Network Entry and Initialization 2006 March Network Entry and Initialization IEEE P802.22 Wireless RANs Date: 2006-07-17 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. > Huawei

Part 1: Network Entry And Initialization 2006 March Part 1: Network Entry And Initialization BS Selection When CPEs Turn on in the Overlapping Region with the Same Frequency Huawei

Background A scenario considered: 2006 March Background A scenario considered: In an overlapping area there is no active CPE. Then BSs can not communicate with each other through these CPEs. And interference maybe exist in this overlapping area. When a CPE in the overlapping area turns power on, it can not select a service BS because of interference. For this scenario, new network entry algorithms need to be suggested. Huawei

Different Frequency Channels Assigned in an Overlapping Area 2006 March Different Frequency Channels Assigned in an Overlapping Area If BS1 power > BS2 power, CPE selects BS1 as a service BS. If BS1 power < BS2 power, CPE selects BS2 as a service BS. If BS1 power equal to BS2 power, CPE selects a service BS through pre-determined order. Huawei

A Frequency Assigned in an Overlapping Area 2006 March A Frequency Assigned in an Overlapping Area If no interference in the overlapping area : CPE selects a service BS according to the solution introduced in the previous slide (For example, they use different subcarriers from one another). If interference exists: If interference is not serious, The BS can utilize this CPE to communicate with each other and adjust own frequency to eliminate interference. Then CPE selects a service BS by using the solution introduced in the previous slide. If interference in overlapping area is serious, CPE needs to decode BS preamble signals for the following four cases: 1. Preamble signal is not coincident and PN code is different 2. Preamble signal is not coincident and PN code is same 3. Preamble signal is coincident and PN code is different 4. Preamble signal is coincident and PN code is same Huawei

2006 March Simulation Although the interference is serious in the overlapping area, CPE can decode preamble signals for the above four cases. Huawei

A Frequency Assigned in an Overlapping Area (cont’d) 2006 March A Frequency Assigned in an Overlapping Area (cont’d) Interference in overlapping area is serious (cont’d): CPE decodes the PN code, then send IE-REQ (Interference Existence-Request) to BSs to notify BSs of interference condition. BSs send ACK feedback messages to the CPE, and two BSs finish synchronization and co-existence through this CPE. BSs change own frequency to eliminate interference, then CPE select a service BS by using the solution introduced in the case that different frequency channels are assigned in the overlapping area. Huawei

2006 March Flow chart Huawei

2006 March Conclusions Schemes for a CPE to select a service BS in various scenarios are suggested. A scheme for network entry is proposed for the case that serious interference exists in an overlapping area. Without broadcasting control information periodically in occupied channel, spectrum efficiency can be improved. Huawei

Part 2: Network Entry and Initialization 2006 March Part 2: Network Entry and Initialization Load Balance for Different Frequencies Huawei

2006 March Background WRAN system utilizes cognitive radio technologies to identify vacant frequency bands to communicate. Therefore when many CPEs need to make use of confined frequency resources, it makes WRAN system cell be overloaded. To reduce this cell load, BS needs to move some CPEs in this overlapping area to another neighbor cell. Huawei

Our Proposal 2006 March Huawei Cell A Cell B CPE in cell A CPE in cell B Overload CPE in cell A, and be shunted to cell B Huawei

2006 March Flow chart (1) Huawei

2006 March Flow chart (2) Huawei

2006 March Conclusions BS can compare load status of its own cell with other cells and select flexibly target cell. While to solve overload, this proposal can achieve the purpose of utilizing frequency resource more efficiently. Before switching to another BS, current BS will keep service with shunt CPEs, which will not interrupt CPEs service and can assure CPEs service continuity and QoS. BS can directly utilize CPEs in overlapping area to finish synchronization and signalling alternation. Huawei