Siemens Mobility Inc v. Metrom Rail LLC

1. Case Identification

• Case #: IPR2024-00947
• Patent #: 9,731,738
• Filed: May 22, 2024
• Petitioner(s): Siemens Mobility, Inc., Ground Transportation Systems USA, Inc., and Piper Networks, Inc.
• Patent Owner(s): Metrom Rail, LLC
• Challenged Claims: 1-18

2. Patent Overview

• Title: Train Control System
• Brief Description: The ’738 patent describes a train control system for enforcing observance of rail signals, speed limits, and vehicle separation. The system uses a vehicle-mounted subsystem (VMCS) that communicates with a wayside control signal interface subsystem (CSIS) using ultra-wideband (UWB) radio communications to determine and enforce behavior rules.

3. Grounds for Unpatentability

Ground 1: Obviousness over Kane and Heddebaut - Claims 1-2, 6-8, and 13-15 are obvious over Kane in view of Heddebaut.

• Prior Art Relied Upon: Kane (Patent 6,957,131) and Heddebaut (Application # 2006/0151672).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Kane, which was not cited during prosecution, teaches a complete train control system with all core elements of independent claim 1. This includes a wayside signaling device (the claimed "control signal interface subsystem") and a vehicle-mounted subsystem with a controller, transceiver, and brake interface. Kane’s system communicates signal indications, determines behavior rules (e.g., target speed) based on those signals, and monitors the train for compliance. The primary element missing from Kane is the specific use of UWB communications. Heddebaut, however, explicitly teaches a train control system that uses UWB radio communications between fixed wayside stations and railway vehicles for positioning and control.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Heddebaut's UWB communication technology with Kane's comprehensive train control system. Kane broadly discloses "radio frequency" communications, and Heddebaut teaches that UWB is a known and advantageous type of radio communication for this exact environment, particularly in tunnels where other signals fail. Heddebaut explains UWB’s benefits, such as resistance to multipath effects and suitability for precise distance measurement, providing a clear motivation to implement it in a system like Kane’s to improve reliability and performance.
  • Expectation of Success: A POSITA would have a reasonable expectation of success in this combination because both references teach train control systems that rely on radio communication between wayside and vehicle-mounted units to exchange similar data types (e.g., signal indications, speed). Integrating a known communication protocol (UWB from Heddebaut) into a system designed for radio communication (Kane) was presented as a straightforward application of known principles.

Ground 2: Obviousness over Kane, Heddebaut, and Das - Claims 3-5 are obvious over Kane and Heddebaut in view of Das.

• Prior Art Relied Upon: Kane (Patent 6,957,131), Heddebaut (Application # 2006/0151672), and Das (WO 2011/125074).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground builds on the Kane/Heddebaut combination to address claims 3-5, which specify behavior rules including a "stop-time duration" and a subsequent speed limit. Petitioner contended that while Kane discloses a "STOP" signal, it does not explicitly teach a timed stop duration. Das, another reference not cited during prosecution, remedies this by teaching a railway signaling system that broadcasts data including "stop durations if any."
  • Motivation to Combine: A POSITA would add the stop-duration signaling of Das to the Kane/Heddebaut system to improve operational efficiency. Petitioner argued that stop-and-stay signals (like Kane's) and timed-stop signals (like Das's) were common, well-known signal types. Incorporating Das's timed stop would allow a train to know when to proceed without requiring a second, separate instruction, which is a predictable improvement for managing rail traffic.

Ground 3: Obviousness over Kane, Heddebaut, and Ackerman - Claims 9-11 and 16-17 are obvious over Kane and Heddebaut in view of Ackerman.

• Prior Art Relied Upon: Kane (Patent 6,957,131), Heddebaut (Application # 2006/0151672), and Ackerman (Patent 5,803,411).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground addresses claims requiring an RFID subsystem to scan external tags for vehicle positioning. Petitioner asserted that the base Kane/Heddebaut system is made obvious by the addition of Ackerman, which was also not cited during prosecution. Ackerman explicitly teaches an automated train control system that uses a vehicle-mounted "train reader" to read track-based RFID tags to pinpoint the train's exact location. It further teaches using this RFID data in conjunction with a tachometer to track the train’s position between tags.
  • Motivation to Combine: A POSITA would have been motivated to add Ackerman's RFID positioning as a complementary technology to the positioning systems in Kane (GPS) and Heddebaut (UWB ranging). Petitioner argued that RFID provides a precise location when the train passes a tag, which is particularly useful in environments like tunnels where GPS is unavailable and UWB signals may be weak, thereby improving the overall system's accuracy and redundancy.

• Additional Grounds: Petitioner asserted additional obviousness challenges based on combinations of the core Kane/Heddebaut references with Hungate (Patent 5,950,966) for adding external access points for data communication (claims 12, 18) and with Grisham (Patent 6,759,948) for further teaching train-to-train UWB time-of-flight ranging for collision avoidance (claims 13-15).

4. Arguments Regarding Discretionary Denial

• §314(a) / Fintiv Factors: Petitioner argued against discretionary denial under Fintiv, stating that the parallel district court litigation against petitioner Siemens has been stayed pending the outcome of IPR proceedings, a factor that weighs heavily against denial. Further, two of the four petitioners are not defendants in any related litigation. Petitioner also asserted a strong showing of unpatentability on the merits.
• §325(d) Factors: Petitioner argued that denial under §325(d) is unwarranted because the petition raises new arguments and prior art not substantively considered during prosecution. Although Heddebaut and an ancestor to Grisham were listed in an Information Disclosure Statement (IDS), the examiner never applied or discussed them. The petition’s primary reference, Kane, and key secondary references Das and Ackerman, were never before the examiner. Petitioner contended that the Office therefore erred by overlooking persuasive combinations of these references.

5. Relief Requested

• Petitioner requests institution of inter partes review and cancellation of claims 1-18 of Patent 9,731,738 as unpatentable under 35 U.S.C. §103.