Payphone metering in a wireless telephone system

• US 5,946,614 A
• Filed: 06/13/1996
• Issued: 08/31/1999
• Est. Priority Date: 06/13/1996
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Karmi, Gadi, Robbins, Barry R.
• Primary Examiner(s): Urban, Edward F.
• Assistant Examiner(s): Nguyen, Thuan T.
• Application Number:
  US08/662,565
• Time in Patent Office: 1,174 Days
• Field of Search: 379/114, 379/130, 379/131, 379/132, 379/143, 379/144, 379/145, 379/146, 379/154, 379/155, 379/112, 455/405, 455/406, 455/407, 455/408, 455/410, 455/458
• US Class Current: 455/407
• CPC Class Codes: H04M 15/28 with meter at substation or with calculation of charges at terminal
• CPC Class Codes: H04M 15/81 Dynamic pricing, e.g. change of tariff during call
• CPC Class Codes: H04M 17/02 Coin-freed or check-freed systems , e.g. mobile- or card-operated phones, public telephones or booths
• CPC Class Codes: H04M 2215/0112 Dynamic pricing, e.g. change of tariff during call
• CPC Class Codes: H04M 2215/2026 Wireless network, e.g. GSM, PCS, TACS
• CPC Class Codes: H04M 2215/32 Involving wireless systems
• CPC Class Codes: H04W 4/24 Accounting or billing

Abstract

The wireless system includes one or more payphones from which users may initiate payphone calls. A mobile switching center connects telephone calls initiated from wireless payphones to external telephone systems such as the public switch telephone network (PSTN). To meter charges incurred during the telephone call within an external system, the external system transmits periodic metering pulses to the mobile switching center. Each pulse is representative of a predetermined amount of money associated with the telephone call. The rate at which the periodic pulses are transmitted to the mobile switching center depends upon the current billing rate and may be affected by, for example, the time of day. Rather than the forwarding all of the metering pulses to the wireless payphone, therefore consuming a portion of the bandwidth available for wireless telephone calls, the mobile switching center calculates a steady state billing rate from the metering pulses, then transmits only the steady state billing rate to the wireless payphone. The ireless payphone calculates charges associated with the telephone call based upon the steady state billing rate and displays the resulting charges to the user. Once the mobile switching center has transmitted the steady state billing rate signal to the wireless payphone, a second steady state billing signal is not transmitted unless and until the billing rate for the telephone call changes as detected from a change in the rate of received metering pulses from the external system. In one arrangement, the mobile switching center filters out all metering pulses and transmits only steady state billing rate signals to the wireless payphone. In another arrangement, the mobile switching center transmits metering pulse signals to the wireless payphone until the steady state rate has been determined, then transmits a single steady state billing rate signal. If the billing rate changes, the mobile switching center again forwards metering pulses to the wireless payphone until the new steady state billing rate can be determined.

Claims

1. A method for determining charges incurred during a telephone call connected to a wireless payphone, said method comprising the steps of:

a) receiving at a mobile switching center individual metering pulses from an external system, each pulse representative of a common predetermined amount of monetary charge to be charged to the telephone call;

b) transmitting from a base station a signal representative of each individual metering pulse to a wireless payphone;

c) calculating in the mobile switching center a steady state billing rate corresponding to a rate at which the individual metering pulses are received;

d) terminating the transmission from the base station of the signals representative of individual metering pulses to the wireless payphone when a valid steady state billing rate can be calculated and simultaneously transmitting a signal representative of the steady state billing rate to the wireless payphone;

e) receiving within the wireless payphone the transmitted signals representative of the individual metering pulses and the steady state billing rate for the telephone call;

f) calculating within the wireless payphone a total amount of charges incurred by incrementally summing the common amount for each individual metering pulse received; and

g) calculating within the wireless payphone additional charges incurred by multiplying the steady state billing rate by an additional time period elapsed since receiving the steady state billing rate signal and adding the resulting value to the previously calculated total amount of charges.

2. The method of claim 1 further comprising the steps of:

determining at the mobile switching center the rate of metering pulses received from the external system has changed;

transmitting from the base station a signal indicating that the previous steady state billing rate signal is no longer valid, then repeating steps a)-d);

receiving in the wireless payphone the signal indicating that the previous steady state billing rate signal is no longer valid, then repeating steps e)-g).

3. The method of claim 2 wherein the signal indicating that the previous steady state billing rate signal is no longer valid comprises an individual metering pulse signal.

4. A wirless payphone system, said system comprising:

means for receiving from an external system a plurality of individual metering pulses each representative of an individual amount of monetary charges incurred during a telephone call;

means for calculating a steady state billing rate corresponding to a rate at which the individual metering pulses are received;

means for transmitting to a wireless payphone signals representative of each individual metering pulse and a signal representative of the steady state billing rate;

means for receiving from the transmitting means the signals representative of each individual metering pulse each signal representative of an individual amount of monetary charges incurred during a telephone call;

means for receiving from the transmitting means signals representative of the steady state billing rate incurred during said telephone call; and

means for calculating in said wireless payphone an amount of charges incurred during the telephone call, said means for calculating utilizing said individual metering signals only during portions of the telephone call when no valid signal representative of a steady state billing rate has been received, and utilizing said steady state billing rate to calculate the amount of charges when a valid steady state billing rate has been received.