Abstract:
A data session with a wireless device ordinarily cannot be initiated from the network side because the wireless device has no predetermined IP or other network address. Methods are disclosed for instead causing the wireless unit to initiate a data session with a target destination, thereby obviating the IP addressing problem. A voice call is first initiated by a requester application to a remote wireless unit. The requester transmits a request message to the remote wireless unit via the wireless voice channel using in-band techniques; preferably including a payload in the polling message that identifies the target destination. In response, the remote wireless unit initiates a packet data session with the target destination.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. application Ser. No. 11/048,623, filed Jan. 31, 2005, which is herein incorporated by reference in its entirety. 
     
    
     COPYRIGHT NOTICE 
       [0002]    ® 2005 Airbiquity Inc. A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever. 37 CFR § 1.71(d). 
       TECHNICAL FIELD 
       [0003]    This invention pertains to data communications via wireless communications networks, and more specifically it relates to use of the voice channel to trigger a network initiated data session such as an IP session. 
       BACKGROUND OF THE INVENTION 
       [0004]    Data transfer services in the wireless domain are known and certainly still evolving. Examples include SMS (short messaging service) and other SS7 control channel services. They can be used, for example, for text messaging. They do not affect the voice channels, but offer very limited bandwidth, so the amounts of data transferred are quite limited. 
         [0005]    The WAP (Wireless Application Protocol) specifications and software offer some improved services. For example, they can be implemented to provide limited Internet access to a mobile unit. (We use the term “mobile unit” herein to refer broadly to any device with wireless connectivity, including without limitation a cell phone, PDA, laptop computer, palmtop, motor vehicle, etc.). The WAP services, however, require that the mobile unit itself be WAP enabled, and that the wireless carrier network also be WAP enabled. Thus, wireless carriers have to deploy and maintain WAP gateways at the edges of the network to provide WAP services. Some mobile units, and some networks or geographic areas may not be WAP enabled, so these services would not be available for data communication. 
         [0006]    One approach to wireless data transfer that does not require changes in the wireless network infrastructure, although it requires specific implementation at both endpoints of a session, is the use of “in-band” data transfer. As the name implies, this technique transfers data in the voice channel, using carefully selected and timed audio frequency tones. (Commonly, wireless data transfer services do not use the voice channel at all.) In-band or voice channel data transfer can be done with little or no interruption of a voice conversation. Details of in-band signaling are explained in U.S. Pat. Nos. 6,144,336; 6,690,681 and 6,493,338 all incorporated wherein by this reference. These types of in-voice-channel data communications have two primary advantages: the wireless voice channel is reliable, and the technique works transparently across networks and carriers throughout the country and beyond. The data simply passes transparently through the voice service, as it “looks” like voice. However, in-band signaling provides only a very low bandwidth up to around 400 bps. That makes it almost useless for transferring significant amounts of data. 
         [0007]    Higher bandwidth wireless data services are rapidly becoming available throughout the world. These services operate over dedicated data channels, not the voice channels. The newer specifications, so-called “3G” or third generation wireless technologies, while not yet widely implemented, promise packet data rates as follows, according to IMT-2000 standards: 
         [0008]    2 Mbps for fixed environment 
         [0009]    384 Mbps for pedestrian (i.e. slow-moving mobile unit) 
         [0010]    144 kbps for vehicular traffic 
         [0011]    One problem, however, with virtually all wireless data services, is the difficulty in accessing those services in a network “polling” type of application. Polling (or “pulling data”) here refers to contacting a mobile unit to pull or retrieve digital data needed by a requester. (The “requester” typically would be an application program.) Preferably, an authorized requester should be able to poll remote mobile units, and fetch data, without manual user intervention at the remote location. In other words, a polling process should be able to be completely automated, although for some applications it can be advantageously initiated by a user at the requester end. 
         [0012]    To illustrate, a wireless automated inventory control system may seek to poll units, say trucks or tanks, to learn their present location, fuel supply, operator ID, etc. A packet data connection, for example an IP connection, cannot be established with a mobile unit from the network side (we call this “network initiated”) using prior technology, because the mobile device has no predetermined IP address. Rather, an IP address is dynamically assigned to a mobile unit only if and when it initiates a session to an IP network. Accordingly, a user application cannot poll a remote mobile unit to establish a packet data transfer session using known technologies. 
         [0013]    A system has been suggested for IP addressing of GPRS mobile terminals that purportedly would enable TCP/IP connection without a phone call. That proposal recognized that there are not enough IP addresses available (under the current Ipv4 regime) to assign one to every wireless terminal. The proposal calls for a combination of Public Addresses (registered with public routing tables) and Private addresses, not to be routed on the public Internet. Rather, the private (IP-like) addresses would only be used within a GPRS operator&#39;s own network. This would require network address translation (NAT) facilities and is generally impractical. Even if implemented, such a scheme does not solve the problem that the mobile (or wireless) terminal address is unknown, and is not publicly discoverable in a convenient way. 
         [0014]    The need remains for a convenient and effective way to poll a remote mobile unit, that is, to request a data packet session, for uploading or downloading data via the wireless network, without changing the wireless carrier infrastructure and in a manner compatible with existing packet data networks and protocols such as IP. 
       SUMMARY 
       [0015]    In accordance with one embodiment of the present invention, a combination of in-band or voice channel signaling together with packet data services is employed to overcome the lack of a predetermined IP address of a mobile unit. A voice call is established between a requester and the remote mobile unit. A short polling message is transmitted in the voice channel from the requester using in-band digital data transmission (“IBS”). The request message includes in its payload data that identifies (directly or indirectly) a target resource such as a URL or IP address. The mobile unit responds by initiating a wireless packet data session with the indicated target resource which may be, for example, a server system. 
         [0016]    This new approach of using the voice channel signaling to enable a network initiated data session will solve the existing problem associated with assigning an IP address (Simple IP and Mobile IP assignment for both IPv4 and IPv6) to a mobile device and do so in a timely and more efficient manner. 
         [0017]    Presently the existing cellular infrastructure does not allow mobile devices to pre-register their IP address with the cellular data network, instead it must be assigned to the mobile device by the cellular data network when a mobile device first initiates a request for a data session using a Simple IP protocol, or the mobile device must initiate an IP address discovery process using the Mobile IP protocol. In either case the cellular data network does not know of the routing location of the IP address for a mobile device until the mobile device first initiates a data session. 
         [0018]    The core data network of any data enabled cellular network can use this unique invention to initiate a data transfer session, which we will call a Network Initiated Data Session (NIDS) and is described as follows: 
         [0019]    According to one aspect of the invention, in-band signaling methods and apparatus are employed to “push” a request to a mobile unit or “node”. We call this a Mobile Terminated (MT) request. (The mobile device is of course in-band signaling enabled, meaning essentially that it can send and receive digital data through the voice channel of a wireless network.) 
         [0020]    The receiving mobile unit (mobile node) detects—and triggers the mobile device (or other system coupled to the mobile device) to initiate a data session with the cellular network using an available data channel, not the voice channel, to transmit data to a specified (or default) destination. 
         [0021]    When a request is made of the mobile device, by using voice channel signaling, the network can initiate a data session between the mobile device and any network or internet entity at any time using the voice channel of the cellular network, or any other radio frequency derived audio channel where voice channel signaling functions. Due to the real time speed and quality of service of in-band (voice channel) services, a distinct time savings and reliability advantage can be made over any other approach for network initiated data sessions. These advantages are of paramount importance for public safety and security applications. 
         [0022]    The present invention is also independent of any digital cellular technology and is not tied to any individual cellular carrier&#39;s voice, data, or messaging service, which is also unique and advantageous offering greater cellular coverage capabilities when compared to existing approaches. 
         [0023]    Additional aspects and advantages will be apparent from the following detailed description of preferred embodiments, which proceeds with reference to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]      FIG. 1  is a simplified high-level diagram illustrating operation of representative embodiments of the invention. 
           [0025]      FIG. 2  is a messaging diagram showing principle interactions among nodes involved in an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0026]    Reference is now made to the figures in which like reference numerals refer to like elements. For clarity, the first digit of a reference numeral indicates the figure number in which the corresponding element is first used. 
         [0027]    In the following description, certain specific details of programming, software modules, user selections, network transactions, database queries, database structures, etc., are provided for a thorough understanding of the embodiments of the invention. However, those skilled in the art will recognize that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. 
         [0028]    In some cases, well-known structures, materials, or operations are not shown or described in detail in order to avoid obscuring aspects of the invention. Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. 
         [0029]      FIG. 1  is a simplified high-level diagram illustrating certain embodiments of the methodology of the present invention. Referring to  FIG. 1 , a requester application program can be provided on a suitable computer  100 . The request or polling application can be activated by a user as needed or preprogrammed for automatic operation at scheduled times. The computer system  100  is coupled to a telephone line which may include a conventional telephone  102  and in any event is connected via  104  to the public switched telephone network PSTN  106 . This connection can be, for example, an ordinary telephone land line as is commonly used for voice calls. It could also be part of a larger enterprise system that may involve a PBX (not shown), or it may be a wireless telecom connection. 
         [0030]    A wireless carrier network  108  is connected to the PSTN  106  for handling wireless call traffic, the details of which are well known. The wireless network  108  includes a series of base stations which include antennas and wireless transceivers, generally referred to as a cell tower  110 . Transceivers are mounted atop the cell tower  110  for two-way wireless communications with various wireless mobile devices such as a cell phone  112  or PDA  114 . The base station antennas need not literally be mounted on a tower. In urban areas, in particular, they are more commonly affixed to buildings. 
         [0031]    In accordance with the invention, a requester or a requester application executing on computer  100  initiates a voice telephone call, via the PSTN or wireless, directed to a remote mobile unit such as the cell phone  112 . The connection from the requester application need not be hard wired to the PSTN but could itself be a wireless telephone link. The requester system  100  also may have access to the Internet  122 , typically through an ISP (internet service provider)  124 . The connection to the ISP could take any of various forms, for example utilizing cable or the PSTN network, as are known. 
         [0032]    According to a preferred embodiment of the invention, a method is provided for polling the remote wireless unit as follows: First, the requester system  100  initiates a voice call to the remote wireless station. This of course requires that the telephone number of the device is known. Other kinds of mobile devices, such as the PDA  114  or even a motor vehicle  116  can include an apparatus that is configured to interact with the wireless network as if it were a cell phone, although it may not actually include a microphone or a speaker. For example, devices can be configured to automatically answer a wireless call, and provide the control channel signaling to emulate answering a cell phone. Once a voice call is established between the requester  100  and the remote wireless unit  112 , the requester system  100  transmits a digital request message to the remote wireless terminal via the wireless voice channel on which the voice call is established. In other words, the digital request message is sent “in band” through the use of audio frequency tones that are arranged so that they will pass through the voice channel unobstructed. 
         [0033]    The request message preferably includes a payload that identifies a target resource. In the remote wireless unit, for example  112 ,  114 , apparatus or software is implemented that will respond to the digital request message by initiating a packet data session with the target resource identified in the request message. By “packet data session” we mean a data transfer session that utilizes one or more of the data services provided by the wireless carrier, as distinguished from voice services. 
         [0034]    The target resource may be, but is not limited to, the requester system  100  itself. In other words, the wireless terminal  112  may be instructed to initiate a packet data session back to the requester system. That session would traverse link  120  from the wireless network infrastructure to the Internet  122  and thence to the requester  100  via the ISP  124 . As noted, this process can be automated by implementing suitable software at the requester  100  and at the wireless unit  112  so that it can occur without user action at either end of the packet data session. 
         [0035]    The target resource can be identified in the request message by a predetermined identifier, such as a simple alphanumeric name or code. The wireless terminal software can perform a look-up in memory to determine a corresponding URL or IP address. Alternatively, the target URL or IP address can be included in the request message itself. 
         [0036]    The target resource need not be the requesting system  100 . In one alternative embodiment, it could be a server  130  which is coupled to the Internet through an ISP and configured to perform data collection, utilizing standard packet data session protocols such as the Internet protocol. The target may be a web server suitably configured to interact with the mobile unit. 
         [0037]    In other embodiments, the request message payload can include various delivery parameters, in addition to identification of a target resource. The delivery parameters might include, by way of example and not limitation, a preferred packet data service, a packet data rate, and/or a priority parameter. These parameters can be recovered from the message payload by the wireless terminal software and it can initiate a responsive packet data session in accordance with those parameters. For example, in the case of a relatively low priority parameter, the application software might select a data service or time of day to initiate the packet data session that is lower performance but incurs lower cost. 
         [0038]    Referring again to  FIG. 1 , the tanker truck  116  is merely illustrative of a wide variety of mobile assets, including but not limited to motor vehicle assets, that could participate in the present system, assuming they are outfitted with a wireless unit as explained above.  FIG. 1  also shows a second wireless base station tower  136  illustrating that the packet data session need not involve the same base station, or even the same wireless carrier, as that which carried the request message via the voice channel. The requested packet data session could occur through a second wireless network  138  which is also coupled to the Internet via  140 . And again, the packet data session could be established with any target resource, including but not limited to the requester application  100  or a separate server  130 . 
         [0039]    In other embodiments of the invention, a live user or operator at a computer  150 , having access to the Internet, could poll one or more remote wireless units to request a data transfer. For example, a user at say a public safety location such as a 911 emergency call taker, could access a web server (not shown) which has voice call telephone access such as  104 . Through the means of a suitably programmed web page interface (using, for example, CGI scripting or the like), a user at  150  could initiate a request message which would take the form of a voice call from the web server, through the PSTN and the wireless network as described above, to a remote or mobile unit. The request message could include identification of the call taker center at  150  as the target resource to deliver requested information via a packet data session. 
         [0040]    The present invention is not limited to downloading data from the wireless terminal to the requester. The requested packet data session could also be used to download information to the wireless terminal. 
         [0041]      FIG. 2  is a messaging diagram that further illustrates principle features and characteristics of certain embodiments of the invention. 
         [0042]    Referring to  FIG. 2 , a signaling or message flow diagram further illustrates methodologies in accordance with the present invention. Beginning with “time interval A” and initiating application  208  essentially places a voice call out to the mobile telephony device  204 . As noted above, the initiating application could be a software application deployed on a computer or on a server and it may or may not necessarily require a conventional telephone. It does require access to the wireless network, directly or through the PSTN. The telephony device, in turn, makes a voice call through the cellular network  202  which in turn makes a wireless call to the mobile unit  200 . The mobile unit answers the call, thereby establishing a voice channel “connection” back to the telephony device  204 . Once that voice call is established, the initiating application, at “time interval B” transmits a request message in the voice channel to the mobile device  200 . Optionally, the mobile device may respond with an acknowledgement message in the voice channel. 
         [0043]    Referring now to “time point C,” responsive to the request message, the mobile terminal  200  initiates a data network connection, which traverses the cellular network  202  and establishes a packet data session via the IP network  206 . Here, the target or destination resource is coupled to the IP network  206 . The IP network in turn responds to the mobile node  200  at “time point D” and then, as indicated at “time point E” a packet data session is established between the mobile node  200  and the IP network or target  206 . “Time point F” indicates that the IP resource may not be the ultimate recipient of the data, but rather, it could be configured to forward that data to an ultimate destination address which may be, but is not limited to, the initiating application  208 . 
         [0044]    The process used by the core data network, internet application, or stand alone device to initiate a data session using aqLink begins with the establishment of a circuit switch voice channel connection to the mobile device. This can be accomplished by any means made available to the initiating application or device. 
         [0045]    It will be obvious to those having skill in the art that many changes may be made to the details of the above-described embodiments without departing from the underlying principles of the invention. The scope of the present invention should, therefore, be determined only by the following claims.