1. doc.: IEEE 802.11-13/0089r0 Submission Listen interval update Jan 2013 Slide 1 Date: 2013-01-13 Authors: Jinsoo Choi, LG Electronics

2. doc.: IEEE 802.11-13/0089r0 Submission Jan 2013 Jinsoo Choi, LG ElectronicsSlide 2

3. doc.: IEEE 802.11-13/0089r0 Submission Jan 2013 Jinsoo Choi, LG ElectronicsSlide 3

4. doc.: IEEE 802.11-13/0089r0 Submission Introduction A STA can operate as different behavior or pattern based on its demand, for example operating as a TIM mode or as a Non-TIM mode [1] –STA’s traffic pattern or remaining battery may be changed –Behavior can change from receiving beacon/control frames from AP to being sleep mode for power saving Listen interval is related to STA’s wakeup interval for power saving, which is mandatorily transmitted in the association request frame and now is able to have very wide range [2] –A STA should behave with power management operation based on the established listen interval –AP can utilize that information for its operation by getting knowledge of STA’s behavior If the STA want to change its operation mode with different wakeup interval for power saving, the listen interval is need to be updated but we don’t have an efficient mechanism to do that (possibly using reassociation request frame but causing unnecessary overhead) In this contribution, we propose the listen interval update procedure Jan 2013 Slide 4Jinsoo Choi, LG Electronics

5. doc.: IEEE 802.11-13/0089r0 Submission Case: change of operation mode When a STA changes its operation mode (e.g. TIM mode to Non-TIM mode), then the STA needs to update its listen interval for power saving and is able to get the buffered data by informing the updated value to AP –Changing of TIM/Non-TIM mode could require far different listen interval so it’s likely to update that (e.g. some sensor devices in Non-TIM mode at a duty cycle of several days/months) –AP can discard and buffer the traffic for the STA based on the updated listen interval Jan 2013 Slide 5Jinsoo Choi, LG Electronics

6. doc.: IEEE 802.11-13/0089r0 Submission Frame for informing the update Option1: reusing reassociation request frame -Pros: reuse existing AP code for processing reassociation request -Cons: burden on overhead Option2: conditionally including the information into a existing frame -Pros: no need to define a new frame format and minimized overhead -Cons: need to clarify the usage from the original frame format (but easily implemented as an option) -Suggestion: optionally adding listen interval field in the AID switch request frame [3]  Consideration on wakeup interval and listen interval In the case of TIM STAs, wakeup interval (linked to AID group interval) in the AID request IE could replace listen interval because they should listen the beacon frame having the TIM segmentation. For Non-TIM STAs, however, listen interval should be updated for power saving while wakeup interval would not be needed because they’re not going to listen the beacon frame having the TIM segmentation.  Conditional update by TIM to Non-TIM mode change: B3 set to 1 + 2 octet listen interval  In the case of no AID switching, the reserved bit could be used to indicate the status (possibly with other cases like addition or deletion, etc). Jan 2013 Jinsoo Choi, LG ElectronicsSlide 6

7. doc.: IEEE 802.11-13/0089r0 Submission Proposal A STA in power save mode can update the listen interval when it changes its operation mode from TIM to Non- TIM mode A STA may inform an AP of the updated listen interval and the AP may response to the STA The informing frame format can be designed as –Conditionally including the information into a existing frame (e.g. AID switch request/response frame) Jan 2013 Slide 7Jinsoo Choi, LG Electronics

8. doc.: IEEE 802.11-13/0089r0 Submission Conclusion Jan 2013 Slide 8 Listen interval update is needed when a STA changes its operation mode –Specifically required for TIM to Non-TIM mode change A STA may inform to AP the updated listen interval for helping AP’s operation such as buffering/discarding DL traffic –The informing frame should not cause critical overhead and need to have a optimized format Jinsoo Choi, LG Electronics

9. doc.: IEEE 802.11-13/0089r0 Submission References [1] 11-12-0891-00-00ah-aid-reassignment-for-tim-and-non- tim-modes-switching [2] 11-12-0656-01-00ah-extended-sleep-mode-for-battery- powered-stas [3] 11-12-1304-00-00ah-aid-assignment-protocol Jan 2013 Slide 9Jinsoo Choi, LG Electronics

10. doc.: IEEE 802.11-13/0089r0 Submission Straw Poll - 1 Do you support that a STA can update the listen interval when it changes its operation mode from TIM to Non- TIM mode? Jan 2013 Slide 10Jinsoo Choi, LG Electronics

11. doc.: IEEE 802.11-13/0089r0 Submission Straw Poll - 2 Do you support that a STA may inform to an AP its updated listen interval and the AP may response to the STA? Jan 2013 Slide 11Jinsoo Choi, LG Electronics

12. doc.: IEEE 802.11-13/0089r0 Submission Straw Poll - 3 Do you support that the updated listen interval is optionally included in an existing frame (e.g. conditional update at TIM to Non-TIM mode change in the AID switch request frame) Jan 2013 Slide 12Jinsoo Choi, LG Electronics