1. Dynamic Interference Mitigation for Femtocell Access Points in IEEE802
Dynamic Interference Mitigation for Femtocell Access Points in IEEE802.16m Network
IEEE Presentation Submission Template (Rev. 9)
Document Number:
IEEE C802.16m-08/607
Date Submitted:
Source:
Yuefeng Zhou, Karthik Sundaresan
Honghai Zhang, Nader Zein, Sampath Rangarajan Voice:
NEC
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Venue:
IEEE Session #56, Denver, CO, USA
Base Contribution:
Purpose:
To discuss and adopt the proposed Interference mitigation scheme for Femtocell herein for the m SDD
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2. Dynamic Interference Mitigation for Femtocell Access Points in IEEE802
Dynamic Interference Mitigation for Femtocell Access Points in IEEE802.16m Network
Authors:
Yuefeng Zhou, Nader Zein
NEC Europe
Karthik Sundaresan Honghai Zhang, Sampath Rangarajan
NEC US Labs

3. Dynamic Interference Mitigation for Femtocell Access Points in IEEE802
Dynamic Interference Mitigation for Femtocell Access Points in IEEE802.16m Network
Femtocell has gained tremendous momentum in the industries. It has been regarded not only a new technology to provide reliable indoor coverage, but also a new business model for higher quality and cheaper integrated services.
3G Femtocell has been deployed in Europe
LTE ( LTE-A) and WiMAX Forum are making efforts on Femtocell standardization
IEEE802.16m has to consider supporting Femtocell Access with spectrum efficiency

4. Dynamic Interference Mitigation Femtocell Access Points in IEEE802
Dynamic Interference Mitigation Femtocell Access Points in IEEE802.16m Network
Interference Mitigation is an important aspect for Femtocell access
Macro cell base station has high transmission power and will interfere the Femtocell, which is under the coverage of the Macro cell; Also, Closer femtocells will interfere each other as well.
Radio environment is dynamically changing
New femtocell being switched on;
Relay stations might have mobility;
Traffic load within a Femtocell might be changing
No need to fix the number of subchannels to a femtocell, less number of subchannels allocated to a femtocell, less probability to cause interference to neighbor cells.

5. Dynamic Interference mitigation
Dynamic Interference Mitigation for Femtocell Access Points in IEEE802.16m Network
Dynamic Interference mitigation
Femtocell access point should support periodically scaning the radio environment, and detect the interference situation surrounding itself.
Femtocell access point should then peridically report following information to high layer network controller, such as ASN-GW;
List of the index of the detected preambles;
List of the signal strength of the detected preambles;
Required traffic load ( or number of MS, which currently connecting to the femtocell );
The index of the preamble with the least received signal strength;
The high layer network controller, such as ASN-GW, will dynamically assign preamble, certain number of subchannels for the femtocell access point to mitigate the interference and allow appropriate traffic load within the femtocell.

6. Proposed Text
-- IEEE802.16m-based Femtocell access point shall support peridical neighbor station measurement. The measurement should include the signal strength and preamble index of neighbor stations/access points with unique IDs, and the index of the preamble with the least received signal strength. The femtocell access point should peridically report these measurements to ASN-GW to facilitate the scheduling algorithm in ASN-GW to allocate preamble and subchannels to the femtocell access point. The femtocell access point may report the number of MS currently connecting to itself to ASN-GW.