Handover Operation with Multi-Carrier Support
IEEE 802.16 Presentation Submission Template (Rev. 9)
Document Number: C802.16m-08/1020
Date Submitted: 2008-09-05
Source:
Kelvin Chou
Yih-Shen Chen
I-Kang Fu
Paul Cheng
[email protected]
[email protected]
[email protected]
[email protected]
MediaTek Inc.
No.1, Dusing Rd. 1, Hsinchu Science-Based Industrial Park,
Hsinchu, Taiwan 300, R.O.C.
Venue:
MAC: Multi-Carrier Operation; in response to the TGm Call for Contributions and Comments 802.16m-08/033 for
Session 57
Base Contribution: This is the base contribution
Purpose: To be discussed and adopted by TGm for the 802.16m SDD
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.
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Multi-Carrier Mobility Management Design Concept
The MS may maintain its normal operations with the serving BS on one carrier (using
one RF) while perform scanning or network re-entry to the target BS on another
carrier (by another RF)
Serving
Base Station
(FA #1)
Target
Base Station
(FA #2)
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RF #2
RF #1
Mobile Station
2
Scanning in Multi-Carrier System
In cell reselection, the MS scans primary (fully-configured) carriers of neighbor BSs
The MS may also scan other primary carriers of its serving BS
S-BS
Partial conf
Full conf
Partial conf
Full conf
Scanning
interval
BS #3
Partial conf
Full conf
Partial conf
Full conf
Partial conf
Full conf
Partial conf
RF
Full conf
MS
BS #2
DL synchronization with
carrier #3 of the Serving BS
DL synchronization with carrier #1 of BS #2
initial ranging
Scanning
interval
Scanning
interval
DL synchronization with carrier #3 of BS #2
initial ranging
DL synchronization with carrier #1 of BS #3
Initial ranging
DL synchronization with carrier #3 of BS #3
Initial ranging
3
Scanning with Multi-Carrier Support (1/4)
Scanning using the RF other than the one for its primary carrier
The MS dedicates its secondary RF for either normal scanning or autonomous scanning
In normal scanning, the scanning request/response messages can be exchanged over either the
primary carrier or the secondary carrier
Scanning operations go in parallel with normal operations on the primary carrier
Scan neighbor cells
using the secondary RF
Maintain normal
operations with the S-BS
on the primary carrier
Frequency band 3
Neighbor BS #2
Normal operations
DL synchronization
Initial ranging
Serving BS
Frequency band 1
Neighbor BS #1
Frequency band 2
4
Scanning with Multi-Carrier Support (2/4)
An example of the MSC for scanning using secondary RF
RF #2 is dedicated to scanning
Scanning request/response can be exchanged via either carrier #1 or carrier #2
MS
RF #1
Primary
carrier
Request scheduled
scanning intervals,
not necessary for
autonomous scanning
Serving BS
RF #2
Secondary
carrier
RF #1
Primary
carrier
RF #2
Secondary
carrier
BS #2
BS #2
RF #1
RF #2
Carrier #1 Carrier #2
RF #1
RF #2
Carrier #1 Carrier #2
Scanning request
Scanning response
DL synchronization with carrier #1 of BS #2
Initial ranging if
possible and needed
Initial ranging (association)
Ranging response
DL synchronization with carrier #2 of BS #3
Initial ranging (association)
Initial ranging if
possible and needed
Ranging response
5
Scanning with Multi-Carrier Support (3/4)
Scanning using multiple RFs simultaneously
Perform DL channel evaluation and synchronization to multiple frequency bands via multiple
RFs simultaneously
To expedite the scanning operation (e.g. fast cell reselection)
Use RF #2 to scan BS #3
and BS #4
Use RF #1 to scan BS #1
and BS #2
BS #4
Frequency band 3
BS #1
Frequency band 1
BS #3
Frequency band 4
BS #2
Frequency band 2
6
Scanning with Multi-Carrier Support (4/4)
An example of the MSC for scanning using multiple RFs simultaneously
MS
RF #1
Primary
carrier
Request scheduled
scanning intervals,
not necessary for
autonomous scanning
RF #2
Secondary
carrier
S-BS
BS #1
BS #2
BS #3
BS #4
Scanning request
(duration=N frames)
Scanning resonse
(start frame = M frames
duration = N frames)
M frames
DL synchronization with BS #1
DL synchronization with BS #2
Scanning interval
(N frames)
DL synchronization with BS #3
DL synchronization with BS #4
Additional
alternations of
scanning interval and
interleaving intervals
7
Intra-Frequency Handover (1/5)
Handover Scheme #1
RF #1: primary carrier with S-BS until T-BS DL synchronization is done
RF #2: DL synchronization (and initial ranging if possible) with T-BS
Description
The MS may use another RF (e.g. RF #2) to acquire the DL/UL channel parameters of the target BS
(e.g. timing/frequency offset ) before disconnecting its primary carrier (e.g. on RF #1) from the serving
BS
After the DL/UL channel parameters are obtained, RF #2 may proceed to network reentry to the target
BS, or it can pass the parameters to RF #1 to complete network reentry
Advantage
Reduced handover interruption time
1. Use RF #2 to acquire
DL/UL channel parameters
Serving BS
2
2. Disconnect the primary
carrier from the S-BS
1
3
3. Network reentry
using RF #1 or #2
Target BS
8
Intra-Frequency Handover (2/5)
Handover Scheme #1 - Scenario 1
The MS synchronizes with the target carrier (the primary carrier to handover to) of the target
BS before disconnecting from the serving BS
The MS maintains its primary carrier with the S-BS (e.g. using RF #1) and uses another RF (e.g. RF
#2) to synchronize to the DL channel on the primary carrier of the T-BS and acquire the DL/UL
parameters
Remaining network reentry procedures (including initial ranging) are completed using RF #2 after the
primary carrier to the S-BS has been disconnected
MS
Serving BS
Target BS
RF #1 on RF #2 on
primary secondary
carrier
carrier
RF #1
RF #2
Carrier #1
Carrier #2
(serving)
RF #1
RF #2
carrier #1
Carrier #2
(target)
Primary carrier connected
HO request
RF #2 performs DL
synchronization to the primary
carrier of the target-BS
HO response
DL synchronization,
DL/UL parameters acquisition
HO indication
RF #2 performs network
reentry to the target-BS
Initial ranging, reauthorization, registration, etc.
Primary carrier connected
9
Intra-Frequency Handover (3/5)
Handover Scheme #1 - Scenario 2
The MS synchronizes with a fully-configured carrier of the target BS other than the target
carrier before disconnecting from the serving BS
The MS maintains its primary carrier with the S-BS (e.g. using RF #1) and uses another RF (e.g. RF
#2) to perform initial ranging to a fully-configured carrier of the T-BS other than the target carrier
Remaining network reentry procedures are completed using RF #1 after disconnecting from the S-BS
The ranging parameters acquired by RF #2 (UL timing, power, etc.) are used by RF #1 to expedite its
network reentry process
MS
Serving BS
RF #1 on RF #2 on
primary secondary
carrier
carrier
RF #1
RF #2
Carrier #1
Carrier #2
(serving)
Target BS
RF #1
carrier #1
(target)
RF #2
carrier #2
Primary carrier connected
HO request
HO response
RF #2 performs initial ranging
with the secondary carrier of the
target BS
Pass acquired parameters
(UL timing, power, etc) to
RF#1 for network reentry
RF #1 performs network
reentry to the target-BS
DL synchronization, DL/UL parameters acquisition,
initial ranging
HO indication
Initial ranging, reauthorization, registration, etc.
Primary carrier connected
10
Intra-Frequency Handover (4/5)
Handover Scheme #2
RF #1:
Primary carrier with S-BS until new primary carrier with the T-BS is established
Scheduled sleeping intervals
RF #2: network reentry to the T-BS within sleeping intervals
Description
The MS puts its primary carrier (e.g. carrier #1) into sleep mode and uses another carrier (e.g. carrier
#2) for network reentry to the target BS within the sleeping intervals of its primary carrier
The primary carrier to the serving BS maintains connected until the new primary carrier to the target
BS is established
Advantage
Make-before-break HO
1. Request sleep intervals for
the primary carrier
2. Use carrier #2 for handover
1
network reentry within the sleeping
intervals of the primary carrier
Serving BS
4
2
4. Disconnect the primary
carrier from the S-BS
3
3. New primary carrier
is established on carrier #2 Target BS
11
Intra-Frequency Handover (5/5)
An example of the MSC for HO scheme #2
Primary carrier goes sleep upon receiving Fast Ranging IE
RF #2 sends RNG_REQ within the sleep interval of the primary carrier
MS
S-BS
RF #1 RF #2
T-BS
Primary carrier
MOB_HO-REQ
HO request
HO response
MOB_HO-RSP (Action Time)
Action
Time
MOB_HO-IND (Serving BS leaving)
HO Confirm (MC HO)
HO Ack
1 frame
Fast Ranging IE
RF #1: sleep
RF #2: NW reentry
RNG_REQ
RNG_RSP
Primary carrier established
MOB_HO-IND (Serving BS release)
12
Inter-Frequency Handover (1/3)
Handover Scheme #1 can also be used for inter-frequency handover
RF #1: primary carrier with S-BS until initial ranging to the T-BS is done
RF #2: initial ranging to the T-BS
Description
The MS synchronizes with the target carrier of the target BS before disconnecting from the serving BS
The MS maintains its primary carrier with the S-BS (e.g. using RF #1) and uses another RF (e.g. RF
#2) to perform initial ranging to the primary carrier of the T-BS
Remaining network reentry procedures (including initial ranging) are completed using RF #2 after the
primary carrier to the S-BS has been disconnected
Advantage
Handover interruption time is reduced
1. Use carrier #2 to acquire
DL/UL channel parameters
Serving BS
2
2. Disconnect the primary
carrier from the S-BS
1
3
Frequency band 1
3. Network reentry
via carrier #1 or #2 Target BS
Frequency band 2
13
Inter-Frequency Handover (2/3)
Handover Scheme #3
RF #1: primary carrier with S-BS until new primary carrier with T-BS is established
RF #2: network reentry to the T-BS
Description
Using the secondary RF (any RF other than the one for the primary carrier) for network reentry
The primary carrier to the serving BS maintains connected until the new primary carrier to the target
BS is established
New primary carrier is established on the secondary RF
Advantage
Make-before-break HO
1. Use carrier #2 to perform
network reentry
Serving BS
3
3. Disconnect the primary
carrier from the S-BS
Frequency band 1
1
2
2. Established primary
carrier to the T-BS on
Target BS
carrier #2
Frequency band 2
14
Inter-Frequency Handover (3/3)
An example of the MSC for HO scheme #3
MS
Serving BS
Target BS
RF #1
RF #2
(carrier #1) (carrier #2)
Carrier #1 Carrier #2
(FA #1)
(FA #2)
Carrier #1 Carrier #2
(FA #1)
(FA #2)
Primary carrier
Disconnect RF #2
from S-BS if it is
connected
HO request/response
HO indication
(serving BS leaving)
Network re-entry
New primary carrier established
HO indication
(serving BS release)
15
Summary of Multi-Carrier Handover Schemes
Handover Scheme #1
Intra-frequency handover
Inter-frequency handover
Handover Scheme #2
Intra-frequency handover
Inter-frequency handover
Make-before-break handover
Handover Scheme #3
Inter-frequency handover
Make-before-break handover
16
SDD Text Proposal
Add the following text into Session 10 of the SDD (IEEE 802.16m-08/003r4)
----------------------- text begin ----------------------------------------------------------------------------10.3.x Handover Operation with Multi-Carrier Support
10.3.x.1 Handover Preparation
During handover preparation, the MS may use multiple RF carriers to maintain normal
communication with the serving BS while performing scanning or association with neighbor
BSs.
10.3.x.2 Handover Execution
During handover execution, the MS may use multiple RF carriers to maintain normal
communication with the serving BS while performing network re-entry signaling with the
target BS.
----------------------- text end -------------------------------------------------------------------------------
17