T 2241/11 (Windfarm network/GENERAL ELECTRIC) of 19.10.2015

European Case Law Identifier: ECLI:EP:BA:2015:T224111.20151019
Date of decision: 19 October 2015
Case number: T 2241/11
Application number: 07107189.8
IPC class: H04L 29/12
Language of proceedings: EN
Distribution: D
Download and more information:
Decision text in EN (PDF, 313.854K)
Documentation of the appeal procedure can be found in the Register
Bibliographic information is available in: EN
Versions: Unpublished
Title of application: Method for configuring IP addresses in a windfarm network
Applicant name: GENERAL ELECTRIC COMPANY
Opponent name: -
Board: 3.5.03
Headnote: -
Relevant legal provisions:
European Patent Convention Art 56
Keywords: Inventive step - (no)
Catchwords:

-

Cited decisions:
-
Citing decisions:
-

Summary of Facts and Submissions

I. This appeal is against the decision of the examining division refusing European patent application No. 07107189.8. The impugned decision was issued "according to the state of the file" as requested by the applicant and refers to two earlier communications. In these communications the examining division expressed the view that the claimed subject-matter lacked an inventive step (Articles 52(1) and 56 EPC) having regard to the following documents:

D1: EP 1 558 002 A1; and

D2: WO 01/82032 A2.

II. With the statement of grounds of appeal, the appellant filed sets of claims of a main request ("Primary Request") and an auxiliary request. A conditional request for oral proceedings was made in the notice of appeal.

III. In a communication accompanying the summons to oral proceedings, the board gave a preliminary opinion as regards inventive step of the subject-matter of claim 1 of the main request and the auxiliary request.

IV. With a letter dated 18 September 2015, the appellant submitted arguments in support of the requests on file.

V. Oral proceedings were held on 19 October 2015.

The appellant requested that the decision under appeal be set aside and that a patent be granted on the basis of the claims of the main request (primary request) or, in the alternative, on the basis of the claims of the auxiliary request, both requests as filed with the statement of grounds of appeal.

At the end of the oral proceedings the chairman announced the board's decision.

VI. Claim 1 of the main request reads as follows:

"A windfarm network, comprising

a plurality of wind turbines (200) connected with each other via a windfarm LAN (300);

a remote control centre (100) connect [sic] to the windfarm LAN (300), wherein each wind turbine (200) is accessible from the remote control centre (100) via the windfarm LAN (300), said remote control centre (100) further comprising a host (110);

each said wind turbine (200) comprising a respective identifier tag sending device (210, 220, 230) which is adapted to send an identifier tag to said remote control centre (100) so that the IP address of a device connected to said windfarm network (300) is uniquely related to a specific wind turbine (200) in said windfarm via said identifier tag;

said control centre (100) being operable to automatically configure the windfarm LAN (300) by:

(a) dynamically assigning (S701) IP addresses to devices connected to the local windfarm network using a dynamic host configuration protocol (DHCP),

(b) automatically determining (S702) network topology of the windfarm network (300) using a link layer discovery protocol (LLDP),

(c) identifying (S703) wind turbine subnetworks by identifying wind turbine switches from LLDP information by receiving (S704) wind turbine numbers from the wind turbine switches; and

(d) relating (S705) the IP addresses of the devices contained in a subnetwork of a specific wind turbine to a respective identified wind turbine."

Claim 1 of the auxiliary request differs from claim 1 of the main request in that features (a) to (d) are replaced by the following features (a) to (f):

"(a) dynamically allocating (S801) IP addresses to devices connected to the local windfarm network using a dynamic host configuration protocol (DHCP),

(b) automatically determining (S802) network topology of the windfarm network (300) using a link layer discovery protocol (LLDP),

(c) identifying (S803) wind turbine subnetworks by identifying wind turbine switches from LLDP information by receiving (S804) device numbers of the wind turbine switches;

(d) reading (S805) an identifier tag corresponding to a respective switch device number from a database;

(e) identifying (S806) a wind turbine including the switch on the basis of the identifier tag; and

(f) relating (S807) the IP addresses of the devices contained in a subnetwork of a specific wind turbine to a respective identified wind turbine".

Reasons for the Decision

1. Claim 1 of the main request - inventive step

(Articles 52(1) and 56 EPC)

1.1 D1 discloses a general purpose automation system in which network addresses are assigned to automation devices. The automation system 100 (Fig. 1) includes a plurality of switches 104 connected to, and accessible from, an address server 122 via a local area network (LAN) 102, e.g. Ethernet (cf. Fig. 1 and paragraphs [0020] and [0048]). Each switch comprises a plurality of ports (110, 112, 114) to which a plurality of automation devices is connected (as an example, automation device 116 is connected to port 110 in Fig. 1). Having regard to the embodiment shown in Fig. 3, it is implicit that a subnetwork is constituted by a switch ("Switch1") and the automation devices ("Gerät1" etc.) associated with that switch ("Switch1"). The IP address of a device is uniquely related to that subnetwork. This is apparent from the structure of IP addresses listed in the right-hand column in the table in Fig. 3, since the respective IP addresses of the switch and each of the automation devices have an identical most significant address portion ("10.0.0") and is distinguished only by the fourth, i.e. least significant address portion. Further, each automation device 116 has stored an identifier tag ("Chassis-ID" or "Stationsname", see paragraphs [0031] and [0036]) and is configured to send the identifier tag to the address server during an initial set-up phase. Hence, the collectivity of automation devices associated with a switch, each having the ability to send an identifier tag, constitutes an identifier sending device in the respective subnetwork. The address server 122 serves to assign IP addresses to the automation devices of the automation system (cf. paragraph [0024]). Therefore, the address server operates as a remote control centre and also constitutes a host. The address server 122 is operable to automatically configure the network by:

(a) dynamically assigning IP addresses to devices 116 connected to the switches using a dynamic host configuration protocol (DHCP)(cf. paragraph [0032]);

(b) automatically determining the network topology of the automation system, in which each device investigates its neighborhood and transmits neighborhood information to the address server using a link layer discovery protocol (LLDP)(cf. paragraph [0034]);

(c) identifying subnetworks, by identifying, on the basis of relationships between devices and ports defined by LLDP information (see Fig. 3), the devices which are associated to a particular switch; and

(d) relating the IP addresses of the devices contained in a subnetwork to a respective identified switch (see the table in Fig. 3, in which, e.g., the IP address 10.0.0.1 of "Gerät1" is related to "Switch1" by the alias "Port4.Switch1", which includes the identifier "Switch1" of the switch and the port ID "Port4" of the port of the switch to which the device is connected).

1.2 The subject-matter of claim 1 differs from the system disclosed in D1 in that in claim 1:

- the system is a windfarm network comprising a plurality of wind turbines;

- each wind turbine comprises a respective identifier tag sending device;

- the IP address of a device connected to said windfarm network is uniquely related to a specific wind turbine in said windfarm via said identifier tag;

- wind turbine subnetworks are identified by identifying wind turbine switches from LLDP information by receiving wind turbine numbers from the wind turbine switches; and

- the IP addresses of the devices contained in a subnetwork of a specific wind turbine are related to a respective identified wind turbine.

1.3 The board does not concur with the appellant's formulation of the objective technical problem, which the latter defines as facilitating the identification of the geographic location of devices in a windfarm network (see also below, points 1.5(a) and 1.6(a)). In the board's view, this problem is not solved by the features of claim 1, since LLDP information describes the network topology only at a logical level, by defining neighbourhood relationships in terms of existing network connections between devices. The LLDP information does not, however, contain any geographic position information and does not allow any conclusions to be drawn about the exact location of a device.

The board, however, notes that D1 suggests that a device 116 may be any device used in automation engineering (cf. paragraph [0022]). Therefore, the objective technical problem to be solved by the skilled person starting out from D1 may be seen as conveniently and automatically configuring a network which includes a plurality of switches and automation devices and applying it to a specific system.

1.4 At the priority date of the application, it was generally known to connect wind turbines in wind farms via a local area network to a central control of the wind farm (cf. see paragraphs [0002] and [0003] of the application; reference is made to the application published as No. EP 1 850 563 A1). This was not contested by the appellant. Therefore, the skilled person, faced with the above-mentioned technical problem, starting out from D1 and using common general knowledge, would consider applying the procedure disclosed in D1 to a windfarm network and configuring it accordingly. The skilled person would thus provide an identifier tag sending function, as disclosed in D1, in each device in a wind turbine. Consequently, each wind turbine would comprise a respective identifier tag sending device, composed by the collectivity of automation devices, each having an identifier tag sending function. The skilled person would be further led by D1 to uniquely relate, by the alias which includes the name of the switch and which is sent as the identifier tag of the device, the IP address of a device in the windfarm network to a specific wind turbine in said wind farm and identify as a windfarm subnetwork that group of devices the IP addresses of which are related to the respective switch by aliases which include the name of the switch (see Fig. 3 of D1). It is solely a matter of naming convention, which does not require any technical considerations, whether a switch (and, hence, the associated wind turbine or the wind turbine subnetwork) is identified by a name composed of alphanumeric characters as in D3 or by a number as in feature (c) of claim 1. This feature relating to device identification does not therefore contribute to an inventive step. Finally, the skilled person would be led by D1 to relate the IP addresses of the devices contained in a subnetwork of a specific wind turbine to a respective identified wind turbine, by setting the IP addresses as outlined in the table in Fig. 3, such that a more significant address portion is the same for all devices in the subnetwork.

Therefore, the skilled person, starting out from D1 and using common general knowledge, would arrive at the subject-matter of claim 1 without the exercise of inventive skill.

1.5 The appellant argued as follows:

(a) The application addressed the specific problem of correctly identifying the physical location of devices related to a particular wind turbine. This problem specifically occurred in the field of wind turbines arranged as a wind farm, since the geographic size of the wind farm was considerable in view of the size of a single wind turbine and the typical number of wind turbines within the wind farm. The knowledge of the exact geographic location of a device within the wind farm was essential in case a device failed and had to be replaced. According to the invention, the location was known by sending the identifier tag from a device to the remote control centre at which it was related to the name of the wind turbine with which it was associated.

(b) D1 did not disclose specific devices, such as the sensor or the controller indicated in the present application. Instead, the disclosure of D1 was limited to a rather abstract level as regards how to connect devices of unspecified kind to a switch, i.e. by associating IP addresses to a device.

(c) D1 taught away from connecting devices to a windfarm network, since it was suggested in D1 that a faulty device may be replaced by a replacement device without the need for manual intervention. However, failure of a physical component within a wind turbine mandatorily required its replacement and it could not simply be replaced by an alternative network component provided at a different location, which is remotely switched in.

(d) D1 did not disclose how a device which was not directly connected to the switch, e.g. "Gerät3" in Fig. 3, could be included in a subnetwork.

1.6 The board is not convinced by these arguments for the following reasons:

Re. (a) The board notes that the configuration of the windfarm network as claimed is not defined in terms of geographic location information, but only in terms of IP addresses relating to the "logical" location of a device, i.e. specifying the topology of network connections of devices within a network. The geographic location of the devices which constitute the network, on the one hand, and the assignment of addresses to devices, on the other hand, are, however, separate and mutually independent issues. Therefore, the specific problem of identifying the geographic locations of devices is not addressed by the windfarm network as defined in claim 1.

Re. (b) Contrary to the appellant's opinion, D1 discloses specific types of devices ("Messwertgeber", "Antrieb", "Steuerung", see paragraph [0022]). Further, the process of associating an IP address to a device as described in Fig. 2 of D1 is not at a more abstract level than it is in the present application.

Re. (c) In the board's understanding, the passage in paragraph [0014] of D1 ("Beispielsweise kann ein defektes Gerät durch ein Austauschgerät ersetzt werden, ohne dass manuell in das Netzwerkmanagement eingegriffen werden muss. Die Zuordnung der IP-Adresse zu dem Austauschgerät kann automatisch ohne jede Nutzerinteraktion erfolgen.") is merely concerned with the question of the extent to which manual intervention is required as regards the network management. However, this does not concern, and is separate from the question of, whether or not a faulty device has to be physically replaced.

Re. (d) The table in Fig. 3 of D1 clearly teaches that, as a rule, the location of a device in the network is defined by the device identification ("Identifikator") and the "Alias" which includes the name of the connecting device and the connecting port of this device. Hence, the skilled person would easily understand that a device which is not directly connected to a switch but indirectly via a bridging device (e.g. "Gerät3" via "Gerät1" in Fig. 3 of D1) would be connected to the network according to the same rule.

1.7 For the above reasons, the subject-matter of claim 1 lacks an inventive step. The main request is therefore not allowable (Articles 52(1) and 56 EPC).

2. Claim 1 of the auxiliary request - inventive step

(Articles 52(1) and 56 EPC)

2.1 As regards claim 1 of the auxiliary request, the board considers that the difference in wording does not establish any difference in substance.

2.2 In particular, the word "allocating" in feature (a) of claim 1 of the auxiliary request is considered as being synonymous with "assigning" in claim 1 of the main request. Features (b) and (f) are identical in wording with features (b) and (d) in claim 1 of the main request. Feature (c) is the same as in claim 1 of the main request, except that "wind turbine numbers from" is replaced by the synonymous term "device numbers of". Features (d) and (e) introduce a separation between an identifier tag read from a database and on the basis of which a wind turbine including the switch is identified, and a switch device number to which the identifier tag corresponds. However, this separation does not further distinguish the claimed network from D1, since the chassis ID, which is considered in the present application (cf. paragraph [0025]) as being a device number, is included in the identifier tag in D1 (see paragraph [0031] in D1) and is therefore implicitly included by the identification tag sent to the address server. Hence, no difference in substance is introduced by features (d) and (e).

2.3 Therefore, claim 1 of the auxiliary request seeks protection for essentially the same windfarm network as claim 1 of the main request, and does not contain any feature which could contribute to an inventive step.

The appellant did not argue otherwise.

2.4 For these reasons and the reasons set out above in respect of the subject-matter of claim 1 of the main request, the subject-matter of claim 1 of the auxiliary request lacks an inventive step (Article 52(1) and 56 EPC). The auxiliary request is therefore not allowable either.

3. There being no allowable request, it follows that the appeal is to be dismissed.

Order

For these reasons it is decided that:

The appeal is dismissed.

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