T 1054/05 (Information management/NEC) of 28.5.2008

Summary of Facts and Submissions

I. This appeal is against the decision of the examining division to refuse European patent application No. 00120751.3.

II. The following documents will be referred to:

D1: US-A-5 924 096

D8: WO-A-98/12650.

III. According to the decision appealed, the method of claim 15 and the system of claim 1 did not involve an inventive step with respect to D1.

IV. With the statement setting out the grounds of appeal, the appellant requested that the decision be set aside and a patent be granted on the basis of claims 1-26 filed with the same letter. It was argued in particular that the new independent claims were directed to a pushing model, meaning that updated information was actively distributed by a server. D1, on the other hand, related to a pulling model.

V. In a communication, the Board observed that independent method claim 14 was largely identical with claim 15 discussed in the decision under appeal, except for the trivial addition that the client device not only received an update but also used it. Therefore, the examining division's argumentation with respect to inventive step, which appeared convincing, still applied. Furthermore, document D8 indicated that the respective advantages of pulling and pushing were well understood.

VI. By letter dated 16 April 2008 the appellant filed an amended set of claims 1-24.

VII. Oral proceedings were held on 28 May 2008. The appellant filed a new independent method claim 13. This claim read:

"An information management method in a system comprising a plurality of network nodes connected to each other via a network, wherein the plurality of network nodes includes a server device and a plurality of client devices, and a gateway server device performing protocol conversion between the server device and each of the client devices, the server device storing a structured document which is a hierarchical set of components, which comprises a plurality of hierarchical subsets of components, and each of the client devices storing a duplication of the structured document, the method comprising:

at the server device,

a) managing an update of the structured document of a minimum subset of components, which is a hierarchical subset of components equal to a component immediately above an updated component in the structured document; and

b) transmitting to a client device a minimum subset of components determined by an updated component of the structured document; and

at a client device

receiving the minimum subset of components from the server device;

c) updating a corresponding subset of the duplication of the structured document stored therein, wherein the corresponding subset of components corresponds to the minimum subset of components received; and

at the gateway server device,

e) managing the structured document stored in each of the client devices;

f) receiving the minimum subset of components from the server device; and

g) transmitting the minimum subset of components received from the server device to a client device".

The remaining claims were not modified but the appellant announced that he would adapt them along the lines of claim 13 if the Board held this claim to be acceptable.

VIII. The appellant requested that the decision under appeal be set aside and a patent be granted on the basis of amended claim 13 as filed during the oral proceedings and claims 1-12 and 14-24 as filed with the letter dated 16 April 2008.

IX. At the end of the oral proceedings the Board announced its decision.

Reasons for the Decision

1. Construction of claim 13

The appellant explained at the oral proceedings before the Board that claim 13 should be interpreted as referring to a pushing model, meaning that the server initiates the update transmissions to the client devices (cf paragraph [0134] of the description). Furthermore, feature e), which stated that the gateway was "managing" the structured document stored in each of the client devices, should be understood as implying not only that there was a protocol conversion but also that the gateway kept a record of all client devices having a copy of the document to be updated (cf paragraph [0070] of the description).

For the purposes of the present decision, the Board will interpret the above claim features in the way suggested by the appellant.

2. The prior art

The appellant regards the system configuration in fig.1 of the present application as the closest prior art. It comprises a plurality of network nodes connected to each other via a network, wherein the plurality of network nodes includes a server device (s), a plurality of client devices (t) and a gateway server device (g) performing protocol conversion between the server device and each of the client devices. The server device stores structured documents, which are typically in HTML, ie consisting of a hierarchical set of components. Some of the client devices will contain copies of the structured documents in the server.

3. Novelty

The appellant has identified three main differences between the invention and the prior art:

1) updates are in the form of minimum subsets of components,

2) the updates are pushed towards the clients (cf point 1 above),

3) the gateway manages the structured document stored in each of the client devices (cf point 1 above).

The Board concurs with this view. Thus the invention is new (Article 54(1) EPC 1973).

4. Inventive step

4.1 In the Board's view, these differences and their associated effects may be considered separately since there is no functional interrelationship that would lead to a synergistic effect (see point 4.5 below).

4.2 The first difference is that not an entire document is transmitted but only updates in the form of subsets of components. The Board cannot see anything inventive in this idea since it is a matter of common sense that unchanged information need not be re-transmitted. If this has nevertheless been done in some prior art systems, it can only be because enough bandwidth was available and the principle is simple since it is not necessary to indicate what parts of the document have been updated. The appellant does not deny that it is well known to transmit updates between a server and a cache (cf eg D1, in particular col.7, l.9-20) but argues that the skilled person would not have applied this technique to the kind of server-gateway-client system to which claim 13 refers. The Board does not accept this argument. Transmitting updates is too fundamental a concept ("delta-encoding") to be restricted to caches, or to be ignored by the skilled person considering bandwidth restrictions in a server-client system (or indeed in any data transmission system). The expression "minimum subset of components" is taken to mean that the updates should be as small as possible, something which is obviously desirable.

4.3 The second difference is that a pushing model is used. The appellant argues that pushing reduces the load on the transmission channels. Previously, clients wanting to access a document had to request (pull) the latest version from the server storing the original. The invention improved on this technique by pushing updates to the client devices whenever the original has been changed. Data requests were not necessary.

The Board notes that the pushing technique as such was well known. D8 discloses a data distribution system consisting of a several layers of servers and a bottom layer of client devices. If the master database in the top layer is updated, this update is pushed to all the lower layers, including the client devices (cf the abstract). D8 states that one advantage with the pushing model is that unnecessary update requests, ie requests for updates which do not (yet) exist, inherent in the pulling model, can be avoided (p.3, l.5-8). The same advantage is mentioned in the present application (cf paragraph [0019]: "Even in the case where a document is not updated, a request from the client device C may occur"). The Board concludes that the idea to switch from a pulling model to a pushing model was obvious since the pushing technique was known to solve the problem of superfluous update requests.

4.4 The third difference is that the gateway keeps track of the client devices having a copy of a certain document. The Board notes that pushing updates of an original document can, as a matter of common sense, only be done in two ways: either to all clients, whether they have a copy or not, or only to the clients known to have a copy. If the communication channel is congested, superfluous messages should naturally be avoided. This implies keeping a record of the clients having copies. The Board regards such straight-forward considerations as well within the capabilities of the skilled person.

4.5 The Board is thus of the opinion that each of the differences the invention makes with respect to the prior art was an obvious addition. It remains to consider whether their combination required an inventive step. The appellant has pointed out that the new measures serve the same purpose of reducing the data load on the system by sending only minimum document updates, and only to client devices actually requiring them. This was a combination effect not rendered obvious by the prior art.

In the Board's view, however, this is not a synergistic effect. Two features interact synergistically if their functions are interrelated and lead to an additional effect that goes beyond the sum of the effects of each feature taken in isolation (cf eg decision T 141/87, not published in OJ EPO, reasons, point 3.8). It is not enough that the features solve the same technical problem or that their effects are of the same kind and add up to an increased but otherwise unchanged effect. In the present case, sending messages in the form of minimum updates saves a certain amount of data per message, and sending the messages to fewer clients saves a certain number of messages. The data reduction achieved by the invention over the prior art is simply the sum of all the messages and message parts that do not have to be transmitted. Hence, there is no additional effect going beyond what could be expected.

4.6 It follows that the subject-matter of claim 13 does not involve an inventive step (Article 56 EPC 1973).

ORDER

For these reasons it is decided that:

The appeal is dismissed.