WO1999049668A2

WO1999049668A2 - High performance single direction wireless transmission systems and technique

Info

Publication number: WO1999049668A2
Application number: PCT/US1999/006806
Authority: WO
Inventors: Thomas Ellenby; Peter Ellenby; John Ellenby
Original assignee: Geovector Corporation
Priority date: 1998-03-25
Filing date: 1999-03-24
Publication date: 1999-09-30
Also published as: AU3455099A

Abstract

An apparatus and method for single direction transmission of information is provided. A server and receiver are in communication by way of a plurality of transmission channels onto which certain information is distributed. The information is distributed among the channels in a manner which allows a receiver to select particular channels to receive information which may be of particular interest. Channel selection is based on parameters associated with the physical state of the receiver. Devices are arranged to measure certain receiver states and to convey that date to a channel selection scheme. Receive channels are changed in response to measured receiver states. Accordingly, receivers of the invention implicitly 'request' particular information in accordance with the physical state of the receiver.

Description

Title "High Performance Single Direction Wireless Transmission Systems and Technique"

Specification for Patent

BACKGROUND OF THE INVENTION Field

This invention is generally concerned with wireless transmission of data and information and specifically concerned with technique to enable single directional communication systems with extremely high performance characteristics.

Prior Art

Advanced modern electronics has enabled communication systems with remarkable function and features. Improvements have been made in both physical devices and systems configuration. These advanced techniques contribute to the wide variety of applied communications which may be found employed in many fields. In particular, we speak of improvements directed with a view towards efficiency. Efficiency whereby the quantity of information conveyed is improved while a reduction is made in system complexity and power requirements. With attention directed to five important concepts, one will more readily appreciate the foundation upon which the present invention is drawn. These five concepts include: 1) receiver power requirements, 2) bandwidth management, 3) spectrum reuse, 4) spatially and temporally dependent content, and 5) highly dynamic, receive-only clients.

For some systems, power supply requirements drive the system design. Indeed, since receivers must be configured to meet certain objectives, a severe constraint with respect to power is frequently encountered by design engineers. As an illustration, one known system has a communication device small enough to be attached to a flying insect without adversely affecting that insect's mobility. Thus, the device must employ very sophisticated power techniques.

Other communication systems have an extremely high number of clients which tend to occupy a limited number of system communication channels. The number of independent channels may be increased with bandwidth management techniques including single frequency band multiplexing. A detailed discussion of how many communication channels may be realized within a single frequency band improves understanding of portions of the invention.

As wireless transmitters tend to have a limited range, special configurations of repeater transmitters may be designed to address objectives relating to improvement of range and redundant broadcast over various regions. Alternatively, the limited range may be manipulated in a favorable manner which allows a high degree of frequency reuse. Details of how the invention is arranged to accomplish these objectives are included in this teaching. The particular information to be conveyed by a communications system may depend upon the location of the client which is receiving the information. Two examples are presented below which illustrate this important feature. The present invention has components which strongly rely on the theory that desired information is dependent on the location and orientation of client receivers. And finally, client transmission/receive capacity must be considered.

Communication system clients may be arranged to transmit only, receive only, or transmit and receive. System complexity often depends on the ability of a client to operate in either of these types of modes. Detailed discussion is directed to these various types of systems and certain advantages and disadvantages of each. All five of these principles tend to drive modern communication system design. However, as a whole, they have never been aligned and put into cooperation with one another to form a communication system similar to that of the present invention. As such, the present invention relates to a pioneering field and is quite broad in scope. The reader will appreciate that many species of devices exist which fully meet the true spirit and scope of the invention are taught in this disclosure.

Although specific examples are suggested as illustrations, one should remain mindful of the "big picture" and realize advantages and benefit of the invention may be attained in various systems which may not be explicitly set forth here as examples. Notwithstanding, techniques have been discovered which provide very novel uses of wireless communication systems, particularly with respect to organization of such systems to enable true one-way communications with the high performance generally found in a more complex and versatile two-way devices. Certain advantage is found for devices of the invention in providing systems with low receiver power supply requirements, improved bandwidth management, and high spectral reuse techniques. A client receiver having no transmission capacity whatever is enabled with highly advanced function allowing performance more like a high quality two- way asymmetric system. With respect to understanding the present invention, significant advantage may be had in consideration of an earlier filed patent application by the same inventors entitled: "Technique for Time Manipulation of Multi-Channel Transmission System", having U.S. serial # 08/881,066. That teaching is hereby incorporated by reference in its entirety as if it were completely set forth here.

SUMMARY OF THE INVENTION

Comes now, John, Thomas and Peter Ellenby with an invention of high performance one-way wireless communication systems including both devices and methods. Systems of the invention provide transmission of information on multiple channels in a manner which enables advanced function with respect to time and content manipulation of received signals. A unique transmission protocol and special manipulation of signals at a client end allow a user to receive content which is dynamic with respect to position, orientation and time. The systems are distinguished from those in the art having dynamic content because systems of the invention do not require establishing a communication "up-link" for client requests.

The system is generally comprised of a server end, a client end and a transmission link which couples the two ends. The server end is arranged to transmit signals or a signal on a plurality of channels in a pre-determined format having organized structure with respect to a position reference, an orientation reference and time reference. The client end, or receiver, is arranged to cooperate with the transmission protocol such that dynamic receipt of signals enables advanced features without need to transmit requests from the client to the server. A client receiver which is located in a particular location, and pointing in a certain direction, at a certain time, will automatically tune to a communications channel or channels which is appropriate for those position, orientation and time conditions. As such, advanced features typically found in a two-way asymmetrical systems are realized in a one-way system with simple design and reduced power and computing requirements. In brief, a broadcast system is arranged to transmit information on a great plurality of channels in a pre-determined arrangement. Each channel may carry specific information and the relationship between the channels and the information carried therein is well organized. Information may be separated into portions which are particular to physical states of a receiver. By distributing information about a plurality of transmission channels in a highly organized and pre-determined fashion which is "known" to a receiver, and providing the receiver with a logic processor to receive information about the physical state of the receiver and cause channel changing between communication channels in response to criteria relating to the receiver physical states, the receiver may change channels in a highly dynamic manner in response to changes in the receiver's position, orientation and time references as measured at the receiver.

Accordingly, it is a primary function of communications systems of the invention to provide versatility and high performance of two directional systems in a simplified receive-only arrangement. In addition, it is a function of systems of the invention to provide receivers having communication channels which are dynamically responsive to client position measurements. Further, it is a function of systems of the invention to provide receivers having communication channels which are dynamically responsive to a receiver orientation reference. Still further, it is a function of systems of the invention to provide receivers having communication channels which are dynamically responsive to time.

It is a contrast to prior art methods and devices that present systems do not require remote receive units to have any transmission function whatever. A fundamental difference between systems of the instant invention and those of the art can be found when considering its unique arrangement of transmission channels which enables the device to perform like a two-way system without need for a transmitter at the client end. Accordingly, an apparatus for transmission of information comprising: an apparatus for unidirectional conveyance of information from an source to a receiver, said apparatus being comprised of: a server; at least one receiver; a plurality of discrete transmission channels; information which is separated into portions which are particular to physical states of a receiver; and receiver physical state measurement means, the server being in communication with at least one receiver by way of at least two discrete transmission channels, and the receiver physical state measurement means being arranged to determine receiver parameters which may be used as references in a channel changing scheme is provided.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims and drawings where: Figure 1 is a block diagram which shows a simple version of a transmitter, receiver and link of the invention;

Figure 2 is a detail drawing of a demuliplexing portion of a receiver of the invention showing relation between a user input, command driver, and signal inputs and signal output; and Figure 3 is a diagram of a server system having a plurality of transmitters distributed over space.

Figure 4 is a field of regard diagram showing a plurality of transmitters and their associated transmission range.

Figure 5 is a similar field of regard diagram showing pointing direction relationships of various regions of the field.

Figure 6 is a plot of channels, channel groups and time.

Figure 7 illustrates how time relationships may be affect channel distribution.

PREFERRED EMBODIMENTS OF THE INVENTION Systems of the invention are generally comprised of a server end, a client end and a transmission link which couples the two ends. The server end is arranged to transmit a signals on a plurality of channels in a pre-determined format having regular structure with respect to time, space and direction references. The client end having advanced information regarding the transmission protocol, is arranged to cooperate such that dynamic channel selection enables implicit content selection based on time, space and direction references without need to transmit requests from the client to the server. So that one may more easily understand the following description, a brief review of certain nomenclature and definition of terms as used in the following description is presented here. For purposes of this disclosure:

A communication system may include a server, a client, and a link which couples the two. A server being a source of information to be conveyed and a client being the recipient of that information. Information may be any intelligible data in analog or digital format which may be encoded as a modulated signal such as an electromagnetic wave. Radio spectrum, high frequency, HF; very high frequency, VHF; ultra high frequency, UHF; infrared, IR; et cetera, all represent particularly useful spectra which may carry information via modulated signals. A transmitter is a device which forms and broadcasts signals which represents information.

A receiver is a device which receives and decodes signals and presents received information in a usable form such as standard audio or video formats. A signal space is defined as a two dimensional coordinate system where signal channels are represented on the ordinate and time is represented on the abscissa.

A transmission channel is a discrete conduit operable for carrying information distinct from other channels. A "transmission channel" includes conventional channels characterized by a spectral band, or "frequency", more accurately a spectral band having a center frequency, or may further include more advanced schemes where several channels share a frequency. Popular techniques for providing such configuration include time division multiple access, TDMA or code division multiple access, CDMA techniques. By use of the term "channel" in this disclosure, it is intended that both frequency bands and these and other advanced techniques that provide transmission channels are included.

While it is very convenient to use an audio signal as an example to illustrate preferred embodiments, and one is used extensively throughout this disclosure, the reader should be advised that the system is in no way limited thereto or intended to be designed exclusively for audio systems. An example of an audio system is developed for clarity as a result of its relationship with certain attributes of the particular example which relates to the best mode taught here. Indeed, the invention will serve well transmission of many other types of data and information. For example, video programs will enjoy the benefits, features and advantages which accompany systems of the invention. One should maintain the notion that systems of the invention are directed to communication systems in general and will work to realize advantages for all communication systems employing the principles taught herein.

By "changing" channels, it is meant that a particular channel or channels coupled to a receiver output are decoupled while other channels not being coupled to the output are then coupled thereto. One may envisage such changing of channels as "tuning" among a group of channels. Receivers of the invention are arranged to be extremely agile with respect to changing among broadcast channels. Traditional systems may tune into a single channel and change that channel infrequently. In contrast systems of the present invention may change channels quite frequently and even many times in a one second time period. In addition, receivers of the invention may simultaneously be turned to several channels or may remain continuously tuned to one channel.

Receivers included as part of the invention have several mechanisms which stimulate the changing of channels. Channels may be changed in response to certain physical states of receivers. For example with space, orientation and time measurements and references. Channels may be changed in a programmed sequence which affects a desired result. A measurement of a receiver's position may be used to advance a channel changing scheme. A user who causes a receiver to be moved from one location to another may cause a corresponding channel changing operation. A device may be arranged to measure a receiver reference direction which corresponds to a user's viewing direction. Orientation of the reference direction may be used to guide a channel changing scheme. If a directional reference is changed, the receiver may respond by tuning to different channel groups. Time may operate to change channels in some configurations. Careful review of a related application identified- above yields detail where a time reference is used to control channel changing. Combinations of the above described channel changing mechanisms may result in further versions of receivers having additional function. One will gain a greater appreciation for the mechanisms which may stimulate channel changes in consideration of the following preferred embodiments which illustrate some of these techniques.

To provide a strong foundation and full enabling disclosure, we revisit in detail five principles on which this invention is found. These five include: 1) receiver power requirements, 2) bandwidth management, 3) spectrum reuse, 4) spatially dependent content, and 5) highly dynamic, receive-only clients.

It is a great advantage in some communication systems to avoid the complexity and bulk associated with receiver power supplies. Devices of the present invention enjoy the benefits of including a power supply at the receiver, however, it is important to note that receivers of the invention cooperate with the transmitted signal in a manner to significantly reduce the required power required at a receiver. Since a receiver need not produce return transmission signal, the complexity, weight and power requirements are reduced. In addition, communication systems have grown extremely sophisticated with respect to bandwidth management. Only a few years ago, systems employed a single frequency band on which information was transmitted. A second "channel", meant an independent frequency band on which a transmitter transmitted and to which a receiver may be tuned. Because the spectrum is limited, there necessarily was a limited number of channels upon which communication systems could be arranged. Advanced bandwidth management techniques such as Code-Division Multiple Access, or "CDMA" and Time-Division Multiple Access, "TDMA", allow many channels to share a single frequency band by multiplexing signals into a single frequency band on various time slots or coded slots. In this way, many more users could occupy a single frequency communication system simultaneously. The present invention employs configurations which require a great plurality of transmission channels. Since it may be prohibitively difficult to arrange a system about many frequency bands which may be in short supply, techniques such as CDMA and TDMA are used in systems of the invention to provide many discrete transmission channels. Still further, communication systems are improved by highly reusable spectrum. Certain spectral components have physical properties associated therewith which advance the cause of high reuse of spectrum over limited areas. A very high frequency band typically has a low transmission range. Although low range may be viewed as a major disadvantage for systems such as cellular telephone systems, systems which may require a large number of cells to cover a particular region repeaters and amplifiers, other systems may realized great advantages from the property of low range/high reuse. The present invention is one such system which takes advantage of this property.

In some communication systems, the content of a conveyance may relate to a receiver's geographic position. For example, automobile mapping systems have been constructed to display a map of a region in which the user is presently located. As a user's position changes, so does the map which is displayed. A user in the San Fernando Valley likely has little interest in a street map of Manhattan Beach. However, as the user travels South and West to the beach community, and in particular to the city of Manhattan Beach, details relating to the streets of Manhattan Beach become more important. A programmed system might then implicitly respond by displaying maps which relate to the region in which a user is, or is going. A second example of content which is dependent upon a receiver position includes a system devised for real estate sales. A low power AM radio transmitter is placed in a building which may be subject to sale. An interested potential purchaser may drive to the building and view it while receiving audio feed on a car radio which can receive the transmission from the building due to the car's proximity with respect to thereto. Without retuning the receive channel, the user may travel to a second building of interest where a different transmitter provides an independent signal which can be similarly received. Proximity to the transmission stations dictates the content played at the receiver. That content to be conveyed is dependent upon the location of a receiver is critically important to the devices and technique of the invention. Receivers of the invention are designed to automatically tune to channels which contain relevant information as that information may relate to receiver location. Therefore a receiver is designed to determine its position and respond to that measurement by tuning to an appropriate channel.

In general, communication systems are highly variable in their design and function. Protocol for information exchange varies in accordance with a particular tasks at hand. In a very broad sense, wireless communication systems may be classified as "two-way" and "one-way" transmission systems. A bi-directional or two- way system sends and receives information at both terminals; while a one-way system transmits at one end and receives at another. A one-way system is characterized by having transmitter which broadcasts a signal which may be received at a remote unit. The remote unit may be very simple in design and power requirements as it does not require a transmitter to return signals. The flow of information is in a single direction. The radio in an automobile is a good example of a one-way system. A two-way system stands in contrast and is characterized by its arrangement which includes two or more transceivers being in communication with each other. Each unit includes both a transmitter and a receiver. Information may be passed to and from each of the units. A cellular telephone system illustrates a typical two-way system. A special class of two-way system is sometimes referred to as an asymmetrical system. Like the one way system, information primarily flows from a server to a client. However, the client may send a "request" to the server which tends to direct the topic or content of information which is transmitted thereafter. The "request" is typically a very brief message. On the other hand, the content dispensed by the server is typically quite extensive in information quantity. More generally, the system may be described as a very high bandwidth in one direction and a low bandwidth in the other; hence an 'asymmetrical' system. Systems of the invention are truly one-way systems where receivers have no ability to transmit requests to a server, however they are highly functional like an asymmetric system as they tune to channels which carry content of interest; i.e. the content received is quasi-selected at the receive end.

Hardware

Best modes of the invention include apparatus for conveyance of information comprised of at least one transmitter, at least one receiver, and a transmission link therebetween. With reference to the drawing figures, and in particular Figure 1 , which shows a block diagram of a simple version of a server transmitter, a client receiver, and link. A transmitter 1 , includes a specially arranged device which multiplexes signals to be transmitted among a plurality of transmission channels. The multiplexer 2 may be arranged to distribute a modulated signal 3, or a plurality of different signals, over a plurality of transmission channels. A transmission link 4 may contain many thousand of discrete transmission channels and couples the transmitter with a receiver 5. The receiver is equipped with a specially arranged demultiplexer 6. In addition, receivers of the invention include a position determining means 7 and orientation determining means 8 which are each in communication with the demultiplexer. The demultiplexer receives transmission of signals on a plurality of channels and provides a single signal at its output. The multiplexer 2 has a single input and a plurality of outputs 9. Similarly, the demultiplexer has a plurality of inputs 10 and a single output 11. A management module 12 may be included to control and direct receive channel switching schemes. A management module may include a general computer and computer program having information about a particular transmission protocol. While in communication with the position and orientation measuring means, the computer program can direct channel changing schemes in response to measurements relating the physical state of the receiver; i.e. position, orientation and time references. A signal 3 may be divided into many segments each which might correspond to a unique program element. The various segments may simultaneously broadcast on the many output channels of the transceiver multiplexer. The output channels, perhaps many in number, may be separate frequency bands or may by CDMA or TDMA channels. The distribution of program elements over the various channel is done in a highly organized fashion, that organization being well known to receivers of the invention. Alternatively, receivers which are not pre-programmed with distribution of program information may receive on a special dedicated channel a schedule of programming. The receiver demultiplexer may be simultaneously tuned to several channels or may merely have the ability to tune to any of the channels. In either case, we say that the demultiplexer has a plurality of inputs. The demultiplexer is in communication with a position determining means and an orientation determining means. Position and orientation measurements influence and direct channel changing routines executed in the demultiplexer. Finally, the demultiplexer provides a signal at its signal output to be converted to a format suitable for human interpretation or to activate other systems.

With reference to drawing Figure 2, one can appreciate further detail of the demultiplexer. The demultiplexer 21 and its plurality of receiver channels 22 cooperate with output 23 via a command controller 24 which is directed and motivated by a user interface device 25. Receive channels are in communication with the command driver. The user interface device is similarly connected to the command driver. The user interface device may include tactile inputs 26 such as push buttons, wheels, dials, knobs, et cetera, which can be used to initiate desired receiver function. Signals received on the demultiplexer inputs can be sorted and selected in accordance with a program resident in the receiver. More particularly, the command controller which may receive input information from the position and orientation determining means from the user interface device and additionally from the management module, drives the demultiplexer receive channels and couple any of those receive channels to the demultiplexer output. Therefore, information which appears as the demultiplexer output may be dependent on receiver position and orientation as measured at the receiver, user inputs, and transmission schedules which may be recalled from the management module. Attention being directed to the block drawing of Figure 3, one can gain a further understanding of a client server of the invention. A client server may be comprised of a plurality of transmitters distributed over space each being in communication with a central station. Central station 31 may include a computer which supplies appropriate information to individual transmitters. Transmitters 32, 33 and 34 may be placed at regular intervals or distances according to a particular distribution pattern. Alternatively, transmitter 35 may be placed in locations which may correspond to objects of interest. Each transmitter may have associated therewith particular power characteristics which may be adjusted in accordance with system design criteria. All transmitters are coupled to and communicate with the central station via a communication paths 36 or 37 which may be simple wire, high bandwidth fiber optic or wireless links. Each transmitter may be equipped with its own multiplexer which operates independently of any others or may operate in cooperation with others as needed in various applications. A server is said to be comprised of at least one transmitter as a general case, but some specific systems will employ a network of transmitters as shown in Figure 3 being spatially distributed.

A further appreciation of a system employing distributed transmitters may be had in view of the drawing of Figure 4. A field of regard 41 contains at least five transmitters therein. A transmitter may be symbolized by a small bold line circle. For example, a first transmitter 42 is shown at the top of the field of regard. A second transmitter 43 is shown below and to the right of the first transmitter. A transmission range boundary is indicated in the drawing by a large fine line circle. Transmitter 42 has a range boundary which is indicated by the circle 44. Similarly, transmitter 43 would have a range boundary indicated by 45. A receiver being anywhere within a range boundary of a particular transmitter may receive signals therefrom. A receiver located at the point indicated by 47 could therefore receive signals from transmitter 48. However, that same receiver could not receive signals from transmitter 42 as it is not within the range boundary 44. It is entirely possible that a receiver be simultaneously in range of two transmitters. A receiver located at the point indicated by 46 could receive signals from transmitter 48 and transmitter 49.

Receivers, as they are carried about from place to place, are said to have a position reference associated with them. The position of a receiver may be determined in many ways. The particular manner in which a receiver's position is measured is not important, but that the receivers position is known to or measured by the system is critical. A receiver, it will be shown, is responsive to position reference data. Therefore, receivers of the invention are equipped with a position determining means.

In addition, receivers may have associated therewith a direction or orientation reference. Some receivers will be used in conjunction with viewing. When a user is looking at an object of interest, we may associate the user's viewing direction with receiver orientation reference. We can say the receiver is oriented along a particular direction. Although the receiver may not have any physical parts which correspond to that direction, we may still associate a reference pointing direction with receivers. Apparatus may be affixed to a user or user's head which operates to define a receiver orientation. It is not important which arrangement be used as they are likely to be highly variable between different applications, however, that a pointing direction or orientation is associated with a receiver is significant for systems of the invention.

Figure 5 shows a field of regard and illustrates important features which relate to direction. Three shaded regions 51, 52, and 53 are defined by angular extents which terminate at a receiver location 54. A receiver located at 54 may have associated therewith a particular orientation. For example, a reference direction "A" may be associated with the receiver. As such, we say that the receiver is addressing region 52. Alternatively a receiver may be oriented along direction indicated by "B". In that case we say that the receiver is addressing region 51.

Since receivers of the invention have position and attitude determining means, their location and orientation may be continuously measured and known to system computers. System computers having such information, can respond to those measurements by adjusting channel changing routines in response thereto. For example, and with reference back to Figure 4, a receiver located at position 47 could measure that position and know to tune to channels which correspond to the broadcast channels of transmitter 48. The broadcast channels of transmitter 48 may be known to all receivers by way of pre-programming or even by way of a universal channel arranged to supply channel directory information.

Figure 6 shows a plurality of channels in three groups. In each group, channels may be displaced in time by some even increment. Such arrangement may be used to control the content received at a client receiver. For example, a client who is located at a particular position, say for example the position as indicated by 54. The client user may be looking into the field of regard in a direction indicated by "A". These conditions being detected by the position and orientation determining means are reported to the receiver computer. The computer responds by selecting a channel group which is appropriate for that position and direction. Channel group A may contain information which relates to objects in the region 52. Channel group B may contain data which relates to objects that are in the region 51. Accordingly, if a user turns and looks in the direction indicated by B, then a receiver may respond to that change. The receiver can switch the channel group and tune to group B channels. In this way, we say the client receiver channel changing mechanisms are responsive to position and orientation as determined by position and orientation determining means of the receiver. Of course one will appreciate that many more than three channel groups are possible. Indeed, it is anticipated that a great plurality of groups be used for most applications. We chose three here in order to make the drawing more simple. It is instructive to point out a few notes with respect to channel changing in view of position changes. Again with reference to drawing Figure 4 where a field of regard includes five transmitters each having a different range. A receiver located in position 47 could only receive data transmissions from transmitter 48 as that position is out of range of all other transmitters. However, if the client receiver moved to the position indicated by 46, it would be possible to tune to transmitter 48 channels or to transmitter 49 channels. A position determining means measures receiver positions and tunes the receive channels in accordance with position changes.

To make systems even more powerful, certain implicit functions might be available. For example, a receiver moving away from transmitter 48 and towards receiver 49 may reasonably imply that the content of transmitter 49 is more important to a user traveling in that direction. In this way, channel changing may not only depend on absolute position, but position change trends.

Similarly, if a receiver first moves in one direction, and shortly thereafter in another and finally in a third direction, and so on, the computer might assume that the user is lost and provide a channel change to a channel which carries information and instruction to guide the user through his surroundings. For example, on detecting that a user is lost, the receive channel may switch to a channel which provides a map image. Still further, if a receiver does not change position for an extended time, then a program may assume the user is particularly interested in the spot where he remains.

In this case, the channel changing mechanism might be arranged to switch to channels having more detailed programming and advanced description which might be outside the scope of a general inquiry.

Each of the elements above can be presented in further detail as follows:

Server

A server of the invention may include a plurality of transmission stations which are spatially distributed. Each transmission station may be under the control of a central processing control. The central processing control has a pre-programmed transmission protocol which is conveyed to a receiver or a plurality of receivers. Each transmission station may be enabled with means to transmit signals which may be distributed about a plurality of communication channels.

Client

A client receiver may be characterized as a portable device having means for measuring its position, orientation and time. Accordingly, it has a directional reference or pointing direction associated therewith which may be arbitrarily arranged within the device. A receiver has means to couple a plurality of communication channels with various outputs. Receivers have control means which direct channel changing routines in accordance with known transmission protocols which may be conveyed to the control means from time-to-time. Transmitter An example of a transmitter may be a video playing device compatible with common video formats and systems. Video signals which may be stored in analog or digital storage systems may be played by a transmitter of the invention. The transmitter may present signals for transmission on either conventional cabling systems or on more modern wireless systems. The transmitter may include sophisticated electronic hardware operable for manipulation of video signals and in particular for processing them for transmission on a plurality of channels Multiplexer

A signal which is applied to the multiplexer input is subject to a special processing and is distributed to output transmission channels in an ordered fashion. A video program may be encoded as a modulated electromagnetic signal. Briefly, the signal may be reproduced or replicated by the multiplexer into several identical signals. Each identical signal being transmitted on a different channel. The identical signals each having a beginning and an end, can be staggered in time such that a first channel has a slight time delay with respect to a second; a third channel having a similar time delay with respect to the second, and so on for all channels. Transmission Link

A transmitter and receiver of the invention are coupled by a transmission link. A transmission link may be radio broadcast, fiber optic, wireless, infra-red optical, or many alternative others without deviation from the spirit of the invention. A transmission link of the invention is characterized by having a great plurality of channels.

As mentioned, a channel includes conventional channels characterized by a "frequency" or may further include schemes where several channels share a single frequency. Both time division multiple access, TDMA and code division multiple access, CDMA techniques may operate to provide a transmission link with many channels onto which signal may be distributed. Receiver A receiver may be a common television tuner which has been arranged to cooperate with and receive the channels of the transmission link of the invention. A receiver includes elements unique to the invention including a demultiplexer, a command driver, and a user interface device. Demultiplexer A demultiplexer operates to receive information signals on many channels and is highly agile as it switches channels and routes signals received on any of the channels to a receiver output for playback on a video device. Channel switching routines may be driven by a command driver and a demultiplexer of the invention is responsive thereto. One should be fully advised that a demultiplexer does not imply that physical electronic receive circuits be in place for each channel which is transmitted. The icons represented as 10 in Figure 1 , and 22 in Figure 2 do not necessarily correspond to actual physical objects, such as antennae or receive circuitry, but merely imply that the demultiplexer is operable for tuning to each of those receive channels. Indeed, some versions will have only one electronic circuit which can receives signals. That circuit being tunable to many channels. The demultiplexer then is said to operably receive many channels without implication that it simultaneously receives more than one channel at a time. Command Driver

A command driver includes routines which drive changing of receive channels. The signals on certain receive channels are more desirable than others at any given time. The command driver receives requests from a user and responds to those requests by selecting the appropriate channel changing sequence to carry out the function requested by the user.

In some preferred versions, a special ancillary channel may be reserved for transmission of a schedule of programming, channels and corresponding start times. Arranged in a matrix or a "look-up" table, this information may be received and stored in a receiver memory. The information may then be quickly accessed by the command driver and the information may be used to direct and control further function.

User Interface Device

A user interface device may be comprised of simple buttons which operate electronic switching in response to tactile inputs from a user. Electronic switching then initiates routines which may be executed by the command driver to select channels in accordance with a particular function.

Examples of systems of the invention are useful for advancing a complete understanding of the invention. Accordingly, the following have been devised to show how position, orientation and time references may be used to drive channel changing schemes to receive selected information which is particular to those position, orientation and time references.

Although many simple schemes have been presented to illustrate how channels may be changed in response to changes in position, time or orientation, more complex schemes are provided where channel changing routines are made responsive to combinations of these parameters. In example, if position is changing in relation to time in a certain manner which meets a chosen criteria, then channel changing schemes can be arranged to cooperate and respond to these conditions. A kinematics expert will note that a regular position change with respect to time is more conveniently referred to as "speed". So, if a receiver's measurement transducers detect a speed which meets a pre-selected condition, then the device can respond thereto.

For example, if the device is moving 40 miles per hour it becomes reasonably certain that the device is in an automobile. A group of channels containing broadcast information relating to automobile travel can be selected. That information may contain elements relating to mountain ranges or other geographical features of interest which may be viewed while traveling at forty miles per hour. In addition, information of particular interest to a motorist may relate to the nearest available service station and the hours of operation. Conversely, if the speed is determined to be five miles per hour for an extended period, the device can reasonably deduce that it is being held by a person walking and would respond by tuning to channels associated with hiking and foot travel. For example items of interest may more likely relate to kinds of trees and more subtle features of the immediate landscape. The distance to the nearest available fuel is likely of no concern to a person hiking. Therefore, a combination of position and time can be used to determine to which channel or channel group a receiver is tuned. The careful observer will appreciate that 'speed' is distinct from 'velocity'. Although velocity is stated in the same units, distance per time, velocity has associated therewith a direction vector; speed is a scalar quantity, velocity is a vector quantity. An automobile may therefore be traveling at a velocity of 70 miles per hour in a Westerly direction. A device arranged to consider the position at a time t and compare that position to a position measurement at a later time t + δt may determine the direction in which the device is moving. In response to such determination, the device may predict that which may lie ahead. For example, if the device were in Santa Cruz, California, traveling at 70 miles per hour in a Westerly direction, then the device may conclude that the Pacific Ocean lies ahead and therefore the device may tune to channels which relate to matters concerning the Pacific Ocean. Users may get information on the water temperature, surf report, and general beach conditions. One will readily appreciate that a traffic jam 40 miles to the East near San Jose is of little concern to a person in Santa Cruz travelling West. The device prepared with the particular velocity information would respond to that information and avoid channels which contained information relating to San Jose traffic. Although speed and velocity information may be fully defined by position and time measurements, it is instructive to consider still further information which may contribute to advanced channel changing schemes. For example, the device may be traveling in one direction while pointing in another. To make a clear example, attention is drawn to a familiar device commonly known as a camcorder. A handheld electronic video camera, a camcorder, has associated therewith a pointing direction; that is the lens symmetry axis which defines the center of a field-of-view. A camcorder coupled with a device of the invention may include a receiver having associated therewith a reference pointing direction, for example a camera imaging axis. The velocity may be determined as well as the reference pointing direction. One should note that these two directions may be different. One might envisage a person using a camcorder while traveling in an automobile. The car may be traveling South while the camera is pointing West. Near and just South of San Clemente, California is a large military base called Camp Pendelton. With knowledge of device position, time, and orientation references, a channel or channel group may be selected in response to the particular values of those parameters. Accordingly, the device may selectively receive information relating to the military exercises which may be occurring as one travels past the military base. A narrative may be arranged to describe ships and helicopters which may be encountered as one passes from the North of the base to the South. The example nicely illustrates how a time, position and orientation references may cooperate together to drive a channel changing scheme.

A further example illustrates a complete system which may be used in a space of more limited extent. A system of the invention which illustrates the invention particularly well relates to an audio tour of a site of interest. Tourists sometimes visit historical sites and may benefit from a narrative which has been prepared to describe various features of the site. For example, Alcatraz island is the site where a famous federal prison once operated. Curious visitors make tours of the jail facility which remains. People travel by boat to the island and walk through the various facilities which contained some of the nation's most hardened criminals. While taking such tour, one may be accompanied by a tour guide. A tour guide might verbally present information from a scripted story as a group passes from one location to another. The script, of course, corresponds to the various sites and locations visited on the tour.

Since human guides are expensive and tend to be highly variable from one to another or from day to day, the quality and expense of such a tour might not be attractive.

In a preferred tour, a visitor may rent an audio device containing a prepared narrative. A recorded narrative assures the tour is uniform from time-to-time. In addition, a recorded narrative replayed over and over, may be quite inexpensive in comparison to a live tour guide. A user may rent a tape player with personal headphones and a pre-recorded cassette. So that the narrative agrees with the views a user encounters, such systems require that a pre-set path or route is followed. The audio narrative may contain a plurality of segments which can be played in a sequential fashion, the audio being advanced under manual control of a user, to correspond to various portions of the facility as the user enters these portions. The system assumes the user can recognize various locations and properly advance the tape in accordance. As one advances to different locations, so too does the narrative under direction of the user. In this way. audio information is synchronized with particular locations. However, tape machines which play recorded narratives are totally unresponsive to changes in the direction a user is looking. Although position is crudely accounted for, by way of a predetermined route, tape machine systems do not make any provision for content which is responsive to the user viewing direction. A user is not free to randomly access any of the views, but rather must follow the same path as all other users of similar tape machines.

As people enjoy advancing through a tour at various pace, the system is difficult to "sync-up" to the preference and whim of everyone. Some users may desire a casual and brief tour while others may wish for a detailed look with attention to many finer features and aspects which may be presented.

It is worth mentioning, and one will do well to make particular note that in the above example information is synchronized with particular locations; albeit in a rather crude fashion. Indeed it is similarly a fundamental objective of this invention to connect information with particular locations or positions. In addition, it is an objective to connect information with time and orientation references as well.

Versions of the invention may be arranged to provide an audio program designed to narrate a tour of a national monument or other tourist attraction. Information may be arranged and distributed about a plurality of transmission channels. A receiver, arranged to cooperate with the distribution protocol, may switch channels in response to position, orientation and time references as measured or initiated at the receiver. As such, a very efficient one-way wireless system enables tourists to receive information in a highly selective manner.

Systems of the invention are particularly suited to be configured for tours of national monuments and other sites of interest. They may be highly responsive to user position, orientation, and time as measured at a receiving unit. A user may tour the various portions of a facility without the requirement of following a predetermined route. Accordingly, a user may have random access to all of the information transmitted. Further, content which is received by a user may be dependent upon the direction in which the user is looking. And still further, the user may restart, rewind, fast forward, etc., a program as may be desired without the cumbersome effects which may accompany tape machines. A server is prepared with recorded information relating to the site of interest. In addition a broadcast scheme is arranged where a plurality of channels are distributed and arranged in a highly organized manner. A server may be comprised of a plurality of transmitters spatially distributed. Groups of channels may be associated with particular positions or directions or time references. A schedule of channels and associated programming is conveyed to a receiver or receivers of the system. A receiver being equipped with position, time and orientation determining means, may automatically tune to various channels which carry content in discrete portions.

While a program may have portions which relate to the entire island, more specific portions will relate to certain locations in the facility. When a user visits that location, the act of going to the location affects a channel changing response and allows the program to synchronize with the location of the user automatically and without manual user input. A user who moves from one location to another implicitly selects a portion of the program which corresponds to that location. The user is not required to manually advance any apparatus as the channel changing scheme operates under influence of results reported to it be a position determining means.

The previous examples are good illustrations of how well organized multichannel broadcasts can be manipulated at a receive-only end to affect desirable function which relates to control of content received, time properties. Although the present invention has been described in considerable detail with clear and concise language and with reference to certain preferred versions thereof including the best mode anticipated by the inventor, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited by the description of the preferred versions contained therein.

Claims

What is claimed is:

1) An apparatus for unidirectional conveyance of information from an source to a receiver, said apparatus being comprised of: a) a server; b) at least one receiver; c) a plurality of discrete communication channels; d) information which is separated into portions which are particular to physical states of a receiver; and e) receiver physical state measurement means, said server being in communication with at least one receiver by way of at least two discrete communication channels, and said receiver physical state measurement means being arranged to determine receiver parameters which may be used as references in a channel changing scheme.

2) An apparatus of claim 1 , said apparatus further comprises a channel changing scheme embodied as a logic processor programed to receive data from said physical state measurement means and cause switching between the plurality of communication channels in accordance with preselected criteria.

3) An apparatus of claim 1 , said receiver state physical measurement means includes a position determining means.

4) An apparatus of claim 1 , said receiver state physical measurement means includes an orientation determining means.

5) An apparatus of claim 1, said receiver state physical measurement means includes a time determining means.

6) An apparatus for receipt of information from an source, said apparatus being comprised of: a) apparatus physical state measurement means; and b) a channel changing scheme embodied as a logic processor programed to receive data from said physical state measurement means and cause switching between the plurality of communication channels in accordance with preselected criteria.

7) An apparatus of claim 6, said physical state measurement means comprising a position determining means.

8) An apparatus of claim 6, said physical state measurement means comprising an orientation determining means.

9) An apparatus of claim 6, said physical state measurement means comprising a time determining means.

10) A method of conveying information from a source to a receiver comprising the steps: a) distributing information to be conveyed among a set of discrete communication channels in accordance with a predetermined protocol; b) broadcasting information from a transmitter on said channel set; c) measuring at least one reference parameter associated with a receiver's physical state; d) selecting communication channels in accordance with the predetermined protocol and with reference parameter measurements; and e) tuning to at least one selected communication channel on which information may be received.

11) A method of claim 10, where a reference parameter is associated with a receiver's position.

12) A method of claim 10, where a reference parameter is associated with a receiver's orientation.

13) A method of claim 10, where a reference parameter is associated with time. 14) A method of claim 10, where a reference parameter is associated with a receiver's speed.

15) A method of claim 10, where a reference parameter is associated with a receiver's velocity.

16) A method of claim 10, where a reference parameter is associated with a combination of time and a receiver's position and orientation.