this paper was submitted on
2 points (100% like it)
2 up votes 0 down votes

papers

subscribe8 readers

Welcome to the public review site of papers appearing in MobiSys 2012. Here you can find the public review written by a PC member for each paper and the authors' rebuttal to it. You can comment on any of them or add your own opinion. Finally you can vote to "like" or "dislike" a paper by clicking the up or down arrows next to its title.

all 3 comments

[–]dongmian 2 points3 points ago

sorry, this has been archived and can no longer be voted on

DRX mode in RRC_connected state has not been implemented in LTE base stations yet (for both ATT and Verizon). The providers are not fully convinced that DRX in such short periods can result in reasonable energy savings when supporting DRX in RRC_connected state will lead to huge scheduling complexity in base stations.

Therefore, this paper is a very timely study to demonstrate the benefit of using DRX mode. My only concern is that the experiment reported in the paper is limited in its scale, only involving 20 users. Such small number of users can not reveal issues in a real base station, such as scheduling delay, etc. A back-of-the-envelope calculation should be useful to demonstrate how the conclusions of this paper will scale when user number increases to a reasonable level.

Also, I suggest the authors leverage the log viewer provided by Qualcomm to access the detailed timing information in the LTE modem. It should generate more accurate result than the current approach reported in the paper does.

[–]ConferenceQA 1 point2 points ago

sorry, this has been archived and can no longer be voted on

Question from Clay Shepard, Rice University: ... We were under the impression that the DRX mode is not currently implemented... [asks regarding experimental setup].

Answer: [Shows graph] These clear spikes demonstrates the DRX mode must be enabled.

Follow up: What phone did you use?

Answer: Thunderbolt

Follow up: [Ask regarding trace based analysis]

Answer: The same trace was appiled to different communication modes.

[–]ConferenceQA 1 point2 points ago

sorry, this has been archived and can no longer be voted on

Question from Rajarshi Gupta, Qualcomm (moderator): When you compare LTE with WIFI, how about that WiFI communicates across a room versus LTE across a city? [Wouldn't that account for part of the power difference?].

Answer: [Agrees] Transmitting power for LTE must be higher than for WiFi. Here trying to compare and see how much difference there is. In the future, it should be possible to make LTE more power efficient. We don't expect LTE to be more efficient than WiFi, but more efficient than it currently is.