Opinion ID: 221848
Heading Depth: 2
Heading Rank: 1

Heading: “Means for Monitoring the Credit”

Text: Claim 9 describes a “means for monitoring the credit of the calling party during a completed call.” With respect to the “means for monitoring,” the district court found that: (1) the function is “comparing the amount of money 6 At oral argument, counsel for Aerotel noted that: “Aerotel needs to win on both issues on appeal so if you rule against us on either one then we lose.” Oral Argument at 14:00, available at http://www.cafc.uscourts.gov/oral-argumentrecordings/2010-1515/all. Similarly, Telco’s brief explained that, if the court agrees with the district court’s construction on either the “means for coupling” or the “means for monitoring the credit,” then the Consent Judgment must be affirmed. Appellees’ Br. at 19. 19 AEROTEL LTD v. TELCO GROUP in the calling party’s account with the cost of the call;” and (2) the corresponding structure “is a comparator, which makes use of information from a time and distance computing circuit.” Claim Construction Order, 2010 U.S. Dist. LEXIS 47266 at . On appeal, the parties disagree as to both the function and the structure of the “means for monitoring.” For the reasons explained below, we agree with, and thus affirm, the district court’s claim construction.
Consistent with its interpretation of “monitoring” in Claim 1, the district court found that the “‘credit’ that is ultimately monitored is unambiguously monetary.” Claim Construction Order, 2010 U.S. Dist. LEXIS 47266 at . Recognizing that “credit is the result of a computation involving time and the cost-per-time of the call,” the court noted that the “ultimate purpose of the monitoring is the eventual comparison with credit.” Id. Accordingly, the court found that the function of “monitoring the credit” is “comparing the amount of money in the calling party’s account with the cost of the call.” Id. at -77. 7 Aerotel argues that the function of the “means for monitoring” is either “monitoring by time which is converted to money” or “monitoring by time which is a func- 7 In reaching this conclusion, the court rejected Telco’s proposed construction, which replaced the word “credit” with the phrase “prepayment amount,” a phrase used in other instances in the patent. The court was unwilling to conclude that the inventor intended to use “prepayment amount” in place of the word “credit,” when he had used “prepayment amount” elsewhere in the patent. Notably, however, in its Reply Brief, Aerotel states that “the term ‘remaining prepayment amount’ is simply a synonym for the term ‘credit.’” Appellant’s Reply at 16 n.1. AEROTEL LTD v. TELCO GROUP 20 tion of money.” It also argues that the word “compare” is nowhere in Claim 9, and thus the district court should not have construed “means for monitoring” to mean comparing. According to Aerotel, the district court ignored language in the ‘275 Patent that is broad enough to encompass monitoring by money units as well as monitoring by time. In response, Telco argues that the patent does not disclose monitoring by time. Specifically, Telco argues that: (1) none of the claims recite monitoring time; (2) the term “credit” is used throughout the specification to mean money; and (3) the prosecution history confirms that the patent discloses monitoring of money, not time. We find Telco’s arguments well-taken.
We begin our claim construction by examining the language of the claims. The claims, however, “must be read in view of the specification, of which they are a part.” Markman v. Westview Instruments, Inc., 52 F.3d 967, 979 (Fed. Cir. 1995) (en banc). The specification “is always highly relevant to the claim construction analysis” and “is the single best guide to the meaning of a disputed term.” Phillips, 415 F.3d at 1315 (quoting Vitronics, 90 F.3d at 1582). The plain language of Claim 9 recites a “means for monitoring the credit of the calling party during a completed call.” Nothing in the language of the claim specifically provides for monitoring by time. And, as Telco points out, Aerotel consistently used language associated with monetary units in conjunction with the word “monitoring” in Claims 1 and 23 of the patent: • Claim 1: “monitoring the prepayment amount less deductions for the running cost of the call;” 21 AEROTEL LTD v. TELCO GROUP • Claim 23: “monitoring the running cost of the call.” Telco next argues that the word “credit” is used throughout the specification to mean money. For example, the specification discloses that: • “The amount paid is credited to the acquirer for use against future telephone calls. The credited amount is stored in a memory at the special cen- tral office along with the special code.” ‘275 Patent col. 3 ll. 12-16 (emphasis added). • “[T]he 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 con- nected.” Id. at col. 3 ll. 43-47 (emphasis added). • “The information from the peg counter is sent to a comparator 29 to continuously determine whether the calling party’s credit is sufficient to pay for the call. When the credit equals the used time rate the call is automatically ended by the computer as indicated by the block 31.” Id. at col. 4 ll. 6-11 (emphasis added). On appeal, Aerotel argues that the district court’s claim construction is based on a misinterpretation of Figure 1, which, according to Aerotel, shows that the credit can be monitored using units of time. In relevant part, Figure 1 shows a series of steps, including the following: AEROTEL LTD v. TELCO GROUP 22 According to Aerotel, Figure 1 and its corresponding written description show that the comparator (29) receives information from the peg counter, which counts the call duration and Block 23, labeled “preset time according to money & distance,” which is the “number of minutes of talking time corresponding to the credit available.” Therefore, Aerotel argues, “the comparator 29 is comparing the call duration to the available talking time, thereby monitoring the credit during the call.” Appellant’s Brief at 40. Aerotel further argues that the ‘275 Patent teaches two ways of “monitoring” a prepaid call, and in “both cases, the call is timed.” 8 It submits that, in Figure 1, 8 Aerotel cites to the declaration of its technical expert, Richard Chandler, for an opinion as evidence of how a person of ordinary skill in the art of telecommunications would construe the term “monitoring.” The parties did not present expert testimony during the Markman Hearing and the district court did not consider extrinsic evidence. On appeal, Aerotel argues that this court should nonetheless consider the Chandler Declaration, which was submitted in the proceedings below as an exhibit attached to an attorney declaration in support of Aerotel’s claim construction briefing. Notably, Chandler’s Declara23 AEROTEL LTD v. TELCO GROUP “before the call is connected the calling party’s credit balance is converted to an available talking time (i.e., a preset number of units, e.g., minutes of talking time).” Id. at 41. Then during the call, the peg counter “measures the duration of the call by counting, which count is compared to the available talking time.” Id. According to Aerotel, the service provider can disconnect the call when the user runs out of talking time. Aerotel also points to the embodiment shown in Figure 2 and argues that the call is also timed in that embodiment. Specifically, Aerotel contends that “the time rate of the call is used to compute (i.e. calculate) the cost of the call, which is then subtracted from the credit balance during the call.” Appellant’s Br. at 41. In response, Telco argues that the system determines available talk time for announcement purposes only. We agree. The specification provides that, in one embodiment: an artificial or prerecorded voice announcement stat[es] the amount of credit available and that the amount of credit is equivalent to so many minutes of talking time on the call being con- nected. This announcement is actively shown at block 22. The announcement is made according to the charge rate for the distance between calling and called parties shown at block 23. ‘275 Patent col. 3 ll. 44-51. As the district court found with respect to Claim 1, the voice announcement “involves tion is directed to Claims 1, 2, 8 and 23 of the ‘275 Patent – not Claim 9. Nothing contained therein specifically addresses the limitation at issue here: “means for monitoring the credit.” In any event, because the weight of the intrinsic evidence contradicts Aerotel’s characterization of Chandler’s declaration, we do not find its arguments based on extrinsic evidence persuasive. AEROTEL LTD v. TELCO GROUP 24 the prepaid exchange’s user interface; it has nothing to do with how the system monitors calls.” Claim Construction Order, 2010 U.S. Dist. LEXIS 47266 at . Based on the specification, we agree with Telco that: (1) this announcement is not part of the monitoring process, particularly given its placement in the flow chart depicted in Figure 1 (off to the side of the vertical sequence); and (2) nothing in the patent describes monitoring the announced talk time. The specification states that the peg counter “provide[s] information for timing the call against the available credit” and that “information from the peg counter is sent to a comparator 29 to continuously determine whether the calling party’s credit is sufficient to pay for the call. When the credit equals the used time rate the call is automatically ended by the computer.” ‘275 Patent col. 4 ll. 6-11 (emphasis added). Based on this language, which uses the term “credit” in the context of payment, the credit monitored is monetary. As the district court correctly notes, although the credit “is the result of a computation involving time and the cost-per-time of the call,” the “ultimate purpose of the monitoring is the eventual comparison with credit.” Claim Construction Order, 2010 U.S. Dist. LEXIS 47266 at . Accordingly, we agree with the district court that the “credit” is the “amount of money in the calling party’s account” and that “monitoring the credit” involves comparing the amount of money in the account to the cost of the call.
The prosecution history also supports the district court’s conclusion that the monitoring set forth in Claim 9 is monitoring by money. See Phillips, 415 F.3d at 1317 (“[T]he prosecution history can often inform the meaning of the claim language by demonstrating how the inventor 25 AEROTEL LTD v. TELCO GROUP understood the invention and whether the inventor limited the invention in the course of prosecution, making the claim scope narrower than it would otherwise be.”). As previously discussed, in an Office Action dated October 2, 1986, the PTO rejected Claim 10 (which issued as Claim 9) as unpatentable over the Peterson and Gehalo prior art references. In response, Aerotel added the limitation “means for monitoring the credit of the calling party during a call.” In the “Remarks” portion of its response to the Office Action, Aerotel specifically distinguished Peterson on grounds that, unlike the ‘275 Patent, “[n]o special central exchange is provided with equipment to monitor the remaining prepayment during a call made using the special code.” A763. Aerotel also distinguished the Gehalo prior art reference on grounds that Gehalo did not involve prepayment and thus did not “provide any way in which to monitor credit information that includes the amount remaining of a prepayment.” Id. at 764-65. These statements make clear that the credit monitored by Claim 9 is the remaining prepayment amount, which is a monetary unit. Even more pointedly, during reexamination, Aerotel presented a PowerPoint slide describing the prepaid telephone system. In the series of slides, Aerotel showed a stove-top type dial counting down the remaining monetary credit from $5 to $3 to $0. As Telco correctly notes, the dial demonstrates that the system monitors the prepayment amount, not time. Accordingly, the prosecution history confirms our conclusion that the district court correctly construed the phrase “monitoring the credit” to include monitoring by money, not by time.
Finally, Aerotel argues that the structure corresponding to the means for monitoring is a comparator which AEROTEL LTD v. TELCO GROUP 26 makes use of information from a peg counter and a circuit that computes the preset time limit. In response, Telco submits that the district court correctly identified the structure as the comparator, which compares the remaining credit with the cost of the call. We agree. The specification provides that: the normal time and distance computing circuit is shown as a peg counter, is put into service to pro- vide information for timing the call against the available credit. The information from the peg counter is sent to a comparator 29 to continuously determine whether the calling party’s credit is sufficient to pay for the call. ‘275 Patent col. 4 ll. 3-9. Based on this language, the district court correctly concluded that the corresponding structure for the “means for monitoring” is “a comparator, which makes use of information from a time and distance computing circuit” (i.e. the peg counter). As Telco argues, it is the comparator which compares the cost of the call to the amount of money in the calling party’s account. Because the specification is clear that the corresponding structure is the comparator and that the comparator compares monetary credit to the monetary cost of the call, we affirm the district court’s construction.