1. ProjectIEEE 802.16 Broadband Wireless Access Working Group Title Proposal for Interference Avoidance and Interference Mitigation of Femtocell BSs (AWD- Femto) Date Submitted 2009-07-14 Source(s) Rong-Terng Juang, Yu-Tao Hsieh, Pang- An Ting, Ming-Hung Tao, Yung-Han Chen, Fang-Ching Ren ITRI Yih-Shen Chen MediaTek Inc. Hsin-Piao Lin and Kun-Yi Lin NTUT Voice: + 886 3 5919024 E-mail: rtjuang@itri.org.tw Yihshen.chen@mediatek.com Re: Call for Contribution on 80216m-09_0028r1 Abstract The contribution proposes text for the Interference Avoidance and Interference Mitigation of Femtocell BSs to be included in 802.16m amendment. PurposeTo be discussed and adopted by TGm for the 802.16m amendment. 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 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 802.16. Patent Policy The contributor is familiar with the IEEE-SA Patent Policy and Procedures: and. Further information is located at and.

2. 2 Motivations The deployment of femtocells should not cause performance impact on existing macrocells If a macrocell uses all the frequency partitions, then femtocell BSs have no chance to operation on a clean frequency partition If femtocells and macrocells are in co-channel operation, a macrocell user may lost its connection due to a strong interference from a closely- located femtocell BS Femtocells are low-cost, user-deployed base stations, and there may be hundreds of femtocells in the network Therefore, we suggest that some restrictions on radio resource utilization may be applied to femtocells, and that femtocells should support interference avoidance/mitigation using low-complexity methods

3. 3 Proposed Text 15.x.x Interference Avoidance and Interference Mitigation To mitigate interference from femtocell BSs, some restrictions on radio resource utilization may be applied to femtocell BSs. A femtocell BS is instructed to utilize a fractional frequency partition for data transmissions by either the overlaid macrocell BS or the SON server. The maximum amount of schedulable resource is carried in an IE, which is TBD. By default, a femtocell is allowed to use all the radio resource. Upon receiving the radio resource restriction message, each femtocell BS allocates data channels on selected radio resource, subject to the maximum schedulable resource size. Alternatively, each femtocell BS switches between pre-defined frequency partitions to average the interference.