European Case Law Identifier: | ECLI:EP:BA:2014:T055711.20140704 | ||||||||
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Date of decision: | 04 July 2014 | ||||||||
Case number: | T 0557/11 | ||||||||
Application number: | 99962936.3 | ||||||||
IPC class: | H04L 12/28 H04M 7/00 H04L 12/56 |
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Language of proceedings: | EN | ||||||||
Distribution: | D | ||||||||
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Title of application: | Telecommunication apparatus and method for forwarding packets using separate collision domains | ||||||||
Applicant name: | Hewlett-Packard Development Company, L.P. | ||||||||
Opponent name: | - | ||||||||
Board: | 3.5.05 | ||||||||
Headnote: | - | ||||||||
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Keywords: | Inventive step - (no): juxtaposition of obvious features | ||||||||
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Summary of Facts and Submissions
I. The appeal is against the decision of the examining division, posted on 21 October 2010, to refuse European patent application No. 99962936.3 on the grounds of lack of inventive step (Article 56 EPC) with respect to a main request and an auxiliary request, having regard to the disclosures of
D1: T. Konoshi et al.: "Voice and Data Integrated Communication on LAN (VOICEHUB)", OKI Technical Review 159, pp. 5-10, July 1997;
D3: EP-A-0 853 405.
II. Notice of appeal was received on 23 December 2010. The appeal fee was paid on the same day. With the statement setting out the grounds of appeal, received on 25 February 2011, the appellant re-filed claims 1 to 3 of the main request underlying the appealed decision as its main request, amended claims 1 to 3 according to first to third auxiliary requests, and amended claim 1 according to a fourth auxiliary request. It requested that the decision of the examining division be set aside and that a patent be granted on the basis of the main request or any of the auxiliary requests. In addition, oral proceedings were requested as an auxiliary measure.
III. A summons to oral proceedings was issued on 13 March 2014. In an annex to this summons, the board gave its preliminary opinion on the appeal pursuant to Article 15(1) RPBA. In particular, objections were raised under Articles 54 and 56 EPC 1973, having regard to D1.
IV. With a letter of reply dated 2 June 2014, the appellant submitted an amended claim 1 according to a new fourth auxiliary request, amended claims 1 to 3 according to a fifth auxiliary request, and an amended claim 1 according to a sixth auxiliary request along with arguments in support of novelty and inventive step with regard to the fourth to sixth auxiliary requests.
V. Oral proceedings were held on 4 July 2014, during which the appellant withdrew the former main request and first to third auxiliary requests. All the pending requests were admitted into the proceedings and their allowability was discussed.
The appellant's final request was that the decision under appeal be set aside and that a patent be granted on the basis of the claims filed as the fourth to sixth auxiliary requests with letter dated 2 June 2014.
At the end of the oral proceedings, the decision of the board was announced.
VI. Claim 1 of the fourth auxiliary request reads as follows:
"A telephone set (10), comprising:
a first media access control (MAC) device (28) in electrical communication with a first network (12) via a first communication path (16) and being part of a first collision domain;
a second MAC device (32) in electrical communication with a second network (14) via a second communication path (18) and being part of a second collision domain; the telephone set (10) being arranged to maintain the first and the second collision domains separate;
an input port (26) for receiving audio signals from an input device (17); and
a packet controller (24) in communication with the first (28) and second (32) MAC devices and the input port (26), the packet controller (24) being arranged to generate packets including voice data from the audio signals received by the input port (26) for transmission to at least one of the first (28) and second (32) MAC devices,
characterised in that.[sic]
the telephone set comprises memory for storing packets,
the packet controller (24) is arranged to forward packets received by the first MAC device (28) to the second MAC device (32) for transmission to the second network (14), and
the MAC devices (28, 32) operate such that both can concurrently transmit packets and/or concurrently receive packets, or one of the MAC devices (28, 32) can receive packets while the other transmits packets, without collisions occurring between the first and second networks (12, 14),
the telephone set (10) having an address to receive data packets including voice data from one of the networks (12, 14) and being arranged to produce audio signals from the packets including voice data having the telephone set's (10) address as destination address and to output the audio signals,
the telephone set (10) can give higher priority to packets including voice data than other packets, the level of priority effecting the order in which the telephone set (10) queues in memory the associated packets for transmission to one of the first and second networks (12, 14), wherein the telephone set (10) preempts the transmission of the other data packets and first queues the voice data packets for transmission."
Claim 1 of the fifth auxiliary request reads as follows:
"A telephone set (10), comprising:
a first media access control (MAC) device (28) in electrical communication with a first network (12) via a first communication path (16) and being part of a first collision domain;
a second MAC device (32) in electrical communication with a second network (14) via a second communication path (18) and being part of a second collision domain; the telephone set (10) being arranged to maintain the first and the second collision domains separate;
an input port (26) for receiving audio signals from an input device (17); and
a packet controller (24) in communication with the first (28) and second (32) MAC devices and the input port (26), the packet controller (24) being arranged to generate packets including voice data from the audio signals received by the input port (26) for transmission to at least one of the first (28) and second (32) MAC devices,
wherein the packet controller (24) is arranged to forward packets received by the first MAC device (28) to the second MAC device (32) for transmission to the second network (14),
wherein the telephone set (10) includes
input/output devices (15) including a microphone, a keypad and a telephone handset, wherein audio signals enter the telephone set through one of the input/output devices (15) and, if the destination addresses in voice data packets indicate that the telephone set (10) is the targeted recipient, the telephone set (10) produces audio signals from the voice data in the packets and outputs the audio signals to one of the input/output devices (15) so that a local user of the telephone set (10) can hear the audio signals, and discards the received voice data packets."
Claim 1 of the sixth auxiliary request comprises all the features of claim 1 of the fourth auxiliary request and further adds:
"wherein the telephone set (10) includes
input/output devices (15) including a microphone, a keypad and a telephone handset, wherein audio signals enter the telephone set through one of the input/output devices (15) and, if the destination addresses in voice data packets indicate that the telephone set (10) is the targeted recipient, the telephone set (10) produces audio signals from the voice data in the packets and outputs the audio signals to one of the input/output devices (15) so that a local user of the telephone set (10) can hear the audio signals, and discards the received voice data packets".
Reasons for the Decision
1. The appeal is admissible.
2. FOURTH TO SIXTH AUXILIARY REQUESTS
These requests, replacing all the previous requests, were filed in response to the objections raised in the board's communication under Article 15(1) RPBA (cf. point IV above) and claim 1 of those requests further limits the underlying subject-matter in a convergent way. Therefore, the board admitted them into the appeal proceedings under Article 13(1) RPBA.
2.1 Claim 1 of the sixth auxiliary request, having the largest number of features and thus the narrowest scope compared to claim 1 of the other requests, is directed to a telephone set which has the following features, as labelled by the board:
A) a first MAC device in electrical communication with a first network via a first communication path and being part of a first collision domain;
B) a second MAC device in electrical communication with a second network via a second communication path and being part of a second collision domain;
C) the telephone set being arranged to maintain the first and the second collision domains separate;
D) an input port for receiving audio signals from an input device;
E) a packet controller in communication with the first and second MAC devices and the input port;
F) the packet controller being arranged to generate packets including voice data from the audio signals received by the input port for transmission to at least one of the first and second MAC devices and to forward packets received by the first MAC device to the second MAC device for transmission to the second network;
G) the telephone set comprising memory for storing packets;
H) the MAC devices operate such that both can concurrently transmit packets and/or concurrently receive packets, or one of the MAC devices can receive packets while the other transmits packets, without collisions occurring between the first and second networks;
I) the telephone set having an address to receive data packets including voice data from one of the networks and being arranged to produce audio signals from the packets including voice data having the telephone set's address as destination address and to output the audio signals;
J) the telephone set includes input/output devices including a microphone, a keypad and a telephone handset, wherein audio signals enter the telephone set through one of the input/output devices;
K) if the destination addresses in voice data packets indicate that the telephone set is the targeted recipient, the telephone set produces audio signals from the voice data in the packets and outputs the audio signals to one of the
input/output devices so that a local user of the telephone set can hear the audio signals, and discards the received voice data packets;
L) the telephone set can give higher priority to packets including voice data than other packets, the level of priority effecting the order in which the telephone set queues in memory the associated packets for transmission to one of the first and second networks, wherein the telephone set preempts the transmission of the other data packets and first queues the voice data packets for transmission.
Claim 1 of this request differs from claim 1 of the main request underlying the appealed decision in that it further comprises features G) to L).
Feature G) is supported e.g. by claim 2 of the application as filed whilst feature H) is based on page 15, lines 14-17. Feature I) is supported e.g. by page 9, lines 6-11 of the application as filed, while feature J) is based on page 8, lines 13-16 and page 11, lines 18-20. Feature K) is particularly based on page 12, lines 8-14 and feature L) is supported by page 21, line 21 to page 22, line 16 of the application as filed.
Thus, the above amendments comply with Article 123(2) EPC.
2.2 Article 52(1) EPC: Novelty and inventive step
In the board's judgment, claim 1 of all the pending requests do not meet the requirements of Article 52(1) EPC in conjunction with Article 56 EPC 1973, for the following reasons:
2.2.1 The board concurs with the finding of the decision under appeal (cf. section II.2) that D1 is the closest prior art for the claimed subject-matter.
2.2.2 Document D1 is related to an Ethernet hub, named "VOICEHUB", involving voice terminals and supporting integration of voice and data communication within and between different networks via distinct interfaces (see e.g. D1, Figure 1). Since the VOICEHUB is connected to voice terminals such as a general telephone and a LAN phone, it can well be read onto the "telephone set" as claimed.
As to features A) and B), the examining division found that D1 did not disclose two medium access control (MAC) devices within the VOICEHUB (cf. appealed decision, page 4, first paragraph). However, the board holds that both interfaces of the VOICEHUB in D1, namely the LAN interface ("LIF"), interfacing with a local area network (LAN), and the IP network interface ("RIF"), interfacing with the Internet, represent "10BASE-T Ethernet ports" (see Figure 1 in conjunction with Table 1, items 3 and 4) and thus correspond to two distinct MAC devices (i.e. Ethernet devices) connected with two different collision domains (i.e. the LAN and the IP network domains).
As regards feature C), the VOICEHUB interconnects distinct networks like the Ethernet-based LAN and the IP network (see e.g. Figure 1), which inherently constitute independent domains in which packet collisions only internal to those domains may occur. That means that different collision domains are kept separate by the VOICEHUB, in accordance with feature C).
Also, features D) and E) are anticipated by D1 since the VOICEHUB contains an input port (e.g. "LAN-PHONE interface LPIF") for receiving audio signals from an attached input device (e.g. "LAN-PHONE"), and a packet controller ("MPU") being in communication with the respective interfaces RIF, LIF, and LPIF (see e.g. Figure 2).
As to feature F), essentially specifying that voice packets originating from the telephone set itself may be sent to the connected networks whilst those packets arriving from the first network may be relayed to the second network, the appellant argued that D1 did not disclose any data connection or gateway functionality between the LAN and the IP network, i.e. that D1 failed to show that any data packets from the IP network received at the VOICEHUB could be forwarded to the LAN or vice versa (cf. statement setting out the grounds of appeal, section IV). The board cannot subscribe to this interpretation of D1. In fact, D1 teaches that the VOICEHUB implements voice communication by means of the Internet (see page 5, left-hand column, last paragraph), that inter-office communication may be performed via the integration of the VOICEHUB into a wide area network (WAN) such as an IP network (see page 6, section 2.2), and that a communication environment integrating data and voice traffic can be implemented on the LAN and IP networks (see page 6, section 2.4, first sentence). Document D1 also teaches that a FAX modem ("FAXM") is used for inter-connecting different LANs (see page 8, left-hand column, first paragraph). Contrary to the assertion of the appellant, the skilled reader reasonably understands from the above that
inter-communication between the IP network and the LAN, i.e. forwarding voice and data packets received at the IP interface RIF to the LAN interface LIF, is indeed performed in the system of D1, as required by feature F).
As regards feature G), D1 indicates that voice packets are supposed to be compressed and packetised (see page 8, right-hand column, second paragraph: "... IAM manages voice communication, including the compression and packeting of voice data ..."). This implies that the respective packets have to be stored in a typical memory prior to performing the corresponding compression and packeting operations, in compliance with feature G).
Concerning feature H), the board finds that simultaneous packet transmission/reception without causing mutual packet collisions, as suggested by feature H), is inherently executed in D1 by way of employing independently operating interfaces RIF and LIF connected to the separate LAN and IP networks (see e.g. Figure 2).
Feature I), which covers the case that the claimed telephone set represents the intended destination of the voice packets originating from either of the connected networks, is at least implicitly disclosed by D1 in view of the voice terminals attached to the VOICEHUB as potential voice packet recipients (see Figure 1). In order to receive those voice packets, a network address, being used as "destination address", has commonly to be assigned to a network device like the VOICEHUB such that it has its unique address to be able to receive voice packets, as mandated by feature I).
2.2.3 In summary, the board concludes that D1 anticipates features A) to I) of claim 1. However, features J) to L) are not directly and unambiguously derivable from D1. Consequently, the subject-matter of claim 1 of the sixth auxiliary request is new having regard to D1 (Article 54 EPC 1973).
2.2.4 Next, it has to be ascertained whether distinguishing features J) to L) provide a non-obvious synergistic technical effect and thus contribute to an inventive step. To this end, according to the "problem-solution approach" as generally applied, the technical effects associated with those features and the objective problem(s) to be solved are to be identified:
(a) The technical effect of feature J) is believed to be that the telephone set constitutes a combined telephone apparatus and network device, thus providing an integrated telephone device with added network functionality (cf. appellant's letter of reply dated 2 June 2014, section III). Accordingly, the objective problem to be solved by this feature may, with regard to D1, be regarded as "how to provide for a consolidated multi-functional VOICEHUB".
(b) Feature K) expands upon feature I) by stating that the received voice packets are supposed to be discarded in the event that the telephone set is the targeted recipient of the voice packets arriving from either of the connected networks. Its technical effect can therefore be seen in freeing up memory space not needed any more. The corresponding objective problem may be formulated as "how to avoid wasting internal memory capacity within the VOICEHUB in the event that voice packets are not to be forwarded".
(c) Feature L) allegedly provides the technical effect of facilitating on-time delivery of real-time data via a specific internal memory configuration (cf. page 22, lines 10-16 of the application as filed). However, as queue preemption (i.e. interruption of packet transmissions in a packet queue) in the field of digital data communications typically makes sense only if a single transmission buffer is utilised in a network device, the board considers the related objective technical problem to consist in "how to facilitate on-time delivery of real-time data in the event that the VOICEHUB comprises only a single transmit buffer".
It is apparent from the above that distinguishing features J) to L) do not interact with each other in such a manner that they give rise to an overall synergistic effect, since the corresponding implementation measures may be enforced in an entirely independent way to solve unrelated technical problems. Therefore, the board considers that the distinguishing features are associated with separate technical effects and thus distinct partial objective problems to be solved. This means in turn, in accordance with established case law, that the contribution of those features to an inventive step can be individually assessed, i.e. on the merits of each distinguishing feature per se.
The appellant argued at the oral proceedings before the board that the distinguishing features had a combined technical effect consisting in both collision avoidance and a simpler prioritisation of voice packets. However, this argument must fail since, firstly, collision avoidance is already achieved by features A) to C), which are also disclosed in D1 (cf. point 2.2.22.2.2 above), and, secondly, because the appellant could not plausibly argue why a queue preemption scheme, which typically requires intricate transmission interruption and resumption operations to be applied within a single queue, should credibly be simpler than a prioritisation scheme consisting of two individually controlled queues. Thus, the technical problem, as formulated by the appellant, cannot qualify as an acceptable objective technical problem to be solved in the present case.
2.2.5 As to feature J), the skilled person would notice that the VOICEHUB of D1 accommodates telephone terminals (see in particular page 6, section 2.3 and Figure 1) as they are connected to the VOICEHUB via different input and output ports (e.g. "LPIF", "APIF"). Such terminals inherently comprise a microphone, a keypad and a telephone handset, as required by feature J). Even though the board concedes that D1 fails to demonstrate clearly that those terminals are "included", as claimed, within the VOICEHUB, the board holds that the incorporation of those terminals into the same "box", i.e. the VOICEHUB, represents an obvious implementation detail, the application of which depends merely on practical constraints such as implementation complexity, user preferences or standardisation frameworks. The latter point was not traversed in substance by the appellant at the oral proceedings before the board. Hence, feature J) cannot contribute to an inventive step.
2.2.6 Regarding feature K), the board considers that discarding or forwarding the received voice packets in the system under consideration hinges solely on whether the telephone set is intended to be a communication end-device or an intermediary device for a particular voice data connection established in that system. Furthermore, D1 teaches that the VOICEHUB can be used for both intra-communication and inter-communication (see e.g. page 5, section 2.1 and page 6, section 2.2). As a consequence, feature K) may not render the subject-matter of claim 1 inventive over D1 either.
2.2.7 As to feature L), i.e. preempting non-voice packets in favour of prioritised voice packets within the telephone set's memory, the appellant contended that the disclosure of D1, namely according to page 7, right-hand column, last paragraph and page 9, left-hand column, last paragraph in combination with Figures 2 and 4, led away from the solution according to feature L), because this teaching clearly demonstrated that two distinct ports were used in the VOICEHUB, i.e. one preferred port ("UPLINK-B") used only for voice packets and one port ("UPLINK-A") obviously used for non-voice packets, rather than one memory being used together with the preemption technique as claimed. Using two ports, i.e. two hardware connections, at the VOICEHUB, however, automatically meant that a different network infrastructure and a distinct interplay between the VOICEHUB and the router to which the voice packets have to be sent next (according to Figure 4 of D1) is in fact employed.
The board first notes that the disclosure of D1 referred to by the appellant, i.e. page 7, right-hand column, last paragraph, in fact reads:
"... When the router has an interface that can control priority for two ports, RIF allows using the preferred port only for voice." (emphasis added),
while page 9, left-hand column, last paragraph (under the heading "Developments in Future") states:
"... Connecting VOICEHUB to an intranet creates no problems because router configuration makes voice priority control possible ..." (emphasis added).
From the above passages the skilled person would understand that the VOICEHUB supports, as an example, two priority-specific ports by reason only of the fact that the next router attached to this VOICEHUB (see D1, Figure 4) has an interface being able to perform priority control for two ports. Since, moreover, each port must commonly have its corresponding transmit buffer, the above disclosure implies the use of two transmit queues at the VOICEHUB. In view of the partial objective problem associated with feature L) as set out in point 2.2.42.2.4 , item (c)(c) above, a legitimate question is what the skilled person would have envisaged at the present application's priority date if the VOICEHUB comprised only a single transmit buffer or, equivalently, if the corresponding router did not possess an "interface that can control priority for two ports" and did not make "voice control possible", in contrast to the assumptions made in the respective passages of D1.
As regards the internal buffer configuration of a network device, the skilled person in the field of digital data communications would know from his common general knowledge that there are, in principle, only two feasible ways of implementing priority-based queueing under the present conditions, namely (i) using two queues for storing prioritised packets in one queue and non-prioritised packets in the other queue to subsequently select the prioritised packets first for transmission, as obviously done in D1, or (ii) using a single queue for storing both prioritised and
non-prioritised packets upon their arrival and subsequently ensuring that the prioritised packets are selected for being forwarded first, as feature L) implies. These generally applicable storing options are also bolstered by the teaching of the application itself (see e.g. page 16, lines 14-22 in conjunction with Fig. 3 of the application as filed):
"Each transmit region 42,48 is partitioned into a priority block 45,55 for packets having priority and a general block 47,57 for non-prioritized packets. Other ways of using the memory 36 to implement priority are contemplated. For example, the memory 36 can be organized as a buffer to store packets as the packets arrive at the telephone set. Rather than evaluate each packet as that packet arrives to determine the block of memory in which to store that packet, each packet can be directly stored in the memory 36 upon arrival and subsequently examined for prioritizing when selecting a packet to forward to one of the I/O devices."
This was furthermore not contested by the appellant at the oral proceedings before the board. Confronted with the corresponding objective problem and starting out from D1, the board however considers that the skilled person would have only one viable solution at his disposal to perform priority-based transmission of packets in such a case, namely option (ii) relating to the use of a single transmit buffer. Moreover, the skilled person would be aware that preferential (i.e. prior) transmission of a prioritised voice packet, which arrived at the single transmit queue later than any non-prioritised data packet at the head of that queue, would only be rendered possible if an initiated transmission of the non-prioritised data packet was (at least temporarily) preempted. Therefore, he would come up with the solution according to feature L). Hence, the conclusion that only one option is suitable for solving the respective objective problem constitutes sufficient reason why feature L) likewise cannot contribute to an inventive step.
2.2.8 In view of the above, the board concludes that distinguishing features J) to L) are associated with distinct partial objective technical problems and that their solutions constitute a mere juxtaposition of obvious implementation measures which do not produce any surprising synergistic effect, since there is no combined technical effect which differs from the sum of the effects caused by the individual features J) to L) per se. Hence, the subject-matter of claim 1 of the sixth auxiliary request does not involve an inventive step having regard to D1 and the skilled person's common general knowledge (Article 56 EPC 1973).
2.3 As to the remaining requests, claim 1 of the pending fourth auxiliary request differs from that of the sixth auxiliary request in that it does not comprise features J) and K) whilst claim 1 of the fifth auxiliary request lacks features G), H), I), and L). Consequently, since the subject-matter of claim 1 of the remaining requests is broader in scope, it is self-evidently not inventive either in view of D1.
2.4 In conclusion, none of the pending requests are allowable under Article 56 EPC 1973.
Order
For these reasons it is decided that:
The appeal is dismissed.