Opinion ID: 221848
Heading Depth: 4
Heading Rank: 1

Heading: The Embodiments

Text: The ‘275 Patent’s specification discloses two embodiments. The first embodiment, which is illustrated in Figures 1 and 3, is a telephone system where the special exchange processes prepaid telephone calls from any available telephone. The second embodiment, which is illustrated in Figure 2, is a telephone system in which the special exchange processes prepaid telephone calls from dedicated public telephones. Figure 1 is a flow chart depicting a customer’s use of the prepaid telephone system from any private telephone: 5 AEROTEL LTD v. TELCO GROUP In this embodiment, a customer can use any available telephone to dial the “special central office” which accesses the “special exchange” (Blocks 13 & 14). When the customer is connected to the special central office or exchange, “a special dial tone is sent from the special AEROTEL LTD v. TELCO GROUP 6 exchange to the calling station.” ‘275 Patent col. 3 ll. 2326. The customer then inputs: (1) the “special code” which provides access to that caller’s prepaid amount; and (2) the telephone number of the party to be called (Block 17). When the code and credit are verified (Block 18), a normal dial tone is sent to the caller (Block 19) and the system dials the called party (Block 21). 2 At Block 22, the “special exchange equipment provides an artificial or prerecorded voice announcement stating the amount of credit available and that the amount of credit is equivalent to so many minutes of talking time on the call being connected.” ‘275 Patent col. 3 ll. 43-47. After the call is connected, a “time and distance computing circuit [which] is shown as a peg counter, is put into service to provide information for timing the call against the available credit.” ‘275 Patent col. 4 ll. 3-6. Information from the peg counter (Block 28) is sent to a comparator (Block 29) “to continuously determine whether the calling party’s credit is sufficient to pay for the call.” Id. at col 4 ll. 6-9. The call is disconnected if the balance is insufficient to continue the call or if the user terminates the call (Blocks 31 & 34). If there is credit remaining when the call is terminated, the updated prepaid balance is stored in the special exchange for future use. The embodiment in Figure 2 is a telephone system in which the special exchange processes calls made from dedicated public phones. In this embodiment, the dedicated phone automatically connects directly to the special exchange without any dialing. Once connected to the 2 The written description provides that “[t]he calling party’s predialed numbers are transmitted as indicated at block 21. Of course the system can be arranged so that the calling party dials the called party responsive to receipt of regular dial tone.” ‘275 Patent col. 3 ll. 39-42. 7 AEROTEL LTD v. TELCO GROUP special exchange, the caller inputs the special code and the telephone number of the called party. The special exchange validates the code and the credit, and then connects the caller to the party associated with the inputted number.