T 2491/10 (Test pattern with CID and PRBS portions/AGERE) of 22.7.2011

Summary of Facts and Submissions

I. This appeal is against the decision of the examining division announced in oral proceedings held on 4 May 2010, with reasons dispatched 7 June 2010, refusing European patent application No. 06251265.2 on the grounds that independent claims 1 and 10 did not meet the requirement of Article 84 EPC with respect to clarity.

II. The notice of appeal was submitted on 6 August 2010 and the appeal fee was paid on the same day. The statement setting out the grounds of appeal was submitted on 18 October 2010. It was requested that the decision under appeal be set aside and that a patent be granted on the basis of one of the three sets of claims 1 to 10 submitted, along with the statement setting out the grounds of appeal, as a main request and first and second auxiliary requests, the claims of the main request corresponding to the claims referred to in the decision under appeal. Oral proceedings were requested on an auxiliary basis.

III. A summons to oral proceedings to be held on 15 July 2011 was issued on 4 May 2011. In an annex accompanying the summons the board expressed the preliminary opinion that the independent claims 1 and 10 of the main and first auxiliary requests did not appear to meet the requirements of Article 84 EPC in respect of clarity and that the independent claims 1 and 10 of the first and second auxiliary requests did not appear to meet the requirements of Article 123(2) EPC. The board gave its reasons for the objections and expressed its view that the appellant's arguments were not convincing.

IV. By letter submitted on 27 May 2011, the appellant requested a postponement of the date of the oral proceedings because the representative had been summoned to attend jury service in the UK. The appellant filed a copy of the Jury Summons in support of its request.

V. By communication dated 7 June 2011, the board informed the appellant that the oral proceedings were postponed until 22 July 2011.

VI. By letter submitted on 21 June 2011, the appellant filed claims 1 to 10 according to a modified first auxiliary request and claims 1 to 10 according to a modified second auxiliary request.

VII. With a letter submitted on 21 July 2011 and received at the EPO on the same day, the appellant informed the board that it would not be attending the oral proceedings and requested the board to give a decision taking into account its submissions of 21 June 2011.

VIII. Accordingly, nobody appeared on behalf of the appellant at the oral proceedings on 22 July 2011, which were then held in the appellant's absence.

IX. The appellant requested that the decision under appeal be set aside and that a patent be granted on the basis of claims 1 to 10 of the main request as filed with letter dated 18 October 2010, or on the basis of claims 1 to 10 of the first auxiliary request or of claims 1 to 6 of the second auxiliary request as filed with letter of 21 June 2011.

After due deliberation on the basis of the written submissions on file, the board announced its decision.

X. Independent claim 1 of the main request reads as follows:

"1. A method (100) of generating a modified test pattern (212) for testing communications equipment, said modified test pattern being a modified version of a baseline pattern (202) having a baseline consecutive identical digit (CID) portion with m consecutive identical digits and a baseline pseudo random bit sequence (PRBS) portion with p bits of a baseline PRBS, said method characterized by the steps of:

generating a test CID portion comprising n consecutive identical digits; and

generating a test PRBS portion comprising q bits of a test PRBS (106);

wherein at least one of said test CID portion and said test PRBS portion is a modified version of said baseline CD portion (204) and said baseline PRBS portion (206), respectively, wherein said modified test pattern is characterized by a higher diagnostic value with respect to said baseline pattern."

Independent claim 10 of the main request reads as follows:

"10. An integrated circuit (500) for communications applications, with built-in test capability using a modified test pattern that is a modified version of a baseline pattern having a baseline consecutive identical digit (CID) portion with m consecutive identical digits and a baseline pseudo random bit sequence (PRBS) portion with p bits of a baseline PRBS, said integrated circuit characterized by:

a communications portion; and

a built-in test portion (503), said built-in test portion in turn comprising:

a pattern generator that is configured to:

generate a test CID portion comprising n consecutive identical digits;

and

generate a test PRBS portion comprising q bits of a test PRBS;

wherein at least one of said test CID portion and said test PRBS portion is a modified version of said baseline CID portion and said baseline PRBS portion, respectively, wherein said modified test pattern is characterized by a higher diagnostic value with respect to said baseline pattern;

a checker (510) that is configured to measure performance of said communications portion when exposed to said test pattern generated by said pattern generator; and

an interface portion that couples said communications portion to said pattern generator and said checker."

Independent claim 1 of the first auxiliary request reads as follows:

"1. A method (100) of generating a modified test pattern (212) for testing communications equipment, said modified test pattern being a modified version of a baseline pattern (202) having a baseline consecutive identical digit (CID) portion with m consecutive identical digits and a baseline pseudo random bit sequence (PRBS) portion with p bits of a baseline PRBS, said method characterized by the steps of:

generating a test CID portion comprising n consecutive identical digits; and

generating a test PRBS portion comprising q bits of a test PRBS (106);

wherein at least one of said test CID portion and said test PRBS portion is a modified version of said baseline CID portion (204) and said baseline PRBS portion (206), respectively, wherein said modified test pattern comprises one of the following with respect to said baseline pattern: higher frequency data by having at least one of said test CID portions be shorter than the baseline CID portion, higher frequency toggle rate by having said test PRBS be identical to said baseline PRBS and said test PBS portion to a truncated version of said baseline PRBS portion, higher frequency toggle rate by having said test PRBS be a lower order polynomial function than said baseline PRBS, and stretched data by having said test PRBS be identical to said baseline PRBS and said test PBS portion being stretched with respect to said baseline PRBS portion."

Independent claim 10 of the first auxiliary request reads as follows:

"10. An integrated circuit (500) for communications applications, with built-in test capability using a modified test pattern that is a modified version of a baseline pattern having a baseline consecutive identical digit (CID) portion with m consecutive identical digits and a baseline pseudo random bit sequence (PRBS) portion with p bits of a baseline PRBS, said integrated circuit characterized by:

a communications portion; and

a built-in test portion (503), said built-in test portion in turn comprising:

a pattern generator that is configured to:

generate a test CID portion comprising n consecutive identical digits;

and

generate a test PRBS portion comprising q bits of a test PRBS;

wherein at least one of said test CID portion and said test PRBS portion is a modified version of said baseline CID portion and said baseline PRBS portion, respectively, wherein said modified test pattern comprises one of the following with respect to said baseline pattern: higher frequency data by having at least one of said test CID portions be shorter than the baseline CID portion, higher frequency toggle rate by having said test PRBS be identical to said baseline PRBS and said test PBS portion being a truncated version of said baseline PRBS portion, higher frequency toggle rate by having said test PRBS be a lower order polynomial function than said baseline PRBS, and stretched data by having said test PRBS be identical to said baseline PRBS and said test PBS portion being stretched with respect to said baseline PRBS portion;

a checker (510) that is configured to measure performance of said communications portion when exposed to said test pattern generated by said pattern generator; and

an interface portion that couples said communications portion to said pattern generator and said checker."

Independent claim 1 of the second auxiliary request reads as follows:

"1. A method (100) of generating a modified test pattern (212) for testing communications equipment, said modified test pattern being a modified version of a baseline pattern (202) having a baseline consecutive identical digit (CID) portion with m consecutive identical digits and a baseline pseudo random bit sequence (PRBS) portion with p bits of a baseline PRBS, said method characterized by the steps of:

generating a test CID portion comprising n consecutive identical digits; and

generating a test PRBS portion comprising q bits of a test PRBS (106);

wherein at least one of said test CID portion and said test PRBS portion is a modified version of said baseline CID portion (204) and said baseline PRBS portion (206), respectively, wherein said modified test pattern comprises higher frequency data with respect to said baseline pattern by having at least one of said test CID portions be shorter than the baseline CID portion."

Independent claim 6 of the second auxiliary request reads as follows:

"6. An integrated circuit (500) for communications applications, with built-in test capability using a modified test pattern that is a modified version of a baseline pattern having a baseline consecutive identical digit (CID) portion with m consecutive identical digits and a baseline pseudo random bit sequence (PRBS) portion with p bits of a baseline PRBS, said integrated circuit characterized by:

a communications portion; and

a built-in test portion (503), said built-in test portion in turn comprising:

a pattern generator that is configured to:

generate a test CID portion comprising n consecutive identical digits;

and

generate a test PRBS portion comprising q bits of a test PRBS;

wherein at least one of said test CID portion and said test PRBS portion is a modified version of said baseline CID portion and said baseline PRBS portion, respectively, wherein said modified test pattern comprises higher frequency data with respect to said baseline pattern by having at least one of said test CID portions be shorter than the baseline CID portion;

a checker (510) that is configured to measure performance of said communications portion when exposed to said test pattern generated by said pattern generator; and

an interface portion that couples said communications portion to said pattern generator and said checker."

Reasons for the Decision

1. Admissibility

The appeal complies with the provisions of Articles 106 to 108 EPC and is therefore admissible (see Facts and Submissions, point II).

2. Non-attendance at oral proceedings

In its letter of 21 July 2011 the appellant announced that neither it nor its representative would be attending. The board considered it expedient to maintain the date set for oral proceedings. Nobody attended the proceedings on behalf of the appellant.

Article 15(3) RPBA stipulates that the board is not obliged to delay any step in the proceedings, including its decision, by reason only of the absence at the oral proceedings of any party duly summoned, who may then be treated as relying only on its written case.

Thus, the board was in a position to take a decision at the end of the oral proceedings.

Main request

3. Article 84 EPC

Independent claims 1 and 10 of the main request correspond to claims 1 and 10 referred to in the decision under appeal, which was based on the ground that claims 1 and 10 of the main request did not meet the requirements of Article 84 EPC.

3.1 The board agrees with the findings of the examining division in that respect, for the following reasons.

Claim 1 is directed to a method of generating a test pattern by modifying a baseline pattern. The baseline pattern and the test pattern are both defined as having respective consecutive identical digit (CID) portions and pseudo random bit sequence (PRBS) portions. The test pattern is further defined as having at least one of its portions being a modified version of the portions of baseline pattern. Moreover the test pattern is defined as having a higher diagnostic value with respect to the baseline pattern.

In the context of the application, a pattern is a series of digits (CID portion) or bits (PRBS portion). Thus, each pattern portion may be considered as the modified version of any other pattern portion of the same category (CID or PRBS portion), using an appropriate modification function, such as, e.g., a truncation function, a complementing function, etc... Since claim 1 does not define any such modification function, the wording "modified version of ...portion" used in claim 1 encompasses an undefined number of pattern portions and therefore renders the claimed subject-matter unclear.

Furthermore the feature that the test pattern has a higher diagnostic value than the baseline pattern lacks clarity. The wording "diagnostic value" is not defined in the description and appears to be dependent on the communication equipment being tested and on the properties of that equipment that are the subject of the test. Therefore the comparison of the respective diagnostic values of the baseline and test patterns appears even more unclear. Even if the wording "diagnostic value" had a clear meaning in the context of the application, this feature would represent an aim to be achieved since, as mentioned above, claim 1 does not define any technical features of the modifications which are applied to the baseline pattern portions in order to achieve this result.

3.2 The appellant has argued that the wording "characterized by a higher diagnostic value" does not solely define a purpose or result to be achieved, since a test pattern characterized by a higher diagnostic value has inherent technical features which would be recognized by the person skilled in the art, for instance a higher frequency. In the board's view however, technical features of a digits or bits pattern are features related to the digits or bits arrangement of the pattern, for instance the number of digits or bits, the values of particular digits or bits or groups of digits or bits in the pattern, etc.... Properties which can result from the arrangement of digits or bits within the pattern when the pattern is used as a test pattern in communication equipment, such as the effect of a simulated rapidly varying (or high frequency) entry data on the equipment, are not inherent technical features of the pattern but rather the (potential) technical effect of the technical features of the pattern. In the present case, the only technical features of the test pattern defined in claim 1 are the presence in the test pattern of a CID portion having n digits and of a PRBS portion having q bits. The mere presence of these features in claim 1 does not enable the skilled person to make any assumption about the value of the diagnostic achieved by using the test pattern in a piece of communication equipment.

The appellant has further argued that a modification function that encompasses an undefined number of pattern portions does not render the claimed subject-matter unclear. The board is not convinced by this argument either since claim 1 does not define any modification function per se but only defines the result achieved by the employed modification function, which is a higher diagnostic value of the test pattern. Therefore the wording of claim 1 also encompasses an undefined number of modification functions, which, when applied to the baseline pattern, could achieve a higher diagnostic value.

The board therefore judges that claim 1 does not meet the requirements of Article 84 EPC.

3.3 Independent claim 10 is related to an integrated circuit for communications applications with built-in test capability. The circuit comprises, inter alia, a pattern generator configured to perform the method of claim 1. For this reason, the board judges that claim 10 also lacks clarity (Article 84 EPC).

First auxiliary request

4.1 Article 84 EPC

The description mentions (see paragraphs [0016] and [0017]) that a higher frequency toggle rate may be achieved by either truncating the baseline PRBS portion or by using a lower order polynomial function for the test PRBS. The toggle rate of a bit pattern sequence is usually defined in the technical field as a value which measures how often the bit value changes with respect to the bit clock. For a PRBS sequence, the board considers that lowering the order of the generating polynomial function reduces the toggle rate of the pattern since the values given by the polynomial function then change more slowly as a function of time. Since claims 1 and 10 actually define the opposite, i.e. that a higher frequency toggle rate of the pattern is achieved by using a lower order polynomial generating function of its PRBS portion, the board judges that claims 1 and 10 lack clarity in that respect.

The appellant did not provide any argument in response to the above-mentioned objection, which was raised by the board in the communication annexed to the summons to oral proceedings.

Furthermore, claims 1 and 10 define that the modified test pattern may comprise higher frequency data, with respect to the baseline pattern, by having "at least one of said CID portions be shorter than the baseline CID portion". Since however the modified test pattern is previously defined in claims 1 and 10 as having "a test CID portion" only, the board judges that claims 1 and 10 lack clarity in that respect.

Thus, claims 1 and 10 do not meet the requirements of Article 84 EPC.

4.2 Article 123(2) EPC

Moreover, the description only discloses that the test CID portion may be shorter than the baseline CID portion, see column 4, lines 10 to 16. The description does not provide a basis for the amendment "at least one of said CID portions be shorter than the baseline CID portion".

Thus, claims 1 and 10 do not meet the requirements of Article 123(2) EPC.

Second auxiliary request

5.1 Article 84 EPC

Claims 1 and 6 define that the modified test pattern may comprise higher frequency data, with respect to the baseline pattern, by having "at least one of said CID portions be shorter than the baseline CID portion". Since however the modified test pattern is previously defined in claims 1 and 6 as having "a test CID portion" only, the board judges that claims 1 and 6 lack clarity in that respect.

Thus, claims 1 and 6 do not meet the requirements of Article 84 EPC.

5.2 For the reasons set out in points 4.2, claims 1 and 6 do not meet the requirements of Article 123(2) EPC.

6. There being no further requests, the appeal has to be dismissed.

ORDER

For these reasons it is decided that:

The appeal is dismissed.