T 0815/18 (Data payload splitting/ALCATEL) 28-05-2019

1. The appeal is admissible (see point II above).

2. Main request - Admissibility

2.1 This request was filed late by the appellant at the end of the oral proceedings before the board, after the other requests had been examined, and replaced the previous main request which was thus withdrawn.

2.2 In the oral proceedings, the board had previously expressed the opinion that claim 1 of the previous main request did not meet the requirements of Article 56 EPC in view of D2. During discussion of the previous main request, the board held that D2 discloses the following (the references in parentheses applying to this document), in accordance with the essential features of claim 1 of the previous main request, a method of radio transmitting a payload (page 6, line 32 and Figure 5: "user data 140 from a radio bearer 125"), comprising:

- dividing the payload into data portions (page 7, lines 10 to 13: "segments"; Figure 5, reference signs 150),

- grouping said portions so as to form a first packet and a second packet (page 7, lines 9 to 14: "transmission block 145", "next transmission block 145"; Figure 5, reference sign 145),

- selecting a first available radio channel suitable for incorporating the first packet and a second available radio channel suitable for incorporating the second packet (see page 5, line 4: "allow a single mobile station 2 to use several physical channel in parallel"; page 5, lines 18 to 20 in combination with Figure 3: "the data stream... may be split into several physical channels...")

- incorporating the first packet in the first selected radio channel and incorporating the second packet in the second selected radio channel (see the same passages as for the previous feature),

- transmitting the first selected radio channel with the first packet incorporated and the second radio channel with the second packet incorporated (see the same passages as for the previous feature).

The board thus acknowledged that the distinguishing feature between the subject-matter of claim 1 of the previous main request and D2 was that the payload was issued from a line interface instead of coming from multiplexed radio bearers as in D2.

The appellant argued that a line interface is able to transmit a data payload at a much higher bit rate, in the Gbits/sec range, than the radio bearers of D2. The alleged invention solved this problem by dividing the single payload of the line interface and sending the different parts on different radio channels.

The board was not convinced by this argument, however, because the teaching of D2 (see page 5, lines 3 to 4 and 17 to 22 in relation with Figure 3) in respect of splitting data incoming to a single physical channel into several parallel channels does not depend on the origin of the data but only on its data rate. Further, the data issued by the multiplexer 115 in Figure 3 may well be considered a payload in itself.

The appellant had further argued in writing that the radio channels in D2 were not selected based on the basis of their availability and their suitability for incorporating the packets. However, the board holds that, by teaching that the data stream is split when a single physical channel cannot manage the data rate, D2 implicitly discloses that the system of D2 performs an assessment of the physical channels in respect of the supported data rate, which amounts to a test for suitability as broadly defined in claim 1.

For these reasons, during oral proceedings the board concluded that the subject-matter of claim 1 of the previous main request did not involve an inventive step, in view of D2.

2.3 Claim 1 of the main request differs in substance from claim 1 of the previous main request in that the line interface is a baseband wireline interface and the radio transmission is a microwave radio transmission, i.e. that the radio channels operate in the microwave range.

The appellant argued that these amendments were supported by the description in page 1, line 21 and from page 1, line 24 to page 2, line 6, respectively. The board notes, however, that these passages belong to the part entitled "Background of the invention" and that the terms "microwave" and "baseband" do not appear further in the description, so the board is not convinced that the requirements of Article 123(2) EPC are fulfilled.

The appellant further argued that, because of these amendments, D2 did not represent the closest prior art anymore since it did not relate to microwave radio transmissions but to mobile communications. The board holds that, even if this technical argument were accepted, amendments to a claim aiming to change the closest prior art, considered as such during the whole examination proceedings, introduces subject-matter which has not been discussed so far and or probably even searched and could not be dealt with without the adjournment of oral proceedings.

For these reasons, during the oral proceedings the board decided not to admit the main request into the proceedings (Article 13(3) RPBA).

3. First auxiliary request - Inventive step

Claim 1 adds to the substance of claim 1 of the previous main request the feature that selecting the first and second radio channels is performed in accordance with a capacity of these channels, to optimise use of resources in the radio transmission.

In addition to the arguments presented in relation to the previous main request, the appellant further alleged that D2 did not provide any optimisation of the radio resources. The board notes, however, that the claimed optimisation merely represents an aim to be achieved, and that the only passage of the description relating to optimisation of the resources is on page 8, lines 6 to 10 of the description, and appears to specify that the first radio channel is filled with packets before starting to fill the second radio channel. D2 discloses that the splitting of data over radio channels depends on the capacity of the available radio channels in terms of data rate (see page 5, lines 17 to 22) and that variable incoming transmission rates can be accommodated by changing the allocation of data over the different radio channels (see page 7, lines 6 to 28). Therefore, the above-mentioned additional features of claim 1 are already disclosed in D2.

For these reasons, the board holds that claim 1 does not meet the requirements of Article 56 EPC in view of D2.

4. Second auxiliary request - Inventive step

Claim 1 differs from claim 1 of the first auxiliary request only in that the word "capacity" has been replaced by the word "size".

As acknowledged by the appellant in oral proceedings, this amendment does not change the substance of the

subject-matter of claim 1. The reasoning set out in point 3 above applies equally to the second auxiliary request.

Thus, claim 1 does not meet the requirements of Article 56 EPC in view of D2.

5. Third auxiliary request - Admissibility

The claims of the previous main request, the main request, and the first and second auxiliary requests are directed to a method for transmitting payload portions of a single line interface over two different radio channels. In contrast, claim 1 of the third auxiliary request is directed to a method for transmitting payload portions of two different line interfaces over a single radio channel.

Therefore, the third auxiliary request, which was filed one month before the oral proceedings, relates to a different and divergent subject-matter from the other requests on file, as also acknowledged by the appellant in oral proceedings.

Therefore, the board decided not to admit this request into the proceedings (Article 13(1) RPBA).

6. Conclusion.

The main request and the third auxiliary request are not admitted into the proceedings (Article 13 RPBA). The first and second auxiliary requests are not allowed (Article 56 EPC).