T 888/07 – Don’t Be So Negative

The applicant filed an appeal after the Examining Division (ED) had rejected the application under consideration.

The Board found claim 1 of the main request not to comply with the requirements of A 84 because one essential feature was missing from the independent claims. It then dealt with auxiliary request 1, Claim 1 of which read:

A system for supporting mobile IP, comprising:

• a controlling foreign agent (CFA1, CFA2) managing communications in a service region (RA1, RA2); and
• a plurality of paging foreign agents (PFA1, PFA2, PFA3, PFA4, PFA5, PFA6) managing respective paging areas within the service region, the paging foreign agents configured to register new location information of a mobile node (MN) upon the mobile node moving into the paging area of one of the plurality of paging foreign agents from the paging area of another of the plurality of paging foreign agents;

characterized in that the paging foreign agents are configured to transmit the new location information to the controlling foreign agent if the mobile node is in an active mode at the time of entering the respective paging area and to withhold transmission of the new location information to the controlling foreign agent if the mobile node is in an idle mode at the time of entering the respective paging area. (my emphasis)

The Board again raised a clarity issue:

[3] Claim 1 of this request still comprises the wording “withhold transmission” which was objected to during the first-instance proceedings because it was a negative feature.

[3.1] The board is of the opinion that a feature with such wording is originally disclosed (see e.g. original claim 14), in contrast to the ED’s argument presented in point 1.2 of the communication dated 1 April 2005. Such a negative limitation can therefore be deduced from the application as filed (see T 278/88).

[3.2] However, negative limitations may be used only if adding positive features to the claim either would not define more clearly and concisely the subject-matter still protectable (see T 4/80) or would unduly limit the scope of the claim (see T 1050/93). Both of the cited cases relate to a chemical process and use a negative limitation to clearly define a chemical substance used as an agent in the process.

In the present case the negative limitation relates to a registration step which may be omitted under specific circumstances. These circumstances contribute to the claimed solution. Therefore the subject-matter should be specified in this case by using positive features such as for example the principle of regional registration and local registration as disclosed in Figures 6 and 7 and in paragraphs [0060] to [0070] of the published application.

Claim 1 of auxiliary request I therefore does not fulfil the requirements of clarity pursuant to A 84.

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