IEEE C802.16m-09/0033
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Project
IEEE 802.16 Broadband Wireless Access Working Group <http://ieee802.org/16>
Title
Carrier Management for Multi-Carrier Operation - SDD Text Proposal
Date
Submitted
2009-01-05
Source(s)
Jan Suumaki, Roberto Albanese,
Zexian Li
Nokia
jan.suumaki@nokia.com
Chun Joon
NSN
Re:
802.16m-08/052, Call for Comments on 802.16m SDD (802.16m-08/003r6)
Section 19 Support for Multi-carrier Operation
Abstract
Change proposals for the multicarrier management
Purpose
For review and adoption into 802.16m System Description Document
Notice
Release
Patent
Policy
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
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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>.
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Carrier Management for Multi-Carrier Operation - SDD Text Proposal
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Jan Suumaki, Roberto Albanese, Zexian Li, Chun Joon
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Nokia, NSN
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1 Introduction
This contribution proposes changes for the section “19 Support for Multi-carrier Operation” in IEEE 802.16m
System Description Document [1].
The main focus of this contribution is on the secondary carrier management.
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IEEE C802.16m-09/0033
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2 Secondary Carrier Management
Secondary carrier management has the following operations:
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1) Secondary carrier management
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Secondary carrier management is proposed to be divided into long term management and short term
management.
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Long term management:
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Long term management is used to allocate and de-allocate secondary carriers for the AMS. The allocation of
carrier is called ‘carrier assignment’ and the state of the carrier is ‘assigned’ from the AMS point of view.
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The assignment of the secondary carrier may be done during initial network entry, or any phase during
multicarrier operation. Carrier assignment may be based on the ABS and AMS capabilities, negotiated service
flow parameters, network load, etc.
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Secondary carriers may be de-allocated at any time. This is called ‘carrier release’ and the state of the carrier is
‘unassigned’
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Long term management is done infrequently, only when significant changes happen for the negotiated QoS,
network condition or such.
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Short term management:
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Short term management is used to activate or deactivate secondary carriers for the AMS. Only active secondary
carrier can be used for actual data transmission. Activation and deactivation may be based on the negotiated
QoS, traffic pattern, buffer status or ABS/AMS needs.
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So a carrier would have three states from the AMS point of view:
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a) unassigned carrier: The AMS is not needed to monitor the carrier or do any operations on this carrier.
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b) assigned carrier: The AMS shall have valid PHY and other parameters of the carrier. The AMS shall
make periodic ranging for the assigned secondary carrier and make measuring and reporting based on the
ABS instructions. However, the AMS does not need to monitor frequently broadcast or other channels,
or execute continuous CQI feedback or such reporting. MS may shutdown the radio of the secondary
carrier between ranging or reporting interval, but before the AMS will execute ranging and
measuring/reporting the AMS shall ensure validity of the carrier parameters. This ranging and reporting
results may be used in the ABS to select the most optimal carriers for the activation.
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c) active carrier: The AMS shall continuously monitor all relevant channels and send feedback based on the
ABS instructions. Only in active state user data transmission is possible through secondary carrier.
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The following example shows assignment/release and activation/deactivation procedures of secondary carriers.
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IEEE C802.16m-09/0033
Assign
Secondary carrier 1
Release
Deactivate
Activate
Activate
Assign
Primary carrier
Deactivate
2-Phase management – Secondary carrier management
Secondary carrier 2
= Active Carrier
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= Assigned Carrier
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2) Exchanging of carrier PHY parameters and other characteristics
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Each carrier will have significant amount of configurable PHY and other parameters:
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center frequency
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bandwidth
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OFDMA parameters
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…
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This information is typically very static.
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If all of this information would be sent to each AMS during carrier assignment operation, it would cause high
overhead, even if the assignment is done rather infrequently.
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Broadcasting would be the best way to send these PHY and other parameters. All fully configured (potential
primary carrier) would broadcast periodically critical multi-carrier parameters, like center frequency of each
carriers supported within the ABS. So a fully configured carrier may broadcast also the critical parameters of the
other carriers within the ABS.
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Non-critical multi-carrier parameters may be broadcasted only within particular carrier (=within the carrier
where the parameters are relevant).
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Broadcasting may increase latency in carrier assignment procedure, thus it may be allowed to send critical
parameters also in unicast, e.g. during initial network entry.
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Each carrier has a carrier index, and this index shall be used during carrier assignment/release and
activation/deactivation operations.
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3 Text Proposal
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IEEE C802.16m-09/0033
---------------------------------------------------------Start of the Text---------------------------------------------------------19.4.7 Carrier Management
19.4.7.1 Primary Carrier Management
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The ABS may instruct the AMS, through control signaling on the current primary carrier, to switch its primary
carrier to one of the available fully configured carriers within the same ABS for load balancing purpose,
carriers’ varying channel quality or other reasons. AMS switches to the target fully configured carrier at action
time specified by the ABS. The carrier switch may also be requested by the AMS through control signaling on
the current primary carrier. ABS may direct an AMS to perform the primary carrier switching without scanning.
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19.4.7.2 Secondary Carrier Management
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During the initial network entry, an ABS may allocate one or more secondary carriers to an AMS among all
carriers supported by the ABS according to the capability of the ABS and the AMS and the policy of the ABS
(e.g. load condition). Allocation and deallocation of secondary carriers may be executed also any time during
multicarrier operation. The allocated secondary carriers are called as the assigned secondary carriers.
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A part of assigned secondary carriers is used for guaranteeing the QoS requirement of the current services,
which are called to active secondary carriers.
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Any physical layer procedures (e.g. feedback, resource allocation, etc) are not required to be performed for the
unassigned secondary carriers.
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During active/normal mode, an ABS allocates data resource to an AMS on a subset of active secondary carriers
and the primary carrier.
The ABS may instruct AMS to perform scanning on other carriers which are not serving the AMS. In this case,
if the target carrier is not currently serving the AMS, the AMS may perform synchronization with the target
carrier if required.
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To reduce overhead in carrier management some parameters required for the secondary carrier management may
be broadcasted periodically, for example: center frequencies of all carriers supported within the ABS.
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19.4.7.3 Carrier switching between a primary carrier and a secondary carrier
The carrier switching between a primary carrier and a secondary carrier may be periodic or event triggered with
timing parameters defined by multi-carrier switching message on the primary carrier. When an AMS switches to
a secondary carrier, its primary carrier may provide basic information such as timing and frequency adjustment
to help AMS’s fast synchronization with the secondary carrier. The details are FFS.
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----------------------------------------------------------End of the Text----------------------------------------------------------
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IEEE C802.16m-09/0033
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4 References
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[1] The Draft IEEE 802.16m System Description Document, IEEE 802.16m-08/003r6
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