IEEE C802.16m-09/1742
Project
IEEE 802.16 Broadband Wireless Access Working Group <http://ieee802.org/16>
Title
Proposed AWD Text for Coverage and Capacity Optimization (SON)
Date
Submitted
2009-08-28
Source(s)
Jung-Mao Lin, Chie Ming Chou, Frank
Ren
ITRI
Wern Ho Sheen
Chaoyang University of Technology /
ITRI
E-mail: moumou3@itri.org.tw
whsheen@itri.org.tw
Re:
P802.16m/D1 topic (SON), IEEE 802.16m-09/0037: Support for Self Organizing Networks
(SON), Call for Contributions for P802.16m Amendment Proposals for Features
Abstract
The contribution proposes the text of coverage and capacity optimization procedure in the SON
section of the 802.16m amendment.
Purpose
To be discussed and adopted by TGm for the 802.16m Amendment.
Notice
Release
Patent
Policy
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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.
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and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name
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<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>.
Proposed AWD Text for Coverage and Capacity Optimization in SON section
Jung-Mao Lin, Chie Ming Chou, Frank Ren
ITRI
Wern Ho Sheen
Chaoyang University of Technology / ITRI
1.
Introduction
Base on current SDD, the SON functions need a coverage extension method to resolve the blind
areas and achieve the coverage and capacity optimization. In this contribution, we propose an inter-ABS
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IEEE C802.16m-09/1742
coordination based power configuration method to extend the cell coverage.
2.
Discussion and proposal
In most cases, an ABS can’t use the unlimited power to transmit data. This is because it may cause
serious interference to neighbor ABS and inaccessible subscribers. An ABS, especial an Femto ABS may be
requested to reduce its power when an AMS suffers serious interference from it. Once ABS reduces its
transmission power, its cell coverage and capacity will be reduced and some blind areas may be appeared.
Besides, when Femto ABSs are introduced into the network, Femto ABSs may shut down or temporarily stop
services (e.g., Femto ABS goes into low duty mode). In this case, some operating ABSs may have chance to
reconfigure its transmission power without the risk to raise interference. to reconfigure the transmission power
of ABS, an inter-ABS coordination-based mechanism is proposed This mechanism can be event-triggered or
periodic triggered:

Event-triggered scenario:
When there are some blind areas discovered by the services AMS in the ABS, the AMS could request
to trigger power reconfiguration by notifying its serving ABS. When SON server receives this request
from one ABS, the SON server will negotiate with the neighbor ABSs whose geological location are
close to the requested ABS and operate at the same FA with the ABS. During negotiation, the SON
server will coordinate a common time interval and resources for involved ABSs. SON server will
further inform those neighbor ABSs a dedicated sounding signal would be transmitted at coordinated
resources. After that, the SON server will request the ABS which triggers the inter-ABS coordination
based power configuration to transmit corresponding sounding signal at this coordinated resources with
recommended transmitting power. The involved other ABSs will measure the signal quality of this
signal and report the measurement results to the SON server. The SON server will then calculate an
acceptable transmission power and inform the results to the requested ABS The whole process is
described in figure 1.
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IEEE C802.16m-09/1742
Requested
ABS
Neighbor ABSs
SON server
inter-ABS coordination power reconfiguration request
Coordinate a common time interval, resources and a dedicated signal
Sounding signal
Make measurements
Report measurement result
Decide a suitable
transmission power
Power configuration results
Operate
Figure 1, Inter-ABS coordination based power configuration (event-triggered)

Periodic triggered scenario:
Compared with event-triggered, only the requested ABS can be reconfigured its power to improve
the blind area, in periodic triggered scenario, every involved ABSs can configure corresponding
power to increase the network performance. The SON server will coordinate the involved ABSs
and each ABS may have chance to reconfigure its power. Those involved target ABSs may include
all type neighboring ABSs with same FA. Involved ABSs will in-turn transmits a specific
sounding sequence at a coordinated channel. Other neighboring ABSs will receive and measure
the sounding sequence and report to the SON server. The SON server can calculate the suitable
transmission power for every involved ABSs and give commend to reconfigure the power. The
whole process is described in figure 2.
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IEEE C802.16m-09/1742
ABS
Neighbor
ABS
SON
server
Coordinate a common time interval, resources and a dedicated signal
Sounding sequence 1
Make measurements
Report measurement result
Sounding sequence 2
Make measurements
Report measurement result
Power configuration results
Operation
Decide a suitable
transmission power
Power configuration results
Operation
Figure 2, Inter-ABS coordination based power configuration (periodic triggered)
With this mechanism, one or multiple ABSs could be able to configure its transmitting power by themselves.
Based on the sounding action performed by involved ABSs, the power configuration results expected to be able
to ensure the satisfied interference level and optimize the coverage and capacity of a network.
3.
Proposed AWD Text
 Proposed Text for 16.2.1 
---------------------------------------------------- Start of Proposed Text----------------------------------------------------
16.2.1 Coverage and Capacity Optimization
The coverage and capacity optimization aims to detect and resolve the blind areas for reliable and maximized
network coverage and capacity when an MS cannot receive any acceptable signals from any BSs. When an MS
resumes the connection after experiencing service interruption in a blind area, the MS should perform the
measurement (e.g. RSSI, SINR, I and INR) and report the event together with cached information (e.g. last
serving BS ID, neighbor list, location information , timestamp and RTD etc.) to the serving BS. BS can direct
the MS to not report its cached information, in order to limit the amount of data that is reported. The SON
functions process the reported information and then determine the location of the blind areas in order for
subsequent coverage extension and capacity optimization.
16.2.1.1 Inter-ABS coordination for coverage and capacity optimization
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IEEE C802.16m-09/1742
When detecting a blind area or needing to configure transmission power of ABSs, the inter-ABS coordination
could be initiated to coordinate a power sounding process for involved ABSs. An ABS may send an request to
SON server for triggering the process. After receiving the request, the SON server will coordinate ABSs those
locations are close to requested ABS and operate at the same FA. The SON server will coordinate a common
sounding slot (time and resources) and a dedicated sounding sequence. The requested ABS will be
recommended to transmit the dedicated sounding sequence at the common sounding slot with a pre-defined
transmission power. Other involved ABSs will receive the sounding sequence in sounding slot and report the
measurement results to the SON server. The SON server will then calculate an acceptable transmission power
for the requested ABS
Or the SON server can trigger the inter-ABS coordination based power configuration periodically. The SON
server will coordinate several common sounding slots (time and resources) with regarding dedicated sounding
signal for each involved ABSs. Involved ABSs will in-turn transmits a specific sounding sequence in its
coordinated sounding slot. Other ABSs will receive the sounding sequence and report the measurement results
to the SON server. The SON server can calculate the suitable transmission power for every involved ABSs and
give commend to reconfigure transmission power of each involved ABSs.
---------------------------------------------------- End of Proposed Text ------------------------------------------------
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