Modulus Systems LLC v. Coobuy Ltd

Case Overview and Background

This patent infringement lawsuit represents a recent campaign by a non-practicing entity (NPE), Modulus Systems LLC, against technology companies. Filed on April 22, 2026, the case targets Coobuy Ltd, an e-commerce company that sells a variety of consumer electronics and other goods. Public information suggests Coobuy Limited may be associated with a network of online retail sites. Modulus Systems is a frequent filer of patent lawsuits and appears to be a patent assertion entity, a firm whose primary business is licensing and litigating patents rather than producing goods or services. This case is one of several similar lawsuits Modulus Systems filed on the same day against different defendants, all asserting the same patent, indicating a coordinated litigation campaign.

The dispute centers on U.S. Patent No. 8,610,573, titled "Radio frequency module and methods of transmitting/receiving data." The patent generally describes a compact radio frequency (RF) module with a specific physical component layout, such as a "generally U-shape," designed to optimize performance and reduce size for wireless communication in the crowded 2.4 GHz band. Modulus Systems alleges that Coobuy's radio frequency modules, which are used to wirelessly transmit and receive data in its electronic products, infringe upon this patent. The complaint in a parallel case suggests the accused products are not named specifically but are identified as "radio frequency module products."

The case's venue and judge are highly significant in the landscape of U.S. patent litigation. The lawsuit was filed in the U.S. District Court for the Eastern District of Texas (EDTX), a forum that has consistently ranked as the top or one of the top districts for patent litigation, especially for cases brought by NPEs. The case has been assigned to Chief Judge Rodney Gilstrap, who is widely recognized as the busiest and most experienced patent judge in the United States, presiding over a substantial percentage of all patent cases filed nationwide. His experience and the district's specific rules and procedures for patent cases make this a closely watched forum for patent holders looking to assert their rights. The combination of a prolific NPE plaintiff, a popular patent venue, and the nation's leading patent judge makes this case a classic example of modern patent assertion trends.

Key Legal Developments and Case Status

As of May 1, 2026, the patent infringement litigation between Modulus Systems LLC and Coobuy Ltd is in its nascent stage. Filed only nine days prior, on April 22, 2026, the case has seen no significant legal developments beyond the initial complaint. The docket for case number 2:26-cv-00328 in the Eastern District of Texas confirms the filing and assignment to Chief Judge Rodney Gilstrap. There is no public record of the defendant, Coobuy Ltd, having been formally served or having filed a response.

Given the recent filing, key legal milestones such as the defendant's answer, any initial motions, or a scheduling conference have not yet occurred.

Filing & Initial Pleadings

• 2026-04-22: Complaint Filed
  Modulus Systems LLC filed a complaint for patent infringement against Coobuy Ltd, asserting U.S. Patent No. 8,610,573. The case was assigned to Judge Rodney Gilstrap.

• Upcoming: Answer or Responsive Pleading
  Coobuy Ltd's answer, or any initial motion in response to the complaint (such as a motion to dismiss), has not yet been filed. The deadline for this response will depend on the date of formal service of the complaint.

Pre-trial Motions, Claim Construction, and Discovery

There have been no substantive motions, claim construction proceedings, or discovery events to date. Based on the local patent rules for the Eastern District of Texas, the following events are anticipated in the coming months:

• Initial Case Management Conference: The court will likely schedule an initial conference in the near future, after the defendant has appeared in the case.
• Infringement and Invalidity Contentions: Following the court's scheduling order, both parties will be required to serve detailed contentions. Per local patent rules, Modulus Systems will serve its infringement contentions outlining its infringement theories. Coobuy will then have a set period (typically 45 days) to serve its invalidity contentions, detailing the basis for its defense.
• Claim Construction (Markman Hearing): After the exchange of contentions, the parties will engage in the claim construction process, which will culminate in a Markman hearing where Judge Gilstrap will determine the legal meaning of disputed patent claim terms.

Trial, Outcome, and Parallel Proceedings

The case is far from trial, and no outcome has been reached. A web search of the U.S. Patent and Trademark Office's Patent Trial and Appeal Board (PTAB) database shows no Inter Partes Review (IPR) or other post-grant proceedings filed against U.S. Patent No. 8,610,573 by Coobuy Ltd or any other party as of this date.

The case status is currently Open. Future developments will depend on Coobuy Ltd's response to the complaint and the progression through the district's established patent litigation timeline.

Plaintiff's Counsel of Record

As the case was recently filed, only the attorney who submitted the complaint has formally appeared on behalf of the plaintiff, Modulus Systems LLC. Analysis of the dockets in parallel cases filed by Modulus Systems on the same day confirms the identity of plaintiff's counsel.

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Isaac Phillip Rabicoff

• Role: Lead Counsel
• Firm: Rabicoff Law LLC (Chicago, IL)
• Experience Note: A prolific patent litigator who founded his own firm, which has led licensing and litigation campaigns against major technology companies including Amazon, Apple, and Google.

Defendant's Counsel of Record

As of May 1, 2026, counsel for the defendant, Coobuy Ltd, has not yet filed a notice of appearance in this case.

The case was filed on April 22, 2026, and court dockets show no responsive pleadings, motions, or attorney appearances on behalf of Coobuy Ltd. This is typical for a case that is less than two weeks old, as the defendant may not have been formally served with the complaint or is still in the process of retaining legal counsel. Consequently, no attorneys are yet on record for the defense.