Federal Circuit Dismisses Challenge to Mobile Phone Patent

January 30, 2012

Andrew (A.J.) Tibbetts

What This Means To You

  • There is a risk of invalidity of a patent claim when the claim specifies both method steps and structural components.
  • In litigation, when challenging the “means-plus-function” limitation of a claim covering a programmed processor or computer, be sure to challenge the both description of the hardware and software corresponding to the limitation.


In one of the first decisions of the global mobile phone patent battles to reach a U.S. appellate court, the US Court of Appeals for the Federal Circuit (Federal Circuit) rejected a patent challenge that was based on legal technicalities.

The claim at issue in HTC Corporation v. IPCom GmbH & Co. was written in an unusual way, and a district court judge ended the case based on the technicalities. The Federal Circuit reversed, holding that the district court misconstrued the language of the claims, and permitted the trial to proceed.

Case Background

The case involved a dispute over mobile phone “handoff” technology, which covers a way to maintain service as a mobile phone moves from one cell tower to another. The invention was a new way of reducing the chance of interrupted service during handoff and covered a mobile phone able to carry out a part of the new handoff.

In addition to the structural components of the phone, the claim at issue listed method steps carried out by the cell towers and by the phone during the handoff negotiation. Because the claim included both structural limitations and method steps, the claim might have been construed as a “hybrid” claim.

Hybrid claims are considered to be invalid for being impermissibly indefinite, although the determination of whether a claim is a hybrid rests only on the body of the claim, rather than the claim’s preamble. Claim language in the preamble of a claim may not be a limitation of the claim, but may merely define an environment necessary for infringing the claim, and would not be interpreted in determining whether the claims limitations define a hybrid claim.

This was the first legal technicality involved in the decision. The second legal technicality surrounded the sufficiency of the patentee’s description in the text of the patent of the recited structural component of the phone, which the patentee labeled an “arrangement” for carrying out the handoff.

Decision Analysis

The district court in this case had decided the claim was an impermissible hybrid claim. In reviewing this decision, the Federal Circuit was tasked with determining whether the method steps recited in the claim were merely a part of the preamble or a part of the body of the claim.

Based on a review of the grammatical structure of the claim and the patent text, the court concluded the claim’s method steps were merely preamble language defining the environment and were not limitations recited by the body of the claim. The court, therefore, concluded the claim was not a “hybrid” claim.

The Federal Circuit was next tasked with determining whether the patent text sufficiently described the mobile phone component that the patentee had termed an “arrangement” in the claim. Non-structural terms like “arrangement” can be used in a claim in place of a structural term, but are interpreted as only covering the structure described in the patent text that corresponds to the non-structural term. Therefore, a sufficient description in the patent text of the corresponding structure is necessary for a limitation using this “means-plus-function” format. In the case of hardware processors programmed to execute software, the patent text must set out not only the hardware, but also the specifics of the algorithm the software implements.

In this case, the defendant argued in the district court that the claim was invalid because the text did not include a sufficient description. However, the defendant focused only on the hardware, neglecting to challenge the sufficiency of description of the software. The Federal Circuit concluded that, since the patent text described a mobile phone and a person of ordinary skill in the art would understand that a mobile phone includes a processor and transceiver, the necessary hardware for the “arrangement” was sufficiently described in the patent text.

The Federal Circuit then explicitly declined to consider the sufficiency of the description of the software/algorithm, as the defendant had failed to argue that point.

Based on its holding, the Federal Circuit sent the case back to the district court for trial.


This decision provides some clarity to the law surrounding claims that recite both method steps and structural components. Based on this decision, a valid claim that includes both might be drafted. However, to avoid the potential for litigation over mere technicalities, it is best to ensure a claim is clearly directed to a method or a structure, and includes only one type of limitation.

Additionally, the decision highlights the importance of making all available arguments when given the chance. Here, the defendants refused to challenge the sufficiency of description of the software even when expressly invited to do so by the district court, because the defendants were certain that the description of the hardware was insufficient. When the Federal Circuit disagreed with the defendants and upheld the description of the hardware, the defendants did not have another argument regarding the software to fall back on.