Patent Publication Number: US-2007120962-A1

Title: Cordless IP video phone system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      The present application is a continuation of U.S. Patent Application No. 10/449,157, filed May 29, 2003, entitled Cordless IP Video Phone System, and claims priority to U.S. Provisional Application No. 60/444,119, filed on Jan. 31, 2003, entitled Cordless IP Video Phone, the contents of which are both incorporated herein by reference in their entirety. 
    
    
     BACKGROUND OF THE INVENTION  
      Video phones are known in the art. However, video phones in the past have not been widely used. With the proliferation of the Internet and various high bandwidth technologies, use of video phones is becoming more practically feasible. Many past video phones have required the user to interact with equipment that is connected by wire to a data outlet. Other past video phones have provided handheld devices for interacting with a remote wireless network. However, both types of phones have disadvantages. The former type does not allow a user the flexibility of movement that may be desired during a phone call. The latter type typically requires the user to interact with a remote wireless network that may be unreliable or may be undesirable due to high access costs. Also, the latter type does not allow the user the flexibility to select the more advantageous options typically available with hardwire-connected communication systems (e.g., use of a regular telephone network or use of larger display, camera, or other equipment that may be adapted only for hardwire connection).  
      Cordless phones are known in the context of interaction with a Public Switched Telephone Network (“PSTN”) and typically include a base station having a hardwire connection to a PSTN and a handset using radio frequency (“RF”) signals to interact with the base station. This offers the advantage of connection to the regular PSTN network without having to go through a remote wireless network while still allowing the user flexibility of movement in the vicinity of the base station. However, the advantages of cordless phones have not been adequately realized in the context of video phones and IP phones.  
     SUMMARY OF THE INVENTION  
      In the context of video phones and IP phones, a cordless system can provide advantages beyond those realized by past cordless phones. For example, as will be shown in the context of embodiments of the present invention, a robust base station may be provided in the context of a cordless system that allows connection to multiple communication networks and multiple means of media display and capture.  
      An embodiment of the present invention provides a cordless video phone system including a base station that may be coupled for communication of audio and video information through a network and a handset that may be cordlessly coupled to the base station for exchanging audio information. In another embodiment, the network is an Internet Protocol (“IP”) communication network. In another embodiment, the handset includes a camera for capturing video images and the handset is also cordlessly coupled to the base station for sending video information to the base station. In another embodiment, the handset is also cordlessly coupled to the base station for sending control information to the base station and for receiving text and other information from the base station. In another embodiment, the handset is also cordlessly coupled to the base station for receiving video information from the base station and displaying video on the handset. In another embodiment, the handset comprises a speaker for hands-free communication when the handset is at a distance from a user. In another embodiment, the base station comprises a speaker for hands-free communication. In another embodiment, the handset comprises an earphone jack for alternative hands-free communication. In another embodiment, the base station may be coupled either to an IP communication network or to a PSTN telephone network for communication between the handset and the IP or PSTN network. In another embodiment, communication between the base station and handset is accomplished through analog RF signaling and the base station includes analog to digital conversion circuits and digital to analog conversion circuits. In another alternative embodiment, cordless communication between the base station and handset is accomplished through digital signaling. In another embodiment, a cordless phone system is provided including a base station that may be coupled for communicating audio information through an Internet Protocol (“IP”) network and a handset that may be cordlessly coupled base station. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  illustrates a cordless Internet Protocol (“IP”) video phone system in accordance with an embodiment of the present invention.  
       FIG. 2  illustrates a base station of the embodiment of  FIG. 1  in further detail.  
       FIGS. 3   a  and  3   b  illustrate a handset of the embodiment of  FIG. 1  in further detail.  
       FIG. 4  is a block diagram the exemplary handset elements shown in  FIGS. 3   a - 3   b  and also showing additional elements.  
       FIG. 5  is a block diagram of the exemplary base station elements shown in  FIG. 2  and also showing additional elements. 
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS  
      The following description is presented to enable any person skilled in the art to make and use the invention, and is provided in the context of particular applications and their requirements. Various modifications to the exemplary embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.  
       FIG. 1  illustrates a cordless Internet Protocol (“IP”) video phone system  100  in accordance with an embodiment of the present invention and shows peripherals to which system  100  is connectable. System  100  includes a base unit  110  and handset  150 .  
      Base station  110  is shown coupled to ADSL/cable modem  121 , V.90/V.92 modem  122 , secondary camera  123 , television  124 , VGA monitor  125 , and PSTN telephone line  126 .  
       FIG. 2  illustrates base station  110  in further detail. In particular, base station  110  includes broad band Ethernet connector  111 , RS232 connector  113 , TV connector  112 , VGA monitor connector  114 , camera connector  115 , and PSTN telephone line RJ11 connector  116 . These connectors can be used for coupling to peripherals such as, for example, those illustrated in  FIG. 1 , including, respectively, ADSL/cable modem  121 , V.90/V.92 modem  122 , television  124 , VGA monitor  125 , secondary camera  123 , and PSTN telephone line  126 . Base station  110  also includes DC jack  117  for connecting to an external power supply adapter. Base station  110  also includes antenna  118  for receiving RF video signals from handset  150 .  
       FIGS. 3   a  and  3   b  illustrate handset  150  in further detail. Referring to  FIG. 3   a , handset  150  includes microphone  151 , key pad  152 , display  153 , earpiece  159 , and camera  158 . Referring to  FIG. 3   b , handset  150  also includes speaker  154 , ringer  155 , and earphone jack  156 .  
       FIG. 4  is a block diagram of handset  150  illustrating the elements shown in  FIGS. 3   a - 3   b  and also showing additional elements. Cordless handset  150  captures video through camera  158  and then transmits the video signal through RF transmitter  432  to base station  110 . Handset  150  captures audio through microphone  151  and transmits the audio signal through RF audio transmitter  434  to base station  110 . By pressing keys on the keypad  152  of handset  150 , a user may send control signals through transmitter  434  to base station  110  for controlling certain aspects of system  100 . For example, input to keypad  152  can be used to control the base unit  110  to connect to either a broad band modem such as, for example, ADSL/Cable modem  121  or a narrower band modem such as, for example, V.90 N.92 modem  122  for sending digital audio and video signals, or to connect to a PSTN telephone line  126  for analog audio communication. Keypad  152  may be used to initiate other control operations as well, such as, for example, volume control or changing software settings. Also, communication may be initiated through use of keypad  152  by, for example, dialing a telephone number or entering an IP address. Commands or dialing data entered through keypad  152  and/or system status data (e.g. which connection is selected, whether a connection has been successfully established, software settings selected, telephone number dialed or to be dialed, IP address accessed or to be accessed, etc.) may be displayed on handset LCD display  153  (controlled by microprocessor  436 ), or may be displayed on a television (“TV”) such as TV  124  or a monitor such as monitor  125  coupled to base station  110 .  
      Considering  FIG. 4  and the operation of handset  150  in further detail, camera  158  is preferably an analog output camera which captures an image and converts it into an analog video signal. The analog video signal is sent to the video RF transmitter  432 . Microprocessor  436  selects the frequency channel to be used by RF transmitter  432 . Microprocessor  436  is a typical microprocessor such as, for example, an Elan EM78870 microprocessor. The RF transmitter  432  transmits the analog video signal to the base unit  110 .  
      Microphone  151  captures audio (e.g. voice sounds) and converts it into an analog signal that is sent to audio RF transmitter  434 . Microprocessor  436  selects the frequency channel to be used by RF transmitter  434 . The RF transmitter  434  transmits the analog audio signal to the base unit  110 .  
      Audio RF receiver  435  receives an RF analog audio signal (and may also receive other data signals, e.g., control signals) from the base unit  110 . Microprocessor  436  selects the channel used by receiver  435 . If “hands free” is activated, then receiver  435 , as directed by processor  436 , sends the audio signal to the speaker  154  and the earphone jack  156  so that the user may receive audio “hands free” either through speaker  154  or through an external earphone that can be attached to earphone jack  156  (external earphone not separately shown). When an external earphone is attached to earphone jack  156 , speaker  154  will be cut off. If “hands free” mode is not activated, then receiver  435  sends the audio signal to earpiece  159 .  
      When a call signal is received through base unit  110  indicating an incoming call, microprocessor  436  will generate a ring sound (e.g. a beep) through ringer  155 .  
      Memory  437  attached to the microprocessor  436  is used for telephone number memory. In alternative embodiments, other types of data may be stored in a memory such as memory  437  as well such as, for example, email addresses, web-page addresses, system settings, text or voice messages or messages/information in other data formats, etc.  
      A DC power adapter can be attached to the recharge port  462  for charging the power supply  433  on the handset  150  (power adapter not separately shown). Power supply  433  will convert the input voltage from recharge port  462  to different voltages that are needed for camera  158 , audio RF transmitter  434 , audio RF receiver  435 , video RF transmitter  432 , LCD display  153 , memory  437 , and microprocessor  436 .  
       FIG. 5  is a block diagram of base station  110  illustrating the elements shown in  FIG. 2  and also showing additional elements. In one example, camera  158  on handset  150  is utilized to capture video images and transmit them to base station  110  as described above (see  FIG. 3   a  and  FIG. 4  and accompanying text). Video RF receiver  544  receives the RF video signal from handset  150  video RF transmitter  432  and converts it to an analog video signal. The analog video signal is sent to video analog-to-digital (“A/D”) converter  545 . Video A/D converter  545  is a typical analog/digital converter such as, for example, a Philips SAA7113H. Video A/D converter converts the analog video signal to a digital signal. The digital signal is then sent to DSP type processor  550 . DSP type processor  550  is a typical DSP processor such as, for example, an Equator Technology Inc. BSP-15. In another example, by contrast, it may be more convenient for a user to utilize a larger camera than camera  158  on handset  150 . Thus, a camera such as secondary camera  123  may be connected to base station  110  as shown in  FIG. 1 . In this example, referring again to  FIG. 5 , video images are captured by secondary camera  123  and sent as an analog video signal to video A/D converter  549 , which is of a similar type to video A/D converter  545 .  
      Audio RF receiver  558  receives the RF signal from the handset  150  audio RF transmitter  434 . Audio RF receiver  558  is controlled by microprocessor  552  for channel selection. Microprocessor  552  is a typical microprocessor such as, for example, an Elan EM78910. Audio RF receiver  558  converts the received RF signal into an analog signal. Note that the RF signal received may be either an audio signal or a control signal from handset  150 . If the received signal is a control signal, it is sent to processor  552  for initiating control operations. If the received signal is an audio signal, it is sent to switching circuit  553 .  
      In normal telephone mode, microprocessor  552  will control switching circuit  553  to switch the audio signal to PSTN interface  559  so that a regular telephone communication is setup through a PSTN telephone line.  
      In IP phone or IP video phone mode, microprocessor  552  will control switching circuit  553  to send the audio signal to audio A/D converter  554  to convert the analog audio signal into a digital signal. A/D converter  554  is a typical A/D converter such as a Cirrus Logic CS53L32A.  
      Both the video digital signal from video A/D converter  545  (or video A/D converter  549 ) and the audio digital signal from audio A/D converter  554  are sent to the DSP processor  550 . DSP processor  550  compresses the audio and video signal and translates those signals into an appropriate protocol which, in the present example, is the ITU H.323 protocol.  
      DSP processor  550  links with Ethernet interface  560  and RS232 interface  561  through PCI bridge  556 . PCI bridge is a typical PCI bridge such as a VIA Technology VT82C686B. Ethernet interface  560  will connect to a broad band modem such as ADSL modem or a Cable modem (e.g. modem  121 ) for connection to an IP network. The RS232 interface  561  connects to a narrow band modem such as V.90/V.92 modem (e.g. modem  122 ) for connection to an IP network.  
      With respect to digital signals received through either Ethernet interface  560  or RS-232 Interface  561 , operation proceeds as follows: Signals are linked through PCI bridge  556  to DSP processor  550 . Audio signals are processed by DSP processor  550  to decompress and convert the signals from the ITU H.323 protocol. Audio signals are sent to audio digital-to-analog (“D/A”) converter  555 . Audio D/A converter  555  is a typical D/A converter such as a Crystal Semiconductor CS4334. Once the signal is converted to analog, it is sent to switching circuit  553  which, under the control of microprocessor  552 , switches the signal to audio RF transmitter  557 . Audio RF transmitter  557  modulates the audio signal and, under the control of microprocessor  552 , transmits the RF signal to the handset audio RF receiver  435 .  
      Other digital signals (non-audio) including those containing video and/or text or other data received through interfaces  560  or  561  are linked through PCI bridge  556  to DSP type processor  550 . In the case of display on a TV such as TV  124  (see  FIG. 1 ), DSP  550  sends the video or other non-audio signal to video D/A converter  551 . D/A converter  551  is a typical converter such as a Philips SAA 7121. D/A converter  551  converts the digital signal to an analog video signal (which may also include text or other data stream) which is sent to a TV such as TV  124  for display. Processor  550  has a VGA output port (not separately shown) so that video output may be displayed on a monitor such as VGA monitor  125  through VGA monitor connector  114  (see  FIGS. 1-2 ). Other monitors may alternatively be connected through connector  114  such as, for example, an external LCD monitor (external LCD monitor for connection to base station  110  not separately shown). An LCD panel (typically smaller format than an external LCD monitor) such as LCD panel  129  may also be provided as part of base station  110 . Processor  550  has an LCD panel output port (not separately shown) for connecting to an LCD panel such as LCD panel  129  as shown.  
      In one alternative embodiment, video signals may be sent through cordless transmission from a base station to a handset and video may be provided on a display at the handset (e.g., on an LCD display or other display). In such an alternative embodiment, direct connections from a base station to a TV, VGA monitor or other display such as those shown for base station  110  would not necessarily be present.  
      Base station  110  also includes Flash ROM  546 . Flash ROM  546  stores the operating software for DSP processor  550 . In a preferred embodiment, DSP software stored in Flash ROM  546  can be upgraded through an IP connection.  
      Base station  110  also includes RAM  547 . RAM  547  works with DSP processor  550  for operating the DSP software.  
      Although particular embodiments have been described in detail, various modifications to the embodiments described herein may be made without departing from the spirit and scope of the present invention. To cite just one example, the present system may be altered so that cordless communication between base station  110  and handset  150  is accomplished through digital signaling rather than analog RF signaling. In such an alternative an appropriate wireless protocol or other digital signaling protocol may be utilized. Those skilled in the art will appreciate that a handset and base station in accordance with such an alternative would be modified from the handset and base station illustrated herein in accordance with known digital communication techniques. For example, a handset in such an alternative may include a DSP processor to convert captured audio and video information into a digital format prior to transmission to the base station. A handset may, in such an example, include a digital camera rather than an analog output camera and may also include additional circuitry for converting audio into digital signals. These and other variations will be apparent to those skilled in the art and will be understood to be within the scope of the present invention.