WO2000062176A1

WO2000062176A1 - System for establishing and maintaining connections and confirming format compatibility between units, subunits and content

Info

Publication number: WO2000062176A1
Application number: PCT/US2000/010026
Authority: WO
Inventors: Hisato Shima; Jon Ebbe Brelin
Original assignee: Sony Electronics Inc.
Priority date: 1999-04-13
Filing date: 2000-04-12
Publication date: 2000-10-19
Also published as: WO2000062176A8; AU4242000A

Abstract

A system for establishing and maintaining connections and confirming format compatibility between units (40, 46, 50), subunits (56) and content on a network includes a graphical user interface (308) which is utilized to allow a user to establish compatible connections between devices (40, 46, 50, 56) on a network. Within the graphical user interface, the user is presented with selections for compatible source devices (40, 46, 50, 56) to a specified destination device (46, 50, 56), compatible destination devices (46, 50, 56) to a specified source device (40, 46, 50, 56) or available source and destination devices.

Description

SYSTEM FOR ESTABLISHING AND MAINTAINING CONNECTIONS AND CONFIRMING FORMAT COMPAΗBILITY BETWEEN UNITS, SUBUNITS AND CONTENT

RELATED APPLICATIONS:

This application claims priority under 35 U.S.C. § 119(e) of the co-pending U.S. provisional application Serial Number 60/129,012 filed on April 13, 1999 and entitled "Format Compatibility And Connection Management System." The provisional application Serial Number 60/129,012 filed on April 13, 1999 and entitled "Format Compatibility And

Connection Management System" is also hereby incorporated by reference.

FIELD OF THE INVENTION:

The present invention relates to the field of managing the transmission of data between devices. More particularly, the present invention relates to the field of establishing and maintaining connections for the transmission of data between devices.

BACKGROUND OF THE INVENTION:

In most modern computer systems an operating system provides a graphical interface for the computer user. The user can run application programs, manipulate files, and perform most other necessary functions through this graphical interface by manipulating images on the computer's display. This manipulation is accomplished by using cursor control keys and other keyboard keys or by using a cursor controlling peripheral device such as a joystick, mouse or trackball. In such systems, when a program or application is loaded into the system it is frequently represented on the display by a small graphical image or icon which identifies the program to the user. For example, a word processing program might be represented by a graphical image of a piece of paper having lines of text on it and a writing instrument such as a pencil or pen. This is particularly so if the program has been removed from the screen and is running in the background. On a multitasking computer, several programs or applications can be running at once, each of which would be represented by its own graphical image. Other devices, such as a digital television also provide graphical interfaces for the user. Through such graphical user interfaces, the user has the ability to control the operation and function of the device. This control is accomplished through use of an input device, such as a remote control device, to enter control information through the graphical user interface.

The IEEE standard, "IEEE 1394 Standard For A High Performance Serial Bus," Draft ratified in 1995 is an international standard for implementing an inexpensive highspeed serial bus architecture which supports both asynchronous and isochronous format data transfers. Isochronous data transfers are real-time transfers which take place such that the time intervals between significant instances have the same duration at both the transmitting and receiving applications. Each packet of data transferred isochronously is transferred in its own time period. The IEEE 1394-1995 standard bus architecture provides multiple channels for isochronous data transfer between applications. A six bit channel number is broadcast with the data to ensure reception by the appropriate application. This allows multiple applications to simultaneously transmit isochronous data across the bus structure. Asynchronous transfers are traditional data transfer operations which take place as soon as possible and transfer an amount of data from a source to a destination.

The IEEE 1394-1995 standard provides a high-speed serial bus for interconnecting digital devices thereby providing a universal physical I/O connection. The IEEE 1394- 1995 standard defines a digital interface for the applications thereby eliminating the need for an application to convert digital data to analog data before it is transmitted across the bus. Correspondingly, a receiving application will receive digital data from the bus, not analog data, and will therefore not be required to convert analog data to digital data. The cable required by the IEEE 1394-1995 standard is very thin in size compared to other bulkier cables used to connect such devices. Devices can be added and removed from an

IEEE 1394-1995 bus while the bus is active. If a device is so added or removed the bus will then automatically reconfigure itself for transmitting data between the then existing nodes. A node is considered a logical entity with a unique address on the bus structure. Each node provides a configuration ROM, a standardized set of control registers and its own address space.

The IEEE 1394-1995 standard defines a protocol as illustrated in Figure 1. This protocol includes a serial bus management block 10 coupled to a transaction layer 12, a link layer 14 and a physical layer 16. The physical layer 16 provides the electrical and mechanical connection between a device or application and the IEEE 1394-1995 cable. The physical layer 16 also provides arbitration to ensure that all devices coupled to the IEEE 1394-1995 bus have access to the bus as well as actual data transmission and reception. The link layer 14 provides data packet delivery service for both asynchronous and isochronous data packet transport. This supports both asynchronous data transport, using an acknowledgement protocol, and isochronous data transport, providing real-time guaranteed bandwidth protocol for time-based data delivery. The transaction layer 12 supports the commands necessary to complete asynchronous data transfers, including read, write and lock. The serial bus management block 10 contains an isochronous resource manager for managing isochronous data transfers. The serial bus management block 10 also provides overall configuration control of the serial bus in the form of optimizing arbitration timing, guarantee of adequate electrical power for all devices on the bus, assignment of the cycle master, assignment of isochronous channel and bandwidth resources and basic notification of errors.

An exemplary IEEE 1394-1995 consumer entertainment system network including a settop box, a satellite dish, a television and a digital video cassette recorder (NCR) is illustrated in Figure 2. The settop box 20 is coupled to receive broadcast transmissions from the satellite dish 18 by the IEEE 1394-1995 cable 26. Typically, these broadcasts are transmitted from the satellite dish 18 to the settop box 20 in an MPEG format. The settop box 20 is coupled to the television 22 by the IEEE 1394-1995 cable 28. The television 22 is coupled to the digital NCR 24 by the IEEE 1394-1995 cable 30. Through the single plug coupled to the IEEE 1394-1995 cable 28, the tuner 20 transmits broadcasts from the satellite dish 18 to the television 22 and the digital NCR 24. IEC-61883 is a ratified international standard for the transport of audio/video command requests and responses. This standard uses the concept of plugs and plug control registers to manage and control the attributes of isochronous data flows. It should be noted that plugs do not physically exist on an audio/video device, but a plug is used to establish an analogy with existing audio/video devices where each flow of information is routed through a physical plug.

An isochronous data flow is sent from one transmitting device, such as the settop box 20, to one or more receiving devices, such as the television 22, by transmitting isochronous packets on an isochronous channel of the IEEE 1394-1995 serial bus. Each isochronous data flow is transmitted to an isochronous channel through one output plug on the transmitting device and is received from that isochronous channel through one input plug on the receiving device. The transmission of an isochronous data flow through an output plug is reflected by data in an output plug control register (oPCR) and an output master plug register (oMPR) located on the transmitting device. The output master plug register contains all attributes that are common to all isochronous data flows transmitted by the corresponding transmitting device. The output plug control register contains all attributes of the corresponding isochronous data flow that are independent from attributes of other isochronous data flows transmitted by the transmitting device.

The reception of an isochronous data flow through an input plug is reflected by an input plug control register (iPCR) and an input master plug register (iMPR) located on the receiving device. The input master plug register contains all attributes that are common to all isochronous data flows received by the receiving device. The input plug control register contains all attributes of the corresponding isochronous data flow that are independent from attributes of other isochronous data flows received by the receiving device.

An isochronous data flow can be controlled by any device connected to the IEEE 1394-1995 bus by modifying the corresponding plug control registers and by initiating or connecting to an existing transmission. Plug control registers can be modified through asynchronous transactions on the IEEE 1394-1995 bus or by internal modifications if the plug control registers are located on the controlling device.

To transport isochronous data between two audio/video devices on the IEEE 1394- 1995 bus, it is necessary for an application to virtually connect an output plug on the transmitting device to an input plug on the receiving device using an isochronous channel. The relationship between one input plug, one output plug and one isochronous channel is called a point-to-point connection. A point-to-point connection can only be broken by the application that established it. An application can also just start the transmission or reception of an isochronous data flow on its own device by connecting one of its output or input plugs respectively to an isochronous channel. The relationship between one output plug and one isochronous channel is called a broadcast-out connection. The relationship between one input plug and one isochronous channel is called a broadcast-in connection. Broadcast-out and broadcast-in connections are collectively called broadcast connections. A broadcast connection can be established only by the device on which the plug is located, but it can be broken by any device. A plug has four possible states. These states are idle, ready, active and suspended.

A plug is either on-line or off-line. A plug that is on-line is in either the ready or active state. Only a plug that is on-line is capable of transmitting or receiving an isochronous data flow. A plug that is off-line is in either the idle or suspended state. A plug will be off-line, for example, if it relies on resources that are temporarily unpowered or otherwise unavailable. A plug to which no connections exist is referred to as unconnected. A plug which is unconnected is in either the idle or ready state. A plug to which one or more connections exist is referred to as connected. A plug which is connected is in either the suspended or active state. A plug which is connected and on-line is in the active state. Only a plug in the active state shall transmit or receive an isochronous data flow except in the case of a bus reset where the isochronous data flow is resumed immediately after the bus-reset.

The AV/C Digital Interface Command Set is a command set used for transactions between consumer audio/video equipment over an IEEE 1394-1995 serial bus. Neither the IEEE 1394-1995 serial bus nor the AV/C Command Set provide a master-slave relationship between the devices coupled within the IEEE 1394-1995 serial bus network. Instead, both the IEEE 1394-1995 serial bus and the AV/C Command Set operate based on the cooperative peer-to-peer coexistence of devices within the network.

A diverse range of products can be implemented with the ability to connect to an IEEE 1394-1995 serial bus network. These devices can have capabilities and functionality ranging from very simple to very complex. The IEEE 1394-1995 serial bus allows a collection of devices to work together in a high bandwidth, distributed environment to maximize the overall efficiency and functionality of the network. This allows manufacturers to remove expensive pieces of functionality from one device and locate that functionality in another device on the network, instead of duplicating this functionality in all devices on the network. While some of the devices have limited functionality and are relatively inexpensive, such devices require the support and interaction of other devices in order to bring the full functionality of the devices within the network to the user. Each of the different types of devices can transmit or receive data in various formats, such as MPEG, JPEG, NTSC and DV. A transmission between devices can fail if the data transmitted from the source device is in a format not recognized or accepted by the receiving device. There is currently a lack of methods for use with conventional devices that determines compatibility of devices and data format for an isochronous transmission before the transmission begins.

SUMMARY OF THE INVENTION:

A method of and apparatus for establishing and maintaining connections and confirming format compatibility between units, subunits and content on a network includes a graphical user interface which is utilized to allow a user to establish compatible connections between devices on a network. Preferably, the network is an IEEE 1394-1995 serial bus network. Within the graphical user interface, the user is presented with selections for compatible source devices to a specified destination device, compatible destination devices to a specified source device or both available source and destination devices. Through the graphical user interface the user is also presented with compatible device connections based on their data content. Through the graphical user interface, a user is able to select source and destination devices and content streams of data in order to establish a connection between a source and destination device to transmit a content stream of data from the source device to the destination device. The display device presents devices or content streams of data to the user for selection through the graphical user interface that are compatible and can receive or transmit a content stream of data which can be transmitted or received, as appropriate, from or to a designated or default device. Once the user selects devices for a transmission, the controlling device then establishes the connection between the source and destination devices by issuing commands and allocating appropriate resources such as an isochronous channel and bandwidth, if necessary, modifying the appropriate plug control registers and initiating the transmission of the content stream of data from the source device to the destination device.

In one aspect of the present invention, a method of establishing a transmission between a source device and a destination device within a network includes the steps of determining for one of a source device and a destination device, one or more compatible devices within the network, listing the compatible devices within a graphical user interface, determining when one of the compatible devices is selected, thereby forming a selected device and establishing a transmission between the one of the source device and the destination device and the selected device. The step of determining one or more compatible devices within the network includes determining available formats of transmission and reception of the one of the source device and the destination device and available formats of all devices within the network and then determining which of the devices within the network have available formats matching the available formats of the one of the source device and the destination device. The step of listing includes listing available compatible source devices within the network. The step of listing includes listing available compatible destination devices within the network. The step of listing includes listing content streams of data available from compatible devices within the network. Compatible devices include a selective one of units and subunits. The step of establishing includes controlling resource allocation for the transmission and modifying appropriate plug control registers at the one of the source device and the destination device and the selected device. The graphical user interface is displayed on the one of the source device and the destination device. The graphical user interface is displayed on a separate display device within the network. The network preferably substantially complies with a version of an IEEE 1394 standard.

In another aspect of the present invention, a graphical user interface for establishing a connection and transmission between a source device and a destination device within a network includes means for determining for one of a source device and a destination device, one or more compatible devices within the network, a device selection window for displaying the compatible devices for selection and means for establishing a transmission between the one of the source device and the destination device and a selected device selected through the device selection window. The means for determining determines available formats of transmission and reception of the one of the source device and the destination device and available formats of all devices within the network and then determines which of the devices within the network have available formats matching the available formats of the one of the source device and the destination device. The device selection window displays a list of available compatible source devices within the network.

The device selection window displays a list of available compatible destination devices within the network. The device selection window displays a list of content streams of data available from compatible devices within the network. Compatible devices include a selective one of units and subunits. The means for establishing controls resource allocation for the transmission and modifies appropriate plug control registers at the one of the source device and the destination device and the selected device. The graphical user interface is displayed on the one of the source device and the destination device. Alternatively, the graphical user interface is displayed on a separate controlling device. The network preferably substantially complies with a version of an IEEE 1394 standard.

In yet another aspect of the present invention, an apparatus for establishing a transmission between a source device and a destination device within a network includes a determining apparatus to determine for one of a source device and a destination device, one or more compatible devices within the network, a graphical user interface including a device selection window to display the compatible devices for selection and a control apparatus configured to establish a transmission between the one of the source device and the destination device and a selected device selected through the device selection window, wherein the control apparatus allocates necessary resources and modifies appropriate plug control registers at the one of the source device and the destination device and the selected device. The necessary resources include an isochronous channel and isochronous bandwidth on the network. The determining apparatus determines available formats of transmission and reception of the one of the source device and the destination device and available formats of all devices within the network and then determines which of the devices within the network have available formats matching the available formats of the one of the source device and the destination device. The device selection window displays a list of available compatible source devices within the network. The device selection window displays a list of available compatible destination devices within the network. The device selection window displays a list of content streams of data available from compatible devices within the network. Compatible devices include a selective one of units and subunits. The graphical user interface is displayed on the one of the source device and the destination device. The network preferably substantially complies with a version of an IEEE 1394 standard. In still yet another aspect of the present invention, in a system having a control processor, a display, a memory and an input device, a graphical user interface includes a determining apparatus to determine for one of a source device and a destination device, one or more compatible devices within a network, a device selection window to display the compatible devices for selection and a control apparatus configured to establish a transmission between the one of the source device and the destination device and a selected device selected through the device selection window. The control apparatus controls resource allocation for the transmission and modifies appropriate plug control registers at the one of the source device and the destination device and the selected device. The determining apparatus determines available formats of transmission and reception of the one of the source device and the destination device and available formats of all devices within the network and then determines which of the devices within the network have available formats matching the available formats of the one of the source device and the destination device. The device selection window displays a list of available compatible source devices within the network. The device selection window displays a list of available compatible destination devices within the network. The device selection window displays a list of content streams of data available from compatible devices within the network. Compatible devices include a selective one of units and subunits. The graphical user interface is displayed on the one of the source device and the destination device. The network preferably substantially complies with a version of an IEEE 1394 standard.

BRIEF DESCRIPTION OF THE DRAWINGS: Figure 1 illustrates a protocol of the IEEE 1394-1995 serial bus standard.

Figure 2 illustrates an exemplary system including a settop box, a satellite dish, a television and a digital video cassette recorder (VCR) coupled together within an IEEE 1394-1995 serial bus network.

Figure 3 illustrates an exemplary system including a computer system, a television, a video cassette recorder (VCR) and a video camera coupled together within an IEEE

1394-1995 serial bus network in which the present invention is implemented.

Figure 4 illustrates a block diagram of a hardware system resident in each device capable of establishing and maintaining connections and confirming format compatibility according to the preferred embodiment of the present invention. Figure 5 illustrates the internal components of the computer system illustrated in

Figure 3. Figure 6 illustrates a diagram of software layers of a protocol stack implemented within the computer system.

Figure 7 illustrates an exemplary selection menu or list of format compatible unit source devices displayed within the graphical user interface of the present invention. Figure 8 illustrates an exemplary selection menu or list of format compatible subunit source devices displayed within the graphical user interface of the present invention.

Figure 9 illustrates an exemplary selection menu or list of format compatible unit destination devices displayed within the graphical user interface of the present invention. Figure 10 illustrates an exemplary selection menu or list of format compatible subunit destination devices displayed within the graphical user interface of the present invention.

Figure 11 illustrates an exemplary selection menu or list of available source and destination devices displayed within the graphical user interface of the present invention. Figure 12 illustrates an exemplary selection menu or list of format compatible available content streams of data displayed within the graphical user interface of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT: A graphical user interface of the present invention is utilized to allow a user to establish compatible connections between devices on a serial bus network. Preferably, the serial bus network is an IEEE 1394-1995 serial bus network. The user can determine compatible devices with an external controller, a specific transmitting or receiving unit or subunit or by a specific content stream of data. For example, if a user wants to transmit a content stream of data from a particular source device within the serial bus network, the apparatus for establishing and maintaining connections of the present invention determines the format of the content stream of data and then determines destination devices capable of receiving the content stream of data in that format. These destination devices are displayed to the user through the graphical user interface, thereby allowing the user to choose a compatible destination device to receive the content stream of data. Once the user chooses a compatible destination device, the transmission of the content stream of data is then established between the source device and the destination device. In this same manner, when a user specifies a particular receiving or destination device, the apparatus for establishing and maintaining connections of the present invention determines the format or formats that the destination device is capable of receiving and then determines available source devices within the network capable of transmitting a content stream of data in those formats. These source devices are then displayed to the user through the graphical user interface, thereby allowing the user to choose a compatible source device to transmit the content stream of data to the destination device. Once the user chooses a compatible source device, the transmission of the content stream of data is then established between the chosen source device and the specified destination device. A user can also specify a particular destination device and then select a compatible content stream of data. When a user is selecting a content stream of data, the apparatus for establishing and maintaining connections of the present invention determines the format or formats that the destination device is capable of receiving and then determines available content streams of data within the network which are capable of being transmitted in those formats. These available compatible content streams of data are then displayed to the user through the graphical user interface, thereby allowing the user to choose a compatible content stream of data. Once the user chooses a compatible content stream of data, the transmission of the selected content stream of data is then established to the destination device. Figure 3 illustrates an exemplary IEEE 1394-1995 serial bus network of devices including a computer system 40, a television 46, a video cassette recorder (VCR) 50 and a video camera 56 connected together by IEEE 1394-1995 cables 44, 48 and 54. The IEEE 1394-1995 cable 44 couples the computer system 40 to the television 46. The IEEE 1394- 1995 cable 48 couples the television 46 to the VCR 50. The IEEE 1394-1995 cable 54 couples the computer system 40 to the video camera 56.

This configuration illustrated in Figure 3 is exemplary only, it should be apparent that an audio/video network could include many different combinations of components. The devices within such an IEEE 1394-1995 network are autonomous devices, meaning that in an IEEE 1394-1995 network, as the one illustrated in Figure 3, in which a computer system is one of the devices, there is not a true "master-slave" relationship between the computer and the other devices. In many IEEE 1394-1995 network configurations, a computer system may not be present. Even in such configurations, the devices within the network are fully capable of interacting with each other on a peer basis. It should be recognized that data, commands and parameters can be sent between all of the devices within the IEEE 1394-1995 network, as appropriate.

A block diagram of a hardware system resident in each device capable of establishing and maintaining connections and confirming format compatibility according to the preferred embodiment of the present invention is illustrated in Figure 4. In the hardware system illustrated in Figure 4, a printed circuit board 60 is coupled to a user interface 70. The printed circuit board 60 includes a central processing unit (CPU) 62 coupled to a system memory 64 and to an I/O bus interface 66 by the system bus 68. The user interface 70 is subsystem specific, but preferably includes at least a keyboard and display. Alternatively, the user interface 70 also includes other I/O devices for communicating with a user of the subsystem.

A block diagram of the internal components of the computer system 40 is illustrated in Figure 5. The computer system 40 includes a central processor unit (CPU) 150, a main memory 152, a video memory 154, a mass storage device 156 and an IEEE

1394-1995 interface circuit 158, all coupled together by a conventional bidirectional system bus 160. The interface circuit 158 includes a physical interface circuit 162 for sending and receiving communications on the IEEE 1394-1995 serial busses 44 and 54. The physical interface circuit 162 is coupled to the video camera 56 via the IEEE 1394-1995 serial bus cable 54 and to the television 46 via the IEEE 1394-1995 serial bus cable 44. The system bus 160 contains an address bus for addressing any portion of the memories 152, 154 and 156. The system bus 160 also includes a data bus for transferring data between and among the CPU 150, the main memory 152, the video memory 154, the mass storage device 156 and the interface circuit 158. The computer system 40 is also coupled to a number of peripheral input and output devices including a keyboard 164, a mouse 166 and the associated display 42. The keyboard 164 is coupled to the CPU 150 for allowing a user to input data and control commands into the computer system 40. A conventional mouse 166 is coupled to the keyboard 164 for manipulating graphic images on the display 42 as a cursor control device. As is well known in the art, the mouse 166 can alternatively be coupled directly to the computer system 40 through a serial port.

A port of the video memory 154 is coupled to a video multiplex and shifter circuit 168, which in turn is coupled to a video amplifier 170. The video amplifier 170 drives the display 42. The video multiplex and shifter 168 and the video amplifier 170 convert pixel data stored in the video memory 154 to raster signals suitable for use by the display 42. It will be apparent that one or more of the elements of the computer system 40 illustrated in Figure 5 can be omitted or replaced and that elements can be added to the computer system 40 while achieving the principle advantages of the present invention.

A diagram of software layers of a protocol stack implemented within the computer system 40 is illustrated in Figure 6. A user mode / application level of the protocol stack preferably includes one or more application programs 202 based on Microsoft® Windows® (e.g., Windows® 98) and Microsoft® DirectShow™ application programming interface

(API) 204. The API 204 provides an interface between the application programs 202 and a kernal mode / drivers level of the protocol stack.

The kernal mode / drivers level of the protocol stack includes a number of driver modules 206-212 arranged in a hierarchy where a stream class driver 206 is at a highest level and a 1394 port driver 212 is at a lowest level. The stream class driver 206 is available from Microsoft® and interfaces to the API 204 for control of multi-media streams of data, such as a movie. A digital video (DV) mini driver 208 available from Sony Electronics, Inc. is a client of the stream class driver 206. The DV mini driver 208 is a hardware device dependent dynamic link library (DLL) file which uses the stream class driver 206 to accomplish most actions through function calls and handle control of remote devices, such as the video camera 56.

A 1394 bus class driver 210, also available from Microsoft®, is responsible for communications sent and received over the IEEE 1394-1995 serial bus network from the computer system 40. The 1394 bus class driver 210 supports IEEE 1394-1995 bus interfaces to the DV mini driver 208 by communicating with the 1394 port driver 212.

The 1394 port driver 212 is a hardware interface driver available from Sony Electronics, Inc. which interfaces to the physical interface circuit 162. The physical interface circuit 162 includes a command register 214 for sending commands to the serial bus 44 and 54 and a response register 216 for receiving responses to the commands from the serial bus 44 and 54. Preferably, the command register 214 is a FCP_COMMAND register and the response register 216 is a FCP_RESPONSE register.

To ensure the successful transmission and reception of a stream of data, the apparatus for establishing and maintaining connections, first determines the compatibility of the transmitting unit or subunit with the receiving unit or subunit. If it is determined that the transmitting unit or subunit is capable of transmitting in a format that the receiving unit or subunit can receive and process, then the apparatus of the present invention will allow the transmission to proceed. However, if it is determined that the transmitting unit or subunit is not capable of transmitting in a format that the receiving unit or subunit can receive and process, then this incompatibility is identified and the apparatus of the present invention will not allow the transmission to proceed.

The apparatus for establishing and maintaining connections of the present invention includes a graphical user interface through which a user is aided in selecting devices which are capable of transmitting and receiving in compatible formats. Through the graphical user interface, a user has the ability to establish connections and to control the operation of the devices coupled to the serial bus network. The graphical user interface is preferably displayed on a controlling device such as a television, monitor, computer system or other system which is coupled to the IEEE 1394-1995 serial bus network and which includes a display device. In order to control and select devices or content streams of data, a cursor control device is used by the user to choose options displayed on the graphical user interface. The cursor control device can be a mouse, keypad, trackball, remote control or other appropriate device, depending on the configuration of the controlling device. Further, the cursor control device can be wired or wireless using radio, infrared or any other appropriate technology.

The graphical user interface and the apparatus for establishing and maintaining connections of the present invention allows a user to establish and maintain connections of devices preferably coupled together by an IEEE 1394-1995 serial bus network. It should be apparent that the graphical user interface and the apparatus for establishing and maintaining connections can be used to establish and maintain connections of devices coupled together in other types of networks.

In the preferred embodiment of the present invention, when a source device select command is entered at a device, the default destination device is the device to which the source device select command is entered. Correspondingly, when a destination device select command is entered at a device, the default source device is the device to which the destination device select command is entered. Preferably, when a list contents command is entered at a device, the default destination device is the device to which the list contents command is entered. Alternatively, when a list contents command is entered at a device, the default source device is the device to which the list contents command is entered. To select a compatible source device at a unit level to send data to a selected receiving device such as the television 46 within the exemplary network illustrated in

Figure 3, the user preferably enters a unit source device select command to the television 46, using any appropriate input device. Because this unit source device select command is entered to the television 46, the television 46 is the default destination device. The television 46 is also the controlling device and will display the graphical user interface to the user on its display.

When the user enters this unit source device select command, the television 46 then determines compatible unit source devices within the serial bus network which are capable of transmitting data to the television 46, through the network, in a format that the television 46 can receive and process. For example, if the television 46 is capable of receiving data in either an MPEG or NTSC format, the television 46 will then determine unit source devices within the IEEE 1394-1995 serial bus network that can transmit in either the MPEG or NTSC format. Within the graphical user interface of the present invention, a menu or list of format compatible unit source devices capable of transmitting in either the MPEG or NTSC format, is then displayed for the user as illustrated in Figure 7. In this example, the list of format compatible unit source devices displayed within the graphical user interface 300 for selection and capable of transmitting in either the MPEG or NTSC format, includes the television 46, the VCR 50, the computer system 40 and the camcorder 56. From this list, the user then selects a source device to transmit a stream of data to the television 46. When the user has selected a source device within the graphical user interface 300 to transmit data to the television 46, the television 46 then establishes the connection and initiates the transmission from the selected source device to the television 46, specifying the appropriate format of the transmission. Establishing the connection and initiating the transmission includes allocating isochronous bandwidth and an isochronous channel on the IEEE 1394-1995 serial bus network, if necessary, modifying the appropriate plug control registers at the selected source device and the television 46, and communicating with the selected source device regarding the initiation of the transmission. To select a compatible source device at a subunit level to send data to a selected receiving such as the television 46, within the exemplary network illustrated in Figure 3, the user preferably enters a subunit source device select command to the television 46, using any appropriate input device. Because this subunit source device select command is entered to the television 46, the television 46 is the default destination device. The television 46 is also the controlling device and will display the graphical user interface to the user on its display.

When the user enters this subunit source device select command, the television 46 then determines compatible subunit source devices within the serial bus network which are capable of transmitting data to the television 46, through the network, in a format that the television 46 can receive and process, such as the MPEG or NTSC format used in the example above. A menu or list of format compatible subunit source devices capable of transmitting in either the MPEG or NTSC format, is then displayed for the user within the graphical user interface, as illustrated in Figure 8. In this example, the list of format compatible subunit source devices, displayed within the graphical user interface 302 for selection and capable of transmitting in either the MPEG or NTSC format, includes the television 46, the tuner and recorder within the VCR 50, the computer system 40 and the camera and recorder within the camcorder 56. When the user has selected a subunit source device within the graphical user interface 302 to transmit data to the television 46, the television 46 then establishes the connection and initiates the transmission from the selected subunit source device to the television 46, specifying the appropriate format of the transmission. Establishing the connection and initiating the transmission includes allocating isochronous bandwidth and an isochronous channel on the IEEE 1394-1995 serial bus network, if necessary, modifying the appropriate plug control registers at the selected subunit source device and the television 46, and communicating with the selected subunit source device regarding the initiation of the transmission.

To select a compatible destination or receiving device at a unit level to receive data from a selected source device such as the television 46, within the exemplary network illustrated in Figure 3, the user preferably enters a unit destination device select command to the television 46, using any appropriate input device. Because this unit destination device select command is entered to the television 46, the television 46 is the default source device. The television 46 is also the controlling device and will display the graphical user interface to the user on its display. Inputting a unit record command to the television 46, will also preferably implement the same procedure as entering a unit destination device select command.

When the user enters this unit destination select command, the television 46 then determines compatible unit destination devices within the serial bus network which are capable of receiving data from the television 46, through the network, in a format that the television 46 can transmit, such as the MPEG or NTSC formats used in the example above. A menu or list of format compatible unit destination devices capable of receiving in either the MPEG or NTSC format, is then displayed for the user within the graphical user interface, as illustrated in Figure 9. In this example, the list of format compatible unit destination devices, displayed within the graphical user interface 304 for selection and capable of receiving in either the MPEG or NTSC format, includes the VCR 50 and the camcorder 56. When the user has selected a unit destination device within the graphical user interface 304 to receive the data transmitted from the television 46, the television 46 then establishes the connection and initiates the transmission to the selected unit destination device from the television 46, specifying the appropriate format of the transmission. Establishing the connection and initiating the transmission includes allocating isochronous bandwidth and an isochronous channel on the IEEE 1394-1995 serial bus network, if necessary, modifying the appropriate plug control registers at the selected unit destination device and the television 46, and communicating with the selected unit destination device regarding the initiation of the transmission.

To select a compatible destination or receiving device at a subunit level to receive data from a selected source device such as the television 46, within the exemplary network illustrated in Figure 3, the user preferably enters a subunit destination device select command to the television 46, using any appropriate input device. Because this subunit destination device select command is entered to the television 46, the television 46 is the default source device. The television 46 is also the controlling device and will display the graphical user interface to the user on its display. Inputting a subunit record command to the television 46, will also preferably implement the same procedure as entering a subunit destination device select command.

When the user enters this subunit destination select command, the television 46 then determines compatible subunit destination devices within the serial bus network which are capable of receiving data from the television 46, through the network, in a format that the television 46 can transmit, such as the MPEG or NTSC formats used in the example above. A menu or list of format compatible subunit destination devices capable of receiving in either the MPEG or NTSC format, is then displayed for the user within the graphical user interface, as illustrated in Figure 10. In this example, the list of format compatible subunit destination devices, displayed within the graphical user interface 306 for selection and capable of receiving in either the MPEG or NTSC format, includes the recorder subunit within the VCR 50 and the recorder subunit within the camcorder 56. When the user has selected a subunit destination device within the graphical user interface 306 to receive the data transmitted from the television 46, the television 46 then establishes the connection and initiates the transmission to the selected subunit destination device from the television 46, specifying the appropriate format of the transmission. Establishing the connection and initiating the transmission includes allocating isochronous bandwidth and an isochronous channel on the IEEE 1394-1995 serial bus network, if necessary, modifying the appropriate plug control registers at the selected subunit destination device and the television 46, and communicating with the selected subunit destination device regarding the initiation of the transmission.

To select both compatible source and destination devices at a unit level within the exemplary network illustrated in Figure 3, the user preferably enters a list devices command to a control device such as the television 46, using any appropriate input device. Because this list devices command is entered to the television 46 and the television 46 includes an appropriate display, the television 46 is the controlling device and will display the graphical user interface to the user on its display.

When the user enters this list devices command, the television 46 then determines the source and destination devices available on the IEEE 1394-1995 serial bus network. A menu or list of available source and destination devices is then displayed for the user within the graphical user interface, as illustrated in Figure 11. In this example, the list of available source devices includes the television 46, the VCR 50, the computer system 40 and the camcorder 56, and the list of available destination devices displayed within the graphical user interface 308 for selection also includes the television 46, the VCR 50, the computer system 40 and the camcorder 56. When the user has selected a unit source device to transmit the data or a unit destination device to receive the data, the control device then determines the format of this first selected device and lists the corresponding compatible devices to either transmit or receive the data. For example, if the user selects a unit source device to transmit the data, the control device then determines the format of this selected source device and lists the corresponding compatible destination devices to receive the data within the graphical user interface 308 for selection. From this list of corresponding compatible destination devices displayed within the graphical user interface 308 for selection, the user can select a desired destination device. When the user has selected both a source device and a destination device from the graphical user interface 308, the control device then establishes the connection between the source and destination devices and initiates the transmission from the selected source device to the selected destination device, specifying the appropriate format of the transmission. Establishing the connection and initiating the transmission includes allocating isochronous bandwidth and an isochronous channel on the IEEE 1394-1995 serial bus network, if necessary, modifying the appropriate plug control registers at the selected source and destination devices, and communicating with the selected source and destination devices regarding the initiation of the transmission.

A user is also able to select a content stream of data using the apparatus for establishing and maintaining connections, through the graphical user interface of the present invention. To select a compatible content stream of data to be transmitted from an appropriate source device to a selected destination device such as the television 46, within the exemplary network illustrated in Figure 3, the user preferably enters a list content command to the television 46, using any appropriate input device. Because this list content command is entered to the television 46, the television 46 is the default destination device. The television 46 is also the controlling device and will display the graphical user interface to the user on its display.

When the user enters this list contents command, the television 46 then determines available compatible content streams of data within the serial bus network which are capable of transmitting data to the television 46, through the network, in a format that the television 46 can receive, such as the MPEG or NTSC formats used in the example above. A menu or list of format compatible available content streams of data which can be sent in either the MPEG or NTSC format, is then displayed for the user within the graphical user interface, as illustrated in Figure 12. In this example, the list of format compatible available content streams of data which can be transmitted in either the MPEG or NTSC format is displayed within the graphical user interface 310 for selection and includes NBC, CBS, CNN and Home Video. When the user has selected a content stream of data within the graphical user interface 310, the television 46 then determines from which device the content stream of data is available, establishes the connection with that device and initiates the transmission of the content stream of data from the appropriate device to the television 46 specifying the appropriate format of the transmission. For example, if the user selects the content stream of data NBC, then the television 46 determines that this content stream of data is available from the tuner subunit of the VCR 50. The television 46 then establishes the connection and initiates the transmission of the content stream of data NBC from the VCR 50 to the television 46. Establishing the connection and initiating the transmission includes allocating isochronous bandwidth and an isochronous channel on the IEEE 1394-1995 serial bus network, if necessary, modifying the appropriate plug control registers at the source device of the selected content stream of data and the television 46, and communicating with the source device of the selected content stream of data regarding the initiation of the transmission.

A user is also able to select a source or destination device using a controlling device with limited display capability, such as the VCR 50. In this case, when the controlling device to which the command is entered has limited display capability, the list of format compatible available source or destination devices is appropriately displayed on the limited display without the benefits of the added graphics. Alternatively, when the controlling device to which the command is entered has limited display capability, the list of format compatible available source or destination devices is displayed on a device with an appropriate display, such as the television 46. For example, in the exemplary network illustrated in Figure 3, if a user enters a source device select command to the VCR 50, using any appropriate input device, the graphical user interface including the list of available compatible source devices with the VCR 50 as the destination device, from which the user can select, is displayed on a device with a more capable display in the network, such as the television 46. When the controlling device has limited display capability and the graphical user interface of the present invention is displayed on a device with a more capable display, the controlling device preferably communicates with the displaying device to control the display of the graphical user interface. To determine compatibility of devices, the controlling device first determines the available formats of the default or first selected device. For example, if the television 46 is the default destination device, then it first determines its available formats, which in the example used herein is MPEG and NTSC formats. To determine compatible available source devices, the television 46 then polls the available devices within the network to determine the available formats of each device within the network. After determining the available formats of a device, the television 46 then compares the available formats of the device to the available formats of the default destination device. If there is at least one match between the available formats of the device and the available formats of the default destination device, then the device is included on the list of available source devices displayed to the user through the graphical user interface. If there are not any matches between the available formats of the device and the available formats of the default destination device, then the device is excluded from the list of available source devices displayed to the user through the graphical user interface. In an alternate embodiment of the present invention, the controlling device maintains a list of available devices on the

IEEE 1394-1995 serial bus networks and the available formats for each device. From this maintained list, the compatibility of particular devices is determined.

To establish the connection and initiate the transmission of a stream of data between a source device and a destination device, a control device of the present invention, first determines if the appropriate resources necessary for the transmission are currently allocated and available. The appropriate resources necessary for the transmission include one or more isochronous channels and the necessary isochronous bandwidth. If the appropriate resources necessary are currently allocated and available, then the control device next modifies the appropriate plug control registers of the source and destination devices. After modifying the appropriate plug control registers, the control device initiates the transmission by communicating with the source and destination devices and instructing these devices to begin the transmission and reception of the content stream of data. The source and destination devices then begin the transmission and reception of the content stream of data over the IEEE 1394-1995 serial bus network. Otherwise, if the appropriate resources necessary for the transmission are not currently allocated and available, the control device first obtains the necessary resources including one or more isochronous channels and the necessary isochronous bandwidth, before modifying the appropriate plug control registers and initiating the transmission and reception of the content data stream. If the format of the content data stream is changed during the transmission of the content stream of data, the current source device first determines if the format change will result in a format incompatibility between the current source device and the current destination device. When a transmission of a content stream of data is initialized, the controller preferably registers with the source device all formats that the source device and the destination device have in common. The source device then uses these common formats to determine if there is a remaining compatible format between the current source device and the current destination device when there is a format change. If there is a remaining compatible format between the current source device and the current destination device, then the source device notifies the control device that the content data stream has been changed. The control device then determines if the current destination device can receive the content data stream in the new format. If the current destination device can receive the content data stream in the new format, then the current destination device configures the appropriate input plug and internal resources to receive the content data stream in the new format and the transmission and reception of the content data stream is continued. Otherwise, if the current destination device cannot receive the content data stream in the new format, then the transmission of the content data stream is stopped and the user is notified through the graphical user interface at the control device. The user then has the option of selecting another appropriate source or destination device.

Using the apparatus for establishing and maintaining connections and the graphical user interface of the present invention, a user has the ability to select devices to establish and maintain compatible connections over an IEEE 1394-1995 serial bus network. Within the graphical user interface, the user is presented with selections for devices compatible with a particular source or destination device. Through the graphical user interface, the user is also presented with selections for both source and destination devices and content streams of data compatible with a particular destination device. Through the graphical user interface, a user is able to select source and destination devices and content streams of data to establish and initiate a connection between a source device and a destination device to transmit a content stream of data from the source device to the destination device. Once the user selects devices for a transmission of a content stream of data, the controlling device then establishes the connection between the source and destination devices by allocating appropriate resources such as an isochronous channel and bandwidth, if necessary. The controlling device also modifies the appropriate plug control registers at the source and destination devices and initiates the transmission of the content stream of data from the source device to the destination device. The controlling device can be the source device, the destination device or a separate device.

The present invention has been described in terms of specific embodiments incorporating details to facilitate the understanding of principles of construction and operation of the invention. Such reference herein to specific embodiments and details thereof is not intended to limit the scope of the claims appended hereto. It will be apparent to those skilled in the art that modifications may be made in the embodiment chosen for illustration without departing from the spirit and scope of the invention. Specifically, it will be apparent to those skilled in the art that while the preferred embodiment of the present invention is used to represent devices coupled together within an IEEE 1394-1995 serial bus structure, the present invention can also be implemented to manage devices within other bus structures.

Claims

C L A I M SWe Claim:

1. A method of establishing a transmission between a source device and a destination device within a network comprising the steps of: a. determining for one of a source device and a destination device, one or more compatible devices within the network; b. listing the compatible devices within a graphical user interface; c. determining when one of the compatible devices is selected, thereby forming a selected device; and d. establishing a transmission between the one of the source device and the destination device and the selected device.

2. The method as claimed in claim 1 wherein the step of determining one or more compatible devices within the network includes determining available formats of transmission and reception of the one of the source device and the destination device and available formats of all devices within the network and then determining which of the devices within the network have available formats matching the available formats of the one of the source device and the destination device.

3. The method as claimed in claim 1 wherein the step of listing includes listing available compatible source devices within the network.

4. The method as claimed in claim 1 wherein the step of listing includes listing available compatible destination devices within the network.

5. The method as claimed in claim 1 wherein the step of listing includes listing content streams of data available from compatible devices within the network.

6. The method as claimed in claim 1 wherein compatible devices include a selective one of units and subunits.

7. The method as claimed in claim 1 wherein the step of establishing includes controlling resource allocation for the transmission and modifying appropriate plug control registers at the one of the source device and the destination device and the selected device.

8. The method as claimed in claim 1 wherein the graphical user interface is displayed on the one of the source device and the destination device.

9. The method as claimed in claim 1 wherein the graphical user interface is displayed on a separate display device within the network.

10. The method as claimed in claim 1 wherein the network substantially complies with a version of an IEEE 1394 standard.

11. A graphical user interface for establishing a connection and transmission between a source device and a destination device within a network comprising: a. means for determining for one of a source device and a destination device, one or more compatible devices within the network; b. a device selection window for displaying the compatible devices for selection; and c. means for establishing a transmission between the one of the source device and the destination device and a selected device selected through the device selection window.

12. The graphical user interface as claimed in claim 11 wherein the means for determining determines available formats of transmission and reception of the one of the source device and the destination device and available formats of all devices within the network and then determines which of the devices within the network have available formats matching the available formats of the one of the source device and the destination device.

13. The graphical user interface as claimed in claim 11 wherein the device selection window displays a list of available compatible source devices within the network.

14. The graphical user interface as claimed in claim 11 wherein the device selection window displays a list of available compatible destination devices within the network.

15. The graphical user interface as claimed in claim 11 wherein the device selection window displays a list of content streams of data available from compatible devices within the network.

16. The graphical user interface as claimed in claim 11 wherein compatible devices include a selective one of units and subunits.

17. The graphical user interface as claimed in claim 11 wherein the means for establishing controls resource allocation for the transmission and modifies appropriate plug control registers at the one of the source device and the destination device and the selected device.

18. The graphical user interface as claimed in claim 11 wherein the graphical user interface is displayed on the one of the source device and the destination device.

19. The graphical user interface as claimed in claim 11 wherein the graphical user interface is displayed on a separate controlling device.

20. The graphical user interface as claimed in claim 11 wherein the network substantially complies with a version of an IEEE 1394 standard.

21. An apparatus for establishing a transmission between a source device and a destination device within a network comprising: a. a determining apparatus to determine for one of a source device and a destination device, one or more compatible devices within the network; b. a graphical user interface including a device selection window to display the compatible devices for selection; and c. a control apparatus configured to establish a transmission between the one of the source device and the destination device and a selected device selected through the device selection window, wherein the control apparatus allocates necessary resources and modifies appropriate plug control registers at the one of the source device and the destination device and the selected device.

22. The apparatus as claimed in claim 21 wherein the necessary resources include an isochronous channel and isochronous bandwidth on the network.

23. The apparatus as claimed in claim 21 wherein the determining apparatus determines available formats of transmission and reception of the one of the source device and the destination device and available formats of all devices within the network and then determines which of the devices within the network have available formats matching the available formats of the one of the source device and the destination device.

24. The apparatus as claimed in claim 21 wherein the device selection window displays a list of available compatible source devices within the network.

25. The apparatus as claimed in claim 21 wherein the device selection window displays a list of available compatible destination devices within the network.

26. The apparatus as claimed in claim 21 wherein the device selection window displays a list of content streams of data available from compatible devices within the network.

27. The apparatus as claimed in claim 21 wherein compatible devices include a selective one of units and subunits.

28. The apparatus as claimed in claim 21 wherein the graphical user interface is displayed on the one of the source device and the destination device.

29. The apparatus as claimed in claim 21 wherein the network substantially complies with a version of an IEEE 1394 standard.

30. In a system having a control processor, a display, a memory and an input device, a graphical user interface comprising: a. a determining apparatus to determine for one of a source device and a destination device, one or more compatible devices within a network; b. a device selection window to display the compatible devices for selection; and c. a control apparatus configured to establish a transmission between the one of the source device and the destination device and a selected device selected through the device selection window.

31. The system as claimed in claim 30 wherein the control apparatus controls resource allocation for the transmission and modifies appropriate plug control registers at the one of the source device and the destination device and the selected device.

32. The system as claimed in claim 30 wherein the determining apparatus determines available formats of transmission and reception of the one of the source device and the destination device and available formats of all devices within the network and then determines which of the devices within the network have available formats matching the available formats of the one of the source device and the destination device.

33. The system as claimed in claim 30 wherein the device selection window displays a list of available compatible source devices within the network.

34. The system as claimed in claim 30 wherein the device selection window displays a list of available compatible destination devices within the network.

35. The system as claimed in claim 30 wherein the device selection window displays a list of content streams of data available from compatible devices within the network.

36. The system as claimed in claim 30 wherein compatible devices include a selective one of units and subunits.

37. The system as claimed in claim 30 wherein the graphical user interface is displayed on the one of the source device and the destination device.

38. The system as claimed in claim 30 wherein the network substantially complies with a version of an IEEE 1394 standard.