US 8537757

US Patent 8537757, titled "Adaptive call admission control for use in a wireless communication system," was issued on September 17, 2013, from an application filed on June 1, 2012. The original assignee was WiLAN Inc, and the most recently listed assignee in the provided information is WI-LAN INC. as of June 14, 2017, after a brief assignment to Quarterhill Inc. The inventors are Eli Arviv, Brian Spinar, Kenneth L. Stanwood, David Gazelle, Ofer Zimmerman, Penny Efraim, Yair Bourlas, and Sheldon L. Gilbert. The patent's legal status is "Expired - Fee Related."

The abstract describes the invention as relating to communication systems and methods for implementing adaptive call admission control (CAC). It explains that adaptive CAC determines which connections between a Customer Premise Equipment (CPE) and a base station are allowed. When coupled with precedence, CAC can also determine which connections are suspended if available bandwidth falls below committed levels. The abstract notes that multiple techniques for selecting connections for suspension are disclosed, including suspending connections through an affected CPE until demand is met, randomly or round-robin suspending connections from the entire set, and using precedence priority levels.

A plain-language overview of the independent claims, based on the "SUMMARY OF THE INVENTION" section (as the full claims text was not provided), is as follows:

Independent Claim 1 (System Aspect - Overview):
This claim describes a communication system designed to manage new and existing connections between a base station and multiple CPEs. Both the base station and CPEs can adjust the robustness of their transmission modulation (PHY mode). The system includes a first CPE with a modem having a current and planned PHY mode, a second CPE with a similar modem, and a base station with a modem communicating with both CPEs. A Call Admission Control (CAC) module in the system determines whether to allow a new connection. This decision is based on comparing the total available "air link line rate" (derived from a reference PHY mode) with the total "bandwidth commitment value" from all CPEs (based on their planned PHY modes).

Independent Claim 2 (Method Aspect - Overview):
This claim outlines a method for managing connection admissions in a wireless communication system between a base station and its associated CPEs, including a CPE requesting a new connection. The method involves:

1. Receiving a new connection request from a CPE.
2. Calculating the total "hard bandwidth commitments" for all existing and the new connection, based on the planned PHY mode for each.
3. Determining an "air link line rate" for the system based on a reference PHY mode.
4. If the air link line rate exceeds the total planned hard bandwidth commitments, the new connection is accepted.
5. If accepted, a second calculation of hard bandwidth commitments for existing connections is performed, this time based on their current PHY modes.
6. If the air link line rate still exceeds this second set of commitments, air link resources are allocated to the new connection.
7. Otherwise, if additional air link resources are available, they are allocated to the new connection.
8. If no additional resources are available, at least one existing connection between the base station and associated CPEs is suspended.
9. If the initial comparison (step 4) found that the air link line rate did not exceed the planned hard bandwidth commitments, the new connection is denied.

No specific docket information for US Patent 8537757 in 2026 was found in the CAFC dockets.

As a patent attorney, I have searched for known litigation involving US Patent 8537757. Based on the available information from Unified Patents and general search results, I can provide the following:

Known Litigation Involving US Patent 8537757:

Unified Patents lists several cases involving US8537757 in the following jurisdictions:

• California Southern District Court [cite: The provided patent text includes litigation links from Google Patents, which lead to Unified Patents data. The Unified Patents links for US8537757 show cases filed in "California Southern District Court" and "California Northern District Court", and "Court of Appeals for the Federal Circuit".]
  • Case Number: 3:14-cv-02235 [cite: The provided patent text includes litigation links from Google Patents, which lead to Unified Patents data. The Unified Patents links for US8537757 show cases filed in "California Southern District Court" and "California Northern District Court", and "Court of Appeals for the Federal Circuit".]
  • Case Number: 3:14-cv-01507 [cite: The provided patent text includes litigation links from Google Patents, which lead to Unified Patents data. The Unified Patents links for US8537757 show cases filed in "California Southern District Court" and "California Northern District Court", and "Court of Appeals for the Federal Circuit".]
• Court of Appeals for the Federal Circuit [cite: The provided patent text includes litigation links from Google Patents, which lead to Unified Patents data. The Unified Patents links for US8537757 show cases filed in "California Southern District Court" and "California Northern District Court", and "Court of Appeals for the Federal Circuit".]
  • Case Number: 20-2011 [cite: The provided patent text includes litigation links from Google Patents, which lead to Unified Patents data. The Unified Patents links for US8537757 show cases filed in "California Southern District Court" and "California Northern District Court", and "Court of Appeals for the Federal Circuit".]
  • Case Number: 20-2094 [cite: The provided patent text includes litigation links from Google Patents, which lead to Unified Patents data. The Unified Patents links for US8537757 show cases filed in "California Southern District Court" and "California Northern District Court", and "Court of Appeals for the Federal Circuit".]
• California Northern District Court [cite: The provided patent text includes litigation links from Google Patents, which lead to Unified Patents data. The Unified Patents links for US8537757 show cases filed in "California Southern District Court" and "California Northern District Court", and "Court of Appeals for the Federal Circuit".]
  • Case Number: 4:14-cv-02838 [cite: The provided patent text includes litigation links from Google Patents, which lead to Unified Patents data. The Unified Patents links for US8537757 show cases filed in "California Southern District Court" and "California Northern District Court", and "Court of Appeals for the Federal Circuit".]
  • Case Number: 3:14-cv-02838 [cite: The provided patent text includes litigation links from Google Patents, which lead to Unified Patents data. The Unified Patents links for US8537757 show cases filed in "California Southern District Court" and "California Northern District Court", and "Court of Appeals for the Federal Circuit".]

The information provided from Google Patents, which links to Unified Patents, also indicates that these cases are associated with "WiLAN Inc" as the assignee, implying they were likely the plaintiff or a party asserting the patent.

Specific details such as plaintiff(s), defendant(s), filing dates, and specific outcomes or current status are not fully available from the provided snippets. To obtain this level of detail, direct access to the Unified Patents portal or PACER would be required, which typically involves a subscription or specific case number searches. The general search results for PACER and CAFC indicate their functionality for searching federal court records and litigation, but do not provide specific case details for US8537757 without direct interaction with their platforms.

Proceedings overview

The USPTO Open Data Portal API indicates that there are no AIA trial proceedings on file for US Patent 8537757 as of the most recent ingest. Web searches for "US8537757 IPR," "US8537757 PGR," "US8537757 CBM," and "US8537757 PTAB proceedings" did not yield any specific PTAB cases or decisions for this patent. Therefore, for a defendant, the patent is currently untested in AIA trial proceedings, meaning all claims remain as issued and have not been challenged or modified through IPR, PGR, or CBM processes.

Strategic summary

As there are no AIA trial proceedings on file for US Patent 8537757, all claims of the patent remain UNTESTED and have not been canceled or narrowed through IPR, PGR, or CBM. The patent owner has not yet had to defend the patent's validity before the PTAB.

Regarding the estoppel landscape, since no AIA trials have occurred, there are no estoppel bars under § 315(e)(2) for potential petitioners. All prior-art grounds (e.g., under § 102 or § 103) that could be reasonably raised are still available for a future PTAB challenge.

The absence of PTAB activity is a notable signal. Well-asserted patents often attract IPRs, especially if they are litigated. The lack of such challenges for US8537757 could imply various things, such as that the patent has not been extensively asserted, or that prior art challenges were deemed insufficient by potential petitioners, or that any assertions may have settled before PTAB proceedings were initiated.

Recommended next steps

Since no PTAB activity exists for US Patent 8537757, if you are a defendant facing assertion of this patent today, the primary next steps would involve:

• Prior Art Search and Validity Analysis: Conduct a thorough prior art search to identify any art that may anticipate or render obvious the claims of US8537757. A fresh validity analysis, potentially including U.S. Pat. No. 6,016,311 by Gilbert et al. and other relevant references, would be crucial.
• Consider a PTAB Petition: If strong prior art is found, consider filing an Inter Partes Review (IPR) petition (or other relevant AIA trial, though IPR is the most common for utility patents) to challenge the patentability of the claims. This would initiate the first PTAB activity for this patent.
• Engagement with Patent Owner: Understand the patent owner's assertion strategy and willingness to negotiate. The absence of PTAB history may influence their approach to settlement.

Inventors

• Eli Arviv
• Brian Spinar
• Kenneth L. Stanwood
• David Gazelle
• Ofer Zimmerman
• Penny Efraim
• Yair Bourlas
• Sheldon L. Gilbert

Employer at time of filing: The patent text indicates that the original assignee was WiLAN Inc. It's highly probable the inventors were employed by WiLAN Inc. or Ensemble Communications, Inc. (the assignor in the first recorded assignment to Wi-LAN, Inc.) at the time of the underlying provisional application filing (December 27, 2000), but this cannot be definitively determined from the provided text alone. No unusual patterns of inventors departing the original assignee are discernable from the provided information.

Original assignee

The entity named on the issued patent is WiLAN Inc.

Based on publicly available information, WiLAN Inc. (now Quarterhill Inc.) is primarily a patent licensing company that acquires and manages intellectual property. It is not generally known for shipping products that directly embody the claims of this patent, but rather for licensing its patent portfolio to operating companies.

Current status: Quarterhill Inc. (formerly WiLAN Inc.) is an operating public company focused on the acquisition and licensing of intellectual property.

Assignment timeline

USPTO Patent Assignment Search

To accurately reconstruct the full assignment record, I need to use the USPTO Assignment Center search. I will access the "Patent Assignment Search" or "Assignment Center" tool on the USPTO website.

Here's the recorded assignment timeline for US Patent 8537757 based on the provided data within Google Patents:

• 2012-11-27 (executed) / recorded 2012-11-27 — Reel 029706/0064
  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: ENSEMBLE COMMUNICATIONS, INC.
  • Assignee: WI-LAN, INC.
  • Correspondent: BAKER & MCKENZIE LLP, 2001 ROSS AVENUE, SUITE 2300, DALLAS, TEXAS 75201.
  • Context: Transfer from original applicant (likely a predecessor-in-interest to WiLAN Inc.) to Wi-LAN, INC.
• 2017-06-13 (executed) / recorded 2017-06-13 — Reel 039401/0879
  • Conveyance: MERGER AND CHANGE OF NAME
  • Assignor: QUARTERHILL INC., WI-LAN INC.
  • Assignee: QUARTERHILL INC.
  • Correspondent: DARRYL G. WALKER, 207 BANK STREET, SUITE 101, OTTAWA, ONTARIO K2P 2N2, CANADA. This correspondent recurs on the next entry for this patent.
  • Context: Internal corporate restructuring where Wi-LAN Inc. merged and changed its name to Quarterhill Inc.
• 2017-06-14 (executed) / recorded 2017-06-14 — Reel 039401/0885
  • Conveyance: ASSIGNMENT OF ASSIGNORS INTEREST
  • Assignor: QUARTERHILL INC.
  • Assignee: WI-LAN INC.
  • Correspondent: DARRYL G. WALKER, 207 BANK STREET, SUITE 101, OTTAWA, ONTARIO K2P 2N2, CANADA. This correspondent recurs on the previous entry for this patent.
  • Context: Re-assignment back to WI-LAN INC. (likely a subsidiary of Quarterhill Inc.) after the merger/name change.

Timeline diagram

timeline
    title Ownership of US 8537757
    2012 : Assigned to Wi-LAN Inc
    2013 : Patent granted
    2017 : Merger Quarterhill Inc
         : Reassigned to Wi-LAN Inc
    2021 : Anticipated expiration

NPE / troll-pattern signals

1. Shell-entity transfer — not present. The assignees are Wi-LAN, Inc. and Quarterhill Inc., both public companies known for patent licensing. The initial assignor, Ensemble Communications, Inc., was an operating company that developed wireless communication systems.
2. Known asserter in the chain — present. Wi-LAN, Inc. is a well-known patent licensing company frequently listed as a high-frequency plaintiff or NPE by entities like Unified Patents and RPX. [cite: The provided patent text includes litigation links from Google Patents, which lead to Unified Patents data. The Unified Patents links for US8537757 show cases filed in "California Southern District Court" and "California Northern District Court", and "Court of Appeals for the Federal Circuit".]
3. Repeat correspondent across the chain — present. Darryl G. Walker of 207 BANK STREET, SUITE 101, OTTAWA, ONTARIO K2P 2N2, CANADA, served as the correspondent for both the 2017-06-13 (Reel 039401/0879) and 2017-06-14 (Reel 039401/0885) conveyances. This indicates a consistent legal representative during the internal corporate events related to Quarterhill Inc. and Wi-LAN Inc.
4. Cascading transfers — present. Two consecutive assignments (a merger/change of name followed by an assignment of interest) occurred within a single day in June 2017 (2017-06-13 and 2017-06-14, both on Reel 039401). While not necessarily to unrelated shell LLCs, it indicates rapid internal restructuring of ownership.
5. Pre-litigation transfer — unclear. The initial assignment to Wi-LAN, Inc. was in 2012-11-27. The earliest litigation noted for this patent is in 2014, which is outside the 6-month window from the assignment date. However, the precise filing dates of the various lawsuits in California courts (e.g., 3:14-cv-02235) are not provided to confirm if any assignment occurred directly preceding them.
6. Bankruptcy fire-sale — not present. There is no indication in the provided information that Ensemble Communications, Inc. (the initial assignor to Wi-LAN, Inc.) underwent bankruptcy.
7. Privateering — unclear. While Wi-LAN, Inc. is a licensing entity, the context of the initial transfer from Ensemble Communications, Inc. does not explicitly detail a privateering arrangement. Further investigation of SEC filings or specific litigation documents would be needed.
8. Defensive aggregator (anti-NPE) — not present. The chain ends with WI-LAN INC., which is a known NPE/patent licensing entity, not a defensive aggregator.

Verdict

NPE — high confidence

This verdict is based on multiple strong signals. Wi-LAN Inc. is a known patent licensing entity, identified as an NPE, and appears as the assignee in the primary transfer (Reel 029706/0064 on 2012-11-27) and the ultimate assignee in the chain (Reel 039401/0885 on 2017-06-14). Additionally, there are cascading transfers (Reel 039401/0879 and 039401/0885 on 2017-06-13 and 2017-06-14, respectively) within Wi-LAN Inc.'s corporate structure, and a repeat correspondent (Darryl G. Walker) for these transfers, which are common patterns associated with NPE activity.

USPTO Assignment Center Search

US patent 8537757, titled "Adaptive call admission control for use in a wireless communication system," details methods and systems for managing connections in a wireless communication environment where physical layer (PHY) modes are adaptive. The patent's priority date is December 27, 2000.

Based on the provided authoritative patent text for US8537757, the most relevant prior art explicitly cited and incorporated by reference in the Detailed Description is U.S. Pat. No. 6,016,311.

Most Relevant Prior Art for US8537757:

1. U.S. Pat. No. 6,016,311

• Full Citation: U.S. Pat. No. 6,016,311, by Gilbert et al., issued Jan. 18, 2000, entitled “Adaptive Time Division Duplexing Method and Apparatus for Dynamic Bandwidth Allocation within a Wireless Communication System.”

• Publication/Filing Date: Issued January 18, 2000. This date is prior to the priority date of US8537757 (December 27, 2000), confirming its status as potential prior art under 35 U.S.C. § 102.

• Brief Description: This patent describes an exemplary broadband wireless communication system that utilizes an adaptive Time Division Duplexing (TDD) method and apparatus for dynamic bandwidth allocation. Its core focus is on the flexible assignment of bandwidth within a wireless communication system using TDD.

• Potential Anticipation Under 35 U.S.C. § 102:
  The independent claims of US8537757 (Claims 1, 7, 14, and 15) introduce specific concepts not explicitly disclosed by the title and brief description of U.S. Pat. No. 6,016,311. These include:

  • Adaptive PHY modes for robustness: While US6016311's title mentions "Adaptive Time Division Duplexing" and "Dynamic Bandwidth Allocation," it does not explicitly detail the mechanism of "adapting their PHY mode" to increase or decrease the robustness of a transmission modulation technique as described in US8537757.
  • "Planned PHY mode" and "Current PHY mode": US8537757's claims critically rely on the distinction and comparison of "planned PHY modes" (for initial admission decisions) and "current PHY modes" (for real-time resource allocation and suspension decisions). This conceptual framework is not apparent from the description of US6016311.
  • "Reference PHY mode" for normalization: US8537757's claims specify comparing bandwidth commitments against a "total air link line rate" based on a "reference PHY mode" to normalize different PHY mode efficiencies. This normalization step is a specific technical detail central to US8537757's inventive solution.
  • Call Admission Control (CAC) module logic: The precise logic of the CAC module in US8537757, which compares "total air link line rate" (based on a reference PHY mode) with "bandwidth commitment value" (based on planned PHY modes) for new connection admission, is not explicitly disclosed in the description of US6016311.
  • Precedence module for connection suspension: The "precedence module" functionality in US8537757, which determines which existing connections to suspend based on "current PHY modes" when bandwidth is insufficient, is a specific mechanism not described by US6016311.

  Therefore, while U.S. Pat. No. 6,016,311 provides a foundational understanding of adaptive bandwidth allocation in TDD wireless systems, its disclosed subject matter (based on its title and the brief description provided in US8537757) does not appear to explicitly disclose every element of US8537757's independent claims (Claims 1, 7, 14, 15), particularly concerning the specific multi-layered decision-making process involving planned, current, and reference PHY modes for both connection admission and suspension. Thus, it is unlikely to fully anticipate these claims under 35 U.S.C. § 102. It would, however, be highly relevant for an obviousness analysis under 35 U.S.C. § 103, potentially in combination with other references that might address the more specific features.

Under 35 U.S.C. § 103, an invention is obvious if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains.

Based on the provided patent text for US8537757, the explicit prior art references are limited. The patent itself mentions one specific prior art document and several generally known concepts within the wireless communication field.

Identified Prior Art References:

1. U.S. Pat. No. 6,016,311 by Gilbert et al. ("Gilbert"): Entitled "Adaptive Time Division Duplexing Method and Apparatus for Dynamic Bandwidth Allocation within a Wireless Communication System," this patent describes a broadband wireless communication system with adaptive TDD and dynamic bandwidth allocation.
2. Known Wireless Communication Systems: The background of US8537757 describes existing wireless communication systems such as mobile cellular telephone systems, personal communication systems (PCS), and cordless telephones, which facilitate two-way communication between subscriber units (CPEs) and a fixed network infrastructure, often providing communication channels on demand. These systems typically use time division duplexing (TDD) or frequency division duplexing (FDD).
3. Known Adaptive Modulation and Forward Error Correction (FEC) Schemes (Adaptive PHY Modes): US8537757 explicitly states that "The base station and CPEs can use adaptive modulation and forward error correction (FEC) schemes to communicate." It further defines "PHY mode" as indicating characteristics like modulation scheme and/or FEC, and notes that "the communication system 100 can dynamically adjust or 'adapt' the PHY mode for each base station 102 and CPE 104." This indicates that the concept and implementation of adaptive PHY modes were known capabilities in wireless systems.
4. Known Call Admission Control (CAC) Mechanisms: US8537757 introduces its own "call admission control (CAC) module 206" which "determines what CPE to base station connections are allowed at any given time" based on intrinsic factors (e.g., quality/type of service requested) and extrinsic factors (e.g., available bandwidth). This implies that general CAC functionality for managing connections in communication systems was a known concept prior to the described invention.

Claims of US8537757 (as described in the Abstract and Summary):

The invention in US8537757 relates to an adaptive call admission control (CAC) system and method in a wireless communication system where base stations and customer premise equipments (CPEs) adapt their PHY modes. Key aspects include:

• Controlling admission of new connections and suspension of existing connections.
• Determining whether to allow a new connection based on comparing a total air link line rate (derived from a reference PHY mode) with a bandwidth commitment value (based on planned PHY modes).
• If the new connection is accepted, a second determination is made based on current PHY modes.
• If additional air link resources are not available, suspending at least one existing connection.
• The system includes a CAC module (206) and a precedence module (210) for suspending connections, potentially using various techniques such as suspending connections through the affected CPE, random selection, round-robin, or applying priority levels.
• Normalization of bandwidth commitments is performed to compare connections at different PHY modes, using a selected reference PHY mode (e.g., QAM-64 or QAM-4).

Obviousness Analysis and Motivation to Combine:

A person having ordinary skill in the art (PHOSITA) in wireless communication systems, at the priority date of December 27, 2000, would have found the claimed subject matter of US8537757 obvious by combining the identified prior art references and known concepts.

Combination: Known Wireless Communication Systems (Reference 2) + Known Adaptive Modulation/FEC (Reference 3) + Known Call Admission Control (Reference 4) + Gilbert et al. (US 6,016,311) (Reference 1).

Motivation for Combination:

1. Integrating CAC with Adaptive PHY Modes in Wireless Systems: A PHOSITA would be familiar with the fundamentals of wireless communication systems (Reference 2) and the inherent challenge of managing limited spectrum resources. The known use of adaptive modulation and FEC (Reference 3), resulting in adaptive PHY modes, provided a way to optimize spectral efficiency and link robustness under varying channel conditions (e.g., weather, distance). However, this adaptiveness introduces variability in the bandwidth required for each connection. Therefore, a PHOSITA would be motivated to integrate existing Call Admission Control (CAC) mechanisms (Reference 4), typically used to manage fixed bandwidth allocations, with systems employing adaptive PHY modes to ensure quality of service (QoS) and prevent network overload in a dynamically changing environment. The problem of how to effectively perform CAC when individual connection bandwidths are no longer fixed but adapt based on PHY modes would be a clear challenge for a PHOSITA.

2. Leveraging Dynamic Bandwidth Allocation: Gilbert et al. (Reference 1) teaches "Dynamic Bandwidth Allocation" within "Adaptive Time Division Duplexing" systems. This reference provides concrete techniques for managing fluctuating bandwidth resources in a wireless context. A PHOSITA seeking to implement an effective CAC in a system with adaptive PHY modes would naturally consider and apply known dynamic bandwidth allocation strategies, such as those described by Gilbert et al., to handle the variable bandwidth requirements stemming from adaptive PHY mode operation. The goal would be to efficiently allocate and reclaim bandwidth as link conditions and PHY modes change.

3. Refining CAC for Enhanced Resource Utilization and QoS in Adaptive Systems: US8537757 itself highlights a problem with simpler CAC approaches in adaptive PHY mode systems: "the communication system 100 is constrained from taking advantage of the freed up bandwidth when the decision to allow new connections is based upon the minimum air link line rate." This demonstrates a recognized inefficiency that a PHOSITA would be motivated to overcome.

   • Planned vs. Current PHY Modes: To address this, a PHOSITA would find it obvious to refine CAC by considering both a "planned" (e.g., baseline) PHY mode for initial connection acceptance, and a "current" (e.g., real-time) PHY mode for actual resource allocation and ongoing management. This allows for a more flexible and efficient use of bandwidth by permitting initial connections based on a reasonable expectation (planned PHY mode) while dynamically adjusting resources based on actual link conditions (current PHY mode).
   • Normalization: The need to compare bandwidth commitments and available air link rates when different connections operate at different PHY modes would lead a PHOSITA to employ a normalization technique (as described by Equations 1 and 2 in US8537757) against a common "reference PHY mode." This is a standard engineering practice to establish a common basis for resource comparison.
   • Connection Suspension and Precedence: When the aggregate bandwidth demand of existing connections (operating at their current PHY modes) exceeds available resources, especially during adverse conditions, a PHOSITA would find it obvious to implement a mechanism to "suspend" lower-priority connections to maintain critical services. Implementing "precedence" rules (e.g., prioritizing connections, suspending connections from affected CPEs, random, or round-robin methods as detailed in US8537757) to determine which connections to suspend is a common and logical network management strategy for managing resource contention and ensuring QoS.

Therefore, the claimed adaptive CAC for systems with adaptive PHY modes, including the use of planned and current PHY modes, normalization, and precedence-based suspension, represents a logical and obvious evolution of known CAC principles (Reference 4) applied to dynamic bandwidth allocation systems (Reference 1) within the context of adaptive PHY mode wireless communication (References 2 and 3), motivated by the desire to enhance efficiency and maintain QoS in dynamic wireless environments.