An Enhanced Quiet Period Synchronization Method for 802.22 Networks Month Year doc.: IEEE 802.22-yy/xxxxr0 Nov/2008 An Enhanced Quiet Period Synchronization Method for 802.22 Networks IEEE P802.22 Wireless RANs Date: 2008-10-28 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. > Haiguang Wang, Hisilicon Technologies John Doe, Some Company

Month Year doc.: IEEE 802.22-yy/xxxxr0 Nov/2008 Abstract According to our study, we found that the current design of 802.22 standard in quiet period synchronization is incomplete. The mainly problem is the synchronized quiet period cannot be reduced when it could be. This may cause resource wastage. In this proposal, we propose a method that solves the above problem and the synchronized quiet period can be either increased or reduced. This contribution is a proposed resolution for comment for 6.6.1 and 6.21.2.3. Haiguang Wang, Hisilicon Technologies John Doe, Some Company

Two Types of Quiet Period How to specify the quiet period Nov/2008 Quiet Period In IEEE 802.22 Networks, Quiet Period (QPs) are scheduled for Spectrum Sensing and two types of QPs are defined: QP for Intra-frame Sensing, specified by Cycle length Offset Bitmap Duration QP for Inter-frame Sensing Time To Quiet Period (TTQP) Duration of Quiet Period (DQP) Two Types of Quiet Period How to specify the quiet period Haiguang Wang, Hisilicon Technologies

Quiet Period Synchronization Month Year doc.: IEEE 802.22-yy/xxxxr0 Nov/2008 Quiet Period Synchronization Quiet Period (QP) Synchronization is important for 802.22 network。 According to the standard, overlapping are required to synchronize their QP. Quiet period after synchronization Haiguang Wang, Hisilicon Technologies John Doe, Some Company

Problem with Intra-frame Sensing Synchronization Nov/2008 Problem with Intra-frame Sensing Synchronization With the parameters specified by current design, it is hard for the BSs to synchronize to a smaller QP duration than the current one. However, this may happen when the required QP duration of certain BS changes. Variables to describe the QP synchronization : minimal requirement on QP duration of BSi. : the currently synchronized QP duration of BSi. ? 1 2 1 2 1 2 A. Before synchronization B. After synchronization C. Required QP changed, how to process this scenario? Haiguang Wang, Hisilicon Technologies

Our Solution: Using Synchronization Counter (SC) Nov/2008 Our Solution: Using Synchronization Counter (SC) Each BS maintains a synchronization counter, named as , for QPD of Intra-frame Sensing. takes value from 1 to SCmax. SCmax is a predefined value. The value of is transmitted together with the value of , which is corresponding to the field of Intra-frame Sensing Duration in SCH or CBP messages. Haiguang Wang, Hisilicon Technologies

Algorithm to Update the Synchronization Counter Nov/2008 Algorithm to Update the Synchronization Counter Haiguang Wang, Hisilicon Technologies

Simulation Configuration Nov/2008 Simulation Configuration Simulator: NS2 Configuration Parameters Region: 100km x 100km Number of BSs: 20 Tx power of BS: 4 Watts. Antenna gain: 6dB. Path loss model: polynomial power decay with the expontent of 2.6. Radio transmission range: 33 kilometers. Channel bandwidth: 6MHz Modulation: QPSK with 1/2coding. Transmission rate: 4.5Mbps. We choose SCmax : 15. The location of BSs in the region Haiguang Wang, Hisilicon Technologies

Simulation Results The mean time for synchronization. Nov/2008 Simulation Results The mean time for synchronization. Synchronize to a longer duration: 0.93 seconds. Synchronize to a shorter duration: 1.21 seconds. The variation of Synchronized Quiet Period The detailed synchronization process Haiguang Wang, Hisilicon Technologies

Nov/2008 Proposed Text 1/3 Insert text in 6.7.1 table 1 after the entry for “Intra-frame Sensing Duration” as follows: Intra-frame Sensing Duration 5 bits Valid only if Intra-frame Sensing Cycle Length > 0. If this field is set to a value different from 0 (zero): It indicates the number of symbols starting from the end of the frame that shall be used to perform intra-frame sensing. Synchronization Counter for Intra-frame Sensing Duration 8 bits Valid only if Intra-frame Sensing Duration > 0. This field is used for the purpose of Intra-frame Sensing Duration synchronization among overlapping BSs. Haiguang Wang, Hisilicon Technologies

Figure xxx: Algorithm to update the Intra-frame Sensing Duration Nov/2008 Proposed Text 2/3 Insert text and figure in 6.22.3.2 after the third paragraph as follows: In order to allow the Intra-frame Sensing Duration after synchronization adapt to the variation of Intra-frame Sensing Duration, each BS, denoted as BSi, should maintain a variable named Synchronization Counter for Intra-frame Sensing Duration, denoted as .This value is sent together with Intra-frame Sensing Duration in SCH and CBP. It should be updated according to following algorithms: Figure xxx: Algorithm to update the Intra-frame Sensing Duration Haiguang Wang, Hisilicon Technologies

Proposed Text 3/3 And followed by text after the proposed figure: Nov/2008 Proposed Text 3/3 And followed by text after the proposed figure: where is the currently synchronized Intra-frame Sensing Duration of BSi and is the minimum requirement on Intra-frame Sensing Duration by BSi. SCmax is predefined value. Haiguang Wang, Hisilicon Technologies

Nov/2008 Conclusion We need add in one more field for synchronization counter in SCH or CBP messages. The length of field is 8 bits. Similar, the method can apply to the synchronization of following fields for Intra-frame sensing: Intra-frame sensing cycle length Intra-frame sensing bitmap Haiguang Wang, Hisilicon Technologies

Nov/2008 References IEEE P802.22 DRAFTv1.1 Draft Standard for Wireless Regional Area Networks Part 22: Cognitive Wireless RAN Medium Access Control (MAC) and Physical Layer (PHY) speci¯cations: Policies and procedures for operation in the TV BandsMarch 2008. 22-08-0146-18-0000-wran-draft-1-0-draft-comments-database Haiguang Wang, Hisilicon Technologies