APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.

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1 UNITED STATES PATENT AND TRADEMARK OFFICE UNITED STATES DEPARTMENT OF COMMERCE United States Patent and Trademark Office Address: COMMISSIONER FOR PATENTS P.O. Box 1450 Alexandria, Virginia APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO. 11/254,172 10/19/2005 Stephen J. Grant P20746-US1 / /09/2012 COATS & BENNETT, PLLC 1400 Crescent Green, Suite 300 Cary, NC EXAMINER CHAMBERS, TANGELA T ART UNIT PAPER NUMBER 2617 MAIL DATE DELIVERY MODE 04/09/2012 PAPER Please find below and/or attached an Office communication concerning this application or proceeding. The time period for reply, if any, is set in the attached communication. PTOL-90A (Rev. 04/07)

2 UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE BOARD OF PATENT APPEALS AND INTERFERENCES Ex parte STEPHEN J. GRANT, JUNG-FU CHENG, YI-PIN ERIC WANG, KARL J. MOLNAR, and LEONID KRASNY Appeal Technology Center 2600 Before JOHN A. JEFFERY, JEFFREY S. SMITH, and GLENN J. PERRY, Administrative Patent Judges. PERRY, Administrative Patent Judge. DECISION ON APPEAL

3 Appellants appeal under 35 U.S.C. 134(a) from the Examiner s rejection of claims We have jurisdiction under 35 U.S.C. 6(b). We reverse. STATEMENT OF THE CASE In a mobile communication network including a base station, 1 capable of operating in multiple transmission modes, 2 and remote (e.g. mobile) stations. 3 Remote stations provide downlink 4 channel quality feedback on an uplink 5 to the base station. Using this feedback, the base station controls communications between the base station and remote stations in a manner that takes best advantage of higher quality channels. Feedback from many mobile stations can clutter uplink channels from the remote stations to the base station. The invention purports to obviate feedback clutter by providing baseline feedback for one downlink transmission mode (e.g., a particular antenna arrangement) and follow up with additional feedback for other downlink transmission modes (other antenna arrangements) only when the baseline feedback exceeds a threshold. See Abstract; Spec. [005]- [006]. Claim 1 is illustrative with key limitations emphasized: 1. A method implemented by a receiving station in a mobile communication network of controlling feedback load on an uplink channel, said method comprising: 1 Referred to in the specification as a transmitting station. 2 As used in the specification, modes refers to combinations of its multiple antennas. 3 Referred to in the specification as receiving stations. 4 Base to remote communication. 5 Remote to base communication. 2

4 providing channel quality feedback to a multiple antenna transmitting station for a first downlink transmission mode corresponding to a first antenna configuration; generating a performance metric; and if the performance metric exceeds a first threshold, providing channel quality feedback to said transmitting station for one or more additional downlink transmission modes. The Examiner relies on the following as evidence of unpatentability: Walton US 2002/ A1 Nov. 28, 2002 (filed May 16, 2001) Onggosanusi US 2005/ A1 Sept. 22, 2005 (filed Mar. 21, 2005) THE REJECTION The Examiner rejected claims 1-30, of which claims 1, 12, 23, and 27 are independent, under 35 U.S.C. 103(a) as obvious over Walton in view of Onggosanusi. Ans Both Walton and Onggosanusi are directed to wireless networks. Walton describes a base station 104 communicating with plural remote stations referred to as terminal stations 106. See Walton [0026]. Upon receiving a downlink transmission from the base station, a terminal station provides an uplink message to the base station indicating a quality measure of the channel on which the downlink transmission was received. The base station uses quality information collected from the terminal stations to 6 Throughout this opinion, we refer to the Appeal Brief filed April 10, 2009, the Examiner s Answer mailed August 4, 2009, and the Reply Brief filed September 30,

5 schedule uplink transmissions from the terminal stations so as to take advantage of channel conditions. It does so by forming hypotheses (see Walton Fig. 2) corresponding to groups of terminal stations (Walton Fig. 2, step 214) for transmitting data to be uplinked to the base station. It evaluates these hypotheses based on channel conditions and determines from those evaluations how communication should be conducted. See Walton Fig. 2, step 228. As uplink communications are received, channel quality is updated so that future communication decisions become even better. See Walton Fig. 2, step 230. The Onggosanusi wireless network includes a base station 210 (see Onggosanusi Fig. 2 and [0024]-[0025]) in communication with plural remote stations referred to as user equipment 205 (UE). Each UE, upon receiving a downlink message, (1) measures a channel condition, CQI (Onggosanusi Fig. 3, step 325), and (2) transmits the CQI to the base station. See Onggosanusi Fig. 3, step 330. The base station uses collective CQI data to schedule uplink transmissions or downlink transmissions. Claims 1 and 12 Examiner s Findings The Examiner applied the references first to independent claims 1 and 12 as a group because they have substantial commonality of core requirements. Ans The Examiner applied the references separately to independent claims 23 and 27 Ans We first address the Examiner s rejection as to claims 1 and 12. The Examiner reads claims 1 and 12 on Walton in two different ways. First, the Examiner reads claims 1 and 12 on Walton by mapping the 4

6 claimed uplink to Walton s downlink. Ans Claim 1 is illustrative and the Examiner s first reading of claim 1 on Walton is summarized in the following Table 1: Claim 1 The Examiner s Application of Walton at Ans A method implemented by a receiving station in a mobile communication network of controlling feedback load on an uplink channel, said method comprising: providing channel quality feedback to a multiple antenna transmitting station for a first downlink transmission mode corresponding to a first antenna configuration; generating a performance metric; and if the performance metric exceeds a first threshold, providing channel quality feedback to said transmitting station for one or more additional downlink transmission modes. The claimed uplink corresponds to Walton s downlink from base station 104 to mobile terminals 106. The claimed multiple antenna transmitting station is equated to a group of terminals, each having at least one antenna. The claimed first downlink transmission mode corresponds to a communication from one or more terminals to the base station which, as a group, constitute a first antenna configuration (uplink communication in Walton). The claimed performance metric corresponds to a hypothesis (group of terminals designated for a particular transmission) for evaluation. Providing feedback for additional modes corresponds to Walton s scheduling a group of terminals for communication to the base station Table 1 Examiner s reading of claim 1 on Walton The Examiner finds that with the above reading of claim 1 on Walton, there is no transmitter to provide feedback from the base station to the terminals. Ans. 4. The Examiner relies upon Onggosanusi to provide the missing teaching. Id. In the Examiner s Summary of Appellant Argument and Examiner s Response portion of the Answer, beginning at page 9, the Examiner appears to read claims 1 and 12 on Walton using a more traditional reading of 5

7 Walton in which Walton provides feedback from a mobile station (presumably the Examiner is referring to terminals T) to the base station on an uplink. The base station uses the information to decide how to transmit to the mobile on the downlink. Appellants Contentions Appellants argue that: 1) neither Walton nor Onggosanusi discloses the use of a feedback threshold to control an amount of feedback on an uplink channel that characterizes a downlink transmission; 2) neither Walton nor Onggosanusi compares performance with a threshold to control feedback; and 3) neither Walton nor Onggosanusi provides channel feedback for different transmission modes corresponding to different antenna configurations. App. Br. 6. Thus, the issues before us are: ISSUES 1. Do Walton and Onggosanusi collectively teach the use of a threshold to control downlink-characterizing feedback and sending that feedback on an uplink channel? 2. Do Walton and Onggosanusi collectively teach providing feedback for different transmission modes and provide feedback for additional transmission modes only if a baseline feedback exceeds the threshold? ANALYSIS At best, the Examiner s first reading of claim 1 on Walton is strained. We believe that an ordinarily skilled artisan of mobile network design would 6

8 read Walton as transmitting on a downlink from base station 104 to terminals T and receiving channel quality feedback from terminals T to the base station on an uplink in order to characterize the quality of a communication channel. We do not view Walton s terminals as constituting a multiple antenna base station. Nor do we view scheduling of terminals T for transmission to be equivalent to the claimed additional feedback for additional transmission modes. A fair and reasonable reading of Walton is that scheduling of transmitters is the appropriate reaction to feedback (to take advantage of channel quality previously determined and fed back to the transmitter). It is not, itself, feedback. The Examiner s later reading of Walton, beginning at page 9 of the Answer, hits closer to the mark for claim 1. We agree with the Examiner that Walton s base station derives a CSI which is a measure of channel quality. See Walton [0112] for how CSI is calculated. The base station uses the CSI to determine how to schedule uplink and downlink transmissions. Furthermore, we agree that Walton teaches controlling an amount of feedback based on CSI. See Walton [0159] infra. The CSI is reported from the base station 104 to a terminal T using various transmission schemes. It is explained at Walton [0159] as follows: [0159] The CSI may be reported to the scheduled terminal using various CSI transmission schemes. For example, the CSI may be sent in full, differentially, or a combination thereof. In one embodiment, CSI is reported periodically, and differential updates are sent based on the prior transmitted CSI. In another embodiment, the CSI is sent only when there is a change (e.g., if the change exceeds a particular threshold), which may lower the effective rate of the feedback channel. As an example, the date rate and/or coding and modulation scheme may be sent back (e.g., differentially) only 7

9 when they change. Other compression and feedback channel error recovery techniques to reduce the amount of data to be fed back for CSI may also be used and are within the scope of the invention. The threshold referred to in Walton does not correspond to the claimed threshold. We interpret this portion of Walton to say that CSI may be transmitted when a change in CSI exceeds a threshold in order to reduce the amount of data to be fed back. This is consistent with a goal of the claimed invention, namely to de-clutter uplink feedback. However, we part company with the Examiner in drawing the conclusion that Walton teaches obtaining feedback regarding a first downlink transmission mode (a first combination of antennas) and then deciding whether or not to obtain additional feedback corresponding to other transmission modes (other antenna arrangements) based on comparing the feedback for the first transmission mode with a determined threshold. The Walton threshold is simply a threshold used to decide whether CSI feedback has sufficiently changed from a previously transmitted level of CSI feedback to merit updating the CSI value. There is no relationship drawn between an initial value of CSI corresponding to one transmission mode and follow up feedback corresponding to another transmission mode. Onggosanusi does not cure this deficiency. We therefore do not sustain the Examiner s rejection of claim 1 based on Walton and Onggosanusi, or of claims 2-11 dependent thereon. This analysis applies as well to claim 12 and its dependent claims and we therefore do not sustain that rejection as well. 8

10 Claims 23 and 27 Claims 23 and 27 focus on generating a feedback threshold and sending it to one or more remote stations, the feedback threshold to be used to control an amount of feedback to be uplinked to the base station. There is no claimed relationship between the feedback threshold and corresponding transmission modes. Claim 23 is illustrative (emphases added). 23. A base station in a mobile communication network comprising: a controller configured to generate a feedback threshold based on conditions associated with a downlink channel for one or more remote stations; and a transmitter configured to transmit the feedback threshold to one or more of the remote stations to control an amount of channel quality feedback received at a multiple antenna transmitting station from the remote stations. With regard to independent claims 23 and 27, the Examiner finds (Ans. 4-5) that Walton discloses a base station (104) in communication with terminals (106) in a communication network (Walton [0026]; [0028]). Walton discusses a base station in a communication system and a controller configured to generate a feedback threshold based on conditions associated with a downlink channel for one or more remote stations (see Walton Fig. 5, [0037], [0038], [0046], [0106], [0113], [0129], [0151], [0159]) showing a scheduler (564), i.e. controller, connected to the receiver and transmitter, generating a hypothesis metric, i.e. performance metric, based on terminal and system performance metrics and evaluating the hypothesis metric, e.g. using a threshold, and based on the result schedule a group of terminals for transmission)) and transmit the feedback threshold to one or more of the remote stations to control an amount of channel quality feedback received at 9

11 a multiple antenna transmitting station from the remote stations (Walton [0037], [0038], [0046], [0049], [0113], [0129], [0159] (discussing that the scheduler regulates the amount of channel quality feedback sent from the terminals to the base system to not to impact performance)). The Examiner finds that Walton does not disclose a transmitter to transmit signals to the remote station. Ans. 5. The Examiner looks to Onggosanusi to supplement Walton by teaching a transmitter. Id. (citing Onggosanusi ). The Examiner urges that it would have been obvious to one skilled in the art at the time the invention was made to modify Walton to include a transmitter, as taught by Onggosanusi, thus allowing better use of the system. Id. (citing Onggosanusi 0003). Appellants urge that Walton does not disclose transmitting a feedback threshold from a base station to a mobile station to control the amount of channel quality feedback transmitted by the mobile station to the base station, as required by independent claims 23 and 27. App. Br. 9-10; Reply Br Providing scheduled mobile terminals with a particular rate for transmitting data, which dictates the data rate of future transmissions from the mobile terminal, is said not to be the same as providing the claimed feedback threshold to a remote station. Reply Br. 3. We agree with the Appellants. Providing a data rate to mobile stations is an acknowledgement of the channel quality previously determined and an instruction to communicate at a data rate consistent with that channel quality. Providing a data rate does not suggest a threshold that a mobile station should use to determine if additional feedback is sought by the base station. We see nothing in Walton that suggests that a terminal alter its sending of feedback to base station 104 based on a data rate sent to it by the 10

12 base station. Thus, it is not a threshold in the sense required by claims 23 and 27. We must therefore reverse the rejection of claims 23 and 27, as well as their respective dependent claims and CONCLUSION The Examiner erred in rejecting claims 1-30 under 103. ORDER The Examiner s decision rejecting claims 1-30 is reversed. REVERSED babc 11