The opinion of the court was delivered by: Rosemary M. Collyer United States District Judge
MEMORANDUM OPINION ON CLAIM CONSTRUCTION
HTC Corporation and HTC America, Inc., seek a declaratory judgment that their telephony products do not infringe U.S. Patent No. 5,390,216 (" '216 Patent") held by IPCom GMBH & Co., KG. IPCom counterclaims that HTC products infringe the '216 Patent as well as two other Patents that IPCom owns - U.S. Patents Nos. 7,043,751 (" '751 Patent") and 6,879,830 (" '830 Patent"). After discovery and a technology tutorial for the Court, the parties presented their respective constructions of critical patent terms in briefs and oral arguments.*fn1 Pursuant to Markman v. Westview Instruments, Inc., 52 F.3d 967 (Fed. Cir. 1995), the Court has considered the entire record and now construes a limited number of the contested terms from the three patents at issue.*fn2
The Patents arise in the technology of modern mobile telephony, i.e., cell phones. The '216 Patent is titled, "Synchronization Method for a Mobile Radiotelephone." '216 Patent; see IPCOM's Opening Br., Jt. Ex. 2. It discloses "synchronization methods for mobile radiotelephones in a cellular, digital mobile radiotelephone system comprising a plurality of fixed stations and a plurality of mobile radiotelephones, for example operating according to what is known as the GSM Recommendation."*fn3 '216 Patent at 1:10-15.*fn4 Although the "invention is not necessarily limited to the GSM system . . . and is likely to be useful in more or less similar systems," id. at 8:53-55, the specification references characteristics of a GSM system.
The invention disclosed in the '216 Patent aimed "to provide a synchronization method that fulfills all requirements of digital information transmission with the least possible technical complication and expense." Id. at 3:5-8. To "take advantage of that more economical synchronization technique, there is performed for the mobile radiotelephone, first, an initial synchronization, then a normal synchronization and then, an extended synchronization as a background procedure during normal operation." Id. at 3:25-30. These three main steps include substeps, see id. at 3:30-43, and "[b]y this procedure it is possible to realize synchronization of higher precision with a relatively small complication and expense." Id. at 3:44-46. The point of synchronization is, of course, the ability to operate the cell phone with clear transmission and without dropped calls.
The '751 Patent is entitled "Method of Allocating Access Rights to a Telecommunications Channel to Subscriber Stations of a Telecommunications Network and Subscriber Station." '751 Patent; see IPCOM's Opening Br., Jt. Ex. 3. In the '751 Patent's language, a "subscriber station" is a cell phone within a network. Because a broadcast channel cannot accommodate an unlimited number of cell phones, the '751 Patent suggests a method to distinguish between phones. The '751 Patent describes a cell phone that has a transceiver to receive information signals from a network and an evaluation unit that analyzes "access authorization data" within those signals to ascertain whether the cell phone is authorized to access the common channel. Only Claim Thirteen of the '751 Patent is asserted by IPCom.
The '830 Patent is entitled "Method for Handover, Mobile Station for Handover and Base Station for Handover." '830 Patent; see IPCOM's Opening Br., Jt. Ex. 4. The "handover" in question occurs when a mobile cell phone moves from one base station (cell tower) to another; obviously, a smooth handover avoids dropped calls. The '830 Patent discloses "a type of handover to be implemented that can be performed without network support," or, if "the network is capable of supporting handover, that capability can be utilized." '830 Patentat 2:31-35. Another aspect involves a situation where the base station forces the cell phone to attempt a handover and, if it cannot succeed, "the mobile station [cell phone] can return to the original base station without any problem." Id. at 2:12-24.
A. Patent Claims Construction Principles Generally
The "claims" of a patent are those descriptions of the invention that are numbered and follow the introductory phrase, "[w]hat is claimed." An understanding of a patented invention must start and end with the claims themselves which identify and distinguish the inventor's invention. To determine whether a patent claim has been infringed, a court must undertake a two-step process. The court first construes or interprets each contested claim, or phrase or word within a claim, to determine its meaning and scope; only afterward are the claims compared to the accused device(s).*fn5
O.I. Corp. v. Teckmar Co. Inc., 115 F.3d 1576, 1580 (Fed. Cir. 1997).
The interpretation of patent claims is exclusively a question of law. Markman, 517 U.S. 370. In claims construction, a court must interpret the words of each contested claim from the perspective of one skilled in the art at the time of invention, in light of the patent documents and the prosecution history. Phillips v. AWH Corp., 415 F.3d 1303, 1313 (Fed. Cir. 2005). Words in the claims of a patent are given their ordinary and customary meaning, that is, the meaning that the term would have had to a person of ordinary skill in the pertinent art at the time of the invention. Id. at 1312-13. "[T]he 'ordinary meaning' of a claim term is its meaning to the ordinary artisan after reading the entire patent." Id. at 1314. Although words are generally given their ordinary meaning, "a patentee may choose to be his own lexicographer and use terms in a manner other than their ordinary meaning, as long as the special definition of the term is clearly stated in the patent specification or file history." Vitronics Corp. v. Conceptronics Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996). When a specification expressly defines terms or defines terms by implication, the specification will be held to limit the claims accordingly. Phillips, 415 F.3d at 1321. Phillips discredited the approach of prior cases holding that claim terms were to be given the broadest possible ordinary meaning and that the specification should only be consulted for a clear disavowal of such meaning. Id. at 1319-21. The Phillips court reasoned that this approach resulted in unduly expansive claim construction and improperly restricted the role of the specification in claim construction. Id. (disavowing Texas Digital Systems, Inc. v. Telegenix, Inc., 308 F.3d 1193 (Fed. Cir. 2002) and cases following its approach).
Claim construction should be undertaken independent of any consideration of how the claims may or may not be read on the accused product. SRI Int'l v. Matsushita Elec. Corp. of Am., 775 F.2d 1107, 1118 (Fed. Cir. 1985). "[C]laims are not construed to 'cover' or 'not to cover' the accused device. That procedure would make infringement a matter of judicial whim." Id.; see also Wilson Sporting Goods Co. v. Hillerich & Bradsby Co., 442 F.3d 1322, 1326-27 (Fed. Cir. 2006) (the court should not prejudge the infringement analysis by construing claims with an aim to include or exclude a particular product, but knowledge of the accused product is helpful to provide context and focus).
In construing a claim, a court starts with the intrinsic evidence of its meaning - the claims, the specification, and the prosecution history. Vitronics, 90 F.3d at 1582; see Pitney Bowes Inc. v. Hewlett-Packard Co., 182 F.3d 1298, 1305 (Fed. Cir. 1999) (the starting point for claim interpretation must be the claims themselves). The "prosecution history" of a patent is the complete public record of the proceeding before the U.S. Patent and Trademark Office ("PTO"). Phillips, 415 F.3d at 1317. The public record includes the original application and any claim amendments and explanations made by the applicant. Vitronics, 90 F.3d at 1582. For example, a patent applicant may limit claims during prosecution by modifying claim language to overcome examiner rejection, by distinguishing a reference, or by disavowing claim coverage. Omega Eng'g Inc. v. Raytek Corp., 334 F.3d 1314, 1323-25 (Fed. Cir. 2003). The specification of a patent "must include a written description of the invention or discovery and of the manner and process of making and using the same, and is required to be in such full, clear, concise, and exact terms as to enable any person skilled in the art or science . . . to make and use the same." PTO Rules § 1.71(a). "The specification must set forth the precise invention . . . in such a manner as to distinguish it from other inventions and from what is old." Id. § 1.71(b). The specification is the "single best guide to the meaning of a disputed term." Vitronics, 90 F.3d at 1582.
The Federal Circuit has recognized a fine line between reading a claim in light of the specification and reading a limitation into a claim from the specification. Phillips, 415 F.3d at 1323. The former is appropriate and necessary; the latter constitutes error. Id. For example, a discussion in a specification of a particular embodiment of an invention does not normally confine the invention to that particular embodiment. Id. (citing Nazomi Comm., Inc. v. ARM Holdings, PLC, 403 F.3d 1364, 1369 (Fed. Cir. 2005)); see also DSW, Inc. v. Shoe Pavilion, Inc., 537 F.3d 1342, 1348 (Fed. Cir. 2008) ("when claim language is broader than the preferred embodiment, it is well-settled that claims are not to be confined to that embodiment."). "To avoid importing limitations from the specification into the claims, it is important to keep in mind that the purposes of the specification are to teach and enable those of skill in the art to make and use the invention and to provide a best mode for doing so." Phillips, 415 F.3d at 1323. Usually the specification clearly states whether it is setting out specific examples of the invention or whether the patentee intends the embodiments in the specification to be coextensive with the claims. Id. A court does not improperly read a limitation into a claim where the claim contains the term and the court looks to the specification for a definition of the term, even if that definition is set forth in a preferred embodiment. Curtiss-Wright Flow Control Corp. v. Velan, Inc., 438 F.3d 1374, 1378-80 (Fed. Cir. 2006) (claim limited by the term "adjustable" and specification defined term).
B. Avoidance of Redrafting Claims and Interpretations that Render a Term Superfluous
A court may not redraft claims to make them operable or to sustain their validity.
Chef America, Inc. v. Lamb-Weston, Inc., 358 F.3d 1371, 1374 (Fed. Cir. 2004). However, "[w]hen claims are amenable to more than one construction, they should when reasonably possible be interpreted so as to preserve their validity." Modine Mfg. Co. v. U.S. Int'l Trade Comm'n, 75 F.3d 1545, 1557 (Fed. Cir. 1996).
Further, a court should avoid interpreting patent claims in a way that renders any term superfluous. See Bicon, Inc. v. Straumann Co., 441 F.3d 945, 950 (Fed. Cir. 2006) ("claims are interpreted with an eye toward giving effect to all terms in the claim"); Merck & Co., Inc. v. Teva Pharmaceuticals USA, Inc.,395 F.3d 1364, 1372 (Fed. Cir. 2005) (a construction that gives meaning to all the terms of the claim is preferred over one that does not); Cytologix Corp. v. Ventana Medical Sys., Inc., 424 F.3d 1168, 1173 (Fed. Cir. 2005) (if possible, a court should avoid an interpretation of one claim that renders another meaningless). A claim term is considered invalid for indefiniteness "only if reasonable efforts at claim construction prove futile." Exxon Research & Eng'g Co. v. United States, 265 F.3d 1371, 1375 (Fed. Cir. 2001).
"[A] claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers." 35 U.S.C. § 112. In other words, a dependent claim incorporates all of the limitations of the claim from which it "depends" and adds something new; thus, a dependent claim has a narrower scope than the claim from which it depends. Further, "the presence of a dependent claim that adds a particular limitation gives rise to a presumption that the limitation in question is not present in the independent claim." Phillips, 415 F.3d at 1315.
The Court construes the Patent Terms in the order in which they appear in the Joint Statement [Dkt. # 159], Ex. A, Chart of Claim Terms and Proposed Constructions ("Chart").
Claim One of the '216 Patent contains most of the critical terms in dispute. In construing such terms, the nature of Claim One must be kept in focus: the Claim covers the steps of a method of synchronization between a cell phone (mobile station) and one or more cell towers (base station) but does not fully reveal how such steps are actually accomplished. Subsequent claims cover the "how" of Claim One's method. HTC makes a fundamental error in its proposed constructions for Claim One - it argues for constructions that import into Claim One the specifics of one or more of the subsequent dependent claims of the '216 Patent. As noted above, "the presence of a dependent claim that adds a particular limitation gives rise to a presumption that the limitation in question is not present in the independent claim." Phillips, 415 F.3d at 1315.
Claim One is neither so precise nor so complex. Claim One states that the inventors claimed:
A method of synchronizing a mobile radiotelephone in a cellular digital mobile radiotelephone network comprising a plurality of fixed radiotelephone stations and a plurality of mobile radio stations operating in accordance with a GSM standard or its equivalent, in which each communication frequency assignment is subdivided into interleaved time slots, a plurality of said time slots together comprising a frame, comprising the following steps which are carried out in the mobile radiotelephone:
(1) conducting an initial synchronization by means of a frequency correction burst substantially fully occupying a time slot with an unmodulated wave corresponding to repetition of bits of the same binary logic value;
(2) maintaining normal synchronization during communication by means of interspersed normal synchronization bursts, each normal synchronization burst containing a training sequence occupying less than a third of a time slot; and
(3) performing extended synchronization during communication as a background procedure by means of interspersed frequency synchronization bursts, each frequency synchronization burst containing an extended training sequence occupying less than an entire time slot and more than a third of a time slot, and wherein: said step of conducting said initial synchronization comprises the substeps of:
(1.1) conducting a coarse frequency synchronization,
(1.2) conducting a coarse frame synchronization over a plurality of said time slots which comprise a frame,
(1.3) conducting a fine frequency synchronization, and
(1.4) conducting a fine frame synchronization over said plurality of time slots which comprise a frame; said step of maintaining said normal synchronization comprises the substeps of:
(2.1) conducting a frame synchronization with fine frequency synchronization, and
(2.2) carrying out preliminary data signal processing; and said step of performing said extended synchronization comprises the substeps of:
(3.1) conducting a coarse frame synchronization, and
(3.2) conducting a fine frame synchronization with fine frequency synchronization. '216 Patent 8:62-9:46.
The specification explains that the digital mobile telephone system used in Germany has traffic channels and control channels. Id. at 1:41-42. "The former were sub-divided into encoded speech traffic channels and data traffic channels." Id. at 1:43-44. "The control channels include frequency correction channels for frequency correction of a mobile station, synchronization channels for a frame synchronization of the mobile station and identification of a base transceiver station and broadcast control channels for general information from a base station." Id. at 1:45-50. The specification explains that "[o]ne radio frequency channel of the cell allocation is used to carry synchronization information, known as the BCCH carrier, and serves as the broadcast control channel." Id. at 1:56-59. Further, "[a] radio frequency channel is partitioned into time slots, so that transmission takes place in time division multiple access (TDMA) frames. There are eight time slots to a TDMA frame, which has a duration of a little less than 5 ms." Id. at 1:61-65.
The timing of time slots, TDMA frames, traffic channel frames and control channel frames are all related to a common set of counters which run continuously whether the mobile station and base station are transmitting or not. Thus once the mobile station has determined the correct setting of these counters all its processors are synchronized to the currently serving base station.
The invention is a method of achieving synchronization between a mobile phone and a base station. Whereas at the time of the '216 Patent, synchronization was achieved through a "common set of counters," id., the method of the Patent allowed the use of frequency correction bursts and synchronization bursts from the base station to achieve synchronization more readily and with less expense. As the specification explains, "[i]t is an object of the invention to provide a synchronization method that fulfills all the requirements of digital information transmission with the least possible technical complication and expense." Id. at 3:5-8. As noted above, Claim One describes the order of the process, but provides little detail as to how actually to achieve synchronization. Claim Two gives detail as to how to achieve synchronization as generally described in Claim One - by using continuous calculations of phase angles. The specification states, "[t]he synchronization method of the invention is based on the evaluation of a continuously running phase angle, which is calculated again and again from an in-phase component I and a quadrature component Q." Id. at 3:9-12. "The method of the invention is based on evaluation of phase angle [sic] many times per bit interval." Id. at 3:47-48. "For taking best advantage of evaluating phase angles by I, Q samples, it is important to utilize the various different transmitted synchronization bursts in accordance with the various steps that usefully make up the various aspects of the invention." Id. at 8:47-52.
The parties ask the Court to construe "synchronizing" as used in Claim One of the '216 Patent, where the inventors claimed "[a] method of synchronizing a mobile radiotelephone in a cellular digital mobile radiotelephone network." '216 Patent at 8:62-64. IPCom proposes that synchronizing means merely "[b]ringing the mobile station's operation in step with the corresponding operation of a base station." Chart at 1. HTC proposes that synchronizing means "[b]ringing a mobile station's operation in step with the corresponding operation of a base station by performing processes that evaluate a continuously running phase angle calculated from burst signals received from the base station." Chart at 1.
While HTC's proposed construction finds support in the specification, see '216 Patent at 3:9-1 ("The synchronization method of the invention is based on the evaluation of a continuously running phase angle . . . ."), it confuse Claim One and Claim Two and therefore cannot be adopted. Phillips, 415 F.3d at 1315. Claim Two of the '216 Patent depends from Claim One and describes the "further steps of: calculating (continuous evaluation of) a phase angle from sequences of pairs of values . . . and thereafter performing a continuous evaluation of said calculated phase angle." '216 Patent at 9:49-54. Given the specificity of Claim Two's disclosed method and the generality of Claim One, HTC's proposed construction erroneously conflates the two.
HTC argues strenuously that the evaluation of phase angles is the only disclosed mechanism for every claimed substep. While this is a slight overstatement, since substep (1.1) does not evaluate phase angles, it remains basically accurate. The point is, however, that Claim One - the only independent claim in the '216 Patent - does not reveal how to accomplish its method. Those particulars are in the dependent claims that follow. Indeed, the prosecution history reflects the understanding of the Patent and Trademark Office (PTO) that the invented method resided in the multiple steps, not in "phase course" analysis. IPCom's Opening Br., Ex. 5, Prosecution History at 1194 ("none of the references teaches or suggests the arrangement of the steps of initial synchronization, normal synchronization and extended synchronization with the substeps of each respective step in order to form a method of synchronization"); see also Tr. 2/16/10 at 43 (IPCom).
HTC additionally argues that the inventors clearly limited the scope of the invention by three statements:
* The synchronization method of the invention is based on the evaluation of a continuously running phase angle, which is calculated again and again from an in-phase component I and a quadrature component Q. '216 Patent at 3:9-12.
* The method of the invention is based on evaluation of phase angle many times per bit interval. Id. at 3:48-49.
* For taking best advantage of evaluating phase angles by I, Q samples, it is important to utilize the various different transmitted synchronization bursts in accordance with the various steps that usefully make up the various aspects of the invention. Id. at 8:47-52.
An inventor may disclaim or disavow the scope of a claim in the specification.
Phillips, 415 F.3d at 1316. To limit the scope of his own patent, a patentee must have had "a clear intention to limit the claim scope using 'words or expressions of manifest exclusion or restriction.'" Liebel-Flarsheim Co. v. Medrad, Inc., 358 F.3d 898, 906 (6th Cir. 2004). "In that instance . . . the inventor has dictated the correct claim scope, and the inventor's intention, as expressed in the specification is regarded as dispositive." Phillips, 415 F.3d at 1316.
While the specification in the '216 Patent describes evaluation of phase angles, no expressly limiting language is used in Claim One. The focus of Claim One is the method of sequential steps and substeps, not the precise contours of how one practices the invention. Claim One is not bounded by the limitations of relying on evaluating phase angles, as these limitations appear in dependent claims and not in Claim One. Given the structure of the '216 Patent, the Court cannot conclude that Claim One is so limited.
The Court construes "synchronizing" to mean "bringing the mobile station's operation in step with the frame and frequency of a base station."*fn6
2. "Conducting an initial synchronization by means of a frequency correction burst"*fn7 Claim One of the '216 Patent provides for three steps to be carried out in the mobile radiotelephone: (1) initial synchronization; (2) normal synchronization; and (3) extended synchronization. '216 Patent at 9:4-20. In step (1), Claim One provides for "conducting an initial synchronization by means of a frequency correction burst." '216 Patent at 9:4-5. The purpose of the initial synchronization is "to provide the initial connection between a mobile radiotelephone and a fixed station." Id. at 5:23-24. The specification gives background information:
A base station sends signals on a broadcast control channel to enable a mobile station to synchronize itself to the base station and if necessary correct its frequency standard so as to put it in line with that of the base station. The signal[s] sent by the base station for these purposes are (a) frequency correction bursts and (b) synchronization bursts. A burst is defined as an interval within which the radio frequency carrier is modulated by a predetermined data stream.
The parties dispute whether the initial synchronization is conducted before or after the mobile station (i.e., cell phone) has selected a carrier*fn8 frequency. HTC maintains that initial synchronization is conducted after the cell phone has selected a carrier frequency, asserting that the correct construction is: "[h]aving selected a carrier frequency, synchronizing during initial connection by performing the claimed steps (1.1), (1.2), (1.2), and (1.4) on frequency correction burst 12." Chart at 1 (referring to Fig. 1).*fn9 IPCom proposes a broader construction: "[c]ontrolling a process to achieve an initial, synchronized connection between a mobile station and a base station through use of one or more frequency correction bursts." Chart at 1.
HTC's definition will not suffice because it requires substep (1.1), i.e., "conducting a course frequency synchronization," see '216 Patent at 9:24-25, while the specification explains that substep (1.1) is not always necessary. Once the receiver in the cell phone detects a carrier frequency, it immediately makes a "first frequency estimation" to determine "whether the frequency of the discovered carrier lies within or outside of a tolerance region TR (compare FIG. 3)." Id. at 5:34-39. "With sufficient precision of carrier frequency tuning[,] the coarse frequency determination which is burst-independent can ...