Bell Communications Research, Inc. v. Fore Systems, Inc.

MAYER, Chief Judge,

dissenting.

While I do not take issue with the court’s construction of the simultaneous transmission language or the empty payload field requirement, Bell Communications (“Belcore”) conceded that under the district court’s claim construction, it could not prove infringement of these limitations as well as the frame limitation of claims 1, 3, and 4 of United States Patent No. 4,893,306 (“’306 patent”). Because the district court correctly concluded that the ’306 patent requires generation of a complete frame prior to filling, however, I would affirm, the judgment of non-infringement.

Claim 1 of the ’306 patent requires, inter alia, “generating a bit stream comprising a sequence of frames, each of said frames including a transmission overhead field containing frame timing information and an empty payload field, and filling the empty payload fields in said frames with data in packetized format from a plurality of sources ...” ’306 patent, col. 17, 11. 47-53, (emphasis added). While the steps of method claims may not necessarily have to be performed sequentially or each step fully completed before the next begins, there are method claims that require full *961completion of each step prior to the start of the next and a strict adherence to the sequential order. The plain meaning of the claims themselves, the place that all claim construction must begin, mandates that the generating step must be completed prior to the beginning of the filling step. CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 1366, 62 USPQ2d 1658, 1662 (Fed.Cir.2002) (There is a heavy presumption that the plain meaning of the claim language controls and can only be overcome in limited circumstances.).

“Fill” is defined as “to supply with as much as can be held or contained; to put or pour something into (a receptacle) till no more can be received.” 5 Oxford English Dictionary 908 (2nd ed.1989). The Webster’s Dictionary provides almost the identical definition. Webster’s Third New International Dictionary 849 (1993). Logic dictates that an incomplete container or frame cannot be filled because filling requires a finite volume. The patentee could have chosen alternative language to convey partial frame filling, whether by expressly stating the possibility or using a verb such as “placing” which would not require a finite volume, but did not do so. The prosecution history confirms this construction. In overcoming the Baran reference, the patentee stated that the claims require “first generating a bit stream comprised of frames with empty payload fields____ The packets are then inserted into the empty payload fields ...” The patentee stated that first frames, plural, are generated and then data is inserted. The patentee makes no mention of generating the transmission overhead field of a frame and the first boundary of the payload field and then inserting data on a byte-by-byte basis. And the fact that Baran uses a different type of multiplexing is of no matter. Clear assertions made during prosecution in support of patentability, whether or not actually required to secure allowance of the claim, can create an estoppel. Texas Instruments, Inc. v. United States Int’l Trade Comm’n, 988 F.2d 1165, 1174, 26 USPQ2d 1018, 1025 (Fed.Cir.1993).

The court frames the issue as whether the specification or the prosecution history obviates the construction that filling could begin into a partially generated frame and answers in the negative. While the specification may not expressly exclude such a construction, nothing supports it either. The specification only speaks of generated frames and is silent as to anything less.

The court cites to a paragraph in the specification and argues that it presents a possible mechanism for byte-by-byte insertion prior to completion of the frame. Ante, at 955-956. The cited portion of the specification states: “Typically, the bit rate of the DTDM bit stream illustrated in FIG. 1 is about 150 Megabits/see. The following information may be available in the overhead field of every DTDM frame; frame alignment word for frame timing, empty/full status of the frame, and span identification.” ’306 patent, col. 6,11. 61-65. This statement offers nothing more than the components that make up a frame and certainly does not provide support for partial frame filling. While the court is correct that it is fair to say that the specification is silent about whether frames are generated byte-by-byte or whether complete frames are generated before data insertion begins, the patentee should bear the burden for the lack of information and the plain meaning of the language chosen by the patentee should control.