March 2007 doc IEEE 802 22 yy0136 r

March 2007 doc. : IEEE 802. 22 -yy/0136 r 0 Overview of CBP IEEE P 802. 22 Wireless RANs Date: 2007 -03 -15 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. > Submission 1 Carlos Cordeiro, Philips

March 2007 doc. : IEEE 802. 22 -yy/0136 r 0 Introduction • The purpose of this presentation is to educate the WG on the CBP self-coexistence protocol adopted in the current Draft 0. 2 spec • We detail the MAC aspect of CBP, while the PHY aspects were already presented and are available in document 22 -07 -0115 Submission 2 Carlos Cordeiro, Philips

March 2007 doc. : IEEE 802. 22 -yy/0136 r 0 CBP Overview • CBP is fully controllable by the BS that decides who sends/listens and when to send/listen for CBP packets – The source of a CBP packet can be either a BS or CPE • CBP packets carry control information only (no data) • CBP can be used for communication and coexistence of WRANs on the same operating channel as well as across channels • CBP packets can be transmitted – Over the backhaul (not specified in the standard or in this presentation) – Over the air Submission 3 Carlos Cordeiro, Philips

March 2007 doc. : IEEE 802. 22 -yy/0136 r 0 CBP Usage Scenarios (1) Case 1: Neighboring out-of-range BSs • • • CPE B 1 CPE A 1 BS A BS B This situation may happen when BSs A and B belong to the same operator. In this case, the operator would try to minimize the overlapping area, but some users would suffer from interference if no coexistence mechanism is in place. Submission 4 BS A selects CPE A 1 to send CBP packets BS B selects CPE B 1 to send CBP packets CPEs A 1 and B 1 receives each other CBP packets and report to their BSs, this enables: – Network discovery – Spectrum etiquette (BSs may decide to switch channels) – Interference-free scheduling – Resource sharing (renting/offering, spectrum contention) Carlos Cordeiro, Philips

March 2007 doc. : IEEE 802. 22 -yy/0136 r 0 CBP Usage Scenarios (2) Case 2: Neighboring in-range (or collocated) BSs • The BSs can use the CPEs (A 1 and B 1) to transmit CBP packets, as in case 1 • The BSs can choose to transmit the CBP packets CPE B 1 CPE A 1 – In this case, the BSs shall also use the Coexistence Window (at the end of the frame) to send the CBP packet BS A BS B This situation may happen when BSs A and B belong to different operators. Multiple operators will likely to place their BSs close to each other to reach the same set of consumers. Submission 5 Carlos Cordeiro, Philips

March 2007 doc. : IEEE 802. 22 -yy/0136 r 0 CBP Packet Transmission Submission 6 Carlos Cordeiro, Philips

March 2007 doc. : IEEE 802. 22 -yy/0136 r 0 CBP Access during the SCW (1) • The CBP access during the Self-Coexistence Window (SCW) is contention-based – But, the contention parameters (Coexistence Backoff Start (CBS) and Coexistence Backoff End (CBE)) are fully controllable by the BS and sent in the UCD message • In transmit mode, the CPE/BS generates a contention window (CW) randomly between [0, CBS] and performs the backoff process as to access the medium – CW is used to reduce the collision probability amongst stations with CBP packets to transmit during the same SCW Submission 7 Carlos Cordeiro, Philips

March 2007 doc. : IEEE 802. 22 -yy/0136 r 0 CBP Access during the SCW (2) SCW at Frame i x x+1 CW 1=4 x+2 SCW at Frame i+1 SCW at Frame i+2 x x x+1 CBP packet … Rx Rx … … CW 2=4 … Rx CW 3=4 CBS = 16 Submission Rx CW 2=7 CW 2=10 CW 3=7 x+2 … CBP packet … x+1 x+2 Rx … CBP packet … Rx … CW 1, CW 2, and CW 3 are backoff intervals at closeby CPEs 1, 2, and 3 8 Carlos Cordeiro, Philips

March 2007 doc. : IEEE 802. 22 -yy/0136 r 0 BS’ Selection of Transmitting CPEs • The BS decides which CPEs are to transmit CBP packets • While we believe this decision to be implementation dependent, we recommend the following mechanisms: – Based on CPE’s location information (being developed by Geolocation/Database tiger team) – Based on statistics reported by the CPE (e. g. , PER) Submission 9 Carlos Cordeiro, Philips

March 2007 doc. : IEEE 802. 22 -yy/0136 r 0 CBP-based Neighboring Network Discovery – Case 1 • • CPE B 1 – – CPE A 1 BS A selects CPE A 1 to send CBP packets BS B powers-up and scans the channels (but does not detect BS A) CPE B 1 powers-up and associates with BS B schedules CPE B 1 to scan for CBP packets • BS B schedules CPE B 1 to send CBP packets After that, BSs A and B can coexist through CBP and other mechanisms operating on top of it, e. g. – The same procedure can be used when BSs A and B operate in the same channel or in different channels. Submission 10 B 1 receives a CBP packet from A 1 and reports to BS B discovers BS A and B can switch channels, or share the same channel using coexistence mechanisms Carlos Cordeiro, Philips

March 2007 doc. : IEEE 802. 22 -yy/0136 r 0 CBP-based Neighboring Network Discovery – Case 2 • • CPE B 1 – BS B receives A’s SCH during the scanning process – BS B receives a CBP packet from A 1 CPE A 1 • • BS A selects CPE A 1 to send CBP packets BS B powers-up, scans the channels and detects BS A BS B CPE B 1 powers-up and associates with BS B can hear BS A and it decides to send CBP packets – BS A discovers BS B • • BS A decides to send CBP packets After that, BSs A and B can coexist through CBP and other mechanisms operating on top of it, e. g. – BS A and B can switch channels, or share the same channel using coexistence mechanisms Submission 11 Carlos Cordeiro, Philips

March 2007 doc. : IEEE 802. 22 -yy/0136 r 0 CBP-based Coexistence Framework • Comprised of four elements (see doc. 22 -07 -121 r 1) – – Submission Spectrum etiquette Interference-free scheduling Dynamic resource renting and offering Adaptive on demand channel contention 12 Carlos Cordeiro, Philips

March 2007 doc. : IEEE 802. 22 -yy/0136 r 0 After Reception of a CBP Packet • In case of a CPE – Report it to its associated BS – Future upstream bandwidth reservation requests can contain time allocation constraints • For example, a CPE can specify: “Give me 100 Kb of airtime, but not between T 1 and T 2” • In case of the BS – Perform the CBP-based self-coexistence mechanisms, namely, spectrum etiquette, interference-free scheduling, dynamic resource renting and offering, and adaptive on demand channel contention – Information carried in the CBP packet can be used as the fall-back mechanism for frame synchronization in case GPS is not available, does not have coverage, etc. Submission 13 Carlos Cordeiro, Philips

March 2007 doc. : IEEE 802. 22 -yy/0136 r 0 Under Consideration • CBP was meant to be primarily a broadcast protocol • If more reliability is required, an optional CBP-ACK could be included to confirm reception of transmitted CBP packet Submission 14 Carlos Cordeiro, Philips

March 2007 doc. : IEEE 802. 22 -yy/0136 r 0 Conclusion • CBP provides a flexible means for 802. 22 WRANs to communicate and coexist – Controllable by the BS – Over the air or through the backhaul – On the same channel or in different channels • A comprehensive self-coexistence framework is defined based on CBP, which allows WRANs to coordinate and efficiently share resources Submission 15 Carlos Cordeiro, Philips

March 2007 doc. : IEEE 802. 22 -yy/0136 r 0 Appendix Submission 16 Carlos Cordeiro, Philips

March 2007 doc. : IEEE 802. 22 -yy/0136 r 0 Performance Evaluation • All aspects of the MAC have been implemented in OPNET – OPNET is considered the most well-reputated and reliable network simulation tool available today • In all simulations: – In case of quiet periods (QP), every CPE performs detection in all in-band channels (e. g. , N-1, N, and N+1 in case of a single TV channel) – DFS model is implemented as per the requirements document – No fragmentation or packing • Some common simulation parameters – – Submission Superframe size = 12 frames, where Frame size = 40 ms Packet size = 1 Kbyte Detection time per TV channel = 13 ms 64 -QAM rate 2/3 and Symbol time = 310 µs 17 Carlos Cordeiro, Philips

March 2007 doc. : IEEE 802. 22 -yy/0136 r 0 CBP/Synchronization • Evaluate the self-coexistence mechanisms of the proposed MAC 1 cell: – Synchronization – CBP in every frame • The number of overlapping 802. 22 cells are progressively increased – Up to 4 cells are simulated – BSs and CPEs start at random 2 cells: • Network is fully loaded and traffic is uniform Submission 18 Carlos Cordeiro, Philips

March 2007 doc. : IEEE 802. 22 -yy/0136 r 0 CBP/Synchronization (cont. ) 3 cells: 4 cells: Submission 19 Carlos Cordeiro, Philips

March 2007 doc. : IEEE 802. 22 -yy/0136 r 0 CBP/Synchronization (cont. ) Local Drift Time Network Synchronization Time Submission 20 Carlos Cordeiro, Philips

March 2007 doc. : IEEE 802. 22 -yy/0136 r 0 CBP/Synchronization (cont. ) • Simple scheduler • CBP together with Synchronization can provide significant performance improvements Submission 21 Carlos Cordeiro, Philips