[Considerations of SCH functions in IEEE 802.22b Systems] September 2013 doc.: IEEE 802.22-12-00xx-02-000b September 2013 [Considerations of SCH functions in IEEE 802.22b Systems] IEEE P802.22 Wireless RANs Date: 2013-09-13 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 Chair Apurva Mody <apurva.mody@ieee.org> 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. Gwangzeen Ko, ETRI Gwangzeen Ko, ETRI

September 2013 doc.: IEEE 802.22-12-00xx-02-000b September 2013 Abstracts In this document, we investigate advantage and disadvantage of SCH employment in IEEE 802.22b Systems Gwangzeen Ko, ETRI Gwangzeen Ko, ETRI

September 2013 IEEE 802.22 SCH Overview The IEEE 802.11-2011 standard defined SCH in order to support below functions Frame allocation map  location of SCH during super-frame period Super-frame number  SCH sequence control CP  information of cyclic prefix factor FCH encoding flag  FCH PHY encoding mode notice Self-coexistence capability indicator  Self-coexistence method notice MAC version Quiet period control  To control QP properly, total 12 fields are defined Gwangzeen Ko, ETRI

September 2013 IEEE 802.22 SCH Overview The IEEE 802.11-2011 standard defined SCH in order to support below functions(continue) SCW control  To exchange CBP packet, total 3 fields are defined DS/US Split  To align the DS/US split boundary between interfered BSs, if this split information not matched between BSs, there are some additional interference under overlapped area, total 3 fields are defined Incumbent detection reporting inhibit timer inhibit reporting of CPE incumbent detection during certain time duration HCS Padding bits Gwangzeen Ko, ETRI

September 2013 IEEE 802.22 SCH Overview As a conclusion, SCH, defined in the IEEE 802.11-2011 ,supports many features for both Frame control and Coexistence mechanism between BSs Gwangzeen Ko, ETRI

SCH features handover to FCH September 2013 SCH features handover to FCH In current IEEE 802.22b WG consider that SCH features moves from SCH to FCH as shown in [2] This looks like there is no difference between SCH in [1] and FCH in [2] However, there are some issues on this change as followed slides For convenience later parts of this document, we will say that SCH and EFCH are represented SCH in [1] and FCH in [2], respectively Gwangzeen Ko, ETRI

Super-frame Structure[1] September 2013 Super-frame Structure[1] Super frame Structure Frame Structure Gwangzeen Ko, ETRI

Super-frame Structure[2] September 2013 Super-frame Structure[2] Super frame Structure Frame Structure Gwangzeen Ko, ETRI

Structure comparison September 2013 Super frame Structure – SCH Parameters are held during super-frame duration Robust preamble Extended Frame Structure – EFCH Parameters can change during super-frame duration Gwangzeen Ko, ETRI

Coexistence between BSs September 2013 Coexistence between BSs For coexistence between BSs SCH and CBP take care of coexistence between BSs If SCH is removed EFCH, include both FCH and Extended FCH, can not replace with SCH EFCH should be modified for coexistence functions CBP should be modified, A CBP is composed of SCH+CBP IEs It is required that L/S-CPE side coexistence functions In order to coexistence mechanism working properly, more CBP should be exchanged because there is no SCH exchange Less allocation of SCW  less overhead for coexistence mechanism Gwangzeen Ko, ETRI

SCH Pros Cons Robust preamble for SCH September 2013 SCH Pros Robust preamble for SCH No change of coexistence part of existing standard Coexistence mechanism CBP All SCH related parts No additional coexistence functions in CPE Less allocation of SCW  less overhead for coexistence mechanism Cons Parameter change duration larger than EFCH Gwangzeen Ko, ETRI

EFCH Pros Cons Parameter change duration smaller than SCH September 2013 EFCH Pros Parameter change duration smaller than SCH Simple structure  if coexistence functions are not frequently required, all frames are the same format Assuming 2 sec minimum sensing time, an EFCH transmits at most every 12.5 super-frames including channel switching time in hardware 700us Cons A lot of works for coexistence functions Change of existing standard New definition of CPE side Gwangzeen Ko, ETRI

Conclusions SCH EFCH Less change for coexistence mechanism than EFCH September 2013 Conclusions SCH Less change for coexistence mechanism than EFCH Less transmission of CBP Coexistence mechanisms between BSs are unique feature of other 802 standards. LTE deal with those functions in higher layer EFCH Faster reaction to situation change than SCH Simpler frame structure than SCH Required a lot of functions for coexistence Gwangzeen Ko, ETRI

September 2013 References [1] “IEEE P802.22-2011: Standard for Wireless Regional Area Networks Part 22: Cognitive Wireless RAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: Policies and procedures for operation in the TV Bands”, Jul. 2011. [2] “802.22b General Frame,” 22-13-0074-03-000b, July, 2013. Gwangzeen Ko, ETRI