Insights When 10 seconds can make all the difference: High Court declares European telecoms patent invalid and not infringed by Facebook’s live broadcast feature



Voxer IP LLC, owns a European Patent (UK) entitled “Telecommunication and multimedia management method and apparatus”. In May 2020, Facebook Ireland Ltd issued proceedings against Voxer for, inter alia, revocation of the patent, alleging invalidity for lack of novelty and/or for obviousness over two items of prior art.

Voxer counterclaimed for infringement of the patent by the live broadcast feature offered to users via the Facebook website and through the Facebook and Instagram Apps as they operate on iOS devices (i.e. devices sold by Apple). Voxer argued infringement on, inter alia, a normal construction of the relevant claims and on the basis of the doctrine of equivalents.

On equivalents, in addition to its denial, Facebook contended that it had a Formstein defence.

The patent

Voxer made an unconditional application to amend the claims, and it is useful to set out here the amended claim 1, on which the case focuses:

1a      A media communication method,

1b      which supports a live communication mode

1c      and at least one time-shifted communication mode,

1d     for communicating both voice and video media

1e      on a first communication device (13)

1f      over a communication network (14),


1g      progressively encoding, progressively and persistently storing on the first communication device (13) and progressively transmitting media of an outgoing message originated on the first communication device over the communication network, as the media is created; and

1h      progressively receiving, progressively and persistently storing on the first communication device (13) and progressively rendering media of an incoming message received over the communication network at the first communication device as the media is progressively received in a real-time rendering mode,

1i       wherein the outgoing message and the incoming message are asynchronous messages (such that the media of an incoming message may be time-shifted with respect to the media of the outgoing message)

1j       that are transmitted over the communication network from the first communication device to the second communication device and received over the communication network at the first communication device from the second communication device without first establishing a connection over the communication network between the first communication device and the second communication device

1k      and wherein the outgoing message and the incoming message are stored and transmitted at each hop along a path over the communication network.

The patent claims that the invention enables two modes of conversation: (i) a live mode; and (ii) a time-shifted mode. The user can transition between the two modes, thereby participating in multiple conversations and archive the messages. In particular, according to the patent, users can conduct communications in either: (i) a near-synchronous or “live” conversation, providing a user experience similar to a standard full duplex phone call; or (ii) in a series of back and forth time-delayed transmissions (i.e. time-shifted mode). Two individuals using the system can therefore send recorded voice messages back and forth to each other and review the messages when convenient, or the messages can be sent at a rate where they essentially merge into a live, synchronous voice conversation. The invention therefore enables a conversation that consists of a series of discrete recorded messages stored not only in the sender and receiver’s device but in the servers on multiple transmission hops across the network.


The patent

Construing the patent, Lord Justice Birss considered, amongst other things, the distinction between the ‘live communication mode” and the “time-shifted communication mode” as stated in cclaim 1, and exactly how much delay would still be within the ambit of a live communication mode. In his view, the distinction between the live mode and the time-shifted mode was simply a matter of the degree of time shifting. “Nearly live” would still be within the live mode, but appreciable time shifting, whatever its cause, would take the conversation into the other mode. The claimed method required the system to be capable of doing both. Therefore, if there was a significant delay from the point of view of the experience of the participants that would be the time shifted mode, not the live mode.

Birss LJ noted that the word “conversation” did not appear in claim 1. However, he understood Voxer to accept that the claimed invention was all about a method of carrying out conversations, as that was how it framed its own understanding. For example, Voxer said: “Rather than thinking of a conversation as a single synchronous event, the Patentee recognises that a conversation can be considered as being made up of a series of asynchronous messages between pairs of participants”.

In any event, in Birss LJ’s judgment, the two modes referred to in claim 1 would be understood to be modes of carrying on a conversation. The fact that the word used was in fact “communication” did not mean that the patentee would be understood as to be trying to encompass a mode of communication that was not part of a conversation.

Facebook’s live broadcast feature allows a user to broadcast a live video stream to others, either publicly or to friends/followers. This is different from posting a pre-recorded video clip. The receiving user can then click on a link to the live broadcast and the video data will be sent from the Facebook network to the viewer’s device.

When the broadcast is finished the broadcasting user can choose to “delete”, “share” or “save” the video data. Sharing the video makes the video available via a link on the user’s timeline as a “was live” video, which in effect amounts to a post of the video.

For various reasons there is a transmission delay of about ten seconds between the broadcaster broadcasting the video and the viewer viewing it. Birss LJ found that this delay was sufficiently large that the methods alleged to infringe did not support a “live communication mode”, as stated in claim 1 of the patent. The experience of a minimum of ten seconds between broadcast and receipt was too great a delay to call it “live”.

In fact, if two parties were communicating using this method, the round trip delay was 20 seconds, which made it even clearer that this was not a method that supported a live mode for having a conversation.

As for storage, claim 1 described “persistent storage” and stated that both the outgoing and incoming messages are stored and transmitted at “each hop” along a path over the communication network. Voxer contended that the Facebook networks consist of a distributed server system in which at least one copy of the message is stored (persistently) somewhere and that therefore, the claim is satisfied. Birss LJ rejected this, finding that, although Facebook has servers in its networks that have the capability for storage, they did not all do so. Therefore, there were hops at which the messages were not stored and the claim’s requirement for storage “at each hop” was not satisfied.

Accordingly, there was no infringement on a normal construction of the patent.


In case the matter went further, Birss LJ considered Facebook’s submission on equivalents.

Facebook argued that the requirement for “persistent storage” of the incoming message was not satisfied because the retrieval function in its live broadcast feature was supplemented by network storage.

Birss LJ was not convinced that the live broadcast feature, if it did not satisfy claim 1 in that respect, would infringe by the doctrine of equivalents. Considering the Actavis questions (Actavis v Eli Lilly [2017] UKSC 48), Birss LJ assumed in Voxer’s favour the second question (i.e. whether it would be obvious to the skilled person that the variant achieves substantially the same result in substantially the same way as the invention). Considering the first and third Actavis questions together, Birss LJ said that the skilled reader would understand that in order to allow time-shifting, some persistent storage of the message was necessary since otherwise, after it had been played, it would not be available to be time-shifted. There were only two places in which it could be stored: the local device or the network, which were both clearly described in the patent. The reader would understand the similarities and differences between them. If the reader focussed on the similarities then it could be said that it made no material difference where the data was stored, thereby answering “no” to the first Actavis question that, notwithstanding that it was not within the literal meaning of the claim the variant achieved substantially the same result in substantially the same way as the invention. However, that made it more significant that Voxer, who plainly knew that too, had positively chosen to claim only local and not network storage in claim 1, meaning that the answer to the third Actavis question, i.e. whether the skilled reader would conclude that Voxer intended strict compliance with the literal meaning of the claim as being an essential requirement of the patent, was “yes”.

Conversely, the reader might focus on the differences and conclude that it did make a material difference whether to store on the network or locally, since (for example) the network might not be available or there might be network delays. Again, the answer to the third Actavis question would be “yes”. Either way, the equivalents analysis was against Voxer and there was no infringement.

Formstein defence

Facebook also said that it had a Formstein defence to the case of equivalents. The Formstein defence comes from German case law. Although the UK courts have recognised it as a possible way forward, it has not actually yet been dealt with here. Essentially, it states that where an infringement is found as a result of the doctrine of equivalents, but such infringement is obvious over the prior art, then the patent should be held to its normal construction (as otherwise it would also be obvious and thus invalid).

Given the findings of no infringement, Birss LJ did not have to decide the matter. However, he said that if he did have to make a finding, he would hold that the right approach would indeed be the Formstein approach such that the conclusion, if the equivalent device lacked novelty or was obvious, was that the claim scope should be confined to its normal construction. In Birss LJ’s view, if the claim on its normal construction was valid, then it seemed harsh to invalidate it on this ground. Further, since it was clear that other EPC countries apply the defence, that was a reason in itself for this EPC state to take the same approach.


Finally, Birss LJ found that claim 1 and claim 5 were, in fact, obvious over one of the pieces of cited prior art. Accordingly, the patent was invalid. (Facebook Ireland Ltd v Voxer IP LLC [2021] EWHC 1377 (Pat) (26 May 2021) — to read the judgment in full, click here).