1. 1 Multi-RAT Coexistence Analysis and Frame Configuration (15.3.3) Document Number: IEEE C802.16m-09/2124 Date Submitted: 2009-08-31 Source: Yujian Zhangyujian.zhang@intel.comyujian.zhang@intel.com Hujun Yinhujun.yin@intel.comhujun.yin@intel.com Xinrong Wangxingrong.wang@intel.comxingrong.wang@intel.com Yuan Zhuyuan.y.zhu@intel.comyuan.y.zhu@intel.com Intel Corporation Re:IEEE 802.16m-09/0037, Call for Contributions on Project 802.16m Amendment Content Venue:IEEE Session#63, Jeju Base Contribution: None Purpose: Discussion and Adoption by TGm Notice: This document does not represent the agreed views of the IEEE 802.16 Working Group or any of its subgroups. It represents only the views of the participants listed in the Source(s) field above. It is offered as a basis for discussion. It is not binding on the contributor(s), who 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 IEEEs name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEEs 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 802.16. Patent Policy: The contributor is familiar with the IEEE-SA Patent Policy and Procedures: and.http://standards.ieee.org/guides/bylaws/sect6-7.html#6http://standards.ieee.org/guides/opman/sect6.html#6.3 Further information is located at and.http://standards.ieee.org/board/pat/pat-material.htmlhttp://standards.ieee.org/board/pat

2. 2 Executive Summary (1) For 16m CP ratio 1/8, BW 5/10/20 MHz. Legends: – –For TD-SCDMA: Yes/No: whether coexistence is possible or not. – –For LTE TDD All: all cases in LTE-TDD can coexist with 16m scenario. Most: two DwPTS categories of LTE-TDD can coexist with 16m. Few: only 3 OFDM symbol DwPTS category of LTE-TDD can coexist with 16m. N/A: the case violates the constraint that there should be at least 2 type-1 subframes / frame. Notes – –D:U ratio in bracket is 16m D:U ratio which can coexist with TD-SCDMA/LTE TDD. – –UL-DL Configuration 1 is the most important LTE-TDD case to consider. # of type-3 subframes / frame TD-SCDMALTE TDD 4:35:2UL-DL Cfg. 0UL-DL Cfg. 1UL-DL Cfg. 2 1No All (3:5)Few (4:4)Most (6:2) 2NoYes (6:2)N/A (3:5)Most (5:3 & 4:4)Most (6:2) 3Yes (5:3)Yes (6:2)N/A (3:5)All (5:3)Most (6:2)

3. 3 Executive Summary (2) Changes to Frame Structure – –For 16m 1/8 CP ratio, BW 5/10/20 MHz, allow 2 and 3 DL type-3 subframes. – –This effectively increases TTG, which is friendly for cell coverage. Configurations to add: (please refer to contribution C80216m-09/1971). 2 type-3 subframes, 6:2 3 type-3 subframes, 5:3 2 type-3 subframes: 5:3

4. 4 Current Status in 802.16m Examples are given in section 11.4.4.1 of SDD.

5. 5 Criterion of Coexistence (1) Principle: avoid simultaneous transmission of DL from one RAT and UL from another RAT, i.e. align switching points of two RATs. Assumption: base stations of two RATs are co-site. Notations: –D 1, T 1, U 1, R 1 and D 2, T 2, U 2, R 2 denote the length of DL, TTG, UL, and RTG for RAT1 and RAT2 respectively, with the constraint D 1 +T 1 +U 1 +R 1 = D 2 +T 2 +U 2 +R 2 = F = 5 ms –Assume the UL end of RAT1 can be left shifted x relative to the UL end of RAT2. –60μs RTG assumed for LTE-TDD, although not officially specified. When considering BS-to-BS interference only –At UL->DL switching point, to avoid interference: -R 2 xR 1. –At DL->UL switching point, to avoid interference between RAT1 DL to RAT2 UL: U 2T 1 +U 1 +x; to avoid interference between RAT1 UL to RAT2 DL: U 1 +xT 2 +U 2 –So if there is any x satisfying both -R 2 xR 1 and U 2 -U 1 -T 1 x U 2 -U 1 +T 2, then coexistence is possible. It is equivalent to max(-R 2, U 2 -U 1 -T 1 ) x min(R 1, U 2 -U 1 +T 2 ). –The simplified criterion is D 1 +U 2F, and D 2 +U 1F. Distributions of TTG and RTG within each RAT does NOT impact coexistence.

6. 6 Criterion of Coexistence (2) When considering MS-to-MS interference in addition to BS-to-BS interference –Requirements for BS-to-BS interference should be satisfied. –For every RAT, at MS side, TTG is reduced by RTD while RTG is increased by RTD, with RTD = 2r/c, where r is cell radius and c is the speed of light. RTD is 0. 667 ms for 100 km cell radius. –Additional inequalities to satisfy: max(-(R 2 +RTD), U 2 -(T 1 -RTD)-U1) x min(R 1 +RTD, T 2 -RTD+U 2 -U 1 ). –It is equivalent to D 1 +U 2F-RTD, D 2 +U 1F-RTD, and T 1 +T 22RTD. –There is NO need to support quite large cell radius, since in that case, even the same RAT will have MS-to-MS interference. In the analysis, we assume the maximum cell radius is 5 km, which corresponds to 33.3 μs. In addition, RTD should be selected so that there is no self-interference for each RAT, i.e. RTD = min(33.3 μs, F-D 1 -U 1, F-D 2 -U 2, T 1, T 2 ).

7. 7 16m CP ratio 1/8 – 1 type-3 subframe LTE UL-DL Configuration 1 (16m D:U=4:4) LTE UL-DL Configuration 2 (16m D:U=6:2) LTE UL-DL Configuration 0 (16m D:U=3:5) Background color Green: coexistence possible Yellow: coexistence impossible Cyan: coexistence is possible when MS-to-MS interference is not considered; impossible when such interference is considered.

8. 8 16m CP ratio 1/8 – 2 type-3 Subframes LTE UL-DL Configuration 1 (16m D:U=5:3, 4:4 for 4 cases) LTE UL-DL Configuration 2 (16m D:U=6:2) LTE UL-DL Configuration 0 (16m D:U=3:5)

9. 9 16m CP ratio 1/8 – 3 type-3 Subframes LTE UL-DL Configuration 1 (16m D:U=5:3) LTE UL-DL Configuration 2 (16m D:U=6:2) LTE UL-DL Configuration 0 (16m D:U=3:5)

10. 10 Backup

11. 11 TD-SCDMA Frame Structure In current TD-SCDMA deployment, the common D:U ratios are 4:3 and 5:2.

12. 12 LTE TDD Frame Structure (1)

13. 13 LTE TDD Frame Structure (2)