High bandwidth communications technique for mobile communications devices

Description of equivalent WO 2004068877 A1

HIGH BANDWIDTH COMMUNICATIONS TECHNIQUE FOR MOBILE

COMMUNICATIONS DEVICES

TECHNICAL FIELD

This invention relates to a technique for providing high bandwidth information to a mobile communications device, such as a wireless telephone or the like.

BACKGROUND ART

Presently, users desirous of obtaining wireless telephony service typically subscribe to one of the many providers of such service. Many of today's wireless telephony service providers not only offer voice-calling capability, but also offer data services, such as General Packet Radio Service (GPRS), thereby affording subscribers the capability of exchanging data packets via a mobile terminal. While mobile data service exists in many areas, data transmission rates typically do not exceed 128 Kbs and the costs incurred by wireless network service providers to support this service remain high, making mobile data service expensive. The relatively high cost and relatively low throughput of present-day public mobile data networks makes the data service offered through such networks impractical for providing "high bandwidth" information. For purposes of discussion, high bandwidth information comprises large files of text, data, audio and/or video that require high bandwidth for transmission in a timely manner. For example, transmission of a large video file, say 100 Mbytes, at a rate of 128 Kbs rate will typically take hours, whereas transmitting the same file at a rate of 11 Mb/s or higher will take but a few minutes. The ability of many new wireless telephones to access the Internet is of somewhat limited value given the low data transmission rate available through present day public mobile data networks. Despite the availability of useful information, such as maps, and tour guides for example, available from the Internet, most wireless telephone subscribes avoid accessing the Internet because of the time and cost involved to obtain such information. Consequently, the relatively low data rate offered by present-day public mobile networks has impeded the development of various information services that require high bandwidth.

A prior mobile communication system for overcoming this problem comprises a direct link for communicating information between a network and a selected mobile communications device, and a broadcast link for simultaneously broadcasting information from the network for intended receipt by all of the communications devices. The broadcast link takes the form of a satellite or terrestrial television transmission. While both satellite and television transmission afford high bandwidth, obtaining such spectrum for the purpose of providing a second channel to mobile communications devices could prove problematic, given the relatively high cost of such spectrum.

Thus, there is a need a technique for providing a relatively low cost, high bandwidth channel for providing information to mobile communications devices.

BRIEF SUMMARY OF THE INVENTION

Briefly, in accordance with present principles, a method is provided for establishing a high bandwidth, unidirectional communications channel to a mobile communications device already in communication with a first network via a low bandwidth bi-directional communications channel. The method commences upon receipt in a second network of a request by the mobile communications device to establish the high bandwidth, unidirectional communications channel. In practice, the second network comprises a Wireless Local Area Network (LAN) or the like linked to the first network. Upon receipt of the request, the second network (e.g., the wireless LAN) then undertakes to verify the requesting mobile communications device, typically by verifying identification information utilized by the mobile communications device to access the first network. Following verification, the second network establishes the high bandwidth, unidirectional communications channel, which in the case of the wireless LAN, takes the form of an IP channel. After establishing the channel, the second network will provide information to the mobile communications device. Such information could include information selected by commands entered by the mobile communications device to the first network and forwarded to the second network.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGURE 1 depicts a block schematic diagram of a communications system for practicing the method of the present principles for establishing a high bandwidth, unidirectional communications channel; and FIGURE 2 depicts a timing chart depicting the sequence of events associated with establishing the high bandwidth, unidirectional communications channel in the communications system of FIG. 1.

DETAILED DESCRIPTION

FIGURE 1 illustrates a block schematic diagram of a communications system 10 that includes a mobile telephone network 12. In practice, the network 12 provides data communications in accordance with the 2.5G GPRS standard or the 3G Universal Mobile Telephone Standard (UMTS). For that reason, the network 12 thus bears the designation

GPRS/UMTS network in FIG. 1. Other wireless telephony standards exist and could easily be employed in place of the GPRS or UMTS standards without departing from the present principles. A mobile communications device 14, such as a wireless telephone, wireless PDA or wireless modem associated with a personal computer, accesses the GPRS/UMTS network 12 via a radio node 14 connected to the network. Communications between the radio node 14 and the mobile communications device 12 occurs over a radio channel 18 that typically has a relatively low bandwidth, which in practice, typically supports no more than 128 Kbs data service. While the bandwidth of the channel 18 supports bi-directional communications of both voice and data between the mobile communications device 14 and the radio node 16, the relatively low bandwidth of the channel does not support efficient accessing of large audio, video and/or data files, such as could be requested from a data network 20 like the Internet.

In accordance with the present principles, a mobile communication device can advantageously access high bandwidth information via a high-bandwidth unidirectional radio channel 22 established between the mobile communications device and an Access Point (AP) 24 associated with, for example, a Wireless Local Area Network (LAN) 26. In many geographic areas, there exists publicly accessible Wireless LANs, such as wireless LAN 26, that afford relatively high bandwidth (usually in excess of 10 Megabits/second) at a reasonable cost, thus offering a relatively cheap mechanism for providing information to the mobile communications device 14. An Internet Protocol Gateway (IP GW) 28 provides an interface between the wireless LAN 26 and the Internet 20 to permit accessing of information, and in particular, high bandwidth information, from at least one application server 30 connected to the Internet.

Control of the information provided by the server 30 occurs in response to instructions received through the GPRS/UMTS network 12 from the mobile communications device 14. Within the GPRS/UMTS network 12, a Gateway GPRS Support Node (GGSN) 32 provides an interface between the network and the Internet 20. Thus, the GGSN 32 enables information selections received in GPRS/UMTS network 12 from the mobile communications device 14 to ultimately pass to the server 30, which in response provides such selected information for transmission through the wireless LAN 26 and the channel 22 for receipt by the mobile communications device.

FIGURE 2 depicts the sequence of events associated with establishing the high bandwidth unidirectional radio channel 22 between the mobile communications device 14 and the AP 24 associated with the wireless LAN 26, all of FIG. 1. Initially, the mobile communications device 14 establishes a communications session with the GPRS/UMTS network 12 through the radio node 16 in a well-known manner. In the process of establishing a communications session with the GPRS/UMTS network 12, the mobile communications device 14 will verify its identity typically using a Public Key (PBKu) and a Private Key (PVKu) assigned to the device. Once in communication with the GPRS/UMTS network 12 through the radio node 16, the mobile communications device 14 will send and receive traffic to and from the Internet 20 through the GGSN 32 during event 100 of FIG. 1. Such uploaded (uplinked) traffic can include information requests made to the server 30 of FIG. 1.

As discussed above, the radio channel 18 through which the communications device 14 sends and receives traffic to and from the GPRS/UMTS network 12 typically has a low bandwidth; making accessing of large files impractical. To open the high bandwidth channel 22 in accordance with the present principles, the mobile communications device 14, upon entering the coverage area of the wireless LAN 26, will "listen" for an identification signal (designated as "APid") from an access point, such as the AP 24. In addition to broadcasting the APid, the AP 24 will also broadcast the identification (i.e., the IP address) of the IP GW 28. The broadcast of the identification signal APid and the addresses (hereinafter referred to as GWip) of the IP GW 28 occur during event 102 of FIG. 2.

Upon receipt of the APid and GWip, the mobile communications device 14 then verifies itself to the IP GW 28 by transmitting the PBKu and PVKu of the device along with its Manufacturer's Identification Number (MNid), as well as the APid and GWip, to radio node 16 for receipt at the GGSN 32. In turn, the GGSN 32 communicates this information to the IP-GW 28. The transmission of such verification information occurs during event 104 in FIG. 2. After verifying the mobile communications device 14, the IP GW 28 will assign the device an IP address (IPa) and a Media Access Control (MAC) layer address (MACa) based on the APid and shared key (Ks) provided by the device. The IPa address obtained from the IP GW 28 must enjoy visibility outside the wireless LAN 26. Should a Network Address Translator (NAT) (not shown) exist in the IP GW 28, then there needs to be a pool of addresses and port number pairs available for assignment to the mobile communication device 14. The IP GW 28 encrypts the addresses using the public key (PBKu) of the mobile communications device 14 prior to transmission to the device during event 106 of FIG. 2.

Following receipt of the addresses IPa and MACa from the IP GW 28, the mobile communications device 14 can initiate a communications session with the wireless LAN 26 to provide information from the server 30 via the communications channel 22 of FIG. 1 during event 108 of FIG. 2. To initiate a communications session with the wireless LAN 26 to access information from the server 30, the mobile communications device 14 replaces its source address (SCRip) by which it is known in the GPRS/UMTS network 12 with a source address (dstllP) by which the device will be known in the wireless LAN 26. To upload (uplink) information to the GPRS/UMTS network 12, the mobile communications device 14 will utilize its original source address (SCRip) by which it was previously known in the GPRS/UMTS network 12. The wireless LAN 26 accounts for the information accessed on the channel 22 for billing the mobile terminal device, either directly, or as part of the billing performed by the GPRS/UMTS network 12.

Establishing the unidirectional communications channel 22 in the manner discussed above advantageously provides a low cost, high-speed solution to the problem of enabling a mobile communications device to access high bandwidth information. As compared to terrestrial television and satellite transmission schemes, utilizing the wireless LAN 26 to access high bandwidth information incurs far less cost. Moreover, the growing number of wireless LANs currently available makes the present solution far more practical than seeking terrestrial television and/or satellite spectrum. Since the mobile communications device 14 does not upload information to the wireless LAN 26 (such uploading being confined only to the GPRS/UMTS network 12), a typical access point, such as the AP 24 can offer a much wider coverage area than if the AP had to unload traffic from the mobile communications device. Further, since the mobile communications device 14 uploads no information to the wireless LAN 26, the security of the wireless LAN remains relatively unaffected since the likelihood of hackers causing any disruption is extremely small. In addition, the present approach of establishing an unidirectional IP link, such as the channel 22 through the wireless LAN 26 provides for seamless throughput. The foregoing describes a technique for providing a mobile communications device with separate downlink and uplink channels to enable the device to readily downlink high bandwidth information.