Voice channel control of wireless packet data communications

Technical Field

0001This 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

0002Data 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.

0003The 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.

0004One 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 <patcit id="pcit0001" dnum="US6144336A"><text>U.S. Patents No. 6,144,336</text></patcit>; <patcit id="pcit0002" dnum="US6690681A"><text>6,690,681</text></patcit> and <patcit id="pcit0003" dnum="US6493338A"><text>6,493,338</text></patcit> 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.

0005Higher 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: <ul id="ul0001" list-style="bullet" compact="compact"><li>2 Mbps for fixed environment</li><li>384 Mbps for pedestrian (i.e. slow-moving mobile unit)</li><li>144 kbps for vehicular traffic</li></ul>

0006One 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.

0007To 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..

0008A 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 to be used within a GPRS operator'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.

0009The need remains for a convenient and effective way to poll a remote mobile unit, that is, to request a packet data 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. <patcit id="pcit0004" dnum="WO03034235A"><text>WO 03/034235</text></patcit> (Infocus Corporation) discloses a data conferencing system for voice and data communications between live participants at geographically separate conference sites. Each of the conferencing sites has a telephone receiver and a data conferencing appliance. To establish a data communication session between local and remote sites, a user manually activates a system using an input key located on one of the data conferencing appliances. Preferably the input key is a pushbutton that can be manually actuated by a user. Manually activating the input key throws a switch within the initiating data conferencing appliance that causes it to begin an access negotiation procedure. <patcit id="pcit0005" dnum="US2003088619A"><text>US 2003/088619</text></patcit> describes another conferencing system for participants to converse as well as exchange multimedia data among the user stations that have packet data network capability. For those participants on user stations connected to the packet network, when a user station joins the conference call, the user station software transmits its own IP address over the phone connection to the conference master. A conference master responds by sending its own IP address over the voice connection, and then extra-audio connections can be negotiated and established. Other stations on the call can receive and decode the IP address message from the first user as well. <patcit id="pcit0006" dnum="CA2242495A1"><text>CA-A1-2242495</text></patcit> discloses to perform data sessions between nodes of a network by employing a specialized central phone server to manage sending IP addresses over the telephone network to nodes on the data network to enable data sessions. The central phone server utilizes a ringing suppressed (SRC) class of service to send IP address messages in FSK format to participating nodes. <patcit id="pcit0007" dnum="US20040209614A"><text>US 2004/0209614</text></patcit> provides a method for an exchange of broadband addresses by using SMS messaging. The mobile network (MSC) detects a broadband request flag in a communication from a first mobile subscriber, and generates an SMS (short message service) data message to send an IP address to the called party. Accordingly, the IP address is not sent through the voice channel, and customization of the network is required, as distinguished from a transparent solution.

Summary

0010In 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.

0011This 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 manor.

0012Presently 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 ether 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.

0013The 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:

0014According to one aspect of the invention, in-band signaling methods and apparatus and 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.)

0015The 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.

0016When 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.

0017The present invention is also independent of any digital cellular technology and is not tied to any individual cellular carrier's voice, data, or messaging service, which is also unique and advantageous offering greater cellular coverage capabilities when compared to existing approaches.

0018Additional 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

0019<figref idref="f0001">FIG. 1</figref> is a simplified high-level diagram illustrating operation of representative embodiments of the invention.

0020<figref idref="f0002">FIG. 2</figref> is a messaging diagram showing principle interactions among nodes involved in an embodiment of the invention.

Detailed Description of Preferred Embodiments

0021Reference 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.

0022In 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.

0023In 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.

0024<figref idref="f0001">FIG. 1</figref> is a simplified high-level diagram illustrating certain embodiments of the methodology of the present invention. Referring to <figref idref="f0001">FIG. 1</figref>, a requestor 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.

0025A 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.

0026In accordance with the invention, a requestor or a requestor 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 requestor application need not be hard wired to the PSTN but could itself be a wireless telephone link. The requestor system 100 also may have access to the Internet 122, typically through an ISP (internet service provide) 124. The connection to the ISP could take any of various forms, for example utilizing cable or the PSTN network, as are known.

0027According to a preferred embodiment of the invention, a method is provided for polling the remote wireless unit as follows: First, the requestor 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 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 requestor 100 and the remote wireless unit 112, the requestor 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.

0028The 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.

0029The target resource may be, but is not limited to, the requestor system 100 itself. In other words, the wireless terminal 112 may be instructed to initiate a packet data session back to the requestor system. That session would traverse link 120 from the wireless network infrastructure to the Internet 122 and thence to the requestor 100 via the ISP 124. As noted, this process can be automated by implementing suitable software at the requestor 100 and at the wireless unit 112 so that it can occur without user action at either end of the packet data session.

0030The 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.

0031The 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.

0032In 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.

0033Referring again to <figref idref="f0001">FIG. 1</figref>, 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. <figref idref="f0001">FIG. 1</figref> 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 requestor application 100 or a separate server 130.

0034In 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.

0035The present invention is not limited to downloading data from the wireless terminal to the requestor. The requested packet data session could also be used to download information to the wireless terminal.

0036<figref idref="f0002">FIG. 2</figref> is a messaging diagram that further illustrates principal features and characteristics of certain embodiments of the invention.

0037Referring to <figref idref="f0002">FIG. 2</figref>, 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.

0038Referring 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.

0039The 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.

0040It 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.