From secon-tpc-chairs@comsoc.org Tue Feb 27 12:01:33 2007 Date: Tue, 27 Feb 2007 13:32:16 -0500 From: secon-tpc-chairs@comsoc.org To: Xue Yang Cc: Nitin Vaidya , almeroth@cs.ucsb.edu, rhk@cs.uiuc.edu, almeroth@cs.ucsb.edu, rhk@cs.uiuc.edu Subject: [SECON '07] Your paper #1569015945 Dear Ms. Xue Yang: Congratulations - your paper #1569015945 ('A Spatial Backoff Algorithm Using the Joint Control of Carrier Sense Threshold and Transmission Rate') submitted to the Fourth Annual IEEE Communications Society Conference on Sensor, Mesh, and Ad Hoc Communications and Networks has been accepted. With approximately 300 submitted papers and 60 accepted, the acceptance rate was roughly 20%. The reviews are attached below and can also be found at http://edas.info/showPaper.php?m=1569015945. Please take the reviewers' feedback into account in preparing the final version of your paper. In order to ensure that the quality of SECON 2007 is as high as it can be, please do as much as possible to improve the quality of the paper in response to reviewer feedback. The submission deadline for the camera-ready copy of your paper is March 22nd, 2007 at 11:59pm PDT. This is a hard deadline, and failure to upload your paper by then WILL result in its withdrawal from the conference program. Please note that registration by one author at a non-student/full rate is required prior to camera-ready paper submission (see the Author Kit for additional details). After registering, you will receive a code that you will need for the upload of the final version of your paper. You will also need to submit an IEEE copyright form as part of the submission process. Detailed instructions on how to format and submit the paper, as well as a link to the conference registration website, can be found at: http://www.ieee-secon.org/2007/authorskit.html The link is still listed as TBA, but will be available soon. In the meantime, the key details for preparing the camera ready submission are: The page limit is 10 (TEN) 2-column pages with 11 pt Times Roman font, formatted in IEEE conference style. PLEASE NOTE: formatting will be checked for consistency. Incorrectly formatted papers will be rejected. We are happy to have such a high-quality program this year, and look forward to welcoming you in San Diego in June for a great conference. Regards, SECON 2007 TPC Chairs ===== Review ===== *** Recommendation: Your overall rating of paper. (Try to give as few borderlines as possible) Weak Accept (3) *** Confidence: What is your level of familiarity with paper topic? High (2) *** Relevance: Is this paper relevant to SECON? Will it be of interest to SECON attendees? Yes, definately (2) *** Detailed Comments: Please provide detailed comments that will be helpful to the TPC for assessing the paper, as well as feedback to the authors. In this paper, the authors propose spatial backoff as an alternative approach to address medium access control along the spatial dimension. The proposed dynamic spatial backoff algorithm jointly controls the carrier sensing threshold and the transmission rate. It is a novel concept to treat the spatial separation using contention resolution. However, this paper can not justify the optimization of proposed scheme. Detailed comments follow: 1). The structure of section A in Page 4. Since the definition of eq. (1) does not change with the different error reasons, it is better to move the part of the description of the two reasons to the beginning of Section A. 2) in Page 5. 2) The design of the CS threshold in this paper depends highly on the assumption that the transmitters experiences the same interference with the receivers. However, in practical systems, the interference a transmitter experiences may be quite different from that of the receiver. Will this scenario have significant effects on the design parameters? 3) In the performance evaluation, RTS and CTS are disabled, which makes the simulation results not very convincing since RTS and CTS have the function of spatial reuse. It would be better to include the function of RTS and CTS and compare the performance of the proposed dynamic spatial backoff algorithm with other classic methods. ===== Review ===== *** Recommendation: Your overall rating of paper. (Try to give as few borderlines as possible) Weak Accept (3) *** Confidence: What is your level of familiarity with paper topic? Medium (1) *** Relevance: Is this paper relevant to SECON? Will it be of interest to SECON attendees? Yes, definately (2) *** Detailed Comments: Please provide detailed comments that will be helpful to the TPC for assessing the paper, as well as feedback to the authors. This paper deals with the problem of how to maximize the spatial reuse in multihop networks. Different from previous work, the authors include both multi-rate capability and carrier sensing sensitivity. It is quite interesting since conventional approaches in general have been taken consider either transmit power or carrier sensing sensibility alone. This work provides a new perspective on this problem. The paper first addresses the difficulty of the joint optimization with two different parameters. Then a heuristic search algorithm is proposed, which is called dynamic spatial backoff algorithm. Even though the proposal cannot fix MAC protocolâ~@~Ys optimum operating point, it at least makes it stay around there by following established rules. Some feedback to strengthen the paper - The interference model used in performance evaluation does not include any fading effects. It would be helpful to obtain more wireless-friendly results from ns-2. - The analysis behind the obtained numerical results of the proposed would give a lot more insight. More detail should be provided. - The authors should justify the assumptions (approximation of an interference level of a receiver to that of a transmitter, and inference that consequently reduced search space has near-optimal candidates with high probability) to simplify the algorithm design in the evaluation section. ===== Review ===== *** Recommendation: Your overall rating of paper. (Try to give as few borderlines as possible) Strong accept (4) *** Confidence: What is your level of familiarity with paper topic? High (2) *** Relevance: Is this paper relevant to SECON? Will it be of interest to SECON attendees? Yes, definately (2) *** Detailed Comments: Please provide detailed comments that will be helpful to the TPC for assessing the paper, as well as feedback to the authors. This paper proposes mechanisms for spacial backoff based on efficiently choosing the best combination of carrier sense threshold and transmission rate. On p. 4, paragraph 3, in the second column, the last but one sentence states the assumption that the interference at the receiver is based on the interference at the source. That is assumption is very inaccurate. How strongly does it influence the output of the algorithm? Please increase the size of your figures! The paper is very well-written. It studies an important problem and provides a good practical solution and a good evaluation of the proposed solution. ===== Review ===== *** Recommendation: Your overall rating of paper. (Try to give as few borderlines as possible) Borderline (2) *** Confidence: What is your level of familiarity with paper topic? Medium (1) *** Relevance: Is this paper relevant to SECON? Will it be of interest to SECON attendees? Somewhat (1) *** Detailed Comments: Please provide detailed comments that will be helpful to the TPC for assessing the paper, as well as feedback to the authors. The topic of this paper is not closely related to SECON. In this paper, the authors didn't provide any emphasis or discussion regarding ad hoc, mesh, or sensor networks. The authors proposed an algorithm with joint rate adaptation and carrier-sense-threshold adjustment, which is based on the observation in their previous paper: low rate with high carrier-sense (CS) threshold can have higher throughput due to relatively-lower MAC overhead and higher spatial reuse. The problem considered in this paper is dynamic adjustment of rate and CS threshold. However, the problem is not clearly defined in this paper. Besides, "spatial backoff" doesn't seem to be an appropriate name since backoff is not related to the algorithm. The motivation of the algorithm is not strong enough. The authors didn't provide a convincing reason to increase spatial reuse with rate and CS threshold, instead of power control. There are still some unclear points about the solution. For example, the authors implicitly assume a corresponding scale of rate control and CS threshold adjustment. However, this is not the normal case. In fact, most drivers of 802.11 products, such as MadWifi, don't support manual adjustment of CS threshold. The core algorithm, i.e. 4 rules to adjust rate or CS threshold, doesn't seem to be very novel. It can be regarded as the extension of ARF rate adaptation algorithm with an additional dimension, i.e. CS threshold. Besides, the authors use transmitter-side interference to approximate receiver-side interference without using RTS/CTS. This makes the algorithm suffer from location-dependent contention and hidden terminal problem. There's no justification of reasons to choose such a transmitter-centric approach. As for performance evaluation, there're still some unclear details, such as the derivation of SINR thresholds in Table I. The performance improvement is not very surprising. Simply ARF provide similar performance with appropriate CS threshold value. Only one-hop flows are considered in the evaluation. The impacts from multi-hopping and intra-flow contention are not discussed. The presentation of this paper is not very good. The motivation and contribution of this paper are not highlighted in the abstract and introduction. Most figures, especially those of performance evaluation, are too small. ===== TPC Review =====