Power Saving Considerations for IEEE 802 16 m

Power Saving Considerations for IEEE 802. 16 m Femtocell IEEE 802. 16 Presentation Submission Template (Rev. 9) Document Number: IEEE C 802. 16 m-08/1411 r 1 Date Submitted: 2008 -10 -31 Source: Ming-Hung Tao, Mamadou Kone, Ying-Chuan Hsiao, Richard Li ITRI E-mail: mhtao@itri. org. tw Venue: TGm call for contributions on IEEE 802. 16 m-08/040. Specific topic : “Support for Femtocells” Base Contribution: N/A Purpose: To be discussed and adopted 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 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: <http: //standards. ieee. org/guides/bylaws/sect 6 -7. html#6> and <http: //standards. ieee. org/guides/opman/sect 6. html#6. 3>. Further information is located at <http: //standards. ieee. org/board/pat-material. html> and <http: //standards. ieee. org/board/pat >. 1

Micro-sleep in femtocell • Time zones – Because a femtocell supports only few MSs (no more than 10), the superframe in femtocell can be divided into several time zones, each zone can be either dedicated to a specific MS or public to all MSs. – MSs in active mode knows the distribution of time zones from the SFH, and monitor only its dedicated zones and public zones. – A time zone is composed by one or multiple subframes. 2

Time zones in femtocell Super-frame Public B A C Public SFH A Dedicated to MS A C Dedicated to MS C B Dedicated to MS B Public to all MSs 3

Sleep mode in femtocell • Sleep mode procedure (including timer, signaling) in femtocell is the same as in macrocell. • During the MS listening interval/window, an MS first knows the zone distribution information from SFH, then checks the traffic indication from BS or transmits data to BS only in its dedicated zones or public zones. 4

Idle mode in femtocell (cont. ) • The femto BS maintains a paging group ID which is different from the PG ID of the macro BS, this PG ID may be shared by multiple femto BSs that have the same access set. • The paging message for an MS staying in a femto BS is broadcast to the femtocells in the same group only. • When an idle-mode MS moves from femtocells to macrocells or from marcocells to femtocells, it will observe a different PG ID and perform location update. • During paging listening interval, an idle-mode MS monitors only the public time zone for the paging message. 5

Idle mode in femtocell (cont. ) • In femtocell, shall we count idle-mode MSs as normal MSs when considering cell capacity? – If yes, the resource utilization will be low. – If no, the femto BS shall notify the existed idlemode MSs that the maximum capacity is reached when it happens, as well as notify the new idlemode MS who is coming from other femtocell or marcocell. 6

Idle mode in femtocell (cont. ) A femtocell with capacity = 5 MSs Idle-mode MS Active-mode MS New coming idle-mode MS Full notification The notification can be done through either location update or paging messages 7

Proposed text for SDD 17 Support for Femtocell 17. x Frame structure in femtocell The superframe in femtocells can be divided into several time zone, each zone can be either dedicated to a specific MS or public to all MSs. A time zone is composed by one or multiple subframes. The zone distribution information should be carried within SFH. 17. y Idle mode in femtocell When considering the capacity of a femtocell, idle-mode MSs should not be counted into the number of MSs. The femtocell should be able to notify idle-mode MSs that the maximum capacity is reached if it happens. 8