Abstract:
A system for communicating over a plurality of wireless data networks, the system comprising a software defined radio capable of being configured to operate with a plurality of wireless network services; a radio controller for reconfiguring the radio to operate over a wireless data network; a first database containing information about wireless data networks; wireless location technology used to determine a location of the radio; wherein the wireless location technology determines a location of the radio and the controller compares the location with information contained in the first database to determine available wireless data networks.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    This invention relates to wireless communications, and more specifically to using a single radio to communicate from a remote mobile asset as it passes through a plurality of wireless data networks.  
           [0002]    Existing wide area network, that is to say cellular, radios are usually designed and configured to operate with a specific wireless data network. Thus, when a user travels outside of the coverage area of its chosen wireless data network, its radio ceases to function. Some wireless data networks have established cooperative roaming agreements which allow a travelling user with a compatible radio design to operate on a second, foreign wireless data network. Roaming agreements help to alleviate coverage limitations but cannot provide for seamless, global operation due to the existence of wireless data network incompatibilities. Current wide area wireless voice and data networks communicate using different technologies, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Global System for Mobilization (GSM), Cellular Digital Packet Data (CDPD), DataTac, Mobitex, and General Packet Radios Service (GPRS). The utilization of various frequency bands also segregates wireless networks. While portable radio devices have emerged offering operation on multiple frequency bands, few commercial devices have been realized offering multiple communication modes based upon the different technologies listed above. Thus, when a user enters a region serviced by a non-compatible wireless data network, the user may need to either rent or purchase a radio that is compatible with that region&#39;s local network.  
           [0003]    A mobile asset, like an individual, may also travel outside of its selected wireless data network. However, it may not be physically or economically possible to install a new, compatible radio device in a mobile asset such as a truck or locomotive. Furthermore, some mobile assets such as railcars, trailers and containers, are typically unattended while in transit. Mobile remote assets would benefit from a suite of radios employing different radio communication technology and, thus, affording communication redundancy in the event that any single radio is outside of its network coverage region. A remote asset with such a suite of differing radios would also benefit from the ability to select that radio and associated wireless data network with appropriate data transfer characteristics (speed, latency) and lowest service costs for the exchange of data. The cost of a redundant radio suite typically prohibits its utility as it includes the parallel hardware as well as recurring service costs associated with the underlying wireless data networks.  
           [0004]    A fleet of mobile remote assets would benefit from a radio that is configured to allow each individual mobile asset to communicate with a central service facility regardless of where each respective mobile asset is located and regardless of which wireless data network is available for each respective geographic location.  
           [0005]    To address these problems, software defined radio technology is being developed. Software defined radio is an emerging technology, thought to build flexible radio systems with multi-serviced, multi-standard, multi-band operation via re-configurable and re-programmable software instructions. The flexibility of a software defined radio derives from the ability to operate in a multi-serviced environment without being constrained to a particular standard but able to offer, in theory, services in an already standardized or future system, on any radio frequency band. It is believed that U.S. Pat. No. 6,052,600 discloses a software defined radio which must communicate with a base station to receive valid operation licenses and appropriate software configuration instructions in order for the radio to communicate over a plurality of wireless data networks. However, if a system is unable to obtain this information from a base station prior to losing a current wireless data network connection, the radio is not able to dynamically select a new software configuration and wireless data network without directions from the base station.  
         SUMMARY OF THE INVENTION  
         [0006]    Towards this end, a fleet of mobile assets would benefit from a software defined radio that is able to dynamically determine available wireless data networks and configure its software to operate over these networks. A fleet of mobile remote assets would also benefit from a system which emphasizes least cost routing, or in other words, the ability to select from many available data links where the radio could select the lowest cost network regardless of the type of wireless network. Furthermore, a fleet would also benefit from improved reliability if a radio can switch between wireless networks that overlap a given geographic region regardless of the type of wireless networks available to communicate over the clearest network.  
           [0007]    Thus, fleets of mobile remote assets would benefit from a method and a system for a programmable software radio to communicate over a plurality of wireless data networks with a central service facility, the method comprising providing the radio with wireless location technology, providing the radio with data about wireless data networks, determining a location of the radio with wireless location technology, comparing the location of the radio with data about wireless data networks, determining available wireless data networks based on the location of the radio, selecting a wireless data network, configuring the radio to communicate over the selected wireless data network. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    The features and advantages of the present invention will become apparent from the following detailed description of the invention when read with the accompanying drawings in which:  
         [0009]    [0009]FIG. 1 is a block diagram illustration of the components used in the present invention.  
         [0010]    [0010]FIG. 2 is a block diagram of the steps taken by the present invention.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0011]    [0011]FIG. 1 is a block diagram illustration of the components used in the present invention. A software defined radio  10  resides on a remote mobile asset  12 , such as train, bus or truck. The remote asset  12  could be one asset in a fleet of mobile remote assets. The radio  10  is part of a system  5  that comprises the radio  10  connected to a radio controller  14 , a database  16  containing information about wireless networks  27 , and a second database  18  containing data about pre-selected radio and television broadcast channels  26 . The first database  16 , which contains wireless network information, includes such network information as coverage area, data transfer capability and service activation/authorization. Radio controller  14  contains software configuration parameters (i.e. network profiles) used to configure the software radio  10  in order to communicate with each respective wireless network contained in the first database  16 .  
         [0012]    The second database  18  contains pre-selected broadcast media frequencies for known channels  26 . Broadcast media includes television and radio. The second database contains television channels broadcast over either Ultra-High Frequency (UHF) or Very High Frequency (VHF) bandwidths. As for radio frequencies, this includes radio channels that broadcast of either Amplitude Modulation (AM) and Frequency Modulation bandwidths. The data or information contained in this database  18  include, but is not limited to, commercial broadcast licenses and operation geographic regions.  
         [0013]    The remote asset  12  also has an antenna  20  for transmitting and receiving information over a wireless network from a central service facility  22 . The central service facility  22  also maintains a wireless data network database  24  and a broadcast media database  29 . In one embodiment, the central service facility&#39;s wireless data network data bases  24  and  29  are master databases where the wireless network databases  16  and  18  residing on the remote asset  12  are subsets of the central service facility&#39;s database  24  and  29 , respectively. In operation, the central service facility  22  can send updates from its wireless network database  24  to the remote asset&#39;s wireless network database  16  and/or from its broadcast media database  29  to the remote asset&#39;s broadcast media database  18 .  
         [0014]    In operation, as disclosed in FIG. 2, when the remote asset  12  must begin, step  30 , by selecting an available wireless network  27  in the remote asset&#39;s geographic region, a decision, step  32 , must first be made about which type of wireless location technology to use to determine a location of the remote asset  12 . Either remote wireless location technology or wireless location technology dedicated to the radio can be used. If the decision is made to use remote wireless location technology, the next step, step  34 , is to determine which remote wireless technology to use. Specifically, the decision, step  34 , consists of determining which type of remote wireless location technology to use. Remote wireless technology is technology which requires external location estimation systems to assist in determining a given location. One example of remote wireless location technology to use is integrated into the radio  10 , and is referred to as handset-based wireless location technology. Examples of this type of wireless location technology include, but are not limited to Global Positioning System (GPS), assisted GPS, differential GPS or Enhanced Observed Time Difference (E-OTD). A second example of remote wireless location technology involves using a network-based wireless location technology. Such technology includes, but is not limited, Cell Identification with Timing Advance (CI+TA), Angle of Arrival (AOA), Uplink Time of Flight (UL-TOF), or multi-path fingerprinting. The network-based wireless technology is generally available from individual service providers offering wireless data network connections.  
         [0015]    In one embodiment, a decision, step  34 , is made whether to use handset-based wireless location technology. In another embodiment, this decision could involve determining whether to use network-based wireless location technology. If the decision is to use handset-based technology, the next step, step  36 , is to locate a geographical position of the radio system  5  or remote asset  12  using the handset-based technology. If the decision is to use network-based technology, the next step, step  38 , is to apply this technology and locate a geographical position of the radio system  5  or remote asset  12 .  
         [0016]    If the decision, step  32 , is not to use remote wireless location technology, another locating option, steps  40 ,  42 ,  44 , is incorporated into the system  5 . This option involves, step  40 , the radio controller  14  configuring the software radio  10  as a broadcast television and/or radio receiver using antenna  20 , or a frequency scanning device, and initiating a scan to detect pre-selected media broadcast channels over the airwaves at the location of the remote asset  12 . The scan, step  42 , can either determine the presence or absence of pre-selected media broadcast channels  26 . The resulting vector of the broadcast channel scan is then matched with the media database  18  to evaluate broadcast licenses and operation to coarse geographic regions to determine the location of the mobile asset  12 , step  44 . Thus, the software defined radio  10  is configured to scan commercial broadcast television and radio frequency bands to identify those frequency channels (i.e. stations) carrying broadcast signals in the vicinity. This knowledge is compared with the second database  18  containing information related to the license, frequency allocation and geographic location of commercial broadcast television and radio station operation. Comparison with this second database  18  allows the mobile asset  12  to determine its approximate position and then select a wireless data network  27  providing coverage in the vicinity.  
         [0017]    Under either approach, using handset-based location technology, steps  34 ,  36 , using network-based location technology, steps  38 , or using media broadcast channels to determine location, steps  40 ,  42 ,  44 , the next step, step  46 , is to match the estimated mobile asset location information against the wireless data network database  16  to determine those wireless data networks providing coverage at that geographic location. The next step, step  48 , is to select an accessible wireless data network  27 . In one embodiment, the selection is based on which network licenses are owned by the fleet. Once selected and configured by the radio controller  14 , step  50 , the radio  10  can now communicate over the selected wireless data network, step  52 . In another embodiment, the selection of a network  27  is based on the most cost effective network available.  
         [0018]    In operation, if a network is selected but the communication connection is not reliable, or in other words the communication network is not clear because of noise or other propagation channel impairment, the radio  10 , though the radio controller  14 , can dynamically select another network  27  by using media broadcast channels to determine its location, steps  40 ,  42 ,  44 ,  46  and select a clearer network, or by using one of the remote wireless location technology approaches to select a clearer network. In another embodiment, after matching its location with the wireless database to determine accessible networks, step  46 , the radio  10  can sample all available networks to determine the clearest communication network  27  available for communication.  
         [0019]    The decision about which wireless location technology to use may be made either by a user or may be preprogrammed into the remote asset  12 . For example, a pre-sent command directing which technology to use may be sent from the central service facility  22  to the remote asset  12 , specifically, to the radio controller  14 , commanding a temporal or spatial trigger for initiation of the wireless network selection process. Such a command from the central service facility  22  to the remote asset  12  may also specify which wireless location technology is to be employed. In another embodiment, a user located on the remote asset  12 , can make the determination into which wireless location technology to use. In another embodiment, the radio system  5  can autonomously select the technology or apply a plurality of technologies.  
         [0020]    While the invention has been described by what is presently considered to be the preferred embodiment, many variations and modifications will become apparent to those skilled in the art. Accordingly, it is intended that the invention not be limited to the specific illustrative embodiment but be interpreted within the fall spirit and scope of the appended claims.