Inter-Cell Quiet Period Synchronization Nov. 2009 doc.: IEEE 802.22-09/0117r0 Nov. 2009 Inter-Cell Quiet Period Synchronization IEEE P802.22 Wireless RANs Date: 2008-10-18 Authors: Notice: This document has been prepared to assist IEEE 802.22. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) 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 802.22. Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures http://standards.ieee.org/guides/bylaws/sb-bylaws.pdf including the statement "IEEE standards may include the known use of patent(s), including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to patents essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the Working Group of patent information that might be relevant to the standard is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chair Carl R. Stevenson as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being developed within the IEEE 802.22 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at patcom@iee.org. > Cheng Shan, Samsung Electronics

Nov. 2009 doc.: IEEE 802.22-09/0117r0 Nov. 2009 Abstract This contribution proposes an improved method to improve the efficiency when distributing QP scheduling to neighboring cells This contribution provides a suggested resolution for comment 652 Cheng Shan, Samsung Electronics

QP Synchronization as in D2.0 Nov. 2009 QP Synchronization as in D2.0 SCH (Table 1) the QP information in SCH includes the start time of a QP, as well as the duration of QP On which TV channel the present QP is scheduled is not defined 6.22.3.2 “The BS that receives information about other collocated 802.22 cells (either directly or reported by CPEs) shall synchronize with all quiet periods scheduled by the other cells, which includes those for both intra frame and inter-frame sensing.” Cheng Shan, Samsung Electronics

Problem with Global Synchronization Nov. 2009 Problem with Global Synchronization Synchronizing to any QP information regardless if it is in-band or out-band is not efficient if the two cells are operating on two channel so far apart that QP synchronization is unnecessary. Cheng Shan, Samsung Electronics

Problem with In-band Synchronization Nov. 2009 Problem with In-band Synchronization If a WRAN cell follows the QP only when the present cell is working on one of the in-band channel where the QP is received (a) as QP scheduling propagates, cell 4 working on channel N+3 must follow the QP originally scheduled on channel N; (b) cell 3 working on in-band channel N+1 may not follow the QP relayed by cell 2, since N+1 is not in-band with N-1; (c) cell 2 may not relay the QP of cell 1 to cell 3 which is in-band with cell 1 Cheng Shan, Samsung Electronics

Improved QP Distribution Nov. 2009 Improved QP Distribution When delivering/relaying QP information to the neighboring cells, the channel index on which the QP is originally scheduled should be transmitted along; On receiving the QP information from neighboring cells, a WRAN should synchronize to the QP as described in 6.22.3.2 if the QP is scheduled on its in-band channel not necessarily synchronize to the QP if the QP is scheduled on its out-band channel. The BS should instead relay the QP information to its neighbors in its SCH and/or CBP Cheng Shan, Samsung Electronics

Proposed Text Change: Table 1 Nov. 2009 Proposed Text Change: Table 1 Syntax Size Notes Superframe_Control_Header_Format() { … Channel Number on which QP is originally Scheduled 8 bits Indicates which channel the QP is originally scheduled on. TTQP 12 bits Time To Quiet Period DQP 4 bits Duration of Quiet Period } Cheng Shan, Samsung Electronics

Nov. 2009 Propose Text Change: 6.22.3.2 The BS that receives information about other collocated 802.22 cells (either directly or reported by CPEs)shall synchronize with all quiet periods scheduled on its in-band channels by the other cells, which includes those for both intra-frame and inter-frame sensing. Cheng Shan, Samsung Electronics

Nov. 2009 Summary The current SCH definition along with the QP synchronization process described in 6.22.3.2 cannot efficiently handle the inter-cell QP scheduling problem: Relaying any QP information regardless if it is in-band or out-band may result in QP flooding in the network; Relaying in-band QP information only cannot efficiently deliver the information to those cells who need it; Proposal QP timing information should be bundled with channel number on which it is originally scheduled, so that a neighboring cell can decide whether to synchronize to it or not. Cheng Shan, Samsung Electronics