## Facts

- A wireless-network patent (U.S. Patent No. 7,756,129) was originally owned by Azure Networks, LLC.
- Azure transferred the patent to Tri–County Excelsior Foundation, then obtained an exclusive license.
- The license gave Azure exclusive rights to practice the patent, sublicense, and control enforcement and litigation (including settlement), subject to notice/cooperation obligations.
- Tri–County retained legal title, a share of proceeds from enforcement/licensing, and certain residual/reversionary interests.
- Azure and Tri–County sued multiple semiconductor and wireless-device companies for infringement in the Eastern District of Texas.
- The district court (1) dismissed Tri–County for lack of standing, finding the license an effective assignment to Azure, and (2) construed “MAC address” as “a device identifier generated by the hub device.”
- After the claim construction ruling, Azure stipulated to noninfringement to allow appellate review.

## Issues

1. Whether the exclusive license transferred “all substantial rights” such that Tri–County lacked standing to sue as a co-plaintiff.
2. Whether “MAC address” should be construed narrowly as hub-generated, or according to its ordinary technical meaning as a unique device/network-interface identifier.
3. Whether the stipulated judgment of noninfringement should be vacated if the claim construction was erroneous.

## Decision

- Affirmed dismissal of Tri–County: the license was an effective assignment for standing purposes because Azure received all substantial rights.
- Reversed the district court’s construction of “MAC address,” holding the term was improperly limited by importing an embodiment-based restriction.
- Vacated the stipulated judgment of noninfringement and remanded for further proceedings under the corrected construction.

## Legal Principles

- Whether a patent agreement transfers “all substantial rights” is a practical, substance-focused inquiry; a transaction labeled as a “license” can be treated as an assignment for standing.
- When the licensee holds exclusive rights to practice, to enforce, to license/sublicense, and to control litigation and patent maintenance, the licensee may be the effective patentee with standing to sue alone; retention of bare legal title and a revenue share may be insufficient to preserve the licensor’s standing.
- Claim terms generally receive their ordinary and customary meaning, including ordinary technical meaning, unless the intrinsic record clearly redefines the term or shows a clear disclaimer.
- Courts may not limit generally worded claims by importing features from disclosed embodiments absent clear intent to confine the claims.

## Conclusion

The Federal Circuit held that Tri–County could not remain a plaintiff because its agreement transferred all substantial rights to Azure, but it corrected an overly narrow claim construction of “MAC address,” requiring vacatur of the noninfringement judgment and remand.


Azure Networks, LLC v. CSR PLC, 771 F.3d 1336 (Fed. Cir. 2014)