T 2087/17 (Multi-code signalling/SISVEL) 05-02-2020

1. Background of the invention

1.1 The present application concerns spread-spectrum communications and in particular a method for forming a codeword representing the number of multi-codes M or m (i.e. spreading codes) to be used within a set of available multi-codes, as well as a code offset P or Delta which indicates the position in the code set of the first multi-code in compact form. The codeword formed in accordance with the application has seven bits and is a concatenation of two values, a "code group indicator CW1" (four bits) and an "offset indicator CW2" (three bits).

1.2 In the application as filed, essentially two encoding schemes and one decoding scheme are disclosed. The first encoding scheme (hereinafter to be referred to as "encoding scheme 1") is represented by equations (1) and (2) (cf. paragraph [0029] of the application as published). The second encoding scheme (hereinafter to be referred to as "encoding scheme 2") is represented by equations (5) and (6) (cf. paragraph [0034]). The decoding scheme, associated with encoding scheme 1 and represented by equations (3) and (4), is not relevant to this decision.

2. Main request - claims 4, 11 and 16 - validity of the priority claim

2.1 In accordance with established jurisprudence of the boards of appeal, the test for the "same invention" requirement of Article 87(1) EPC is the same as that for compliance with Article 123(2) EPC, namely that the claimed subject-matter must be directly and unambiguously comprised in the priority document, taking into account the priority document as a whole and using common general knowledge as regards matters which are implicit (cf. G 2/98, Reasons 1 and 9; G 2/10, Reasons 4.3). It is further established jurisprudence that the introduction of previously non-disclosed equivalents infringes Article 123(2) EPC (cf. e.g. T 685/90, Reasons 2.4.2). This principle applies, mutatis mutandis, to determining whether a claim enjoys the right to priority from the earlier application in accordance with Article 87(1) EPC.

2.2 The priority document PR1 describes essentially one detailed encoding embodiment beginning on page 8, last line, which corresponds to encoding scheme 1 of the present application.

2.3 Claims 4, 11 and 16 are however based on encoding scheme 2. This scheme includes the requirement to determine (i) the minimum of M-1 and 15-M, and (ii) M/8 rounded to the nearest lower integer, for respectively determining the group code indicator and the offset indicator. These formulae are not disclosed in PR1. In this respect, they are at most equivalent to the equations in the priority document (corresponding to encoding scheme 1), but are not the same, despite the resulting codeword being the same. As an example to illustrate this point, calculating a = (19 + 31) using longhand arithmetic (e.g. by adding 9 + 1, carrying 1, adding 1 + 3 + 1 to form the result 50) is not the same method as calculating a = (20 - 1) + (30 + 1). This is corroborated by the description, which presents the embodiment based on equations (5) and (6) as "another encoding embodiment" (cf. paragraph [0034] of the application as published). Therefore, there is no basis in the priority document for the subject-matter of claims 4, 11 and 16.

2.4 The appellant counter-argued essentially that PR1 is not intended to be limited to encoding scheme 1, as shown by the following disclosures of PR1: claim 1; page 3, lines 9-11; and the paragraph bridging pages 10 and 11. From these hints to broaden the disclosed scheme, the encoding scheme 2 was directly and unambiguously derivable by the person skilled in the art.

2.5 However, the board notes that a hint to broaden the disclosed scheme is not the same as the disclosure of a specific mathematical equivalent out of many possible equivalents. The appellant's argument is therefore not convincing.

3. Main request - claims 4, 11 and 16 - novelty and inventive step

3.1 In view of the invalid priority for claims 4, 11 and 16, D1 (published 19 November 2001) is comprised within the state of the art under Article 54(2) EPC for assessing novelty and inventive step (Articles 54 and 56 EPC).

3.2 D1 discloses equations (1) and (2) of the present application (encoding scheme 1), but not equations (5) and (6) on which claims 4, 11 and 16 are based (encoding scheme 2). The subject-matter of those claims is therefore new with respect to the disclosure of D1.

3.3 However, the difference with respect to D1 concerns merely the use of a simple alternative, mathematically equivalent expression (as indeed already argued by the appellant in connection with the right to claim priority, see point 2.4 above). The appellant made no argument that the use of encoding scheme 2 involved an inventive step starting out from encoding scheme 1. The board can also see no reason to attribute the second encoding scheme with an inventive step, inter alia as there is no suggestion that any technical problem has credibly been solved with respect to encoding scheme 1.

The board concludes that the subject-matter of claims 4, 11 and 16 does not involve an inventive step (Articles 52(1) and 56 EPC).

4. First to fourth auxiliary requests - inventive step

The same objection applies, mutatis mutandis, to claims 4, 11, and 16 of the first to fourth auxiliary requests respectively.

5. Fifth to seventh auxiliary requests - admissibility

5.1 According to Article 13(1) RPBA 2007 (which still applies in this case under the transitional provisions, cf. Article 25 RPBA 2020), any amendment to a party's case after it has filed its grounds of appeal or reply may be admitted and considered at the board's discretion. The discretion shall be exercised in view of, inter alia, the complexity of the new

subject-matter submitted, the current state of the proceedings and the need for procedural economy. Other well-established criteria relevant to the admissibility issue may also be taken into account, such as the question whether a request is likely to overcome the objections in response to which it has been filed or whether it is "clearly allowable".

5.2 In claims 2, 6 and 11 of the fifth and sixth auxiliary requests (which correspond to claims 4, 11 and 16 of the higher-ranking requests) and claims 2 and 6 of the seventh auxiliary request, the expression

"P-1-((M/8 rounded to the nearest lower integer) multiplied by 15)"

has been replaced by:

"P-1-(a parameter multiplied by 15),

wherein said parameter is equal to 0 if M<=7

wherein said parameter is equal to 1 if M>7".

5.3 An expression which was part of encoding scheme 2 has been replaced by an expression taken from encoding scheme 1, so that these claims comprise a mixture of encoding schemes 1 and 2, a combination which is not disclosed in the application as filed. Although the appellant argued that the expression "the minimum of M-1 and 15-M" is the same as the expression

"min(m, 16-m)-1" of encoding scheme 1, so that these claims now concern only encoding scheme 1 and thus comprise subject-matter directly and unambiguously disclosed in the application as filed, the board notes that it is at least arguable that they are only mathematically equivalents but not identical, however trivial the difference. These claims are therefore not clearly allowable with respect to Article 123(2) EPC.

5.4 Furthermore, for the sake of argument, even if the appellant's argument that there is no difference were accepted, the board sees no reason at this late stage of the proceedings to admit amendments shifting the scope of the above claims from encoding scheme 2 to encoding scheme 1, because the latter is already claimed in claim 1, albeit expressed in a different way. If the appellant had wished to claim encoding scheme 1 in the form now proposed in claim 2 et al, this should have been done at a far earlier stage of the proceedings.

5.5 The board therefore decides to not admit the fifth to seventh auxiliary requests into the appeal proceedings (Article 13(1) RPBA 2007).

6. Eighth auxiliary request - admissibility

6.1 The appellant submitted this request late at the oral proceedings before the board on being informed by the chair that the fifth to seventh auxiliary requests were not to be admitted. It consists of only claim 1 of the fifth to seventh auxiliary requests.

6.2 The appellant however has hitherto expressed no interest in filing a request directed only at encoding scheme 1 (cf. points 10-12 of the minutes of the oral proceedings before the examining division). There can be no justification for filing this request at such a late stage of the appeal proceedings.

6.3 Furthermore, if the board were to admit the request, examined claim 1 and concluded that it was clear and complied with Article 123(2) EPC as well as being entitled to claim priority from PR1 under Article 87(1) EPC, the issues of novelty and/or inventive step would still have to be considered. For the board, this would mean effectively having to deal with a fresh case based on other documents as potentially representing the closest prior art, on the assumption that D1 is not comprised within the state of the art. Alternatively, the case would have to be remitted to the examining division, but this would run entirely contrary to the need for procedural economy.

6.4 The appellant argued that the request was filed in response to the discussion at the oral proceedings at which the objections of the board had been better understood. It also referred to the excessive length of the examination proceedings (18 years) which had not been the applicant's fault, and to the fact that a divisional application has now been filed, which could be withdrawn if the present case were remitted.

6.5 However, the board considers that it is clear from its communication under Article 15(1) RPBA 2007, points 5.4 and 5.7, why the board held that encoding scheme 2 lacked an inventive step. The fact that the board confirmed its preliminary opinion in the oral proceedings after having heard the parties on this issue cannot thus be taken as a surprising or an unforeseeable event. In other words, the earliest point in time at which a party should make new submissions (such as an amended claim set) cannot be the instant at which it eventually believes that it cannot indeed convince the board. Rather, it must be the time at which - on an objective basis - an unforeseeable event becomes apparent during the proceedings (see e.g. T 2072/16, Reasons 4.1.7). Accordingly, at the very latest, the eighth auxiliary request should have been submitted in response thereto. Moreover, neither the length of the examination proceedings nor the filing of a divisional application justify the filing of the eighth auxiliary request at such a late stage of the oral proceedings. The reasons given by the appellant are therefore not convincing.

6.6 For these reasons, the board decides to not admit the eighth auxiliary request into the appeal proceedings (Article 13(1) RPBA 2007).