IEEE P802.22 Wireless RANs Date: 2008-12-18 March 2008 doc.: IEEE 802.22-08/0xxxr0 December 2008 IEEE P802.22 Wireless RANs Date: 2008-12-18 Cluster-based self-coexistence mechanism (Comments #131, #149, #150 and #664) 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. > Gerald Chouinard, CRC Gerald Chouinard

WRAN Self-coexistence considerations December 2008 WRAN Self-coexistence considerations MAC self coexistence schemes PHY co-existence mechanisms Spectrum Etiquette Different TV channel selection Adaptive on-demand channel contention Frame allocation signalled by the superframe control header (SCH) (SFN or distributed SCH transmission) Interference-free CPE scheduling (Under consideration) Gerald Chouinard, CRC

Self-coexistence capacity allocation scheme December 2008 Self-coexistence capacity allocation scheme Inter-BS communication using the CBP bursts Input from spectrum manager Interference-free scheduling Adaptive on-demand channel contention Dynamic resource renting/offering Scheduling of non-concurrent probing frames Self-coexistence capacity allocation algorithm at each BS Interference-free scheduling Adaptive on-demand channel contention Dynamic resource renting/offering Scheduling of non-concurrent probing frames Self-coexistence capacity allocation algorithm at each BS Self-coexistence capacity allocation algorithm at each BS Output by SCH Capacity loading at each BS (stack loading) Frame scheduling for the upcoming superframe transmitted by the 16-bit pattern for each BS QoS requirement per service for each BS (type of service: UGS, rtPS, nrtPS, BE) Cluster-based self-coexistence mechanism Local incompatibility table Information to be exchanged among all overlapped BSs in preparation for the next frame capacity allocation Information to be transmitted by all overlapped BSs in their superframe header Gerald Chouinard, CRC

Cluster-based self-coexistence mechanism March 2008 doc.: IEEE 802.22-08/0xxxr0 December 2008 Cluster-based self-coexistence mechanism Based on construction of an incompatibility matrix among WRAN cells to identify which cells cannot use the same frame locally Incompatibility will be based on CPE identifying that they can be interfered with by other WRAN cell’s transmissions (i.e., located in overlap areas) CPEs report the results of the signal measurements (RSSI) and the origin of the signals (MAC address of the BS) to their BS The BS built its one-dimensional local incompatibility table (based on CPEs where the difference between the desired RSSI is the interfering RSSI is less than the appropriate threshold given the modulation used) The BS propagates its local incompatibility table to all adjacent WRAN cells through the CBP BSs build a common incompatibility matrix from all tables. Gerald Chouinard, CRC Gerald Chouinard

Cluster-based self-coexistence mechanism (cont’d) March 2008 doc.: IEEE 802.22-08/0xxxr0 December 2008 Cluster-based self-coexistence mechanism (cont’d) Classic “map coloring” algorithms are then applied to the incompatibility matrix to find the number of different groups of frames needed to accommodate all WRAN cells These groups of frames are then allocated to all WRAN cells with as many groups as possible allocated to each cell The relative size of each group (number of frames) is then determined/negociated and modulated according to the relative demand in capacity from the WRAN cells belonging to each group (i.e., relative capacity loading at each BS will be transmitted by the BSs) This is where heuristic algorithms will need to be standardized to make sure that all BSs arrive at the same frame capacity allocation. If the total size, in frames, of all the groups is larger than 16 (beyond a frame, the type of traffic (QoS) will be used to determine which group needs to be repeated more often. Gerald Chouinard, CRC Gerald Chouinard

Coexistence Scenarios December 2008 Coexistence Scenarios A A A E E B B F B D D C C D C Complete Cycle Wheel Incompatibility matrices 1: cells are incompatible 0: cells are compatible Note: These matrices may not be symmetrical around the diagonal from the aggregation of the incompatibility tables from the various BSs but they are made symmetrical to consider the worse case. Gerald Chouinard, CRC

Coexistence Scenarios December 2008 Coexistence Scenarios A A A E E B B F B D D C C D C Map coloring Needs 4 different groups of frames 2 possible groups of frames in this cell Needs 4 different groups of frames Needs 3 different groups of frames 2 possible groups of frames in this cell Gerald Chouinard, CRC

Extended Coexistence Scenario (cont’d) December 2008 Extended Coexistence Scenario (cont’d) Incompatibility matrix 1: cells are incompatible 0: cells are compatible Gerald Chouinard, CRC

Extended Coexistence Scenario (cont’d) December 2008 Extended Coexistence Scenario (cont’d) Map coloring First group of frames Second group of frames Third group of frames Largest mutually incompatible groups of cells: 3 = ABD ACD CDG GDH DHE GHK HEI EFI IFJ IJL LNO OPQ OPR OQR 2 = KM MN (Needs a minimum of 3 different groups of frames) Option B: Option A: Less efficient 2 possible groups of frames in cell M Gerald Chouinard, CRC

Extended Coexistence Scenario (cont’d) December 2008 Extended Coexistence Scenario (cont’d) Incompatibility matrix 1: cells are incompatible 0: cells are compatible Gerald Chouinard, CRC

Extended Coexistence Scenario (cont’d) December 2008 Extended Coexistence Scenario (cont’d) Map coloring First group of frames Second group of frames Third group of frames Fourth group of frames Largest mutually incompatible groups of cells: 4 = NOST 3 = ABD ACD CDG GDH DHE GHK HEI EFI IFJ IJL LNO OPQ OPR OQR 2 = KM MN (Needs a minimum of 4 different groups of frames) Option A: Option B: Option C: Less efficient 3 possible groups of frames in cell M 3 possible groups of frames in cell M 2 possible groups of frames in green cells Gerald Chouinard, CRC

March 2008 doc.: IEEE 802.22-08/0xxxr0 December 2008 Conclusions The cluster-based self-coexistence mechanism assumes that all the information on the incompatibility among WRAN cells is available at all BSs from the CBP burst exchange. Such incompatibility information will vary very slowly and will only need to be updated from time to time. The variability in capacity split between the different groups of frames will depend on the capacity loading at the BSs which will be provided on a more regular basis to all BSs (only changes in capacity will need to be signalled). Standardized heuristic algorithms will be needed to make sure that all the BSs converge to the same capacity split. Information on the type of traffic transmitted by each BS will be exchanged among all BSs to determine the rate of transmission of these specifci groups of frames (e.g., groups of 2 frames transmitted every superframe rather than 4 frames every two superframe) to try to preserve QoS as much as possible. Gerald Chouinard, CRC Gerald Chouinard

December 2008 Conclusions (cont’d) The performance of this cluster-based self-coexistence mechanism is proposed to be used as a reference for the evaluation of the performance of the various proposed “organic-based” contention algorithms (specifically slide 11) Parameters to be considered are: Efficiency of capacity allocation for each BS Reaction of the schemes to changes in: WRAN cells incompatibility, BS capacity changes (i.e., initiation of new contention), and type of traffic change (QoS) Network reaction during the transient period between the changes in requirement and the new steady state (reaction time and damping factor for schemes that involve ripple effects) How close is the final steady state to the capacity allocation resulting from the cluster-based self-coexistence mechanism Comparison of the required CBP traffic among BSs to reach the new capacity allocation. Gerald Chouinard, CRC

References 22-08-0137-03-0000-wran-coexistence-considerations.ppt December 2008 References 22-08-0137-03-0000-wran-coexistence-considerations.ppt 22-08-0325-00-0000-performance-evaluation-methods-of-inter-wran-coexistence-protocols.ppt Gerald Chouinard, CRC