Secondary Carrier Control in Multicarrier Sleep Mode Operation ( ) Document Number: IEEE C80216m-09/2299 Date Submitted: Source: Yih-Shen Chen, Kelvin Chou, I-Kang Fu, Peikai Liao and Paul Cheng MediaTek Inc. Venue: IEEE Session #64, Atlanta, USA Response to Letter Ballot #30a on the Draft Amendment (IEEE P802.16m/D2) Base Contribution: This is base contribution Purpose: Propose to be discussed and adopted by TGm for the m Amendment Notice: This document does not represent the agreed views of the IEEE Working Group or any of its subgroups. It represents only the views of the participants listed in the “Source(s)” field above. It is offered as a basis for discussion. It is not binding on the contributor(s), who reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE Patent Policy: The contributor is familiar with the IEEE-SA Patent Policy and Procedures: and. Further information is located at and.
2 Introduction The goal of sleep mode operation is power saving Sleep mode operation in single-carrier m system –A set of sleep mode parameters is configured –Traffic indication (TRF-IND) is applied to command an MS to receive the buffered traffic now –The MS wakes up to receive DL data at a pre-defined timing if TIMF=0 In multicarrier case, people have already agreed that –Single set of sleep mode configuration parameters is applied –All the control information transactions are proceeded via primary carrier The multicarrier operation can be categorized as –Contiguous bandwidth allocation –Non-contiguous bandwidth allocation Question: How to efficiently wake up the secondary carriers? –The maximal bandwidth in OFDMA numerology is 20 Mhz. That is, it’s impossible to decode 40Mhz by a single RF module –For non-contiguous multi-carrier allocation, it’s also impossible to decode the DL signal by a single RF module
3 Possible Solutions (1/3) Option-1: All the secondary carriers wake up as the primary carrier does –Pros: simply –Cons: power waste due to unnecessary wake-up
4 Possible Solutions (2/3) Option-2: Each secondary carrier is configured with a set of dedicated sleep mode configuration parameters –Pros: High flexibility –Cons: Violate current consensus (i.e., control over primary carrier)
5 Possible Solutions (3/3) Option-3: Secondary carrier is controlled by a wakeup indication –The indication can be embedded in TRF-IND message or a MAC header Pros: power efficient, wakeup on demand Cons: additional bits are required in TRF-IND
6 Discussions on Option-3 (1/2) RF configuration issue –Multi-carrier assignment can be done in contiguous band or non-contiguous band –Right now, OFDMA parameters for 5, 10 and 20Mhz are defined (Table 647) To support 40 MHz bandwidth, for example, it takes two RF chains (2 x 20MHz) It’s not practical for AMS to apply single RF to receive 2 x 20MHz because the widths of guard band are different between 40 MHz and 20 MHz –Case I: AMS has a single RF to handle 40Mhz bandwidth Option-3 can provide power saving gain when non-contiguous carriers are assigned –Remove unnecessary baseband operation processing –Case II: AMS has multiple RF chains to handle 40Mhz bandwidth Option-3 can provide power saving gain whatever contiguous and non-contiguous carriers are assigned –Remove unnecessary RF turn-on and baseband processing Overhead issue of wakeup indication –The number of active carrier can be smaller in the sleep mode Lost-of-TRF_IND issue –The issue can be alleviated by properly choosing and re-selecting primary carrier during the sleep mode –The same issue is still applied in other options –Normally, primary carrier is the one with best channel quality
7 Discussions on Option-3 (2/2) Resource flexibility issue –BS can evenly distribute MSs over multiple fully configured carriers –Most of the time, the DL transmission is done via primary carrier. And, the secondary carriers are waked up by demand Scheduling delay issue –BS/MS can negotiate a set of sleep mode parameters based on the traffic characteristics of real-time services Ex: rtPS, ertPS, or aGPS –Schedule non-real-time traffic over primary carrier or secondary carrier while necessary Those kinds of traffic are delay-tolerance
8 Conclusions Three possible options are discussion in the document To power-efficiently control the secondary carriers in the sleep mode, we think option-3 is a better solution
9 Text Proposal Modify the text in section Sleep mode