(12) United States Patent
`KO et al.
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 7,702,279 B2
`Apr. 20, 2010
`
`US007702279B2
`
`(54) PORTABLE MEDIA PLAYERASA LOW
`POWER REMOTE CONTROL AND METHOD
`THEREOF
`
`
`
`WO
`
`2002/0042282 A1 * 4/2002 Haupt ........................ 455/509
`2004/0078812 A1* 4/2004 Calvert ................
`... 725/46
`2004/0090984 A1* 5/2004 Saint-Hilaire et al. ....... 370/463
`2004/0133914 A1* 7/2004 Smith et al. ................... 725/86
`2004/0183756 A 1 * 9/2004 Freitas et al. ................. 345/73
`75
`-
`-
`-
`2005/0042983 A1* 2/2005 Borgward .................. 455/3.06
`(75) Inventors: Ý ??.??. (US), CA
`2005/0273790 A1 12/2005 Kearney et al.
`epnen U. Lemay, San Francisco,
`2006/0085821 A9 * 4/2006 Simmons et al. .............. 725/61
`(US)
`2006/01946 12 A1* 8/2006 Chen ....................... 455/556.1
`-
`-
`2007/0015457 A1
`1/2007 Krampfet al.
`(73) Assignee: Apple Inc., Cupertino, CA (US)
`2008/0163049 A1
`7/2008 Krampf
`(*) Notice:
`Subject to any disclaimer, the term of this
`FOREIGN PATENT DOCUMENTS
`patent is extended or adjusted under 35
`02/065732
`8/2002
`U.S.C. 154(b) by 807 days.
`OTHER PUBLICATIONS
`(21) Appl. No.: 11/314,291
`International Search Report & Written Opinion re: PCT/US2006/
`(22) Filed:
`Dec. 20, 2005
`
`-
`
`
`? ?? 0.47825 ??? ?.
`U.S. Appl. No. 1 1/245,937, filed Oct. 7, 2005.
`e
`-
`- -
`Prior Publication Data
`Salling Clicker 2.2.1, User Manual, Sailing Software AB, 2005.
`|US 2007/01691 15 A1
`Jul.19, 2007
`Remote for iTunes (URM-15T), product information datasheet,
`Keyspan, http://www.keyspan.com/products/usburm 15t, down
`loaded Sep. 25, 2005, pp. 1-2.
`(Continued)
`-
`-
`-
`Primary Examiner–Tan Trinh
`(` 7)
`ABSTRACT
`A portable multimedia plaver is used to wirelessly access and
`?
`play
`?
`control a media server that is streaming digital media by way
`of a wireless interface to a media unit such as a stereo/speak
`ers in the case of streaming digital audio. In one embodiment,
`the portable multimedia player is wirelessly synchronized to
`a selected one(s) of a number of digital media files stored on
`the media serverin sucha way that digital media file metadata
`(song title, author, etc.) associated with the selected digital
`media file(s) only is transferred from the media server to be
`stored in the portable media player.
`
`(65)
`
`(51) Int. Cl.
`(2006.01)
`H04H 7/(){}
`(52) U.S. Cl. .................... 455/3.06; 455/3.03; 455/3.04;
`455/420; 725/86; 725/61
`(58) Field of Classification Search ................ 455/3.06.
`???????())???? ????????? i“s7S??0? ? ? ? ()4, 420??
`345/73, 716, 722; 725/37, 135, 81, 31, 61.
`. -
`-
`725/86
`-
`See application file for complete search history.
`References Cited
`
`(56)
`
`|U.S. PATENT DOCUMENTS
`
`5,845,282 A 12/1998 Alley et al.
`6, 192,340 B1 * 2/2001 Abecassis ................... 704/270
`6,914,551 B2
`7/2005 Vidal
`7,230,563 B2
`6/2007 Vidal
`7,231,516 B1 * 6/2007 Sparrell et al. .............. 713/156
`7,574,177 B2
`8/2009 Tupman et al.
`
`21 Claims, 7 Drawing Sheets
`
`112
`
`Stereo system
`110
`
`*
`*
`l
`|
`|
`p
`*
`r
`
`Media serve?
`
`* ----
`
`request
`502
`
`Requested
`rmetadata
`
`Portable multimedia player
`
`. . "
`
`100
`
`CHS Ex. 2006
`Apple v. CHS IPR2016-00794
`
`

`

`US 7,702.279 B2
`Page 2
`
`OTHER PUBLICATIONS
`
`Express Remote (URM-17A), product information datasheet,
`Keyspan, http://www.keyspan.com/products/usb/urm15t, down-
`loaded Sep. 25, 2005, pp. 1-2.
`“Keyspan Express Remote Supports Apple's Airport Express.” Press
`Release, Keyspan, Nov. 10, 2004.
`
`Keyspan: DMR Software v1.3 for Mac OS X=User Manual, rev.
`04.09.01A1, Keyspan.
`“Keyspan Express Remote,” Product Fact Sheet, Keyspan, Nov.
`2004,
`Communication pursuant to Article 94(3) EPC for European Patent
`Application No. 06845481.8, dated Oct. 31, 2008.
`* cited by examiner
`
`

`

`U.S. Patent
`
`Apr. 20, 2010
`
`Sheet 1 of 7
`
`US 7,702,279 B2
`
`
`
`Stereo system
`110
`
`|
`
`
`
`100
`
`FIG. 1
`
`Portable multimedia player
`102
`
`

`

`U.S. Patent
`
`Apr. 20, 2010
`
`Sheet 2 of 7
`
`US 7,702,279 B2
`
`SPEAKER
`214
`
`CODEC
`212
`
`WIRELESS
`NETWORK
`INTERFACE
`226
`
`200
`???
`
`??ER
`INPUT
`208
`
`DISPLAY
`210
`
`PROCESSOR
`202
`
`218
`
`216
`
`BUS
`????? F???
`
`224
`
`G??? E
`
`
`
`FILE SYSTEM
`(STORAGE DISK)
`204
`
`RAM
`220
`
`ROM
`222
`
`Fig. 2
`
`

`

`U.S. Patent
`U.S. Patent
`
`Apr. 20, 2010
`Apr. 20, 2010
`
`Sheet 3 of 7
`Sheet 3 of7
`
`US 7,702,279 B2
`US 7,702,279 B2
`
`
`
`FIG. 3
`FIG. 3
`
`

`

`U.S. Patent
`
`Apr. 20, 2010
`
`Sheet 4 of 7
`
`US 7,702,279 B2
`
`Media player generates and
`forwards a multimedia metadata
`request to the media server
`
`402
`
`In response to the multimedia metadata
`request, the media server locates the
`requested metadata associated with the
`media file(s) stored on the media server
`
`
`
`
`
`
`
`Media server provides a multimedia
`metadata response back to the multimedia
`player
`
`404
`
`406
`
`Display plurality of multimedia
`metadata by multimedia player
`
`408
`
`Receive user selection of at least one
`of the displayed multimedia metadata
`
`410
`
`In response to the user selection, the media
`player generates and forwards a multimedia
`file request to the media server
`
`
`
`Media server locates and retrieves an
`appropriate media file based on the
`descriptive information provided in the
`media file request
`
`Wireless transfer media file from the media
`server to a media unit for play
`
`400
`
`412
`
`414
`
`416
`
`FIG. 4
`
`

`

`U.S. Patent
`
`Apr. 20, 2010
`
`Sheet 5 of 7
`
`US 7,702,279 B2
`
`\
`\
`TN Media unit
`106
`
`Stereo system
`110
`
`|
`|
`|
`?
`?
`
`1 ? ?
`
`
`??? ??
`??
`/
`f
`f
`
`
`
`T - ?? ?? - - - ?
`
`
`
`
`
`r
`???
`A. /
`|
`
`112
`
`|
`|
`|
`\
`\
`\
`w
`\
`?? ?
`~ J
`
`Media server
`104
`
`109
`108
`
`116 +
`
`FIG. 5A
`
`Portable multimedia player
`102
`
`
`
`
`
`
`
`Metadata
`request
`502
`
`Requested
`metadata
`504
`
`
`
`100
`
`

`

`U.S. Patent
`
`Apr. 20, 2010
`
`Sheet 6 of7
`
`US 7,702,279 B2
`
`\
`
`\\
`
`
`
`Stereo system
`110
`
`\
`
`\"\M d
`e la unit
`\
`106
`‘,
`I‘
`I
`,’
`
`I’
`
`,’
`
`ZZZ
`
`//
`
`//
`
`//
`
`ll
`I
`I
`
`/
`,—‘
`
`112
`
`/
`
`[I
`
`I
`i
`‘
`
`/'
`II
`|
`',
`I
`'
`
`i‘
`\
`
`\
`
`\
`
`\
`
`\\\
`
`\\\\
`
`\\
`
`\\
`
`\\
`
`Media server
`‘I04
`
`I
`‘ ‘ ~\ ‘ _,//
`
`
`Requested
`media file
`504
`
`
`
`
`
`
`Media file
`
`
`
`
`request
`602
`
`100
`
`FIG. 5B
`
`Portabie multimedia player
`102
`
`

`

`U.S. Patent
`
`Apr. 20, 2010
`
`Sheet 7 of 7
`
`US 7,702,279 B2
`
`READ MEDIA PLAYER
`INFORMATION FROM THE
`MEDIA DATABASE ON
`
`
`
`602
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`
`?????R? ??? ?L???R ??D??
`??F?R?????? ????? ??S?
`??D?? ??F?R?????? FR??
`THE MEDIA DATABASE ON THE
`HOST COMPUTER
`
`604
`
`DETERMINE WHICH MEDIA
`????S ?? ???? ??S??? ?? ??? ??
`?????R?S?? ??F?R??????
`606
`
`COPY THE DETERMINED MEDIA
`ITEMS AND UPDATE THE TN 60s
`???R??R???? ??D??
`DATABASE(S)
`
`600
`
`FIG. 6
`
`

`

`US 7,702,279 B2
`
`1
`PORTABLE MEDIA PLAYER AS A LOW
`POWER REMOTE CONTROL AND METHOD
`THEREOF
`
`BACKGROUND
`
`Due to the increasing capacity and capability of personal
`computers, it has become popular to use a personal computer
`as a repository for multimedia content, such as songs, movies,
`etc. Particularly with music, the increased popularity of stor-
`ing multimedia data (in the form of digital audio files having
`various formats such as MP3, AAC and AIFF) on a personal
`computer has resulted in a variety of products and services.
`For example, music players (e.g., MP3 player), such as the
`iPod® multimedia device, and media management applica-
`tions, such as iTunes software, which as produced by Apple
`Computer, Inc. of Cupertino, Calif., are popular products.
`With the ability to store large numbers and types of digital
`audio files in such portable music players, services (such as
`iTunes® Music Store provided by Apple Computer, Inc. of
`Cupertino, Calif.) have been developed that allow consumers
`to purchase music (and other digital multimedia data) in a
`form suitable for storage and playback using portable music
`players and personal computers. In so doing, many consum-
`ers use their personal computer as a primary vehicle for
`obtaining, storing, and accessing multimedia data.
`Although the quality ofmultimedia playback by computers
`has improved dramatically in the last several years, these
`systems still lag behind typical entertainment devices (e.g.,
`stereos, televisions, projection systems, etc.) in terms of per-
`formance, fidelity, and usability for the typical consumer.
`Therefore, in order to utilize the higher quality playback
`systems,
`it has become common to install home network
`systems whereby an individual’s personal computer is linked
`(either wirelessly or wired) to a home entertainment system
`forming in the process a media system. The media system
`integrates several interfaces and feature sets into an integrated
`platform. In this way, the individual is able to listen, view or
`otherwise access this multimedia data stored on a personal
`computer using these various entertainment devices. For
`example, a wireless network interface (e.g., 802.1 lg based
`Airport Express® wireless network interface manufactured
`by Apple Computer, Inc. of Cupertino, Calif.) communicates
`wirelessly with other devices and to serve as a wireless base
`station or as a repeater (to increase the range of a pre-existing
`wireless network).
`The network interface available on the personal computer
`can be used to link to any entertainment device, such as a
`stereo system, television, or home theatre system. This would
`allow, for example, streaming of multimedia data from a
`personal computer connected to the network interface (wired
`or wireless) to an entertainment device connected to the mul-
`timedia interface. Unfortunately, however, in order to control
`certain aspects of the playback of the multimedia data (such
`as changing a song, an entire playlist, or even controlling
`volume) a listener wishing to make such changes must be in
`physical contact with the personal computer in which the
`multimedia data being played is stored. For example, if a
`listener is in a living room listening to music being streamed
`to a living room based stereo by a computer wirelessly linked
`thereto located in an upstairs den, changing the song being
`played would require the listener to physically walk to the
`upstairs den where the computer was located and select the
`desired song.
`One approach used to solve the problem of remote access
`and control is provided by a zone based system exemplified
`by Sonos Digital Music System manufactured by Sonos, Inc.
`
`2
`that utilizes distributed units
`of Santa Barbara, Calif.
`(SonosTM Zone
`Players)
`and
`a
`controller
`unit
`(SonosTMController). Unfortunately, these units require sub-
`stantial investment in equipment in order to provide the req-
`uisite zone based remote access and control. For example,
`Sonos Digital Music System requires a user to purchase, or
`otherwise acquire, a controller as well as one or more zone
`players depending upon the area.
`Therefore, what is desired is a system that leverages exist-
`ing devices (such as an iPod, AirPort Express, a Mac running
`iTunes) to provide the remote access and control that would
`otherwise require the purchase of specialized equipment such
`as zone controller units and zone players.
`
`SUMMARY OF THE INVENTION
`
`A portable multimedia player (such as the iPodTM manu-
`factured by Apple Computer, Inc. of Cupertino, Calif.) is used
`to wirelessly access and control a media server (such as a
`personal computer running iTunes software) that is streaming
`digital media by way of a wireless interface to a media unit
`(such as a stereo/speakers in the case of streaming digital
`audio). In one embodiment, a method of using a portable
`multimedia player arranged to store digital media files to
`wirelessly access and/or control a media server configured to
`stream digital media data to a media unit is described. The
`method is performed by binding the portable multimedia
`player and the media server, wirelessly transmitting a signal
`from the multimedia player to the media server, and stream-
`ing the digital media data from the media server to a media
`unit by way of a wireless interface using the received signal.
`In another embodiment, a portable digital multimedia
`player remote controller unit arranged to store multimedia
`media file metadata used to wirelessly control a remote media
`server is described. The remote controller unit includes a
`
`wireless network interface, a display device arranged to dis-
`play a user interface having a number ofuser selectable items,
`and a processor unit that in response to a user selection of one
`of the user selectable items generates a signal that is wire-
`lessly sent by the wireless network interface to the remote
`media server, the signal including multimedia file meta data
`identifying a multimedia file stored on the media server that,
`in turn, responds to the signals by accessing the identified
`multimedia file and once accessed, wirelessly sends the iden-
`tified multimedia file to a remote media unit.
`
`In yet another embodiment, a method ofproviding wireless
`remote control of a remote media unit through use of a por-
`table multimedia player and a personal computer is described.
`The method is carried out by wirelessly receiving at the
`personal computer a multimedia file indication from the mul-
`timedia player, identifying a multimedia file stored on the
`personal computer using the received multimedia file indica-
`tion, accessing the identified multimedia file; and wirelessly
`sending the identified multimedia file from the personal com-
`puter to the remote media unit.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 shows a representative wireless media network and
`a wireless battery powered portable multimedia player in
`accordance with an embodiment of the invention.
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`FIG. 2 shows a schematic functional block diagram of a
`portable media player according to one embodiment of the
`invention.
`
`65
`
`FIG. 3 illustrates a representative multimedia player in
`accordance with an embodiment of the invention.
`
`

`

`US 7,702,279 B2
`
`3
`FIG. 4 shows a flow diagram ofremotely accessing a media
`server in order to effect a change to a streamed digital media
`file according to one embodiment of the invention.
`FIGS. 5A-SB shows how the multimedia player can be
`used to remotely access the personal computer to effect any
`number of changes in the music being streamed to and played
`by the stereo.
`FIG. 6 that is a flow diagram of synchronization processing
`according to one embodiment of the invention.
`
`DETAILED DESCRIPTION
`
`Reference will now be made in detail to a particular
`embodiment of the invention an example of which is illus-
`trated in the accompanying drawings. While the invention
`will be described in conjunction with the particular embodi-
`ment, it will be understood that it is not intended to limit the
`invention to the described embodiment. To the contrary, it is
`intended to cover alternatives, modifications, and equivalents
`as may be included within the spirit and scope ofthe invention
`as defined by the appended claims.
`According to one embodiment, a battery-operated portable
`multimedia player is used to wirelessly access and/or control
`a media server. The media server can be implemented by a
`variety of computing devices. As an example, the media
`server can be implemented by a personal computer. In
`response to such wireless access and/or control, the media
`server can operate to stream digital media by way of a wire-
`less interface to a media unit (e.g., a home audio system, such
`as a stereo, in the case of streaming digital audio).
`In one embodiment, the portable multimedia player wire-
`lessly communicates with the media server so as to receive a
`media catalog of available media items on the media server.
`Here, the media catalog is a listing of the available media
`items, e.g., digital media files, stored on the media server. In
`one embodiment, the media catalog contains media item
`metadata (song title, author, etc.). In this embodiment, the
`digital media items (e.g., digital media files) themselves need
`not be transferred to the portable media player. As a result,
`only a relatively small amount of data is required to be trans-
`ferred to the portable multimedia player, thereby saving valu-
`able battery resources. In addition, by not transferring the
`digital media items themselves, potential copyright infringe-
`ment issues can be avoided.
`When a user wishes to access and/or control the media
`
`server in order to effectuate a change in the media item data
`being streamed to the media unit (e.g., changing a song being
`played as an example), the user selects a new media item (e.g.,
`song) to be played by interacting with the portable multime-
`dia player. In one implementation, the portable multimedia
`player can display a plurality of user selectable items that
`correspond to different digital media items (e.g., song files).
`The user of the portable multimedia player can select one of
`the user selectable items to specify a media item to be played.
`Once selected, the portable multimedia player wirelessly
`informs the media server of the specified media item to be
`played. In one example, the portable multimedia player trans-
`mits only some or all of the metadata corresponding to the
`new media item along with a control signal indicating, for
`example, that a media item currently being played is to be
`replaced by the new media item associated with the control
`signal.
`In another implementation, the portable multimedia player
`can display a user interface that enables the user to control
`how a media item is to be played. For example, the control
`provided can alter, change or provide play characteristic, such
`as volume, equalization, etc., or navigation, such as next,
`
`5
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`4
`
`previous, play, stop, etc. In such cases, a control signal alone
`can be sent since the associated media item is already known
`by the media server.
`Once received by the media server (e.g., personal com-
`puter), the media server can then inform the media unit ofthe
`control operation requested by the user via the portable mul-
`timedia player. For example, if the control operation is a new
`selected media item to be played, the current media item
`being played by the media unit is discontinued and transfer of
`media data pertaining to the new selected media item begins,
`such that the new selected media item can be played. In this
`way, the user can indirectly remotely control the output ofthe
`media unit using a battery powered portable multimedia
`player in a power efiicient manner.
`In yet another embodiment, a portable digital media player
`(such as an iPod), is bound to a personal computer in such a
`way that the digital media player wirelessly controls the com-
`puter. It should be noted, that the binding of the personal
`computer and the digital media player includes synchronizing
`the digital content stored in the digital media player with the
`media items stored in the computer over a connector such as
`a USB 2.0 or FireWire cable. In this way, the requirement of
`additional user interface on the digital media player for
`choosing, connecting to, and authenticating with the com-
`puter is eliminated. Therefore, in this way, only an additional
`user interface having a top level menu (“remote control” as an
`example) is needed to control the computer which, when
`selected, automatically connects and authenticates the com-
`puter bound to the portable digital media player.
`FIG. 1 shows wireless media system 100 that includes a
`battery powered portable multimedia player 102, a media
`server 104, and a media unit 106 in accordance with an
`embodiment ofthe invention. As configured, the media server
`104 includes a local storage medium 108 that can take any
`appropriate form such as a hard disk drive, flash memory, etc.
`arranged to store multimedia content 109 that can include
`digitized music (e.g., songs), short video files, or full-length
`video files (e.g., movies). For the sake of this discussion, the
`media server 104 is taken to be a personal computer arranged
`to store a number of digital audio files (e.g., song files) in the
`local storage medium 108 configured as a hard drive. In the
`described embodiment, the media server 104 is wirelessly
`coupled to the media unit 106 that in this case takes the form
`of a stereo system 110 having a number of speakers 112. In
`the described embodiment, the stereo system 110 includes a
`wireless network interface 114. The wireless network inter-
`
`face 114 supports a wireless network. The wireless network
`can take the form of, for example, a “WiFi” interface accord-
`ing to the IEEE 802.1 lb or 802.1 lg standards. Other wireless
`network standards could also be used, either in alternative to
`the identified standards or in addition to the identified stan-
`dards. Such other network standards could include the IEEE
`802.1 la standard or the Bluetooth standard. An antenna
`
`required for wireless networking is typically included within
`the housing of the wireless network interface 114. Such an
`antenna may take a variety of forms, such as an antenna
`printed on a standard PCB (printed circuit board). Such anten-
`nas are well known to those skilled in the art.
`
`The wireless network supported by the wireless network
`interface 114 can enable wireless communications between
`the media server 104 and the media unit 106. In such case, the
`media server 104 also includes or couples to a wireless net-
`work interface 116 such that the media server 104 and the
`media unit 106 can communicate over the local wireless
`network via the wireless network interfaces 114 and 116.
`
`Furthermore, the portable multimedia player 102 can com-
`municate with the media server 1 04 in a wireless manner, over
`
`

`

`US 7,702,279 B2
`
`5
`the same wireless network (as used between the media server
`104 and the media unit 106) or another wireless network.
`When the media unit 106 described herein is used to play
`multimedia content from the media server 104 (hereafter
`personal computer), the media unit 106 is plugged into a wall
`outlet for power. The wireless network interface 114 acts as a
`wireless base station for the wireless network thus enabling
`the personal computer 104 to communicate with the media
`unit 106. The wireless network interface 114 is also con-
`
`nected to the stereo system 110 to enable playback of audio
`files stored on the computer 104 by the stereo system 110. The
`connection between the wireless network interface 114 and
`
`the stereo system 110 may be by way of a digital fiber optic
`cable that would connect to a digital audio input port on the
`stereo system 110.
`As briefly described above, the wireless network interface
`114 has the ability to receive multimedia information from
`the personal computer 104 over a wireless network connec-
`tion and output this media information to an entertainment
`device (e.g., the stereo system 110). Although it is contem-
`plated that audio, video, audio/video, and/or other forms of
`multimedia may be used with the media system described
`herein, one exemplary embodiment relates to the sharing of
`audio data stored on a personal computer with an entertain-
`ment device, such as a stereo system.
`To provide a relatively simple and user friendly interface to
`the media output features of media unit 106, it is advanta-
`geous to provide access to the media unit 106 from a media
`application running on the personal computer 104, which is
`also preferably the application normally used to create,
`manipulate, or otherwise access the particular type of media
`file. In one exemplary embodiment, the media application be
`the iTunes® software for music management and playback
`produced by Apple Computer, Inc. Using the media applica-
`tion, the media unit 106 may be selected as a destination for
`media playback. The personal computer 104 can be pro-
`grammed such that the audio content of a media file to be
`played will be sent to the media unit 106, while system sounds
`(e.g., beeps, alerts, etc.) will continue to be presented at the
`personal computer 104.
`Communications between the personal computer 104 and
`the media unit 106 over a wireless network (e.g., wireless
`network 100) is initiated through a discovery process. One
`example of such a discovery process uses Bonjour, which is a
`technology that enables automatic discovery of computers,
`devices, and services on IP networks. Also known as Zero
`Configuration Networking, Bonjour uses standard IP proto-
`cols to allow devices to automatically find each other without
`the need for a user to enter IP addresses or configure DNS
`servers. Various aspects of Bonjour are generally known to
`those skilled in the art, and are disclosed in the white paper
`entitled “Bonjour” dated October 2003, and published by
`Apple Computer, Inc., which is hereby incorporated by ref-
`erence in its entirety. Additional implementation details may
`be found in the following co-pending patent applications,
`commonly owned with the present application, which are
`hereby incorporated by reference in their entirety:
`(1)
`“Method and Apparatus for Configuring a Wireless Device
`Through Reverse Advertising,” application Ser. No. 10/102,
`321, filed Mar. 19, 2002; (2) “Method and Apparatus for
`Supporting Duplicate Suppression When Issuing Multicast
`DNS Queries Using DNS_Forrnat Message Packets,” appli-
`cation Ser. No. 10/102,174, filed Mar. 19, 2002; and (3)
`“Method and Apparatus for Implemented a Sleep Proxy for
`Services on a Network,” application Ser. No. 60/496,842,
`filed Aug. 20, 2003.
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`6
`To facilitate communications between the personal com-
`puter 104 and the media unit 106, such as to provide media
`sharing functionality, the wireless network interface 114 for
`the media unit 106 will advertise over the network that it
`
`supports audio streaming to the media unit 106. As required
`for standard Bonjour operation, the wireless network inter-
`face 114 will publish the availability of a service, the name of
`the device providing the service, the network address of the
`device, and one or more configuration parameters that are
`related to the service. The registration of this service adver-
`tises particular audio capabilities of the system (e.g., 44.1
`kHz sample rate, 16-bit sample size, and 2-channel/stereo
`samples). The registration of the service might also include
`security, encryption, compression, and other capabilities and/
`or parameters that are necessary for communicating with the
`device.
`
`In alternative embodiments, additional services may be
`designed to specify a variety of parameters relating to one or
`more multimedia input or output devices attached to the
`media unit 106. Devices that might have particular applica-
`bility in a home network environment include speakers, video
`display terminals, cameras, microphones, etc.
`The automatic discovery aspects of devices within the net-
`work permit its use in architecting easily configured home
`networks according to a user’s preferences and designs. For
`example, a user with a large library ofmusic on a computer in
`one room ofa house can create a wireless multimedia network
`
`for his entire home simply by deploying a few ofthe disclosed
`wireless network interfaces throughout his home. For
`example, he can put one near the stereo in the living room, and
`one by the television in the bedroom. By connecting the
`appropriate multimedia interface, he can serve audio, video,
`or other content to these devices with a simple selection at his
`personal computer. For example, he may direct the living
`room stereo to play his favorite album, and he may direct the
`bedroom television to show a home movie. This extensible
`
`architecture allows a user to configure relationships between
`sources and destinations ofmedia data without regard or need
`for buying all components from the same vendor, or other
`such considerations that might otherwise be required to per-
`mit interoperability of disparate devices on a wireless net-
`work.
`Once the wireless network interface 114 is discovered on
`
`the wireless network, the media software running on personal
`computer 104, e.g.,
`iTunes, will recognize the associated
`stereo system 110 as a destination for audio data, and will
`automatically provide the particular device (e.g., stereo sys-
`tem 110) as a selectable destination within the user interface.
`When the user selects a particular device from those avail-
`able, a variety of authentication and security exchanges can
`take place. For example, ifpassword protection is provided as
`a security feature, the user may be prompted for a password
`required to use the media unit 106 (i.e., stereo system 110) for
`audio file playback. Additionally, ifthe user attempts to select
`a device that is already in use (for example, by another user),
`the media unit 106 (i.e., wireless network interface 114) will
`send a message indicating that it is busy through the user
`interface.
`Once a connection is established between a media source,
`e.g., a personal computer 104, and the wireless network inter-
`face 114 media data corresponding to one or more media
`items (e.g., songs) can be transmitted from the personal com-
`puter 104 to the wireless network interface 114. The trans-
`mission can pertain to a file transfer of the media data (media
`file) or streaming of the media data. The connection remains
`open so long as media data is being transmitted. Once media
`data is no longer being transmitted, for example, at the end of
`
`

`

`US 7,702,279 B2
`
`7
`playback of a song or album, the connection enters an “idle”
`state. While in this idle state, the media source can begin
`successfully transmitting data at any time, as the connection
`has not been closed. Thus, it would not be necessary to rene-
`gotiate or otherwise reestablish the connection.
`However, while the media source has a connection in this
`“idle” state, it can also accept an attempt to establish a con-
`nection with another media source. If such an attempt occurs,
`the connection with the first media source will be closed and
`
`a new connection will be established. Preferably, in such case,
`the first source will also be notified that its connection has
`been terminated.
`
`Additionally, for digital rights management purposes, it
`may be desirable to determine that the media unit 106 is
`authorized to receive an audio data stream and/or that the
`
`communications link between the personal computer 1 04 and
`the media unit 106 is secure (e.g., encrypted). Typically, this
`requires some form of authentication, and is preferably based
`on a public key/private key system. In one embodiment, each
`media unit 106 may be provided with a plurality of private
`keys embedded in read only memory (ROM). The media
`software is then provided with a corresponding plurality of
`public keys. This allows identification data transmitted from
`the media unit 106 to the media software to be digitally signed
`by the media unit 106 using its private key, by which it can be
`authenticated by the media software using the appropriate
`public key. Similarly, data sent from the media software to the
`media unit 106 may be encrypted using a public key so that
`only a media unit 106 using the corresponding private key can
`decrypt the data. The media software and the media unit 106
`may determine which of their respective pluralities ofkeys to
`use based on the exchange of a key index, telling them which
`of their respective keys to use without the necessity of trans-
`mitting entire keys.
`It is preferable that authentication ofa media unit 1 06 occur
`upon initial establishment of a connection to the media soft-
`ware. Upon successful authentication, the media software
`running on personal computer 104 will open a network con-
`nection to the media unit’s audio channel and begin sending
`data. In this embodiment, the media data is “pushed” from the
`media software to media unit 106 rather than being “pulled”
`by the media unit 106 from the media software. The media
`data received by the media unit 106 can be played by the
`media unit 106, namely, played by the stereo system 110. The
`media unit 106 receives this audio data, buffers some portion
`of the data, and begins playing back the audio data once the
`buffer has reached a predetermined capacity. For example, the
`media unit 106 may have a total of 8 seconds ofbuffering, but
`may begin playback when 2 seconds of audio data have been
`received. Additionally, it is also possible for the buffer to have
`a varying capacity, determined, for example, by network traf-
`fic or reliability conditions.
`In a preferred embodiment, the audio channel is separate
`from a control charmel. For reasons explained below, it is
`advantageous to have the data charmel separate from the
`control channel. However, a single channel could be used for
`data and control information.
`
`One advantage to using separate control and data charmels
`is improved response to user commands. As noted above, the
`media unit 106 includes buffer