Abstract:
An improved information presentation system and method enable the automatic connection of a presenter&#39;s device to a projection screen or other projection target. The system and method allow device discovery and session establishment with minimal effort on the part of the presenter. In an embodiment of the invention, a reverse terminal server model is utilized to establish a connection from a presentation server, or projection device, to a presentation client, or projection target. The discovery by the projection device of the projection target is by way of the Universal Plug and Play protocol, whereas exchange of data to be exhibited or manifested is by way of a terminal services session commenced via a reverse terminal server model. With respect to visual materials, shadowing may be used to provide the display on the terminal services server host while the terminal services client host renders the information for presentation.

Description:
TECHNICAL FIELD  
         [0001]    This invention relates generally to the technology of information sharing and, more particularly, relates to a system and method for simplified information projection to a projector or other device or devices.  
         BACKGROUND OF THE INVENTION  
         [0002]    Despite the technological advances realized in recent years, many traditional business activities still have a prominent place in today&#39;s workplaces. One such activity is the meeting or conference. Often, such a collaborative effort will involve a presentation of material by one participant to a number of other participants. Traditional means for presenting information include projection on a screen, display on a monitor or other optically active device, or presentation in hard copy form, such as on a white board, chalkboard or easel. While each of these methods has benefits and drawbacks in terms of cost, complexity, and effectiveness, projection and display are typically best suited for rapidly changing data such as may be presented via slides or video. Additionally, projection and display are also ideal for sharing of information from the screen of a computer or other computing device, such as during a MICROSOFT brand POWER POINT slide presentation.  
           [0003]    Unfortunately for projection technology users and participants, traditional mechanisms for projection and display of information from a computing device, while highly effective once initiated, have often been complex to establish, requiring the connection of cords, such as VGA cables, and the setting of various parameters. This complexity can lead to complications before and during a presentation, and often lead to delay in commencing a presentation. Additionally, such mechanisms do not allow simple and rapid transfer of control of the presentation from one speaker to another. Thus, for example, if a first speaker is using a PC to present a POWER POINT slide show and wishes to cede the floor to a second speaker, the second speaker typically must physically leave their chair and walk to a location next to the first speaker&#39;s PC, during which time there will be discontinuity, delay, and distraction for the other participants.  
           [0004]    A system and method of conferencing presentation are needed whereby set up of a conferencing presentation is simplified and whereby control and transfer of presentation management can occur with decreased complexity and improved speed.  
         SUMMARY OF THE INVENTION  
         [0005]    A novel system and method are described for increasing the effectiveness and simplicity of information projection. The scenarios enabled involve the automatic connection of a presenter&#39;s device to a projection screen or other projection target. Rather than being required to find and connect various wires and cables in order to make a presentation, the presenter simply walks into a room, whereupon his or her laptop computer or other device discovers and connects to the desired projection target, such as a conference room projector, with minimal effort on the part of the presenter.  
           [0006]    In an embodiment of the invention, a reverse terminal server model is utilized to establish a connection from a presentation server, or projection device, to a presentation client, or projection target. The discovery by the projection device of the projection target is by way of the Universal Plug and Play protocol. Once discovery has been accomplished, a terminal services session is commenced via the reverse terminal server model to enable the exchange of screen data and/or other data between the projection device and the projection target. In an embodiment, shadowing is used to provide the display on the terminal services server while the terminal services client renders the information for presentation.  
           [0007]    Other features and advantages of various embodiments of the invention will become apparent from the detailed description set forth hereinafter. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    While the appended claims set forth the features of the present invention with particularity, the invention, together with its objects and advantages, may be best understood from the following detailed description taken in conjunction with the accompanying drawings of which:  
         [0009]    [0009]FIG. 1 is a block diagram generally illustrating an exemplary computer system usable in an implementation of an embodiment of the invention;  
         [0010]    [0010]FIGS. 2A and 2B are schematic diagrams showing alternative architectures of a network system within which an embodiment of the invention may be implemented, including multiple computers comprising a projecting computer and multiple projection target computers, as well as an electronic conference room display screen or projector;  
         [0011]    [0011]FIG. 3 is a schematic diagram illustrating in greater detail the placement and interconnectivity of projection application program components and related components in an embodiment of the invention; and  
         [0012]    [0012]FIG. 4 is a flow chart describing the steps taken in an embodiment of the invention to initiate a projection session between a projecting device and a projection target device. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0013]    Turning to the drawings, wherein like reference numerals refer to like elements, the invention is illustrated as being implemented in a suitable computing environment. Although not required, the invention will be described in the general context of computer-executable instructions, such as program modules, being executed by a personal computer. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Moreover, those skilled in the art will appreciate that the invention may be practiced with other computer system configurations, including hand-held devices, multi-processor systems, microprocessor based or programmable consumer electronics, network PCs, minicomputers, mainframe computers, and the like. The invention is primarily for use in a networked environment and may further be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices.  
         [0014]    [0014]FIG. 1 illustrates an example of a suitable computing system environment  100  usable in an implementation of the invention, and according to which either or both of a projection device and a projection target device may operate. The computing system environment  100  is only one example of a suitable computing environment and is not intended to suggest any limitation as to the scope of use or functionality of the invention. Neither should the computing environment  100  be interpreted as having any dependency or requirement relating to any one or combination of components illustrated in the exemplary operating environment  100 . Furthermore, note that the term “projector” includes, but is not limited to, any group display mechanism with wireless capability. It is not required that the projector comprise a wireless interface, since, for example, in some embodiments of the invention the projector may be physically wired to an infrastructure.  
         [0015]    The invention may be implemented by way of numerous other general purpose or special purpose computing system environments or configurations. Examples of well known computing systems, environments, and/or configurations that are suitable for use with the invention include, but are not limited to, personal computers, server computers, hand-held or laptop devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments that include any of the above systems or devices, and the like.  
         [0016]    An exemplary system for implementing the invention includes a general-purpose computing device in the form of a computer  110 . Components of the computer  110  generally include, but are not limited to, a processing unit  120 , a system memory  130 , and a system bus  121  that couples various system components including the system memory to the processing unit  120 . The system bus  121  may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. By way of example only, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Associate (VESA) local bus, and Peripheral Component Interconnect (PCI) bus also known as Mezzanine bus.  
         [0017]    Computer  110  typically includes a variety of computer readable media. Computer readable media can be any available media that can be accessed by computer  110  and includes both volatile and nonvolatile media, removable and non-removable media. By way of example only, and not limitation, computer readable media may comprise computer storage media and communication media.  
         [0018]    Computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by computer  110 .  
         [0019]    Communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics (such as, for example, voltage or current level, voltage or current pulse existence or nonexistence, voltage or current pulse width, voltage or current pulse spacing, etc.) set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media. Combinations of any of the above are also included within the scope of computer readable media.  
         [0020]    The system memory  130  includes computer storage media in the form of volatile and/or nonvolatile memory such as read only memory (ROM)  131  and random access memory (RAM)  132 . A basic input/output system  133  (BIOS), containing the basic routines that help to transfer information between elements within computer  110 , such as during start-up, is typically stored in ROM  131 . RAM  132  typically contains data and/or program modules that are immediately accessible to and/or presently being operated on by processing unit  120 . By way of example, and not limitation, FIG. 1 illustrates RAM  132  as containing operating system  134 , application programs  135 , other program modules  136 , and program data  137 .  
         [0021]    The computer  110  may also include other removable/non-removable, volatile/nonvolatile computer storage media. By way of example only, FIG. 1 illustrates a hard disk drive  141  that reads from or writes to non-removable, nonvolatile magnetic media, a magnetic disk drive  151  that reads from or writes to a removable, nonvolatile magnetic disk  152 , and an optical disk drive  155  that reads from or writes to a removable, nonvolatile optical disk  156  such as a CD-ROM or other optical media. Other removable/non-removable, volatile/nonvolatile computer storage media that can be used in the exemplary operating environment include, but are not limited to, magnetic tape cassettes, flash memory cards, digital versatile disks, digital video tape, solid state RAM, solid state ROM, and the like. The hard disk drive  141  is typically connected to the system bus  121  through a non-removable memory interface such as interface  140 , and magnetic disk drive  151  and optical disk drive  155  are typically connected to the system bus  121  by a removable memory interface, such as interface  150 .  
         [0022]    The drives and their associated computer storage media, discussed above and illustrated in FIG. 1, provide storage of computer readable instructions, data structures, program modules and other data for the computer  110 . In FIG. 1, for example, hard disk drive  141  is illustrated as storing operating system  144 , application programs  145 , other program modules  146 , and program data  147 . Note that these components caneither be the same as or different from operating system  134 , application programs  135 , other program modules  136 , and program data  137 . Operating system  144 , application programs  145 , other program modules  146 , and program data  147  are given different numbers herein to illustrate that, at a minimum, they are different copies. A user may enter commands and information into the computer  110  through input devices such as a keyboard  162 , pointing device  161  (commonly referred to as a mouse), and trackball or touch pad. Other input devices (not shown) may include a microphone, joystick, game pad, satellite dish, scanner, or the like. These and other input devices are often connected to the processing unit  120  through a user input interface  160  that is coupled to the system bus, but may be connected by other interface and bus structures, such as a parallel port, game port or a universal serial bus (USB). A dedicated monitor  191  or other type of display device may also be connected to the system bus  121  via an interface, such as a video interface  190 . In addition to the monitor, computer  110  may also include other peripheral output devices such as speakers  197  and printer  196 , which may be connected through an output peripheral interface  195 .  
         [0023]    In the implementation of an embodiment of the invention, the computer  110  operates in a networked environment using logical connections to one or more remote computers, such as a remote computer  180 . The remote computer  180  may be a personal computer, a router, a network PC, a peer device or other common network node, or a dedicated projection target device such as an electronic projection screen or monitor, and in any case the remote computer or computers typically include many or all of the elements described above relative to the personal computer  110 , although only a memory storage device  181  has been illustrated in FIG. 1, and although in some cases the remote computer can lack much of the functionality contained in the computer  110 . The logical connections depicted in FIG. 1 include a local area network (LAN)  171  and a wide area network (WAN)  173 , but the computer  110  may additionally or alternatively use one or more other networking environments. For example, the computer  110  may reside on an ad hoc network via a communications interface such as a wireless interface. Networking environments of all types are commonplace in offices, enterprise-wide computer networks, intranets and the Internet.  
         [0024]    The computer  110  should include facilities for accessing the networks to which it is attachable. For example, when used in a LAN networking environment, the personal computer  110  is connected to the LAN  171  through a network interface or adapter  170 . Another node on the LAN, such as a proxy server, may be further connected to a WAN such as the Internet. When used in a WAN networking environment, the computer  110  typically includes a modem  172  or other means for establishing communications directly or indirectly over the WAN  173 , such as the Internet. The modem  172 , which may be internal or external, may be connected to the system bus  121  via the user input interface  160 , or other appropriate mechanism. Typically, wireless network interfacing, be it to a LAN, WAN, ad hoc network, or other network type, will allow the greatest freedom to reap the benefits of the invention, although the invention also contemplates the use of more traditional hard wired interfaces.  
         [0025]    In a networked environment, program modules depicted relative to the personal computer  110 , or portions thereof, may be stored in the remote memory storage device. By way of example, and not limitation, FIG. 1 illustrates remote application programs  185  as residing on memory device  181 . It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used. It is not intended to limit the invention to use in a permanent network infrastructure, since it may also be used in transiently connected environments, such as for example a wholly or partially wireless network environment interconnected wholly or partially via optical, infrared, and/or radio frequency wireless connections.  
         [0026]    Herein, the invention is described with reference to acts and symbolic representations of operations that are performed by one or more computers, unless indicated otherwise. As such, it will be understood that such acts and operations, which are at times referred to as being computer-executed, include the manipulation by the processing unit of the computer of electrical signals representing data in a structured form. This manipulation transforms the data or maintains it at locations in the memory system of the computer, which reconfigures or otherwise alters the operation of the computer in a manner well understood by those skilled in the art. The data structures where data is maintained are physical locations of the memory that have particular properties defined by the format of the data. However, while the invention is being described in the foregoing context, it is not meant to be limiting as those of skill in the art will appreciate that various of the acts and operation described hereinafter may also be implemented in hardware.  
         [0027]    [0027]FIG. 2A illustrates schematically a networking environment within which the present invention may be implemented. In particular, the network environment shown in the figure includes a projection device  201 , which may be any computing device such as, for example, those described above in reference to FIG. 1, for projecting information to one or more projection target devices  203 ,  205 ,  207 , and  209 . Projection target devices  203 - 207  are illustrated as non-dedicated computing devices similar to the projection device  201 . In this case, for example, the devices  201 - 207  may be, by way of example and not limitation, laptop computers, desktop computers, handheld computing devices, any other multi-purpose computing devices, or any combination of these types of devices. A projection target device need not be a traditional computing device, and may be for example a television system. Network  211  is usable to transfer information between the target devices  203 - 207  and the projection device  201 .  
         [0028]    Similarly, the projection targets may additionally or alternatively include a dedicated projection device such as an electronic conference room projector or display device  209 . As with the other projection targets  203 - 207 , the target device  209  preferably communicates with the projection device  201  via network  211 . Network  211  may be any type of network, but will typically comprise wireless interfaces between the projecting device  201  and the network  211 , and between the network  211  and the projection targets  203 - 207 . Furthermore, the interface between the network  211  and the dedicated projection device  209  may desirably be either wired or wireless. For example, since the dedicated projection device  209  can remain in a particular location, such as a conference room, for a long period of time, there is no significant decrease in device utility by having a wired interface from the device  209  to the network  211 . The network  211  itself will generally, although not necessarily, be a wired infrastructure such as a corporate LAN, a WAN, or other traditional wholly or partially wired network.  
         [0029]    An alternative network environment is shown schematically in FIG. 2B. In particular, projection device  201  and projection targets  203 - 209  are interconnected via an ad hoc wireless network consisting of wireless links  213 - 225 . Note that not all of connections  213 - 225  are necessary since an ad hoc network does not require direct connection of every node to every other node. For example, a node may be connected to all nodes of the ad hoc network indirectly via a single connection to another node. Thus, ad hoc topologies include rings, lines, webs, hub-and-spokes, and/or other topologies as needed. Often, the physical distance of a particular device from other devices will determine to which device or devices, if any, of the ad hoc network the particular device connects directly.  
         [0030]    The usage and interaction scenarios of the aforementioned components will be described briefly hereinafter before proceeding to a detailed description of the interaction mechanics. The projection device  201  is in the possession of a presenting individual wishing to project material of interest to receiving individuals, typically in a conference room or meeting room setting, although the inventive system is also usable in nonbusiness settings, such as in a home environment, as well. The material of interest may be graphical, such as images or video, or textual such as in a document, chart etc., and may also include audio elements. In an embodiment of the invention, the material of interest is entirely audio information. Although the material of interest need not be computer-generated, it is preferably accessible to the projection device  201  locally or remotely in a computer-readable format. The projection target devices  203 - 207  may be the laptop computers of the receiving individuals, while the projection target device  209  may be a dedicated projection system, such as a conference room projector or large screen monitor or other display not typically associated physically with any one user, unlike a mobile laptop or handheld device.  
         [0031]    The network connectivity between the devices  203 - 209  typically commences as each device comes into communication range of the projection device  201  associated with the presenting user. Thus for example, assume that the dedicated device  209  resides permanently in a conference room. When the presenting user enters the conference room with the projection device  201 , a wireless connection, either ad hoc or via a network infrastructure, is formed between the dedicated device  209  and the projection device  201 . The presenting user is then able to project material from his device  201  onto the screen of the dedicated device  209  for the receiving individuals to observe. In this manner, the presenting user has effected a presentation without physically connecting any cables or cords, and can similarly end the presentation, or transfer its control to another presenting individual using another projection device, without disconnecting any cables or cords.  
         [0032]    In much the same way, the presenting user can present material of interest to a number of target devices such as devices  203 - 207 . For example, the network connection between the projection device  201  and the target devices  203 - 207  is automatically executed after automated discovery without requiring the user to locate and manipulate physical connections. In this case, the presentation of material occurs from the projection device  201  to the screens of the target devices, which may be laptop computers belonging to receiving individuals.  
         [0033]    Specific exemplary architectures of the projection device  201  and a projection target  301  are illustrated in greater detail schematically in FIG. 3. Although only one projection target is illustrated in FIG. 3, it will be appreciated that the invention contemplates the use of multiple and varied such devices as well, as illustrated by way of FIG. 2. It can be seen that the projection device  201  architecture comprises a projector control point  303 , a Universal Plug and Play component  305 , and a terminal services server  307 . The projector control point  303  is an application that controls the function of the Universal Plug and Play component  305  and the terminal services server  307  to establish and maintain a projection session. The projector control point  303  is also responsible for presentation of user interface information to the presenting individual via a display of the device  201 . Such user interface information preferably comprises a selection window within which the presenting user may view available projection targets and select desired connection targets. Other connection information such as time, status, control change requests and so forth may also be presented in the user interface by the projector control point  303 .  
         [0034]    Similarly, the projection target  301  architecture comprises a projector device point  309 , a Universal Plug and Play component  311 , and a terminal services client  313 . As with the projection device  201  architecture, the projector device point  309  is an application that controls the Universal Plug and Play component  311  and the terminal services client  313  during the set up and utilization of a projection session. The Universal Plug and Play component  311  of the projection target  301  cooperates with the Universal Plug and Play component  305  of the projection device  201  to facilitate discovery by the projection device  201  of the projection target  301  in an embodiment of the invention as will be described hereinafter. In a similar manner, the terminal services client  313  of the projection target  301  cooperates with the terminal services server  307  of the projection device  201  during the projection session to facilitate the exchange of presentation information from the projection device  201  to the projection target  301 , as will be described hereinafter in greater detail.  
         [0035]    Although not explicitly shown, each of the projection device  201  and the projection target  301  preferably also includes an operating system for controlling the basic operation of the relevant device. Although there is no limitation within the invention as to suitable operating systems, it has been observed that the XP brand operating system and the WINDOWS CE brand operating system, both by MICROSOFT of Redmond, Wash., are ideally suited for use within the invention. In particular, the projection target  301  can advantageously use the WINDOWS CE brand operating system since the projection target  301  may have both limited computation demands and limited computational resources.  
         [0036]    Note that the projection target  301  architecture also comprises a codec module  315  in an embodiment of the invention. The codec module  315  is used to interpret or decode information received by the projection target  301  from the projection device  201  when the received information comprises encoded audio or video information, as will be described in greater detail below with respect to FIG. 4. Note that multiple and/or diverse codecs may be used without limitation.  
         [0037]    [0037]FIG. 4 illustrates in flow chart form the operation of the aforementioned system components during establishment of a projection session, and while the projection session continues in progress. Before a projection session can begin, a connection should be formed between the projection device  201  and the projection target  301  to the extent such a connection is not already open. Thus, at step  401 , the projection device  201  forms a connection via an appropriate network interface to the network upon which the projection target  301  resides. If the projection target  201  has not yet connected to the relevant network then it too should connect at this time via an appropriate network interface. In an embodiment of the invention, the network comprises an  802 . 11  compliant wireless link, operated either in infrastructure mode or as part of an ad hoc network as discussed above.  
         [0038]    At this point, the projection device  201  and the projection target  301  are both connected to a common network. Still, each of the projection device  201  and the projection target  301  may remain unaware of the presence of the other as such. If so, then at step  403  the Universal Plug and Play component  305  of the projection device is apprised of the presence of the Universal Plug and Play component  311  of the projection target  301 . This step may be carried out either via the standard plug and play announcement mechanism whereby the Universal Plug and Play component  311  of the projection target  301  announces its presence and capabilities to the Universal Plug and Play component  305  of the projection device. Alternatively, the Universal Plug and Play component  305  of the projection device  201  may affirmatively search for and locate the Universal Plug and Play component  311  of the projection target  301 .  
         [0039]    Although Universal Plug and Play will be familiar to those of skill in the art, a brief overview is provided herein for the convenience of the reader. The reader is invited to consult published standards information for further information if desired. Universal Plug and Play refers to a standardized set of methods for device interaction. In particular, UPnP allows peer-to-peer connectivity of intelligent devices, appliances, and so on. UPnP is applicable within managed, unmanaged, and ad hoc networks. UPnP employs existing TCP/IP and Internet technologies to provide for the exchange of control information and data between networked devices. UPNP networking is designed to be independent of the particular network medium or media being used.  
         [0040]    The UPnP control point typically exposes a set of COM (Component Object Model) interfaces through which applications may find and control the host device. Applications use device objects to retrieve information or properties pertaining to the host device. Such information can include, among other information, device hierarchy information, device properties, device manufacturer information, device model information, device display information, and services provided by the device. Note that the UPnP control point need not be a COM entity, although such is discussed herein for purposes of explication. UPnP-enabled devices can be controlled by way of the services they expose, there typically being one service for every primary function that the device can perform. Note that a complex device may be represented by some simple services in addition to other nested devices. A service typically comprises a set of state variables and a set of actions that an application may invoke to operate on one or more variables in the set of state variables. Services are identified by a service type as well as a service ID.  
         [0041]    Once the UPnP components  305 ,  311  of the projection device  201  and the projection target  301  have connected, the UPnP component  305  of the projection device downloads a UPnP service document advertised by the UPnP component  311  of the projection target  301  in step  405 . A service document is a computer-parsable document typically containing a description of commands that the associated device will recognize as well as perhaps some other basic device information such as proper name, number of interfaces, etc. In an embodiment of the invention, the service document comprises, in addition to other information, a description of the device resolution, color depth, a current control point, a current state, as well as brightness, contrast, and tint values. In step  407 , the retrieved service document is passed to the projector control point  303  of the projection device  201 . In this manner, the projector control point  303  is able to enumerate the services that the projection target  301  provides.  
         [0042]    At this point, the projection device  201  is aware of the existence and capabilities of the projection target  301  via the UPnP exchange, and a projection session may be connected. A unique reverse terminal server connection technique is followed to create the presentation data exchange connection for the projection session. Thus, at step  409  the projector control point  303  of the projection device  201  generates a session ticket for its terminal services server  307 . The session ticket is preferably generated in coordination with the Remote Desktop Protocol (RDP). RDP is a multichannel capable protocol that is an extension of the T.120 family of protocol standards. The protocol supports a plurality of virtual channels, each for exchanging a particular type of information, such as presentation data, input data and so forth. RDP maintains a stack (for the terminal services client or server) that is similar to the stack prescribed by the OSI seven-layer model. In particular, data to be transmitted from the server is processed downward through the protocol stack, sectioned, sent to an appropriate channel, encrypted if appropriate, wrapped, framed, packetized according to a network protocol, addressed, and transmitted to the client. The generated ticket presents information regarding how the projection target  301  should connect (via the terminal services client  313  of the projection target  301 ) to the projector control point  303  of the projection device  201 , as well as in what mode to connect. For example, the connection mode may be specified as a projection mode, extended desktop mode, a mode for display of a particular application&#39;s screen information, etc. In addition, the generated ticket is given an unusually limited time out period such as, for example, ten seconds, in order to provide for a more secure connection process between the projection device  201  and the projection target  301 . Note that although an embodiment of the invention is described herein by way of RDP, use of RDP is not required in every embodiment, as other technologies such as HTML may alternatively be used.  
         [0043]    In step  411 , the generated ticket is passed to the projection target  301  via its UPnP component  311  from the UPnP component  305  of the projection device  201 . At this point, the ticket information can be used by the projector device point  309  to connect a terminal services session. To facilitate this, the UPnP component  311  of the projection target  301  passes the received ticket to the projector device point  309  at step  413 . The projector device point  309  then passes the ticket to the terminal services client  313  at step  415 . As the final step to creation of the terminal services connection, the terminal services client  313  of the projection target  301  uses the ticket in step  417  to establish a connection back to the terminal services server  307  of the projection device  201 . Note that in an embodiment of the invention, this connection is timed so that it will time out if it remains inactive for longer than a predetermined period of time, such as ten minutes. In this manner, a projection device user will not be able to inadvertently monopolize the projection target, such as by walking away without closing the connection, when another user could be waiting to use the target. In step  419 , with the terminal services connection having been established, the terminal services server  307  of the projection device  201  transmits presentation data such as screen data from the screen of the projection device  201  to the projection target  301  via the connection.  
         [0044]    Note that the data transmitted at step  419  or subsequently may consist of or comprise audio and or video information. This information is preferably encoded to conserve bandwidth, and as such the codec module  315  of the projection target is used to decode the information. In an embodiment of the invention, the audio and/or video information of interest may not be played at the projection device  201  itself but rather only at the projection target  301 . In this manner, copyright restrictions regarding numbers of licensed users may be adhered to when present. Similarly for text or other non-video visual information, copyright restrictions should be respected where appropriate by restricting the number of screens upon which, or users to which, the relevant information is displayed. It is also contemplated, but less desirable, to transmit audio and/or video information from the projection device  201  to the projection target  301  in unencoded form.  
         [0045]    In step  421 , the projection target  301  renders and/or plays the received information as appropriate via a display screen, speakers, etc. as needed. Certain technologies usable to implement embodiments of the invention, such as Terminal Services by MICROSOFT of Redmond, Wash., do not automatically allow display of information simultaneously on both a terminal client screen and a terminal server screen. In such cases, shadowing, such as is used in MICROSOFT Remote Assistance, may be used to provide the terminal server display.  
         [0046]    It can be seen from the foregoing description that the terminal services session described herein actually involves a reverse terminal server model, wherein the server initiates a connection by instructing the client to connect. It is this model, among other improvements, which allows the some of the beneficial behavior described above with respect to certain embodiments of the invention.  
         [0047]    Although the embodiments of the invention have been variously described using either a group of one or more user-associated devices, such as laptop computers, as the projection target devices, or using a dedicated device such as a conference room projector as the projection target device, it will be understood that the invention also contemplates situations wherein both one or more user-associated devices and one or more dedicated devices simultaneously serve as projection targets. For example, while a conference presentation may occur primarily via a dedicated projection device, a particular user may wish to see the presentation at his or her laptop computer due to deficiencies in eyesight, or for other reasons. Additionally, although the foregoing description has treated the projection target(s) as being somewhat distant from the projection device  201  (although generally in the same room) such is not necessary. For example, the invention can be used in one embodiment to provide dual screen functionality for the projection device  201 . That is, the projection target screen may display some further portion of the desktop shown by the projection device screen. Alternatively, although less desirably, the invention may be used in one embodiment to project or receive information beyond the bounds of a physical room. For example, an authorized user in an office may operate a projection device or target, such as a desktop PC, to participate in a conference in a nearby room.  
         [0048]    According to an embodiment of the invention, the projector control point  303  of the projection device  201  uses additional information available from the projection device  201  or from a network to which the projection device  201  is attached or attachable to further refine its operation. For example, the projector control point  303  may access the calendar of the user of the projection device  201  to select a projection target device from a number of possible candidate devices. For example, the OUTLOOK brand mail utility by MICROSOFT can maintain a user&#39;s schedule including information such as the room in which a scheduled conference is to be held. The projector control point  303  of the projection device  201  can use this information to select which of a number of nearby projection devices is the appropriate one with which to connect at the scheduled time. In particular, the projection device associated with the conference room in which the conference is scheduled should be selected, or presented to the user as a probable best selection.  
         [0049]    All of the references cited herein, including patents, patent applications, and publications, are hereby incorporated in their entireties by reference. That is, each and every part of every such reference is considered to be part of this disclosure, and therefore no part of any such reference is excluded by this statement or by any other statement in this disclosure from being a part of this disclosure.  
         [0050]    In view of the many possible embodiments to which the principles of this invention may be applied, it should be recognized that the embodiments described herein with respect to the drawing figures are meant to be illustrative only and should not be taken as limiting the scope of invention. For example, those of skill in the art will recognize that the elements of the illustrated embodiments shown in software may be implemented in hardware and vice versa or that the illustrated embodiments can be modified in arrangement and detail without departing from the spirit of the invention. Furthermore, although network connections are illustrated herein as lines, no limitation should thereby be imparted to the invention. Except where otherwise noted, network connections may be circuit-switched, packet-switched, or otherwise, and may be transient or permanent, hard-wired or wireless, operating via any suitable protocol. Moreover, the exact values such as for time periods given in the above description are exemplary only, and may be varied without departing from the scope of the invention. Therefore, the invention as described herein contemplates all such embodiments as may come within the scope of the following claims and equivalents thereof.