Innovation does not happen in isolation; it is a battleground where ideas clash, rivalries ignite, and ownership defines the future. Behind the technologies we rely on every day lie stories of groundbreaking inventions entangled in fierce legal disputes. Patents have driven progress, and sometimes stalled it. Welcome to Patent Feuds™. In this series, we uncover the rivalries that transformed industries, the inventions that triggered legal wars, and the lasting impact of Intellectual Property on the world. Get ready to explore the drama, the ambition, and the ideas that shaped modern history.
Imagine you’re flying at 35,000 feet.
Your aircraft is not talking to just one system on the ground. It’s constantly exchanging data flight routes, operational messages, and system updates through multiple communication channels: satellites, ground stations, and short-range radios.
Now imagine that an entire patent protecting this smart communication logic collapses… because of one missing comma.
That is exactly what happened to Boeing.
The Invention: How Aircraft Choose the “Best” Communication Network
At the heart of this dispute lies European Patent EP1798872, filed by Boeing in 2006 and granted in 2011.
The invention addressed a very practical aviation problem:
Aircraft have access to multiple communication networks, but not all of them are always available. So how does the aircraft decide which network to use at any given moment?
The Core Idea
Boeing proposed a preference-based communication system, where:
- Multiple networks are available (satellite, ground-based, short-range, etc.)
- A preference list ranks these networks
- The system automatically selects the highest-priority network that is currently available
Inside the Aircraft’s Smart Communication System
Understanding the Technology (With the Figures)
Figure 1 shows the overall communication environment:
- An aircraft (10) in flight
- Communicating with
- Satellites (14, 16)
- Ground stations (12, 18)
- Ground-based computers (17, 19)
The zig-zag arrows represent data transmission paths, highlighting that:
- Multiple networks exist simultaneously
- Availability can change dynamically
- The aircraft must constantly decide which path to use
This is where Boeing’s invention steps in.
Figure 2 – Inside the System
Figure 2 illustrates the internal technical architecture of the communication system, showing both the onboard computer (30) located within the aircraft and the ground-based computer (54) positioned on the ground. Each of these systems includes a processor, memory, an operating system, and a communications module, along with configuration data that stores preference lists, priority values, and network availability information. These preference lists define the order in which communication networks are selected, indicating which network is preferred first, which comes next, and so on. When the availability of any network changes, the system automatically re-evaluates the preference list, identifies the highest-priority network that is currently available, and seamlessly switches communication to that network. The result is a system that is elegant in design, efficient in operation, and at least on paper entirely patent-worthy.
Airbus Steps In: The Opposition That Changed Everything
Airbus, Boeing’s long-standing competitor, opposed Boeing’s patent by filing an opposition before the European Patent Office, arguing that the claims were unclear and not properly supported by the patent description. Rather than challenging the underlying technology, Airbus focused on weaknesses in the claim wording. This strategic opposition led to closer legal scrutiny and ultimately played a key role in the patent being revoked.
The Comma That Changed the Meaning of the Claim
The dispute ultimately centred on the wording of Claim 1 of Boeing’s European patent. A critical portion of the claim stated:
“Evaluating a preference to determine a preferred network of the plurality of transmission networks, wherein the preference comprises a preference list identifying a selection of the plurality of broadcast networks in order of preference and identifying the highest in preference of the plurality of broadcast networks in the preference list that is available.”
At first glance, the sentence appears clear. However, a closer look reveals a subtle drafting issue. While a comma appears after the phrase “plurality of transmission networks”, there is no comma separating the two “identifying” actions that follow the word preference.
Because of this missing punctuation, both identifying actions were read together. As a result, the claim was interpreted to mean that the preference list itself had to both rank the networks and determine which network was the highest-priority option that was currently available. This interpretation significantly narrowed the scope of the claim.
The problem for Boeing was that this combined requirement was not clearly supported by the patent’s description or figures. The application did not sufficiently explain a preference list performing both of these functions in the way the claim wording suggested.
Revocation, Appeal, and the Appeal Board’s Strict View
Following this interpretation, the patent was revoked. Boeing appealed the decision, arguing that the claims should be read in a reasonable and technically informed manner. Boeing maintained that the description and drawings should be consulted to understand the intended meaning of the claim language, relying on the principle that a patent should be read with “a mind willing to understand.”
The Appeal Board, however, disagreed. It held that referring to the description is not an automatic solution when a claim is unclear. If a claim allows more than one plausible interpretation due to ambiguous wording, the claim must be assessed on its own terms.
In this case, the absence of a clarifying comma caused the features to be read together, and the patent application did not provide adequate support for that interpretation. As a result, the claim was found to lack clarity and technical consistency, and the revocation of the patent was upheld.
Where the Comma Should Have Been?
The problem was not the technology, was the sentence structure.
In the claim, two separate actions were written without a separating comma. This made it appear that the preference list itself had to perform both tasks: ranking the networks and deciding which one was currently available.
If a comma had been placed before “and identifying the highest…”, the meaning would have been clear. The claim would have shown that the list only ranks the networks, while the system independently selects the highest-priority available network.
Without that comma, both actions were read as a single requirement, and that interpretation was not supported by the patent description.
Why This Case Still Matters
For Boeing, the consequences were immediate and significant. Once the patent was revoked, the invention entered the public domain, meaning competitors were free to implement similar communication systems without restriction. A strategically important technology that could have provided a long-term competitive advantage lost its exclusivity.
For the wider patent community, the case became a classic reminder of how critical claim drafting is. It is frequently cited in EPO practice and patent training to show how even small drafting errors, like a misplaced comma, can decide the fate of an otherwise valuable patent.
Final Lesson for Inventors & Patent Professionals
This case makes one lesson unmistakably clear: innovation may be explained in the description, but it is protected only through the claims. Even the most advanced technology, supported by strong figures and sound engineering, can lose protection if the claim language is not precise. A small drafting slip, sometimes as small as a comma, can undo years of innovation.
The takeaway is simple and practical: careful claim drafting is not a formality; it is a strategy. In the world of patents, every word matters and sometimes, one comma decides everything.
R K Dewan & Co. stands among the best IP law firms in India, trusted for over 83 years of excellence. We help startups, businesses, and global corporations protect patents, trademarks, copyrights, and designs with ease. With 6,000+ clients worldwide, our team delivers end-to-end IP filing, prosecution, enforcement, and litigation services in India and abroad. From strategy to courtroom representation, we safeguard your innovations at every step.