1. Field of the Invention
The present invention relates generally to providing telephone service and more particularly to a system and method for placing a mobile call on a secondary network rather than over the mobile network.
2. Description of the Prior Art
It is well known in the art to place a mobile telephone call to another telephone using commercially available cellular services. Cellular telephone networks operate using well-known principles with systems of base stations and access into landline public switched telephone network PSTN services.
In some systems, it is cheaper to place a toll call (long distance) or other call over an alternate network (such as a PSTN or other secondary network) between two points than a cellular call between the same two points. In particular, it might be cheaper to place a toll call between two mobile stations or between a mobile station and a fixed station if a third party station were to initiate outgoing calls to each of the two end stations using the secondary network then for one of the end stations to directly call the other. In this case, the third party or “Manager” station could connect the two calls after they are set up in a manner similar to a conference.
It would be advantageous to have a service that could take advantage of the price difference where a cellular subscriber could have cheaper secondary network calls placed for him by a third party station when he desires to make a mobile toll call.
The present invention relates to placing cellular calls over a secondary network to allow a subscriber to save money or enjoy some other advantage. Either a small software package can be downloaded to a mobile user's telephone to act as an interface into the service or the internet can be used with a wireless application protocol (WAP) using a WAP browser on the mobile telephone. A manager station operated by a third party (generally not the cellular network owner or the secondary network owner) can receive request calls for cellular users to place toll calls. In a particular embodiment, the software in the user's mobile telephone can transmit the number desired to be called via a mobile data service like GPRS, WAP over GPRS (or other data service) to the manager station. Any method of transmitting this number is within the scope of the present invention including a direct mobile telephone call to the manager station. The manager station can then place two outgoing calls over a secondary network, the first to the called number, and the second a callback to the originating mobile telephone. The called number can be either a mobile or fixed station. When each of the two outgoing calls is set up, the manager can connect or conference the two calls together. Any method of connecting or conferencing two or more calls is within the scope of the present invention. The number of calls is not limited to two. It is within the scope of the present invention to connect or conference any number of locations in the manner described. After the calls are connected, the manager can track of billing for the service using methods known in the art.
Attention is directed to several illustrations to aid in understanding the principles of the present invention:
Several drawings and illustrations have been presented to explain the present invention. The scope of the present invention is not limited to what is shown in the figures.
The present invention relates to a system and method for placing calls from mobile stations over a secondary network when that is cheaper, or there is some other advantage in doing this rather than simply placing mobile calls. A secondary network could be a landline such as a PSTN, a TDM network, another mobile network, the internet voice over IP, Session Initiated Protocol (SIP) or any other type of network capable of carrying voice traffic. In this system, a small software package can be downloaded into a subscriber's mobile telephone. This package can be written in Java, C++ or any other programming language. This package should be compatible with the mobile operating systems commonly in use. When the subscriber wishes to place a mobile call using the service, the software package asks the subscriber to enter a desired called telephone number. This target number along with a call setup request containing an ID of the subscriber telephone is transmitted to a third party manager station. If the subscriber has a valid account, call setup can begin. The call setup request including the target number and basic subscriber information can be transmitted between the mobile telephone and the third party manager station via the internet using a mobile data service such as GPRS. It should be noted that any mobile data service can be used as well as a direct cellular call to the manager station. Any method of transmitting setup information including the target number is within the scope of the present invention. The use of a data service such as GPRS is particularly attractive because of the relatively fixed cost to use this service. The manager station can be geographically remote from the mobile station and still provide the service without incurring higher costs.
The call control server 7 can be connected via a LAN 15 or other data connection to a calling system 8. The calling system 8 can contain IP PBX units or any other type of PBX-like unit, switch or conferencing unit. A preferred type of PBX unit can be an OM100 IP-PBX manufactured by New Rock Technologies, Inc. of China. The LAN 15 can also be tied to a media gateway 9 which converts packet voice data to TDM, SIP, VoIP or other format compatible with the secondary network 17 along with signaling information. The call control server 7 causes the two outgoing calls to be placed over the secondary network using standard call signaling techniques known in the art. Voice data from each of the calls can be converted to packet and switched (connected) by the IP PBX units in the calling system 8 or can be directly coupled using methods known in the art. This is typically handled in a manner similar to a standard conference call. Any PBX type unit, voice transport or method of placing and connecting the calls is within the scope of the present invention. In particular, the gateway 9 should be able to interface on an IP or other type of LAN 15 on one side and into a particular secondary network 17 on the other side. The link into the secondary network should be able to handle an analog line with requirements such as Loop Start, Ground Start, E&M, etc., digital TDM or other digital interface such as DS-1, E1 or International TDM systems, number relay such as ISDN-PRI, out of band signaling such as CCITT 7 Common Channel Signaling, ISUP, and a basic IP agreement such as SIP, H.323, H.248, MGCP or others.
In addition to using the originator's actual telephone number, the system of the present invention supports the use of virtual telephone numbers. Virtual telephone numbers are numbers that can be owned and can follow a particular individual. The call back and the caller ID number seen by recipients can be the virtual number. In addition, the called telephone number and any other telephone numbers involved in the transaction can be virtual telephone numbers.
The general functioning of embodiments of the present invention are as follows: The call control server 7 receives a message sent by a mobile user either directly or via the internet with a WAP browser that includes the account number, password, mobile telephone number and the called number. The call control server 7 queries the database on the database server 13 to verify the account number, check the account balance to make sure the user has the necessary funds to make the call. After verification, the call control server 7 sends the caller number and the called number to the dialing server 19, and sends a notice in the form of a message to the user. The call control server 7 can also calculate the number of minutes the user can talk based on the rate and amount of funds in the user's account. When the dialing server 19 receives a request from the call control server 7, it generally initiates calls through its interface to the secondary network. Normally, connection is first made to the caller and then to the called number. Once, the call is complete, and a total call time is computed, the billing server 11 can deduct the cost of the call from the user's account. The web server 12 can provide detailed call records to the user of each call, account balance and statistical data.
It should be noted that all of the functions described can be combined and run on a single server or a different mix of servers. The particular examples discussed here represent only a particular embodiment of the invention. Any number or combination of servers is within the scope of the present invention.
Several descriptions and illustrations have been provided to aid in understanding the present invention. One skilled in the art will realize that numerous changes and variations are possible without departing from the spirit of the invention. Each of these changes and variations is within the scope of the present invention.