present invention only require mobile object and LAN to be capable of one-way communication (from the mobile object to the LAN) , two way communication can also be used. Two way communication provides the benefit that it allows the delivery of other services .

The location server could be a database, for instance, accessible otherwise than via the internet . The LAN owning/controlling party may receive a payment for providing the location signal .

Any LAN 6-12 may include wired sections, but it requires the ability to communicate by wireless means with a mobile object .

In a more basic implementation the location signals consist solely of the received object identification signal .

It may be that several wireless LANs are receiving object identification signals in which case triangulation can be used to better locate the mobile object. Alternatively other data such as signal strength information can be included in the location signal to help locate the mobile object .

Thus embodiments of the present invention provide a communication system and method for tracking a mobile object, the system comprising a plurality of wireless local area networks, and the mobile object comprising means for communicating an identification signal to a wireless local area network whereby a location signal is generated by an access point node in the wireless local area network upon detection of the mobile object regardless of whether the mobile object is an authorised client of the network, with a corresponding method.

Preferred embodiments of the present invention can be used to locate mobile objects relatively accurately and in locations that otherwise become problematic, especially deep inside buildings. It will be appreciated that although the present invention is described in relation to four wireless LANs 6-12 it is applicable to any number of LANs.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings) , and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) , may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment (s) . The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings) , or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

1. A communication system comprising a wireless local area network for receiving identification signals communicated from mobile objects and means for transmitting a location signal of the mobile object externally of the receiving wireless local area network regardless of whether the mobile object is an authorised client of the receiving wireless local area network.

2. A communication system according to claim 1 , in which the identification signal comprises a reference signal from a mobile object to identify the mobile object.

3. A communication system according to claim 2 , in which the reference signal is a media access control ("MAC") address .

4. A communication system according to any preceding claim, in which the location signal transmitted by the wireless local area network is the received identification signal.

5. A communication system according to any preceding claim, in which the location signal includes an object identifier.

6. A communication system according to any preceding claim, in which the location signal comprises a location identifier, which location identifier identifies the wireless local area network having received the identification signal from the mobile object .

7. A communication system according to any preceding claim, in which the location signal comprises a location identifier, which location identifier identifies the access point node having received the identification signal from the mobile object.

8. A communication system according to any preceding claim, in which the wireless local area network comprises a personal computer.

9. A communication system according to any preceding claim, in which the system further comprises a location server for receiving the location signal from the wireless local area network.

10. A communication system according to any preceding claim, in which the location signal is transmitted to a predetermined web-site URL.

11. A communication system according to any preceding claim, in which the system comprises a database relating object location signals to physical locations .

12. A communication system according to claim 11 when dependent on claim 10, in which the physical location is provided for the mobile object at the web-site.

13. A communication system according to any preceding claim, in which the system uses any of BLUETOOTH (trade mark), Home RF, hyperlan or IEEE 802.11 communication protocols.

14. A communication system according to any preceding claim, in which the system further comprises a mobile object comprising a communication means for communicating a mobile object identification signal.

15. A communication system according to claim 14, in which the communication means comprises a short range communication device.

16. A communication system according to claim 14 or claim 15, in which the communication means comprises a radio transmitter.

17. A communication system according to any one of claims 14 to 16, in which the communication means comprises a transponder.

18. A communication system according to claim 17, in which the transponder is a network interface card or a bridge .

19. A communication system according to any preceding claim, in which the system is configured whereby the wireless local area network communicates with the mobile object using the frequency band of the wireless local area network.

20. A communication system according to any preceding claim, in which the mobile object comprises a mobile communication device.

21 . A communication system according to claim 20 , in which a mobile communication device comprises a wireless telephone .

22. A communication system according to any preceding claim, in which there is a plurality of such wireless local area networks in the communication system.

23. A communication method for a communication system comprising wireless local area network, a mobile object capable of communication to the wireless area- network, the method comprising the steps of the wireless local area network receiving an identification signal from a mobile object, and the wireless local area network transmitting a location signal for the mobile object externally of the wireless local area network regardless of whether the mobile object is an authorised client of the wireless local area network.

24. A communication method according to claim 23, in which the location signal transmitted by the wireless local area network is the received identification signal.

25. A communication method according to claim 23 or claim 24, in which the identification signal comprises a reference signal from the mobile object to identify the mobile object.

26. A communication method according to claim 26, in which the reference signal is a media access control address .

27. A communication method according to any one of claims 23 to 26, in which the location signal includes an object identifier.

28. A communication method according to any one of claims 23 to 27, in which the location signal comprises a location identifier, which location identifier identifies the wireless local area network having received the identification signal from the mobile object .

29. A communication method according to any one of claims 23 to 28, in which the location signal comprises a location identifier, which location identifier identifies the node having received the identification signal from the mobile object.

30. A communication method according to any one of claims 23 to 29, in which the local area network is a computer network comprising a plurality of networked computer nodes .

31. A communication method according to claim 30, in which a networked computer node is a personal computer.

32. A communication method according to any one of claims

23 to 31, in which there are a plurality of wireless local area networks capable of receiving mobile object identification signals and transmitting location signals externally thereof.

33. A communication method according to any one of claims 23 to 32, in which the location signal is transmitted to a predetermined web-site URL.

34. A communication method according to any one of claims 23 to 32, in which the system comprises a database relating node location signals to physical locations.

35. A communication method according to claim 34 when dependent on claim 33, in which the physical location is provided for the mobile object at the web-site.

36. A communication method according to any one of claims 23 to 35, in which the mobile object comprises communication means including a short range communication device.

37. A communication method according to claim 36, in which the communication means comprises a radio transmitter.

38. A communication method according to claim 36 or claim 37, in which the communication means comprises a transponder .

39. A communication method according to claim 38, in which the transponder is a network interface card or a bridge .

40. A communication method according to any one of claims 23 to 39, in which the system uses any of BLUETOOTH (trade mark), Home RF, Hyperlan, ETSI 300.328 or IEEE 802.11 communication protocols.

41. A communication method according to any one of claims 23 to 40, in which the wireless local area network communicates with the mobile object using the frequency band of the wireless local area network

42. A communication method according to any one of claims 23 to 41, in which a payment is made (which may be any form of consideration) to the local area network party for providing location information.

43. A communication method according to any one of claims 23 to 42, in which the mobile object comprises a mobile communication device.

44. A communication method according to claim 43, in which a mobile communication device comprises a wireless telephone.