1. doc.: IEEE 802.22-08/xxxxr0 Submission July. 2008 Cheng Shan, Samsung Electronics Slide 1 Distributed SCH Design IEEE P802.22 Wireless RANs Date: 2008-07-13 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 Chairhttp://standards.ieee.org/guides/bylaws/sb-bylaws.pdf Carl R. StevensonCarl 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.patcom@iee.org >

2. doc.: IEEE 802.22-08/xxxxr0 Submission July. 2008 Cheng Shan, Samsung Electronics Slide 2 Abstract This contribution proposed a new solution for SCH collision problem in coexistence scenario This contribution is related to the resolution of comments #524

3. doc.: IEEE 802.22-08/xxxxr0 Submission Background The group has agreed the basic unit for coexisting WRAN cells’ capacity sharing is one frame; The current draft 1.0 cannot directly support such an inter-frame sharing, modification must be made; In current draft, every BS sends SCH in the 1 st frame of a super-frame; collision must be resolved in a coexistence scenario July. 2008 Cheng Shan, Samsung Electronics Slide 3

4. doc.: IEEE 802.22-08/xxxxr0 Submission Distributed SCH Proposal In a inter-frame sharing coexistence mode, each BS operates on one or several frames in a super-frame; Each BS transmits its super-frame preamble and SCH during the 1 st allocated frame, not necessarily the 1 st frame of the super-frame; The coexistence-mode SCH at least contains the inter-frame sharing MAP information of the present BS; July. 2008 Cheng Shan, Samsung Electronics Slide 4

5. doc.: IEEE 802.22-08/xxxxr0 Submission One Exemplary Scenario July. 2008 Cheng Shan, Samsung Electronics Slide 5

6. doc.: IEEE 802.22-08/xxxxr0 Submission SCH Modification July. 2008 Cheng Shan, Samsung Electronics Slide 6 SyntaxSizenotes SCH_Format() { SCH_Type1 bit0=normal mode; 1=coexisting mode If SCH_Type=1 { SCH_Offset4bitThe frame index of current frame in a super-frame Inter-frame _Allocation_MAP}16bitIndicate which frames are allocated to present BS { Conventional SCH Contentsvar }

7. doc.: IEEE 802.22-08/xxxxr0 Submission CPE Operation An accessing CPE first scans the super-frame preambles, and decodes the SCH follows; –Coexistence Mode If it is a BS that can be associated with, the CPE proceeds communication with the BS during the allocated frames in a inter-frame coexistence mode; If it is not a BS that can be associated with, the CPE keeps searching another super-frame preamble in a super-frame duration. –Normal Mode (Conventional operation as described in D1.0) CPE can acquire the beginning of a super-frame by calculating [this_frame_starting_time – (SCH_offset-1)*Frame_Duration)] –If a CPE is equipped with a GPS, it can directly know which frame the current SCH is included, since the absolute beginning timing of a super- frame is known, and the propagation delay from any usable BS can never exceed a frame’s duration (10ms). July. 2008 Cheng Shan, Samsung Electronics Slide 7

8. doc.: IEEE 802.22-08/xxxxr0 Submission Trigger the Inter-Frame Sharing among BS’s All operational BS’s should go through the per channel based coexistence protocols, namely, spectrum etiquette, interference-free scheduling, channel renting/offering, and channel contention, as defined in D1.0 before initialization of inter-frame sharing; A new trigger should be defined to trigger the inter- frame sharing –E.g., a BS cannot hold a channel long before it is taken over by another BS through channel contention; July. 2008 Cheng Shan, Samsung Electronics Slide 8

9. doc.: IEEE 802.22-08/xxxxr0 Submission Reusing the per Channel Based Coexistence Protocols The per channel based coexistence protocols can be re-utilized for inter-frame sharing, by replacing the replacing the resource in interest from “a channel” to “a frame in a super-frame”; Per frame based coexistence protocols –Frame Etiquette A BS may first scan the frames in time-line, if there is un-occupied frames, it sets up communication on those found frames; –Frame Renting/Offering A BS rents one or several frames from other operating BSs; –Frame Contention A BS contends one or several frames with other operating BSs; Modification to CBP payloads –Slight modification to CBP messages to indicate if this is a per channel based message or per frame based message July. 2008 Cheng Shan, Samsung Electronics Slide 9

10. doc.: IEEE 802.22-08/xxxxr0 Submission Suggested Flowchart July. 2008 Cheng Shan, Samsung Electronics Slide 10

11. doc.: IEEE 802.22-08/xxxxr0 Submission Summary No SCH collision Chained but not overlapped cells can re-use the same frame resource High flexibility in inter-frame sharing by re-utilizing the coexistence protocols July. 2008 Cheng Shan, Samsung Electronics Slide 11