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IEEE C802.16m-09/1318
Project
Title
Purpose
Notice
IEEE 802.16 Broadband Wireless Access Working Group < http://ieee802.org/16 >
State and Operational Mode of Femtocell BS in IEEE 802.16m
Date
Submitted
2009-07-06
Source(s) Eunkyung Kim, Soojung Jung,
Juhee Kim, Jaesun Cha, Kwangjae Lim,
Hyun Lee, Won-Ik Kim, Chulsik Yoon
ETRI
138 Gajeongno, Yusong-gu, Daejeon,
305-700, KOREA
Re:
Voice: +82-42-860-5415
E-mail: ekkim@etri.re.kr
Contribution on AWD Support for Femtocell BS, in response to the TGm Call for Comments and Contributions on Project 802.16m Amendment Content, IEEE 802.16m-09/0028r1 for session #62
Abstract State and Operational Mode of Femtocell BS in detail of Femtocell operation
Release
Patent
Policy
To discuss and adopt the proposed text in the next revision of 802.16m amendment
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.
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.
The contributor is familiar with the IEEE-SA Patent Policy and Procedures:
< http://standards.ieee.org/guides/bylaws/sect6-7.html#6 > and
< http://standards.ieee.org/guides/opman/sect6.html#6.3
>.
Further information is located at < http://standards.ieee.org/board/pat/pat-material.html
> and
< http://standards.ieee.org/board/pat >.
Eunkyung Kim, Soojung Jung, Juhee Kim, Jaesun Cha, Kwangjae Lim, Hyun Lee, Won-Ik Kim,
Chulsik Yoon
ETRI
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The draft of IEEE 802.16m System Description Document (SDD)[1] describes the support for Femtocell BS and
Section 15.1 in SDD describes some primitive concept of Femtocell BS, which is not enough to cover general concept of support Femtocell BS on the next version of IEEE 802.16m Amendment Working Document (AWD)
[2] . Therefore, in this contribution, we describe the detail description of Femtocell BS operation in IEEE
802.16m on the AWD.
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IEEE C802.16m-09/1318
[-------------------------------------------------Start of Text Proposal---------------------------------------------------]
[ Adopt the following text in the 802.16m Amendment Working Document (AWD) ]
Fig. Xa shows the state transition diagram and operational mode of Femtocell BS. As shown the figure, in order to support Femtocell BS in IEEE 802.16m, states of Femtocell BS are as follows;
Initialization state
Operational state
Power down
Power Off
Power on Power down
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Initialization state
Operational State
Normal operation mode
Low-duty operation mode
Availability interval
Unavailability interval
Fig. Xa. State Transition Diagram and operational mode of Femtocell BSs
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15.2.x.y.1 Initialization State
IEEE C802.16m-09/1318
After Femtocell BS powers on, it prepares to play a role of BS for MS with some functionalities which are as follows;
Configuration of Radio interface parameters such ac acquisition of initial system parameters, PHY/MAC parameter decision, and topology acquisition.
Initial Time and Frequency synchronization from GPS, wired interfaces, IEEE 1588, and etc.
15.2.x.y.2 Operational State
After successfully attaching to the network, a femtocell BS enters the operational state. In the operational state, two operational modes may be supported; normal mode and low-duty mode. In the low duty mode, availability intervals alternate with unavailability intervals (i.e., low-duty operation cycle).
If the Femtocell BS fails the synchronization during operational state or it is unattached to the network, it changes its state to initialization state. In the case of power down of Femtocell BS, the state of the Femtocell BS changes to the power on/off state by sending to the subordinated MSs with out-of-service information to prevent
MSs entry or reentry from other cells.
Before powering down or changing to the initialization state, the Femtocell BS may request the subordinated
MSs to perform handover to neighbor cell if required.
When the backhaul link of the femtocell BS is down or the connection with the service provider network is lost for a configurable pre-defined time, the femtocell BS shall disable air interface with static user information. The user information may help the AMSs to perform optimized network reentry during handover when some of them decide to come back to the femtocell BS when its backhaul link is restored to normal.
15.2.x.y.2.1 Normal Operation Mode
In the normal mode of Femtocell BS in the operational state, it maintains its current state as normal mode if at least one MS is served by the Femtocell BS. During normal mode, the Femtocell BS synchronizes with overlay macro BS periodically. The Femtocell BS changes its mode from low-duty operation mode to normal operation mode if it is requested by overlay macro BS, core network, or MS to perform network entry, HO, and etc. The
Femtocell BS also enters normal operation mode from low-duty operation mode when it cannot decide the lowduty operation cycle at all due to variable paging offset or sleep cycle of subordinated MSs.
15.2.x.y.2.2 Low-duty Operation Mode
Besides the normal operation mode, Femtocell BSs may support low-duty operational mode, in order to reduce interference to neighbor cells. The Femtocell BS may enter low-duty operation mode either if all MSs attached to the Femtocell BS are in idle or sleep mode, or if no MS is in the service range of the Femtocell BS at all.
Upon entering the low-duty operation mode the Femtocell BS should decide the low-duty operation cycle and it can change the low-duty operation cycle during low-duty operation mode. During an available interval, the
Femtocell BS may become active on the air interface for synchronization and signaling purposes such as paging, ranging, or for data traffic transmission opportunities for the MSs. During an unavailable interval, it does not transmit on the air interface but it may be used for synchronization with the overlay macro BS or measuring the interference from neighbor cells. Further functional description of low-duty mode of Femtocell BS is shown in
15.2.x.z low-duty operation mode.
[-------------------------------------------------End of Text Proposal----------------------------------------------------]
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IEEE C802.16m-09/1318
[1] IEEE 802.16m-08/003r9a, “IEEE 802.16m System Description Document,” May 2009
[2] IEEE 802.16m-09/0010r2, “IEEE 802.16m Amendment Working Document,” June 2009
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