GB2427101A

GB2427101A - Communication Terminal and System and a Method for establishing a Communication Link.

Info

Publication number: GB2427101A
Application number: GB0511808A
Authority: GB
Inventors: Jarosalv Novak
Original assignee: Motorola Inc
Current assignee: Motorola Solutions Inc
Priority date: 2005-06-10
Filing date: 2005-06-10
Publication date: 2006-12-13
Anticipated expiration: 2025-06-10
Also published as: GB2427101B; GB0511808D0

Abstract

A terminal such as mobile station (101) includes an RF transceiver (203) for communication by an RF link with another terminal (105) and an infrared transmitter (214) operable to send an infrared signal to the other terminal (105) to establish an initial communication link with the other terminal. Also described is a method of establishing a wireless communication link between a first terminal (101) and a second terminal (105) including sending an infra-red signal from the first terminal to the second terminal to request the second terminal to indicate its identity, sending a signal in response from the second terminal to the first terminal indicating the requested identity and using the requested identity received from the second terminal by the first terminal to establish an RF link with the second terminal. Also described is a system of terminals which can operate to form a communication link by the method.

Description

TITLE: COMMUNICATION TERMINAL, SYSTEM ND A METHOD FOR

ESTABLISHING A COMMUNICATION LINK

FIELD OF THE INVENTION

The present invention relates to communication terminal and a system and a method for establishing a wireless communication link. In particular the invention relates to setting up a communication link between a mobile station and another wireless terminal which may be another mobile station or a base station.

BACKGROUND OF THE INVENTION

Technologies are available to allow a user of a mobile station, such as a mobile telephone, a portable radio, a PDA (personal digital assistant) or a wireless capable computer (e.g. laptop), to send communications over a short range, high frequency RF link to another compatible terminal. Examples of such technologies include Bluetooth and WLAN (Wireless Local Area Network, which is also known as WiFi' or 802.11') both of which operate at an RF frequency of about 2.4 GHz. These technologies allow for example data to be sent wirelessly between related devices, e.g. a computer and a printer, or from a mobile station to a remote terminal by a radio network, a telephone network or the internet using an initial local RF link to obtain connectivity.

Although technologies such as Bluetooth and WLAN are very convenient to set up local RF links there is still a substantial finite delay in first setting up the link. For example, if a mobile station is being used in a public place to set up a local communication link there are likely to be a number of compatible devices in the local area with which the mobile station could communicate via the selected wireless protocol. Thus, it is necessary to request the mobile station to search for compatible devices in the local area by an RF scanning procedure by which identifying signals from the compatible devices present are picked up and decoded by the mobile station. A list of such devices found is produced by the mobile station. The user then has to review the list, select the identity of a target device from the list, e.g. by reference to an alias name familiar to the user, and to enter a PIN (personal identity number), previously agreed upon between the user and the user of the target device, to establish a connection with the selected device. This procedure can be slow and inconvenient to users who wish to establish a rapid connection.

SUMMARY OF THE INVENTION

According to the present invention in a first aspect there is provided a communication terminal as defined in claim 1 of the accompanying claims.

According to the present invention in a second aspect there is provided a method as defined in claim 21 of the accompanying claims.

According to the present invention in a third aspect there is provided a system as defined in claim 24 of the accompanying claims.

Further features of the invention are defined in the accompanying dependent claims and are disclosed in the embodiments of the invention to be described.

Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing an arrangement of wireless terminals in a local area cluster.

FIG. 2 is a block schematic diagram of a layout of components in a mobile station in the arrangement of FIG. 1 and embodying the invention.

FIG. 3 is a front view of a handset which is a mobile station embodying the invention.

DESCRIPTION OF E}ODIMENTS OF THE INVENTION

FIG. 1 shows an arrangement 100 of wireless terminals including MSs (mobile stations) including an MS 101, an MS 103, an MS 104, an MS 105 and an MS 106 in a local area cluster. Also shown in FIG. 1 is a BS (base station) 102. In practice there may be many more MSs in the local area cluster than the MSs shown in FIG. 1.

Assume that it is desired for an RF link to be established between the MS 101 and the MS 105, e.g. to send data from the MS 101 to the MS 105. The RF link required may need to be established directly, e.g. as a Bluetooth link, or may need to be established via the BS 102, e.g. as a WLAN link. Since there are several other MSs near the MS 105 it is necessary for a procedure to be applied by the MS 101 to select the MS 105 as the target MS with which it is to communicate by an RF link.

As mentioned earlier, the known procedure involves the MS 101 or the BS 102 on behalf of the MS 101 scanning the area to detect signals from other compatible MSs that are active in the area and to produce a list of the identities of the detected MS5. The list may be displayed on an electro-optical display included in the MS 101 so that the user may select an appropriate identity. Then the user selects the appropriate identity and enters a PIN to initiate the establishment of the required link. As noted earlier, this known procedure is relatively slow.

In accordance with an embodiment of the invention, each of the MS 101 and the MS 105 is equipped with an infra-red transmitter and an infra-red receiver and an initial link is established rapidly between the MS 101 and the MS 105 by infra-red signalling. Infra-red signalling is known per Se. In a preferred example, the infra-red signalling used may be signalling according to the standards defined by the IrDA (Infrared Data Association') which specifies wireless transfer of data by infra-red radiation. The IrDA standards include specification of physical infra-red devices to be used as well as the protocols such devices should use to communicate with one another. Generally, IrDA devices communicate using transmissions from infra-red light emitting diodes (LED5) operating at a wavelength of 875nm with a production tolerance of about 3Onm. IrDA receivers utilise PIN semiconductor photodiodes working in a generation' mode together with a filter which only allows certain defined frequencies for a particular IrDA modulation to pass. Such infra-red transmitter and receiver devices are known per se and are commercially available.

There is a direct relationship between the energy of the received radiation and the charge generated by the receiver in such infra-red signalling. Generally, data is sent between a transmitter terminal and a receiver terminal using pulse modulation in which infra- red pulses are transmitted with the pulses representing 1' digits and the spaces between pulses representing 0' digits.

It is known that infra-red communication links work well over short distances only, although the maximum suitable distance may be increased by reducing data transmission speed from a possible maximum and by use of suitably designed transmitter and receiver optics. Thus links operating suitably over distances of tens of metres are practicable.

Rapid communication links may be established using IrDA protocols, including IrSimple Connect' in which transfer of data may begin almost instantaneously between a transmitting device and a receiving device. In the context of the present invention, the MS 101 in FIG.l is pointed at the MS 105 and a rapid infra-red link is established. The MS 101 may conveniently include on its user interface a button, e.g. a button 303 as in FIG. 3, to be operated by the user which initiates rapid establishment of the infra-red link between the MS 101 and the MS 105.

FIG. 2 shows a layout 200 of components of the MS 101. The MS 105 and the other MSs shown in FIG. 1, i.e. the MSs 103, 104 and 106, have the same layout 200. The main operations of the MS 101 are controlled by a controller 201 which operates in conjunction with a timer 209 which synchronises operations and a memory 210 which stores data and programs used within the MS 101. A processor 202 processes information to be included in RF signals sent and received by a RF transceiver 203. The processor 202 extracts information, e.g. electrical signals representing speech or data signals, from a received RF signal detected by the RF transceiver 203 and passes speech information to an audio output 204 which is a transducer such as a speaker which converts the information to an output in audible form for delivery to a user. An audio input 205 is a transducer which converts an input audio signal, e.g. in the form of speech, into an electrical form. The audio input 205 passes input electrical signals representing speech to the processor 202. A video input 212 such as a video camera converts an input video signal into an electrical form. The video input 212 passes input electrical signals representing video signals to the processor 202.

Input electrical signals delivered to the processor 202 are processed for sending in an RE' signal by the transceiver 203. The MS 101 includes a user interface 213. This allows control signals and data to be entered by a user. The user interface 213 may for example be a keyboard together with a set of control buttons. Signals from the user interface 213 which are control signals are delivered to the controller 201 which applies appropriate operational functions of the MS as indicated by the signals. Signals from the user interface 213 which represent data required by the user to be sent from the MS 101 to another terminal, e.g. the MS 105, are passed to the processor 202 for processing into signals to be sent by the RF transceiver 203. An electro-optical display 207 operated by a display driver 206 under control of the controller 201 provides displayed information to a user of the MS 101 in a known manner. The display 207 also serves as an output for video or data information to be displayed to the user, including information extracted by the processor 202 from incoming RF signals received by the RF transceiver 203. A battery 211 provides operation power to all operational components of the MS 101.

The RF transceiver 203 provides RF communications to and from other RF transceivers such as in the MSs 103-106. In accordance with an embodiment of the invention, the MS 101 includes an IR (infra-red) transmitter 214, and an IR receiver 215. These devices may be of the form described earlier. Transmitted infra- red signals from the IR transmitter 214 are passed in the form of an IR beam through IR optics 216, typically one or more lenses to enhance directivity of the transmitted beam. Similarly, received IR signals, e.g. from the MS 105 shown in FIG. 1, in the form of an IR beam, are focused by the IR optics 216 onto the IR receiver 215. A processor 217 is operably coupled to the IR transmitter 214 and to the IR receiver 215. The processor 217 serves to code and decode IR signals sent and received by the IR transmitter 214 and the IR receiver 215. The processor 217 is also operably coupled to the processor 202, the controller 201 and the memory 210.

Operation of the MS 101 incorporating the layout to establish communication with the MS 105 may be as follows. The user of the MS 101 can see the user of the MS 105 and the MS 101 is orientated so that the infra- red transmitter 214 is pointed at the MS 105, e.g. in a manner described later with reference to FIG. 3. The user of the MS 101 enters via the user interface 213 a control signal which is received by the controller 201 and is understood by the controller 201 to establish a communication link with the MS 105. The controller 201 instructs the processor 217 to code a message to send by IR signalling from the IR transmitter 214 to the target MS 105. The form of the message to be sent may be a simple standard message stored in the memory 210. The simple standard message may for example be a code number which is to be understood as an identity request by a receiving terminal. The message sent is received by the IR receiver 215 of the MS 105 and is passed via the processor 217 of the MS 105 to the controller 201 of the MS 105. The controller 201 of the MS 105 recognises the received message as a request for its identity to be used in establishing RF communication. The controller 201 instructs the processor 217 of the MS 105 to prepare a message in reply giving the requested identity of the MS 105. The processor 217 of the MS 105 prepares the reply message as a coding for a returned IR signal and this signal is sent by the IR transmitter 214 of the MS back to the MS 101. The returned message may for example comprise a first code indicating that the message is to indicate an identity for use in RF communications and a second code indicating the identity to be used in RF communications to form a link with the MS 105.

In a more elaborate example, where the MS 105 is able to communicate by more than one RF protocol (one at a time), e.g. by Bluetooth and WLAN, it may give identity codes for use with each of these different protocols.

The returned message from the MS 105 is received by the IR receiver 215 of the MS 101 and is decoded by the processor 217 of the MS 101 and passed to the controller 201 of the MS 101 where it is understood. The processor 217 of the MS 101 also passes the required identity information to the processor 202 of the MS 101. The controller 201 of the MS 101 instructs the processor 202 of the MS 101 to establish an RF link with the MS 105 using the received identity information from the MS 105.

The processor 202 thus prepares a message to be sent to the MS 105 to establish an RF connection. This message is included in a signal transmitted by the RF transceiver 203. Formation of an RF link is thereby established and communication of information, which may include speech, although is more likely to include data or video information, as well as system control information required by the communication protocol selected, is exchanged between the MS 101 and the MS 105 by RF communication in a known manner.

Beneficially, the identity of the target MS 105 required for establishment of an RF link between the MS 101 and the MS 105 may, by using an initial IR link in the manner described, be established more quickly, e.g. three or more times more quicly, than in the prior art method involving an RF scanning procedure to obtain a list of potential target MSs described earlier.

Although the embodiment of the invention above has been described in terms of the MS 101 forming an RF link with another MS, namely the MS 105, a similar procedure may be used to form a link between the MS 101 and the BS 102 which is assumed to be fixed in position. In this case the MS 101 is pointed at the BS 102 and an initial IR link is established providing IR signalling between the MS 101 and the BS 102 leading to an RF link using RF link data which has been exchanged by IR signalling.

Although the layout 200 of the MSs 101 and 105 as shown in FIG. 2 includes only one RF transceiver 203, the MS 101 and 105 could include more than one RF transceiver, each dedicated to operate in a particular RF communications system, e.g. a Bluetooth or WLAN system or in a UHF network such as a cellular or trunked wireless network such as a GSM, TETRA or APCO 25 network.

The MSs 101 and 105 (and, if appropriate, the MSs 103, 104 and 106) described with reference to FIG.s 1 and 2 may take various forms. For example these devices may comprise a mobile telephone, a portable radio, a PDA (personal digital assistant), a wireless capable portable computer (e.g. laptop) a portable MP3/DVD player, or a camera such as a digital photographic or video camera. Desirably, the form of the MSs 101 and 105 includes a handset which facilitates a user pointing at another terminal as described earlier. The handset may itself include all of the components of the mobile station or alternatively it may be an auxiliary peripheral device connected to a main body of the mobile station, e.g. where the mobile station comprises a

portable computer.

FIG. 3 illustrates a handset 300 which is a particular form of the MSs 101 and 105, e.g. where these devices are radios or mobile telephone handsets. The handset 300 includes a casing 301 on the front face of which is provided a keypad 302 and several control buttons including a prominent button 303. A display 304 is also provided on the front face. The handset 300 includes an RF antenna 309 inside the casing 301 and an IR transmitter/detector unit 305 also inside the casing 301. The IR transmitter/detector unit 305 is adjacent to the top end of the casing 301 (as seen in FIG. 3) . An indicator light 306 (e.g. comprising a red LED) is also provided on the front face of the casing 301 at its top or front end. A speaker 307 and a microphone 308 are also fitted inside the casing 301.

In operation, the handset 300 is orientated by its user so that the top of the casing 301 as indicated by the light 306 is pointing at the target terminal, e.g. the MS 105, with which a communication link is required.

When the correct orientation has been selected, the button 303 is pressed by the user to initiate an IR link in the manner described earlier. Eventually, an RF link is established and speech, data or video communication takes place by RF communication with the mobile station operating in a known manner. The progress of establishing the communication link may be indicated to a user on the display 304 and/or by the indicator light 306. For example, the display 304 may indicate the identity of the target MS. e.g. MS 105, when the IR link has been established and optionally when the progress steps in establishing the link have been completed.

The RF communication link which is established in the manner which has been described using an initial IR link may be a short range RF link such as a Bluetooth or WLAN link. The short range RF link may be suitable for a required communication to take place between two user MS5. However, the short range link may itself be employed to form a link in a known manner to a wider area communication network such as a TETRA or APCO 25 or a GSM cellular network. This latter link may be established for example where the initial IR link from the MS 101 is with a base station such as the BS 102.

Claims

1. A communication terminal including an RF transceiver for communication by an RF link with another terminal and an infra-red transmitter operable to send an infra-red signal to the other terminal to establish a communication link with the other terminal.

2. A communication terminal according to claim 1 including also an infrared receiver to receive an infra-red signal from the other terminal.

3. A communication terminal according to claim 1 or claim 2 wherein the infra-red transmitter is operable to send to the other terminal an infrared signal including an identity request message requesting the other terminal to indicate its identity.

4. A communication terminal according to claim 2 or claim 3 wherein the infra-red receiver is operable to receive an infra-red signal from the other terminal in response to a sent identity request message, the received signal including a message indicating an identity of the other terminal.

5. A communication terminal according to claim 3 or claim 4 wherein the identity requested is an identity code required by the mobile station to establish an RF link with the other terminal.

6. A communication terminal according to claim 5 wherein the identity code is associated with a RF communication protocol.

7. A communication terminal according to claim 6 wherein the received signal includes a message indicating a plurality of identity codes, each associated with a different RF communication protocol.

8. A communication terminal according to claim 6 or claim 7 wherein the RF communication protocol is Bluetooth protocol or WLAN (wireless local area network) protocol or both.

9. A communication terminal according to any one of claims 5 to 8 which is operable to establish an RF link with the other terminal using an identity code included in the received infra-red signal.

10. A communication terminal according to any one of the preceding claims which includes a first signal processor to process infra-red signals to be sent and received by the terminal, a second signal processor to process RF signals to be sent and received by the terminal and a controller to control functional operations of the terminal.

11. A communication terminal according to claim 10 wherein the controller is operable to instruct the first processor to send via the infra-red transmitter an infra-red signal to establish an infra-red link with another terminal and to instruct the second processor to send via the RF transceiver an RF signal using an identity code for the other terminal obtained by the infra-red link.

12. A communication terminal according to any one of the preceding claims which is operable to communicate with other terminals by a plurality of different RF protocols.

13. A communication terminal according to claim 12 wherein the RF protocols include Bluetooth and WLAN (wireless local area network) protocols.

14. A communication terminal according to any one of claims 10 to 13 wherein at least two of the first processor, the second processor and the controller are formed in a common microprocessor.

15. A communication terminal according to any one of the preceding claims which comprises a mobile station.

16. A communication terminal according to claim 15 wherein the mobile station comprises a portable radio, a mobile telephone, a personal digital assistant, a data communication terminal or a wireless enabled portable computer, disk player or camera.

17. A communication terminal according to claim 15 or claim 16 wherein the mobile station comprises a handset configured to facilitate a user pointing at a target terminal to establish an infra-red link with that terminal.

18. A communication terminal according to claim 15 wherein the handset is a peripheral device connectible to another device.

19. A communication terminal according to claim 18 wherein the peripheral device is connected to a portable computer.

20. A communication terminal according to any one of the preceding claims wherein the terminal is operable to send and receive infra red signals in accordance with standards defined by the IrDA (Infrared Data Association')

21. A method of establishing a wireless communication link between a first terminal and a second terminal including sending an infra-red signal from the first terminal to the second terminal to request the second terminal to indicate its identity, sending a signal in response from the second terminal to the first terminal indicating the requested identity and using the requested identity received from the second terminal by the first terminal to establish an RF link with the second terminal.

22. A method according to claim 21 wherein the signal sent in response from the second terminal to the first terminal is an infra-red signal.

23. A system according to claim 24 and substantially as herein described with reference to FIG. 1 of the accompanying drawings.

23. A method according to claim 21 or claim 22 wherein at least one of the first and second terminals is a mobile station.

24. A communication system including a plurality of terminals operable to communicate with one another, wherein the terminals are as claimed in any one of claims 1 to 20.

21. A communication terminal according to claim 1 and substantially as herein described with reference to FIG. 2 or FIG. 3 or both of the accompanying drawings.

22. A method according to claim 21 and substantially as herein described with reference to FIG. 1 of the accompanying drawings.