US00758.0005B1
`
`(12) United States Patent
`Palin
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 7,580,005 B1
`Aug. 25, 2009
`
`(54) DISPLAY CHANGE BETWEEN MOBILE
`TERMINAL DISPLAY AND EXTERNAL
`DEVICE DISPLAY
`(75) Inventor: Arto Palin, Lemp??l? (FI)
`
`6,453,160 B1* 9/2002 Thomas et al. .............. 455/419
`6,496,122 B2 * 12/2002 Sampsell ............... 340/825.69
`6,580,422 B1* 6/2003 Reilly ........................ 345/169
`:};
`6,611,358 B1
`8/2003 Narayanaswamy .......... 358/442
`
`(Continued)
`FOREIGN PATENT DOCUMENTS
`
`DE
`
`197 19 908 A1 1 1/1998
`
`Continued
`(Continued)
`OTHER PUBLICATIONS
`-
`-
`... -
`-
`EPC Article 96(2) Communication (dated Nov. 5, 2002) in EPO
`Application No. 01660 146.0-1525.
`pplication No
`Primary Examiner—Hau H Nguyen
`(74) Attorney, Agent, or Firm Locke Lord Bissell & Liddell
`LLP
`
`(57)
`
`ABSTRACT
`
`(73) Assignee: Nokia Corporation, Espoo (FI)
`(*) Notice:
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`(21) Appl. No.: 09/639,196
`(22) Filed:
`Aug. 15, 2000
`(51) Int. Cl.
`(2006.01)
`G09G 5/06)
`(52) U.S. Cl. .......................... 345/1.1, 345/1.2: 345/2.1;
`345/2.3
`-
`(58) Field of Classification Search ................ 340/5.61.
`340/825.72: 345/2, 352, 1.1, 1.2, 2.1, 2.3:
`455/550, 576, 41.2, 41.3, 556, 557, 566;
`370/473, 474, 476; 348/552, 555; 715/716–718,
`71.5/961
`See application file for complete search history.
`References Cited
`A system is provided for transmitting an image from a first
`|U.S. PATENT DOCUMENTS
`5,307,055 A * 4/1994 Baskin et al. ................ 345/2.2 . º º º º º a º
`5,550,593 A * 8/1996 Nakabayashi
`1splay device having different display capabilities. The
`5,666,159 A * 9/1997 Parulski et al. ........... 348/211.2
`image may be received by the first display device as data 1Il &l
`5,734,413 A * 3/1998 Lappington et al. ......... 725/141
`packet or plurality of packets. The packets are split by a
`5,831,664 A * 11/1998 Wharton et al.
`splitting application into data to be displayed on the first
`5,850,340 A 12/1998 York .......................... 364/188
`display device, if any, and data to be displayed on the second
`5,880,732 A * 3/1999 Tryding ...................... 345/810
`display device. The data to be displayed on the second display
`6.002450 A
`121999 Darbee et al................. 348/734
`device is reformatted at the first display device to be trans
`6,064,420 A : 52000 Harrison et al. ............. 7.25/136
`mitted over a wireless, short range communication link, such
`6,084,584 A :};
`7/2000 Nahi et al.
`as a Bluetooth link. The system thereby enables the display on
`
`(56)
`
`3-, -, * *
`
`y
`
`-
`
`-
`
`-
`
`-
`
`-
`
`6,097,441 A.
`
`8/2000 Allport. - - - - - - - - - - - - - - - - - - - - - - - 34.8/552
`
`6,122,526 A * 9/2000 Parulski et al. ........... 455/556.1
`6,227,043 B1* 5/2001 Schoenbeck et al. .......... 7.3/116
`6,287,200 B1* 9/2001 Sharma
`6,297,737 B1 + 10/2001 Irvin
`6,357,042 B2 * 3/2002 Srinivasan
`
`the second display device ofan image that either could not be
`
`displayed on the first display device or could not be displayed
`ith th
`biliti
`he first display devi
`with the same capabilities as on the first display device.
`
`16 Claims, 9 Drawing Sheets
`
`
`
`13
`
`248
`
`SERVICE
`PROVIDER
`
`SPLITTING APPLICATION
`
`33
`
`TV
`APPLICATION
`
`GSM/EDGE/
`WCDMA
`PROTOCOL
`STACK
`
`GSM/EDGE/
`WCDMA
`PROTOCOL
`STACK
`
`BLUETOOTH
`PROTOCOL
`STACK
`
`
`
`BLUETOOTH
`PROTOCOL
`STACK
`
`12
`
`22
`
`HTC EXHIBIT 1010
`
`Page 1 of 17
`
`

`

`US 7,580,005 B1
`Page 2
`
`|U.S. PATENT DOCUMENTS
`6,765,557 B1 * 7/2004 Segal et al. ................. 345/173
`6.792,148 B1* 9/2004 Wergeland et al. .......... 382,232
`6,795,715 B1* 9/2004 Kubo et al. .............. 455/556.1
`6,968,365 B2 * 1 1/2005 Hollstrom et al. ........... 709/217
`FOREIGN PATENT DOCUMENTS
`9/1990
`() 426 966 A2
`
`
`
`EP
`
`GB
`WO
`W9
`WO
`WO
`
`2 348 083 A
`WO 98/16062
`WO 99/34564
`WO 99/34599
`WO 00/18025
`
`9/2000
`4/1998
`7/1999
`7/1999
`3/2000
`
`* cited by examiner
`
`Page 2 of 17
`
`

`

`U.S. Patent
`
`Aug. 25, 2009
`
`Sheet 1 of 9
`
`US 7,580,005 B1
`
`BASE STATION
`
`
`
`12
`
`FIG. 1(a)
`
`TV RECEIVER
`
`30
`
`GSM/EDGE/WCDMA
`TERMINAL
`
`
`
`SERVICE
`PROVIDER
`
`SPLITTING APPLICATION
`
`TV
`APPLICATION
`
`GSM/EDGE/
`WCDMA
`PROTOCOL
`STACK
`
`GSM/EDGE/
`WCDMA
`PROTOCOL
`STACK
`
`BLUETOOTH
`PROTOCOL
`STACK
`
`BLUETOOTH
`PROTOCOL
`STACK
`
`FIG. 1(b)
`
`Page 3 of 17
`
`

`

`U.S. Patent
`
`Aug. 25, 2009
`
`Sheet 2 of 9
`
`US 7,580,005 B1
`
`
`
`216
`
`DISPLAY
`
`§§§§§5|| SPLTTING || Nº. 206
`TRANSCEIVERI ºn TRANSCEIVER
`
`STORAGE
`
`MEMORY
`
`FIG. 2
`
`Page 4 of 17
`
`

`

`U.S. Patent
`
`Aug. 25, 2009
`
`Sheet 3 of 9
`
`US 7,580,005 B1
`
`
`
`RECEIVE PACKETS FROM WIRELESS
`COMMUNICATIONS NETWORK
`
`SPLITTING APPLICATION
`
`ASSEMBLE DATA ADDRESSED TO
`EXTERNAL DISPLAY DEVICE
`RECEIVER INTO SHORT RANGE RF
`COMPLIANT PACKETS
`
`FIG. 3
`
`Page 5 of 17
`
`

`

`U.S. Patent
`
`Aug. 25, 2009
`
`Sheet 4 of 9
`
`US 7,580,005 B1
`
`58
`
`54
`
`56
`
`HEADER wºot
`
`TV RECEIVER PART
`
`FIG. 4(a)
`
`58
`
`54
`
`60
`
`56
`
`
`
`HEADER wºot HEADER
`
`TV RECEIVER PART
`
`52
`
`FIG. 4(b)
`
`Page 6 of 17
`
`

`

`U.S. Patent
`
`Aug. 25, 2009
`
`Sheet 5 of 9
`
`US 7,580,005 B1
`
`YT 65
`
`90
`
`T
`82 APPLICATIONS ,84
`——w-M"
`
`86
`
`
`
`\)
`
`AUDIO
`
`'
`LINK MANAGER
`=4–%
`
`
`
`
`
`88
`
`
`
`
`
`
`
`FIG. 5
`
`Page 7 of 17
`
`

`

`U.S. Patent
`
`Aug. 25, 2009
`
`Sheet 6 of 9
`
`US 7,580,005 B1
`
`LSB 72
`
`54
`
`ACCESS
`CODE
`
`D
`HEADER
`
`
`
`95
`
`0-2745
`
`MSB
`
`
`
`PAYLOAD
`
`96
`
`97
`
`98
`
`FIG. 6
`
`Page 8 of 17
`
`

`

`U.S. Patent
`
`Aug. 25, 2009
`
`Sheet 7 of 9
`
`US 7,580,005 B1
`
`ESTABLISH CONNECTION BETWEEN MOBILE
`TERMINAL AND EXTERNAL DISPLAY DEVICE
`
`100
`
`
`
`SEND SHORT RANGE RF DATA PACKETS FROM
`MOBILE TERMINAL TO EXTERNAL DISPLAY
`DEVICE
`
`102
`
`BUFFER DATA PACKETSAT EXTERNAL
`DISPLAY DEVICE
`
`104
`
`STRIP ACCESS CODE AND HEADER(S) FROM
`PAYLOAD
`
`106
`
`REASSEMBLE PAYLOADS INTO DATASTREAMH-108
`
`FIG. 7
`
`Page 9 of 17
`
`

`

`U.S. Patent
`
`Aug. 25, 2009
`
`Sheet 8 of 9
`
`US 7,580,005 B1
`
`PACKET. 1
`
`PACKET2
`
`MASTER
`(MOBILE PHONE)
`20
`
`i
`DATA
`
`SLAVE
`(TV RECEIVER)
`30
`
`
`
`
`
`a
`il---.
`DATA: 110s:
`#11.
`
`FIG. 8
`
`Page 10 of 17
`
`

`

`U.S. Patent
`
`Aug. 25, 2009
`
`Sheet 9 of 9
`
`US 7,580,005 B1
`
`PACKET 1
`
`PACKET 2
`
`MASTER
`(MOBILEPHONE)
`20
`
`
`
`SLAVE
`H–
`(TVRECEIVER)
`30 2–~
`TIMESLOT 1
`TIMESLOT 2
`
`FIG. 9
`
`Page 11 of 17
`
`

`

`1
`DISPLAY CHANGE BETWEEN MOBILE
`TERMINAL DISPLAY AND EXTERNAL
`DEVICE DISPLAY
`
`BACKGROUND OF THE INVENTION
`
`10
`
`15
`
`20
`
`25
`
`30
`
`1. Field of the Invention
`This invention relates to the field of showing images on
`different display devices, and particularly to display devices
`which have different capabilities for viewing the content.
`2. Description of the Related Art
`Messages may be transmitted over a wireless communica
`tions network to a mobile terminal, such as mobile phone,
`together with, or independently of an audio signal. The mes
`sage may contain various types of content to serve various
`functions, that are already publicly available or are becoming
`available shortly. The content may consist of still pictures or
`video. These messages may be automatically sent to a recipi
`ent or there may be services which respond to a recipient’s
`request for a specific service.
`The display capabilities of currently available mobile ter
`minals are limited because of the size and weight require
`ments on these compact devices. A mobile terminal display
`may be provided to view an incoming video signal, but
`because of the above mentioned facts, users would not enjoy
`watching multiformatted images or video on such a display.
`This problem with a small display is especially problematic
`for visually impaired people.
`It is therefore desirable to find a way to view the content
`received with a mobile terminal on a separate display that has
`better display capabilities. A television receiver display or a
`computer monitor are examples of this kind of display having
`better display capabilities. Being able to display video sent
`over a mobile terminal on a larger display device, like a
`television display, would also allow a service provider to
`provide additional optional services to provide a user with
`added value, and avoid unnecessarily draining of the mobile
`terminal’s battery by displaying the video on a separate dis
`play device that has a separate power source.
`Recently, low power RF systems have been proposed for
`providing communications between a plurality of transceiv
`ers through a short range communications link. One such
`short range RF technology is currently under development
`and is referred to as “Bluetooth”. This system will be com
`mercially available in the near future and it operates in the
`45
`open spectrum around 2.45 GHz. This unlicensed radio band,
`called Industrial, Scientific, Medical (ISM) band is globally
`available. The operating range of this RF system is approxi
`mately 10 meters for a normal power mode and has proven to
`be economically efficient. It is planned that a Bluetooth chip
`50
`having these characteristics will be inserted in all kinds of
`electrical devices for enabling communication between sepa
`rate devices. In PCT Application No. WO 0018025, such a
`Bluetooth link between a Bluetooth enabled mobile terminal
`and a Bluetooth enabled data terminal, such as a PC, is dis
`closed.
`It would be particularly advantageous to enable the user to
`view the content, such as a video clip on a larger display,
`while the user is actually holding the mobile terminal, and
`allow the user to select what is viewed using the mobile
`terminal, or to otherwise use the mobile device while viewing
`the video clip. This would be best implemented using a wire
`less link between the mobile terminal and the external display
`device. U.S. Pat. No. 5,880,732 presents a method and appa
`ratus enabling one specific type of usage of a remote display
`device connected to a mobile telephone. However, the inven
`tion offers only a partial solution to the problem, because the
`
`35
`
`40
`
`55
`
`60
`
`65
`
`US 7,580,005 B1
`
`2
`system allows only the textual message appearing on the
`telephone display to be viewed on the remote display. The
`system does not take into consideration the different display
`ing capabilities of the devices such as that the remote display
`may be capable of displaying images that the mobile tele
`phone cannot, which makes the system inadequate for effec
`tive use.
`
`SUMMARY OF THE INVENTION
`
`It is therefore an object of this invention to presenta system
`and method for wirelessly linking display devices having
`different display capabilities to provide better display quality
`to a user of a mobile terminal with an economic and efficient
`short range RF link.
`This invention concentrates on providing better display
`quality to a user of a mobile device. The mobile device, such
`as a mobile phone, laptop computer, or personal digital assis
`tant (PDA), may be provided with a Bluetooth chip conform
`ing to the Bluetooth standards described in Bluetooth speci
`fication v.1.0B, and another display device, like a television
`apparatus in the vicinity of the mobile device, is likewise
`provided with a similar Bluetooth chip, thereby enabling a
`short range RF communications link between the two
`devices. The mobile terminal receives image data from a base
`station in a wireless communications network or from
`another device utilizing any transmission method, including,
`but not limited to GSM, EDGE, WCDMA, DAB, DVB or
`Bluetooth link. As used herein, the term “image” is used
`interchangeably with the term “video” and includes a single
`image, picture, or graphic, a stream or plurality of still pic
`tures, or graphics, or a conventional video.
`The system in this invention consists of a first display
`device and a second display device having a communication
`link between them. The communication link is arranged
`between said display devices by a short range RF communi
`cation link. The image on the first display is viewed as taking
`into consideration the capabilities of the first display device,
`and the image on the second display device is viewed as
`taking into consideration the different display capabilities of
`the second display device. This can be done by splitting the
`received payload at the first display device into a plurality of
`data packets with a specific splitting application and identi
`fying the packets to first display device part(s) and second
`display device part(s), which takes into consideration the
`display capabilities of the first and second display devices.
`The first display device also has means for establishing a
`first wireless communication link with a communications
`network and means for establishing a second wireless com
`munication link with a second display device. After splitting
`the payload into a plurality of data packets, the first display
`device forwards at least one of the data packets to the second
`display device having different display capabilities.
`The image data received by the mobile terminal comprises
`data to be ultimately reassembled into an image to be dis
`played on a display either on the mobile device, on an another
`display device, or on both of these devices. Because the
`mobile device may or may not have a display, and at best, will
`have a relatively small display on which it is difficult to view
`the image, the image data is retransmitted using a short range
`RF link, such as Bluetooth link, to an external display device
`for improved viewing quality. The improved viewing quality
`also enables a service provider to provide more advanced and
`better quality services to customers, such as images and/or
`video movies with higher quality resolution than could be
`effectively displayed on an ordinary display of a mobile
`phone.
`
`Page 12 of 17
`
`

`

`US 7,580,005 B1
`
`3
`The image data received by the mobile terminal is included
`within the first packet or a plurality of packets of a type
`appropriate to the wireless transmission method used. In
`addition to the data to be forwarded to the external display
`device, the packets received by the mobile terminal may
`contain data that may be used exclusively at the mobile ter
`minal, such as voice data, control data, image data, or data for
`a displayable menu for the mobile terminal. The mobile ter
`minal may have an application that splits the data packets
`received by the mobile device and forwards part of the data to
`the mobile terminal’s own display and another part of the data
`for transmission with a short range RF link in an appropriate
`format to the external display device. At the external device,
`the short range RF data packets are reassembled into an image
`or video, as originally sent, for viewing on the external dis
`play device.
`Other objects and features of the present invention will
`become apparent from the following detailed description
`considered in conjunction with the accompanying drawings.
`It is to be understood, however, that drawings are designed
`solely for purposes of illustration and not as a definition of the
`limits of the invention, for which reference should be made to
`the appended claims. It should be further understood that the
`drawings are not necessarily drawn to scale and that, unless
`otherwise indicated, they are merely intended to conceptually
`illustrate the structures and procedures described herein.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`In the drawings wherein like reference numerals denote
`similar elements throughout the several views:
`FIG. 1(a) is a schematic representation of a base station,
`mobile phone and an external display device;
`FIG.1(b) is a block diagram of the basic protocol path from
`base station to television receiver, that may be used in prac
`ticing the present invention;
`FIG. 2 is a simplified picture illustrating the structure of the
`mobile terminal in the view of this invention;
`FIG. 3 is a flow chart of the method for handling the video
`data to be retransmitted to the external display device at the
`wireless device;
`FIG. 4(a) is a plan view of a first possible data frame
`structure for transmitting a combined audio and video signal;
`FIG. 4(b) is a plan view of a second possible data frame
`structure for transmitting a combined audio and video signal;
`FIG. 5 is a schematic representation of the Bluetooth pro
`tocol stack;
`FIG. 6 is a plan view of the standard Bluetooth packet
`format;
`FIG. 7 is a flow chart of the method of transmitting video
`data from the wireless device to the external display device;
`FIG. 8 is a diagrammatical view of a method for broadcast
`ing the video packets from the mobile device to the external
`display device; and
`FIG. 9 is a diagrammatical view of a method for transmit
`ting the video packets from the mobile device to the external
`display device using a specific polling scheme.
`
`4
`Broadcasting) or DVB (Digital video broadcasting); although
`technologies with faster data transmission rates, like EDGE,
`WCDMA or DVB are preferred over GSM and DAB tech
`nologies.
`In FIG. 1(a) is shown the basics of this invention. A con
`ventional wireless connection has a wireless link 12 between
`the base station 10 of a service provider 13 and the mobile
`terminal 20 to exchange the conventional radio frequency
`(RF) signals that pass between the base station 10 of a service
`provider 13 and the mobile terminal 20. Signals may be
`received by and transmitted to base station 10 from the mobile
`terminal 20. A protocol stack 15 specific to the transmission
`method used at the base station 10 handles the transmission
`and a similar protocol stack 25 at a mobile terminal 20
`handles the received signal as shown in FIG. 1(b). A wireless
`short range RF link 22, e.g., a Bluetooth link, is also estab
`lished between the mobile terminal and external display
`device, like a television receiver 30 or a computer monitor.
`This requires that the mobile terminal can establish this short
`range RF link. The Bluetooth link can be established with a
`Bluetooth chip manufactured according to the Bluetooth
`Specification Version 1.0B and standards (available on the
`internet at the “bluetooth.net” Web site).
`In one implementation, a Bluetooth chip is connected to the
`printed circuit board of the mobile terminal 20. The external
`display must also be outfitted with a Bluetooth chip, which
`may be installed on the printed circuit board of the external
`display device (television receiver 30 in this example), or may
`be otherwise connected to the display device, such as with an
`external device plugged in to the display device (not shown in
`FIG. 1(a)).
`The Bluetooth link 22 does not require the mobile terminal
`20 and the TV 30 to be within direct line-of-sight with each
`other, but the devices must be inside the transmission/recep
`tion range of the Bluetooth chips for the signal from the
`mobile terminal 20 to be received in the TV 30. As earlier
`stated, the operating range of Bluetooth using normal 0 dBm
`transmission power is approximately 10 meters, which pre
`sents no problem for mobile terminal users who wish to view
`video on a television display and be able to control the video
`content with the terminal because users rarely watch televi
`sion at distances farther than 10 meters. The Bluetooth stan
`dard presently supports an asynchronous data channel, as
`many as three synchronous voice channels, or a channel,
`which simultaneously supports asynchronous data and asyn
`chronous voice. Associated with each of the Bluetooth chips
`at the mobile terminal 20 and the television receiver 30 is a
`multilayer Bluetooth protocol stack 65, 66, respectively, used
`for setting up and maintaining a Bluetooth link 22 between
`these Bluetooth-enabled devices.
`Where video capabilities are provided, a conventional
`communication link 12 may be set up initially as an audio
`only call with the allowance for subsequent requests for video
`or link 12 may be initially set up to transmit audio and/or
`video. At the setup of service for mobile terminal 20, at a call
`setup, or at some other time, the base station 10 must be
`informed whether or not the mobile terminal 20 has a video
`capability or can transmit the video to a nearby Bluetooth
`enabled display device for viewing, and if so, the level of
`graphics that is enabled, such as whether high quality graph
`ics can be received and viewed. A user may request that a
`radio signal containing video content be transmitted from the
`communications network via a base station 10 to mobile
`terminal 20. Alternatively, the base station 10 may simply
`begin transmitting a video signal when it has a video to send.
`Although the discussion herein focuses on sending a com
`bined audio and video signal, it should be understood that the
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`DETAILED DESCRIPTION OF THE PRESENTLY
`PREFERRED EMBODIMENTS
`
`60
`
`The present invention may be implemented in conjunction
`with a wireless communications network using any wireless
`transmission methods, such as known methods like GSM
`(Global System for Mobile Communications), EDGE (En
`65
`hanced Data Rates for GSM Evolution), WCDMA (Wide
`band Code Division Multiple Access), DAB (Digital Audio
`
`Page 13 of 17
`
`

`

`US 7,580,005 B1
`
`5
`invention is equally applicable to the transmission and han
`dling of a video only signal or an audio only signal. It should
`be further understood that, rather than being transmitted from
`a base station, the signal may be transmitted to a mobile
`terminal from a short range RF-enabled device over a short
`range RF or other wireless link.
`To handle a video feed that has a packet size larger than a
`single data frame, the mobile terminal 20 must receive a data
`stream from the service provider in a format wherein the
`video can be split into several data frames. Thus, basic infor
`mation/control data may be sent by the service provider in a
`first data frame and the high quality graphics signal is split up,
`and transmitted thereafter as additional data frames.
`FIG. 2 shows a simplified picture of a mobile terminal 20
`illustrating necessary components to perform the procedures
`of this invention. In the mobile terminal 20 there is a network
`transceiver 206, to receive transmissions from and to transmit
`requests to the wireless communications network, a short
`range transceiver 204 to enable communication with nearby
`devices, a CPU 208 unit for controlling and executing all
`necessary procedures, a memory unit 210, a storage unit 212,
`a display 202 for displaying the images, and an antenna 216.
`In the case of DVB or DAB, the terminal must also have a
`DVB or DAB receiver (not shown). Also, inside or outside the
`CPU unit is a software-based splitting application 218, which
`enables the handling and splitting of the different data frames.
`FIG. 3. shows a flow chart illustrating the method for
`handling the video data to be sent from the service provider 13
`to the external display device 30 via mobile terminal 20. At
`step 40, the service provider 13 transmits data frames as
`packets to mobile terminal 20 over the wireless communica
`tions network which are received by mobile terminal 20.
`Where both audio and video are sent simultaneously via the
`packets, a packet containing video information may have a
`data frame structure that can be split into a mobile terminal
`part 54 and external display device part 56. Two possible
`basic data frame structures are data frame structure 50 shown
`in FIG. 4(a) and data frame structure 52 shown in FIG. 4(b).
`Mobile terminal part 54 may include any voice data to be
`heard over or otherwise used by the mobile terminal 20 as
`well as images, call feature or other data to be used by the
`mobile terminal such as textual information, caller-ID,
`e-mail, and the like, to be displayed on a display of the mobile
`terminal 20. External display device part 56 is the part to be
`forwarded to the external display device 30 and generally
`follows the mobile terminal part 54 within the signal sent by
`a base station 10 to allow the mobile terminal part 54 to be
`split off first and used by the mobile terminal 20. The external
`display device part 56 generally includes a video portion of
`the signal and may include an audio portion to be played with
`the video on the external display device. In data frame struc
`tures 50, 52 aheader part 58 precedes mobile terminal part 54.
`In data frame structure 52, a separate header part 60 also
`precedes the external display device part 56. The precise
`length of the mobile terminal part 54 and the external display
`device part 56 will depend on the currently utilized transmis
`sion method, i.e. GSM, EDGE, WCDMA, DAB, DVB, Blue
`tooth or some other method. The external display device part
`56 is transmitted from the mobile terminal to the external
`display device, such as a TV 30, over wireless short range RF
`link 22, such as Bluetooth link. It should be noted that the
`various parts of the data frame structures 50, 52 shown in
`FIGS. 4(a) and 4(b) are not necessarily drawn to scale.
`In one preferred embodiment of this invention the short
`range RF link 22 is specified as a Bluetooth link and thereby
`the protocol stack considered in this invention is a Bluetooth
`protocol stack. The features of that particular Bluetooth pro
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`tocol stack are shown in FIG. 5, and the various layers of the
`protocol stack (65, 66 in FIG. 1) at mobile terminal 20 and at
`external display device 30 are discussed in the Bluetooth
`Specification v.1.0B. The lowest layer is the radio layer 70,
`which provides an interface between the host devices and the
`Bluetooth chip. Above the radio layer is the baseband layer 72
`which specifies the procedures to support the exchange of
`real-time voice and data information streams and networking
`between Bluetooth devices. Above the baseband layer 72 is
`the Link Manager 74 which is used for link set-up, security
`and control. The Logical Link Control and Adaptation Pro
`tocol (L2CAP) layer 76 supports higher-level protocol mul
`tiplexing, packet segmentation and reassembly, and convey
`ing the quality of service information. An Applications layer
`90 is the highest layer in the Bluetooth protocol. Data 78
`passes between the L2CAP layer 76 and the Applications
`layer 90 via one or more of the following interfaces: TCP/IP
`80, HID (human interface device/host interface device) 82, or
`RFCOMM 84 (discussed at Part F1 of the Bluetooth Speci
`fication). A control sequence 86 passes between the Link
`Manager 74 and Applications layer 90 to set up the Asynchro
`nous Connection Link (ACL) between Bluetooth devices and
`provides a pathway for the Applications layer 90 to send
`control information, such as to notify Link Manager 74 that a
`packet was lost. An audio component 88 of the multilayer
`protocol stack 65 handles any audio to be transmitted to the
`external display device.
`Returning to the method of FIG. 3, at step 41, the mobile
`terminal’s splitting application 218 (shown in FIG. 1(b)) is
`used to split the mobile terminal part 54 from the external
`display device part 56 at the Applications layer 90. (As an
`alternative to implementing the splitting application 218 at
`the Applications layer 90, data can be processed and delivered
`through the RFCOMM protocol or another layer in the pro
`tocol stack.) The splitting application 218 takes a data frame
`from a data stack (not shown) at mobile terminal 20 received
`from base network 10 over communications link 12 and
`determines where the external display device part 56 is
`located within the data frame structure by knowing the fixed
`length of the mobile terminal part 54. If data frame structure
`52 is used, the separate headerpart 60 indicates the location of
`the external display device part 56. To provide time for the
`splitting application 218 to handle the incoming data from the
`network, the received signal is buffered at the mobile terminal
`20 in a buffer (not shown). Once the data is split, at step 42, the
`external display device part 56 is further processed by the
`Bluetooth protocol stack 65 at the mobile terminal 20 where
`one or more external display device parts are reassembled
`into one or more Bluetooth compliant packets formed in
`accordance with the Baseband Specification within the Blue
`tooth Specification, the number of such packets depending on
`the amount of data to be sent.
`Referring to FIG. 6, each Bluetooth packet 95 comprises an
`access code 96 specific to a master’s address in the connection
`mode and identifying each packet in one piconet, a header 97
`containing link control information, and a payload 98, which
`comprises one or more external display device parts 56 or a
`portion of an external display device part, the organization of
`the data into Bluetooth packets depending on the size of
`external display device part 56 and the size of the payload 98.
`These packets 95 are placed into a data stack within the
`Bluetooth chip and are then ready to be transmitted to external
`display device 30. The various parts of Bluetooth Packet 95
`shown in FIG. 6 are not necessarily drawn to scale.
`A wireless link 22 to send data between mobile terminal
`and external display device 30 is established using the Blue
`tooth protocols. The mobile terminal must be set up as the
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`7
`“master” to control the communication with the external dis
`play device 30 which is a “slave”. The master and slave
`communicate over shared channel and form a “piconet”. The
`channel is defined in the Bluetooth Specification as a pseudo
`random hopping sequence through the defined RF channels
`that is unique to the piconet.
`Generally, the mobile terminal 20 becomes the master
`automatically when video service is ordered with the mobile
`terminal 20 and the connection to external display device 30
`is initiated. However, if the external display device 30 is setup
`as the master, for any reason, the master and slave must
`exchange roles, with the slave becoming the master and vice
`versa, i.e. a master-slave switch is performed in accordance
`with the Bluetooth Specification.
`Referring now to the flow chart of FIG. 7, at step 100, the
`connection is initialized by mobile terminal 20 which serves
`as a master. If an external display device 30 has been previ
`ously identified with a specific device address to the master
`(mobile terminal), which is the case when the same master
`slave relationship was previously set up, the master usually
`transmits a “Page Scan” command to page the known Blue
`tooth unit within the external display device 30. (If the mas
`ter-slave relationship was previously established and was
`maintained in “park” mode, there is no need to set up a new
`connection; a command must only be sent to exit “park” mode
`to restart the communication.) If no such external display
`device 30 has been previously identified to mobile terminal
`20 as a master, the mobile terminal 20 broadcasts an “Inquiry”
`message to determine what other Bluetooth units are within
`the coverage area wherein two Bluetooth units can exchange
`messages with acceptable quality and performance. The
`Bluetooth units that capture the broadcast “Inquiry” mes
`sages will send a response to the mobile terminal 20 providing
`information about the responding Bluetooth unit and its host
`device, which would include any Bluetooth-enabled external
`display device in the coverage area. After locating the exter
`nal display device, a “Connection” state is established in
`which the mobile phone 20 is the master and the external
`display device 30 is the slave, thereby preventing the external
`display device from receiving data from multiple Bluetooth
`devices at the same time, which could cause problems with
`the display on the device.
`During the Connection state, the Bluetooth-compliant
`packets formed at the mobile terminal 20 are sent to the
`external display device 30 (step 102). Upon receipt at external
`display device 30, the packets are buffered at buffer (not
`shown) having a sufficient memory for the data stream (step
`104), and the packets are stripped of the access code 96 and
`header parts 97 (step 106) and the payloads 95 of the various
`packets are then reassembled by the Bluetooth protocol stack
`66 at the external display device 30 into a data stream to be
`played, whether as video only or with audio available (step
`108). The buffer is necessary both to compensate for varia
`tions in the transmission speed of the packets and to capture
`multiple packets before reassembly into a video signal to be
`displayed. If the television re