International Journal of Ad Hoc & Sensor Wireless Networks ========================================================== Special Issue for MSN05 PAPER REVIEW FORM ----------------- Title: Signaling and Routing Protocols for iCAR Author(s): Hongyi Wu, Chunming Qiao, Sudhir S. Dixit Reviewer: Bogdan Carbunar Date To Be Returned: 10 Jan 06 --------------------------------------------------------------------------- -- I. NUMERICAL RATING OF THE PAPER: --------------------------------------------------------------------------- Rating Category Your Rating Scale Definition --------------------------------------------------------------------------- Level of Reader Interest 4=Very good --------------------------------------------------------------------------- Evaluation of Work and Contribution 4=Good solid work of some importance --------------------------------------------------------------------------- Originality Novelty 4=Contains an original contribution --------------------------------------------------------------------------- Practical Utility 3=Good --------------------------------------------------------------------------- Quality of Presentation 4=Basically well written --------------------------------------------------------------------------- Technical Correctness 4=Good --------------------------------------------------------------------------- Overall Rating (could be .5) 4=Accept (good quality) --------------------------------------------------------------------------- II. SPECIFIC COMMENTS & SUGGESTIONS (to be made available to the author(s)): ------------------------------------ The paper presents a novel idea for integrating cellular and Wi-Fi technologies. Mobile hosts inside the cellular coverage of a saturated cellular base station can use specifically installed ad hoc relaying stations ARSs in order to obtain service from neighboring, less crowded cells. The paper provides 3 algorithms for requesting a connection, routing in such a hybrid network and reserving and releasing bandwidth along the chose route. The paper is well written and easy to follow. This work is certainly important and previous versions of it are already being widely cited. The paper has though a few problems that need to be addressed. They are presented in the following. The paper does not address the issue of choosing the best relaying path in terms of achieved throughput. This is important, especially if the devices are used to access the internet. Then other issues need to be considered, such as modelling and computing interference generated by existing flows through ARSs. The second and third protocols generate obviously a lot of traffic. I wonder if more clever ways could be devised to decrease it. Synchronization issues may need to addressed in cases where multiple paths may be reserved by a host. Even though not all the paths may be used, other hosts may need those resources. It would be interesting to investigate how multiple simultaneous requests, possibly from neighboring devices, neighbors to the same ARS, can interfere with each other. Protocol 3 uses a depth first approach for finding routes in order to avoid flooding. This instead will generate longer delays. Of course, a timer prevents long delays with the drawback of potentially missing available routes. Again, routes with higher aggregated throughput should be given priority instead of simply shorter ones. Secondary relaying is also quite expensive, since all active devices are contacted. Moreover, the BTS chooses the first device that responded to its request instead of choosing the one that found the best alternative in terms of throughput. Other metrics could also be devised in this context. III. CONFIDENTIAL COMMENTS (IF ANY) to be withheld from the author(s): ------------------------------------ Comments given under THIS item are for the EDITORS ONLY (to be withheld from the authors).