Systems and methods for switching zero charge callers

Abstract

Asynchronous and/or synchronous zero charge telephony protocol systems and methods may include an asynchronous signaling switch and/or a call duration time quota from a synchronous charging onset to place and complete a call. A first device call request is received with a second device mobile address. The asynchronous systems include instructions to automatically modify the mobile address with a routing prefix when the first device has insufficient balance or independent of balance, route to the asynchronous signaling switch based on an associated modified address trunk path, revert the modified call signal at the asynchronous signaling switch to the call signal, and deliver and automatically disconnect the call immediately when the call is completed. The synchronous systems include instructions to automatically set the call duration time quota upon insufficient balance, and deliver and automatically disconnect the call from the second user mobile device when the call is completed and the call duration time quota is exceeded.

1 - 20 . (canceled) 
     
     
         21 . A zero charge telephony protocol system comprising:
 a controlling node of a cellular network that is configured to at least:
 receive, via the cellular network, from a first communication device associated with a user account of a first user and a first telephony address, a telephony call request addressed to a second communication device associated with a second user and a second telephony address; 
 automatically modify the second telephony address in the telephony call request to generate a modified telephony address associated with a service node so as to result in a modified telephony call request when the user account has insufficient balance to complete the call request, or when the telephony call request is independent of a balance of the user account; and 
 instruct the cellular network to connect the modified telephony call request, thereby routing the telephony call request to the service node. 
   
     
     
         22 . The zero charge telephony protocol system of  claim 21 , wherein the system is configured to automatically present at least one option to the first communication device. 
     
     
         23 . The zero charge telephony protocol system of  claim 21 , wherein the system is configured to:
 revert the modified telephony call request to the call request; and   deliver the telephony call request, reverted from the modified telephony call request, to the second communication device, thereby routing the call to the second communication device.   
     
     
         24 . The zero charge telephony protocol system of claim  1 , wherein the controlling node is configured to:
 look up a pre-configured routing table to identify a communication path to the service node, as associated with the modified telephony address.   
     
     
         25 . The zero charge telephony protocol system of  claim 23 , wherein the system is configured to automatically disconnect the call to the second communication device upon a receipt of the call by the second communication device. 
     
     
         26 . The zero charge telephony protocol system of  claim 25 , wherein the system is configured to disconnect the call from the first communication device after delivering the call to the second communication device, when the user account, associated with the first communication device, has the insufficient balance to complete the call. 
     
     
         27 . The zero charge telephony protocol system of  claim 25 , wherein the system is configured to:
 deliver the call from the service node to the second communication device together with an identification of the first communication device, a ringing permission, an answering restriction, or a combination thereof; and   automatically disconnect the call to the second communication device based on a receipt, by the second communication device, of the identification of the first communication device, the ringing permission, the answering restriction, or the combination thereof.   
     
     
         28 . The zero charge telephony protocol system of  claim 21 , wherein:
 the user account is associated with a balance-dependent subscriber identification module (SIM) card or a balance-independent SIM card; and   the balance-independent SIM card is configured to facilitate the telephony call request without a charge through a balance-independent service key, invoking a no-charge logic separate from the balance-dependent logic when the user account has the insufficient balance to complete the call.   
     
     
         29 . The zero charge telephony protocol system of  claim 28 , wherein the system is configured to:
 receive a payment in the user account; and   modify the balance-independent SIM card into a balance-dependent SIM card having a positive balance sufficient for the call.   
     
     
         30 . The zero charge telephony protocol system of  claim 23 , wherein the system is configured to automatically set a call duration time quota when the user account has the insufficient balance to complete the call. 
     
     
         31 . The zero charge telephony protocol system of  claim 30 , wherein the call duration time quota is 0 to 1 second. 
     
     
         32 . The zero charge telephony protocol system of  claim 31 , wherein the modified telephony address comprises a network routing prefix. 
     
     
         33 . A zero charge telephony protocol method comprising:
 receiving, by at least one controlling node of a cellular network, from a first communication device associated with a user account of a first user and a first telephony address, a telephony call request addressed to a second communication device associated with a second user and a second telephony address;   automatically modifying, by the at least one controlling node, the second telephony address in the telephony call request to generate a modified telephony address associated with a service node so as to result in a modified telephony call request when the user account has insufficient balance to complete the telephony call request, or when the telephony call request is independent of a balance of the user account; and   instructing, by the at least one controlling node, the cellular network to connect the modified telephony call request, thereby routing the telephony call request to the service node.   
     
     
         34 . The zero charge telephony protocol method of  claim 33  further comprising:
 presenting at least one option to the first communication device. 
 
     
     
         35 . The zero charge telephony protocol method of  claim 33  further comprising:
 reverting the modified telephony call request to the call request; and 
 delivering the telephony call request, reverted from the modified telephony call request, to the second communication device, thereby routing the call to the second communication device. 
 
     
     
         36 . The zero charge telephony protocol method of  claim 33  further comprising:
 looking up a pre-configured routing table to identify a communication path to the service node, as associated with the modified telephony address. 
 
     
     
         37 . The zero charge telephony protocol method of  claim 35 ,
 automatically disconnecting the call to the second communication device upon a receipt of the call by the second communication device.   
     
     
         38 . The zero charge telephony protocol method of  claim 37  further comprising:
 disconnecting the call from the first communication device after delivering the call to the second communication device, when the user account, associated with the first communication device, has the insufficient balance to complete the call. 
 
     
     
         39 . The zero charge telephony protocol method of  claim 37  further comprising:
 delivering the call from the service node to the second communication device together with an identification of the first communication device, a ringing permission, an answering restriction, or a combination thereof; and 
 automatically disconnecting the call to the second communication device based on a receipt, by the second communication device, of the identification of the first communication device, the ringing permission, the answering restriction, or the combination thereof. 
 
     
     
         40 . The zero charge telephony protocol method of  claim 33 , wherein:
 the user account is associated with a balance-dependent subscriber identification module (SIM) card or a balance-independent SIM card; and   the balance-independent SIM card is configured to facilitate the telephony call request without a charge through a balance-independent service key, invoking a no-charge logic separate from the balance-dependent logic when the user account has the insufficient balance to complete the call.