Abstract:
A cellular telephone is disclosed that allows a user to access a VoIP service provider using the WAP protocol to send and receive telephone calls to other users via the internet or other data network. The cellular telephone includes a cellular portion that formats messages to be sent to and from a cellular base station, a WAP portion that interfaces with the internet to send, receive, and display data therefrom. The cellular telephone also includes an audio gateway to sample, analog to digital convert, compress, and packetize an audio signal to prepare the audio signal to be transmitted via the internet to the second user,

Description:
BACKGROUND OF THE INVENTION 
       [0001]    This invention relates generally to wireless communications, and, more particularly, to voice over internet protocol (VoIP) wireless communications using a cellular telephone 
         [0002]    Telephone services have traditionally been provided by the public switched telephone network (PSTN), sometimes referred to as the plain old telephone system (POTS). With the development of the internet, hardware and software systems were developed and protocols developed that allowed telephone calls to be placed over the internet using an internet protocol. This voice over internet protocol (VoIP) allowed users to digitize and packetize their voice, send the voice packets across the internet to another user and to communicate back and forth. Typically a user needed a dedicated digital internet phone or a internet gateway connected to a traditional analog telephone and a VoIP service provider. The VoIP service provider would provide the switching information necessary to direct the voice packets back and forth between the users. 
         [0003]    However, although useful, to use VoIP at least one of the users must have access to a broadband internet connection and the necessary internet phone or analog phone-internet gateway, thus limiting the usefulness of VoIP to network nodes. 
         [0004]    A new class of mobile VoIP is being developed that uses the broadband signals of local wireless local area networks (WLAN) that make use of the IEEE 802.11x wireless standard. However, these systems are limited to areas having a suitably strong WLAN signal and unless there is significant overlap between WLAN wireless signals, it is not possible to move about while using the WLAN for VoIP. 
         [0005]    It is therefore a need to provide a system that allows a user to be mobile while making use of a wireless VoIP connection and does not require a static broadband connection to the internet. 
       BRIEF SUMMARY OF THE INVENTION 
       [0006]    The needs of the invention set forth above as well as further and other needs and advantages of the present invention are achieved by the embodiments of the invention described hereinbelow. 
         [0007]    A cellular telephone is disclosed that allows a user to access a VoIP service provider using the WAP protocol to send and receive telephone calls to other users via the internet or other data network. The cellular telephone includes a cellular portion that formats messages to be sent to and from a cellular base station, a WAP portion that interfaces with the internet to send, receive, and display data therefrom. The cellular telephone also includes an audio gateway to sample, analog to digital convert, compress, and packetize an audio signal to prepare the audio signal to be transmitted via the internet to the second user, 
         [0008]    For a better understanding of the present invention, together with other and further objects thereof, reference is made to the accompanying drawings and detailed description and its scope will be pointed out in the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         [0009]      FIG. 1  is diagram of a system that includes the capability of making VoIP calls over a cellular phone; 
           [0010]      FIG. 2  is a schematic depiction of a cellular telephone data message; 
           [0011]      FIG. 3  is a block diagram of one embodiment of a cellular phone compatible with the system depicted in  FIG. 1 ; 
           [0012]      FIG. 4  is a more detailed depiction of the gateway  312  depicted in  FIG. 3 ; and 
           [0013]      FIG. 5  is schematic representation of an interaction between a WAP device and a WAP server. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0014]      FIG. 1  depicts a system  100  that allows a user of a cellular telephone to make VoIP telephone calls over the internet. In particular the system  100  includes a cell phone  102 , which is a registered user of at least data communications services provided by a cellular station  104 . The cellular station  104  includes an antenna  106  to transmit and receive signals from cell phone  102  and a base station  108  that is connected to both the PSTN  110  as well as a network  112 , such as the internet. In operation, the base station  108  communicates with the cellular phone  102  by exchanging data packets that are formatted according to a predetermined protocol, for example, a code division multiple access (CDMA) cellular communication protocol. In general, the base station  108  will communicate with the cellular phone  102  using either a voice packet or a data packet. 
         [0015]    In the present application, the user of cell phone  102  desires to make a voice call via the internet  112  using a VoIP system. In general, the VoIP system allows the user of cell phone  102  to establish voice communication with one of four types of connections: an internet phone  114  connected to the internet  112 ; an analog phone  116  connected to the internet  112  via gateway  118 ; a base station  120  that transmits a cellular telephone signal via antenna  122  to cell phone  124 ; or a gateway  126  that interfaces to the PSTN  110  to connect to analog phone  128 . 
         [0016]    There are two basic methods of using VoIP to establish voice communication between users. First, the originating user may directly provide an internet address of the second user. In this instance, the second user must have a web presence and the necessary software to send and receive voice communication directly. Second, the originating user may use a VoIP service provider. In this instance, the VoIP service provider converts the user provided phone number or other addressing indicia into an internet address and then forwards the audio data packets to the new internet address and will also receive and forward audio packets from the second user to the originating user thereby establishing duplex voice communication between the two users. In the second method, if the second user is directly connected to the VoIP service provider as well, establishing the connection is directly performed by the VoIP service provider. 
         [0017]    In addition, interfacing to the Internet  112  may be accomplished, via the Wireless Application Protocol (WAP). This protocol allows a user of a cell phone or other WAP enabled device to access the Internet directly and to download and view data provided by websites. 
         [0018]      FIG. 2  depicts a typical voice packet and data packet respectively. In general, the data packet contains a header portion  202  and a payload portion  204 . The header portion  202  may include a mobile station identifier  204 , a voice/data service type identifier  204 , and a “other field”  208  for other information associated with the packet. The payload  204  may include compressed voice data, for a voice service packet, or an IP header and IP payload compressed data, for a data service packet. The IP payload may be in any suitable format including TCP/IP or UDP/IP. 
         [0019]    In the present invention, the cellular telephone  102  is a WAP enabled device that enables a user to access a website of a VoIP service provider. As depicted in  FIG. 3 , the cellular telephone  102  includes three main functional areas. Section  302  includes the functions associated with the cellular telephone portion of the cell phone including antenna  304 . The cellular transceiver  302  is responsible for transmitting and receiving properly formatted cellular telephone signals via the tx/rcx portion  302   a . A code/decode portion  302   b  of the cellular telephone  102  is responsible for formatting a signal to be transmitted in the proper cellular signal protocol and also for de-formatting a received cellular telephone signal from the cellular protocol into the actual data suitable for further processing. The cellular telephone  102  further includes a WAP system  306  that provides the interface to the internet and includes a network adapter  306   a , a WAP compatible microbrowser  306   b , a display  308 , and user input controls  310 . The microbrowser  306   b  is responsible for interfacing to the Internet and the network adapter  306   b  is responsible for formatting and de-formatting the digital data in the WAP protocol. The third functional section of the cellular telephone  102  is the VoIP gateway  312 . The VoIP gateway  312 , functionally includes two sections, audio input  314  and audio output  316 . The audio input  314  includes a microphone  318  that provides audio input to the audio input section  314 . The audio output section  316  includes a speaker  320  to provide audio output for the user. 
         [0020]      FIG. 4  depicts the gateway  312  in greater detail. The audio input section  314  is responsible for filtering and conditioning the audio input signal. A codec  326  is responsible for sampling and converting the analog signal into a digital audio signal. The digital audio signal is compressed and packetized by vocoder  328 . The compressed and packetized audio signal is then provided to a network adapter  330  that properly formats a data packet and implements the appropriate Internet communications protocols for carrying the data packets as IP packets over the network  112 . In one embodiment, the network layer protocol is the User Datagram Protocol/Internet Protocol (UDP/IP). In another embodiment, the network layer protocol is the Transmission Control Protocol/Internet Protocol (TCP/IP). Other network protocols known in the art may be used as well depending upon the network used and other system configuration parameters. The TCP/IP and UDP/IP are used for exemplary purposes only and are not meant to be limiting. 
         [0021]    Audio output  316  includes a vocoder  332  receives data packets from the network adapter  330 , which has previously stripped header and other data from the packet that is unnecessary for the final use of the data, and decompresses and depackets the data. A codec  334  converts the digital audio data into analog audio data and provides the analog audio data to an audio output processor that may filter, amplify, or otherwise condition the audio signal for output to a speaker  336 . 
         [0022]    WAP content and applications are specified in a set of well-known content formats based on the familiar WWW content formats. Content is transported using a set of standard communication protocols based on the WWW communication protocols. WAP defines a set of standard components that enable communication between mobile terminals and network servers, including. For example, WWW-standard URLs are used to identify WAP content on origin servers. WWW standard URLs are used to identify local resources in a device, e.g. call control functions. All WAP content is given a specific type consistent with WWW typing, this allows WAP user agents to correctly process the content based on its type. Also, WAP content formats are based on WWW technology and include display markup, calendar information, electronic business card objects, images and scripting language. Furthermore, standard communication protocols are used as WAP communication protocols and enable the communication of browser requests from the mobile terminal to the network web server. The WAP content types and protocols have been optimized for mass market, hand-held wireless devices. 
         [0023]      FIG. 5  depicts a typical WAP interaction between a WAP device  402  and a WAP application server  404 . The WAP device  402  includes a WAP microbrowser  406  that provides a request  408  to the WAP application server  404 . The WAP application server responds to the request  408  with a push signal and/or a response signal  410  that provide the desired content to the WAP device  402 . 
         [0024]    In the present invention, the user must have some sort of carrier agreement to enable the user to access the internet  112  via their WAP enabled device. 
         [0025]    As discussed briefly above, the two users must be identified and a connection be established between them. Thus, before audio or video media can flow between two computers, gateways, IP phones, cell phones, or other devices, various protocols must be employed to find the remote device and to negotiate the means by which media, i.e., audio and/or video will flow between the two devices. The protocols that are central to this process are referred to as call-signaling protocols, the most popular of which are H.323 and the Session Initiation Protocol (SIP). Both of these call signal protocols rely on other protocols to find other users. Once found, these call signaling protocols are used to ensure the accurate transmission of media between the end users. Either call signaling protocol may be employed in the network adapter  330  depending on the system that is being used and other system considerations as is known in the art. 
         [0026]    Although the invention has been described with respect to various embodiments, it should be realized this invention is also capable of a wide variety of further and other embodiments within the spirit and scope of the appended claims.