Vertical Handover for PMIPv6

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Vertical Handover for PMIPv6

• KANG Joon-Suk
• ? ??

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Contents

• Why Vertical Handover
• Wireless technologies
• Handover between 802.11 and 802.16
• Procedure
• 802.16 gt 802.11
• 802.11 gt 802.16
• Remaining Problems
• Comments

3
Agenda

• Why Vertical Handover
• Wireless technologies
• Handover between 802.11 and 802.16
• Procedure
• 802.16 gt 802.11
• 802.11 gt 802.16
• Remaining Problems
• Comments

4
Why Vertical Handover

• Cost/Capacity/Coverage..
• If a laptop might be able to use both a high
  speed wireless LAN and a cellular technology for
  Internet access.
• Wireless LAN connections generally provide higher
  speeds
• benefit of utilizing the higher bandwidth and
  lower cost
• Cellular technologies generally provide more
  ubiquitous coverage.
• better mobility support and larger coverage
• The laptop user might want to use a wireless LAN
  connection whenever one is available, and to
  'fail over' to a cellular connection when the
  wireless LAN is unavailable.

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Cases of Vertical HO

• Switching network to select the best network

Handover
Handover
Handover
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Cases of Vertical HO

• For just seamless connection

Handover
7
Agenda

• Why Vertical Handover
• Wireless technologies
• Handover between 802.11 and 802.16
• Procedure
• 802.16 gt 802.11
• 802.11 gt 802.16
• Remaining Problems
• Comments

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Wireless technologies

• Wireless LAN
• IEEE 802.11
• Hot Spot
• 50200m
• 411Mbps
• Average 2Mbps
• Low cost
• IEEE 802.16(e)
• Based on wireless data communication
• 60km/s(max 100km/s)
• More than 1Mbps(60km/s)
• MAX 70100Mbps
• Hot Zone or Global coverage
• Cell coverage 20km

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Wireless technologies

• 3G
• 3GPP
• UMTS
• 3GPP2
• CDMA
• 3.5G
• HSDPA(High Speed Downlink Packet Access)
• 3GPP release5
• Based on mobile telecommunication
• Voice/Data
• Global coverage
• Average 23Mbps
• MAX 14.4Mbps
• 4G???
• 100Mbps(moving)/1Gbps(standstill)

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Wireless technologies

• COST
• Cellular gt IEEE 802.16 gt IEEE 802.11
• Coverage
• Cellular gt IEEE 802.16 gt IEEE 802.11
• IEEE 802.16 HSDPA WLAN ??

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Wireless Data Communication in Japan

• 2nd market in the world
• 2G
• NTT Docomo
• PDC
• KDDI
• CDMA One
• 3G
• NTT Docomo
• W-CDMA
• KDDI
• CDMA 2000

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Wireless Data Communication in Japan

• Wireless Internet
• NTT Docomo
• Super 3G
• Download speed 100Mbps/Upload speed 50Mbps
• Based on HSDPA/HSUPA
• KDDI
• Ultra 3G
• Similar speed to Super 3G
• Base on Mobile WiMAX(IEEE 802.16e)
• Serving with WiFi, ADSL, FTTH
• SoftBank
• Based on HSDPA
• WilCom
• PHS
• Emobile
• HSDPA

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Wireless Data Communication in Korea

• Netspot
• WiFi
• KT
• Wibro
• Based on IEEE 802.16e
• KT
• HSDPA
• SKT, KTF
• Wibro HSDPA
• KTF KT

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Target L2

• IEEE 802.11
• IEEE 802.16e
• HSDPA

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Agenda

• Why Vertical Handover
• Wireless technologies
• Handover between 802.11 and 802.16
• Procedure
• 802.16 gt 802.11
• 802.11 gt 802.16
• Remaining Problems
• Comments

16
Handover between 802.11 and 802.16
ACR (MAG)
LMA
Router (MAG)
802.16 BS (RAS)
802.11 AP
LMA Local Mobility AnchorMAG Mobile Access
Gateway RAS Radio Access System ACR Access
Control Router
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Handover between 802.11 and 802.16

• A MN that is connected to 802.16 enters a
  hotspot. For cost and bandwidth performance, the
  MN executes a vertical handover to the 802.11
  network. When leaving the cell, the MN reconnects
  to the 802.16 network.

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Handover between 802.11 and 802.16 -
entering WLAN
802.11 AP
802.16 BS
MN
802.16 interface
802.11 interface
Beacon
Link Detected
Authentication Request
Normal operation
Authentication Response
Association Request
Link UP
Association Response
Selecting by user or Automatically Switching
Preparing Layer 3 handover
Keep interface on or shutdown interface???
CompletingLayer 3 handover
Normal operation
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Process To Detect and To Register new 802.16 BS
MN
BS
Channel Scanning
DL_MAP (Downlink map)
Downlink synchronization
Link Detected
DCD (Downlink Channel Descriptor)
0.2-10s
UCD (Uplink Channel Descriptor)
Uplink synchronization
UL_MAP (Uplink map)
0.005-0.110s
Ranging request
Initial ranging
Ranging response
0.005-0.080s
Registration request
Registration
Registration response
Link UP
Establish uplink and downlink data connections
Normal operations (data Tx/Rx and maintain
synchronization)
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Handover between 802.11 and 802.16 -
leaving WLAN
802.16 BS
802.11 AP
MN
802.11 interface
802.16 interface
Normal operation
Link Going Down
Link Detected
Preparing Layer 3 handover
Performed if 802.16 interface was turned off
Link synchronization and registration
Link UP
Layer 3 handover
Normal operation
Keep interface on or shutdown interface ???
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Agenda

• Why Vertical Handover
• Wireless technologies
• Handover between 802.11 and 802.16
• Procedure
• 802.16 gt 802.11
• 802.11 gt 802.16
• Remaining Problems
• Comments

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Procedure - Scenario
ACR (MAG)
LMA
Router (MAG)
802.16 BS (RAS)
802.11 AP
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Procedure - Scenario

• Handover based on Network priority
• Just for seamless Handover
• Based on the current link status
• Does It become weaker?

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802.16 gt 802.11
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Procedure contd.

• Link_Detect event occurs(WLAN)
• MIHs Link_Detect event
• Beacon message
• MN is attached to the 802.11 APnMAG can acquire
  policy profile.
• Perform L2 authentication association process
• nMAG sends PBU to LMA(to perform BU with LMA)

LMA
ACR (pMAG)
3
Router (nMAG)
802.16 BS (RAS)
802.11 AP
2
1
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Procedure contd.
BCE list
4
5
LMA
ACR (pMAG)
6

• LMA checks BCE list to find out if this MN is
  already attaching.
• Register nMAG into the BCE list as a candidate
  MAG
• LMA sends VPBA to nMAG
• Set up virtual tunnel between LMA and nMAG
• VPBA contains the information of pMAG

Router (nMAG)
802.16 BS (RAS)
802.11 AP
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Procedure contd.
BCE list
7
LMA
ACR (pMAG)
Router (nMAG)

• LMA sends New_Network_Detected message to
  MN(User)
• To ask if user want to change network.
• This massage contains information about nMAG
• User selects network.

7
802.16 BS (RAS)
802.11 AP
8
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Procedure - If User Wants to
Keep Current Network
BCE list
9
LMA
ACR (pMAG)
10
11
Router (nMAG)

• User sends boycott message to LMA
• LMA deletes the entry from BCE list
• LMA sends boycott message to nMAG
• L2 connection is canceled between nMAG and MN

9
802.16 BS (RAS)
802.11 AP
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Procedure - If User Wants to
Change Network
BCE list
10
LMA
ACR (pMAG)
Router (nMAG)

• User sends Change_Network message to LMA via pMAG
• At pMAG
• pMAG forward it to LMA
• pMAG sends ACK to MN
• pMAG starts fording packets destined for MN to
  nMAG

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802.16 BS (RAS)
802.11 AP
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Procedure - If User Wants to
Change Network
LMA

• lt MNs actions gt
• As soon as MN receives Ack. from pMAG, MN changes
  layer2 interface.
• MN sends Router_Solicitation via 802.11 interface
• nMAG acknowledges it by Router_Advertisement
• MN performs IP address configuration

ACR (pMAG)
Router (nMAG)
802.16 BS (RAS)
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13
802.11 AP
14
11
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IP Address Configuration
Simple Modification of Auto-configuration process
MN
MN
If. Is ChangingbutIP is not Changing
IP Net Prefix IF ID from MAC2
IP Net Prefix IF ID from MAC1
IP Net Prefix IF ID from MAC1
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Procedure - If User Wants to
Change Network
BCE list
15
LMA
17
ACR (pMAG)
16
Router (nMAG)

• lt Networks actions gt
• As soon as LMA receives Network_Change from pMAG,
  LMA updates BCE list.
• LMA sends Confirm_BU to nMAG
• LMA changes forwarding path

802.16 BS (RAS)
802.11 AP
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Procedure - If User Wants to
Change Network

• After finishing IP configuration of MN, nMAG
  sends Handover_Complete message to pMAG and LMA
• Previous connection is closed
• pMAG LMA clears binding information of MN

LMA
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ACR (pMAG)
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Router (nMAG)
18
802.16 BS (RAS)
802.11 AP
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Automatic Changing- Without Users opinion

• According to the network priority
• ex) 802.11 gtgt 602.16
• According to the first service contract between
  SP and user
• The early steps are same with previous procedure
• 1st step 6th step

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Automatic Changing - Procedure
BCE list
7
LMA
ACR (pMAG)
8
Router (nMAG)

• LMA sends Change_Network message to pMAG
• At pMAG
• pMAG starts forwarding packets destined for MN to
  nMAG
• pMAG forwards it to MN
• pMAG sends Ack. To LMA
• nMAG caches the packes for MN

8
802.16 BS (RAS)
802.11 AP
8
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Automatic Changing - Procedure (contd.)

• lt MNs actions gt
• As soon as MN receives Change_Network from pMAG,
  MN changes layer2 interface.
• MN sends Router_Solicitation via 802.11 interface
• nMAG acknowledges it by Router_Advertisement
• MN performs IP address configuration

LMA
ACR (pMAG)
Router (nMAG)
802.16 BS (RAS)
10
11
802.11 AP
12
9
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IP Address Configuration
Simple Modification of Auto-configuration process
MN
MN
If. Is ChangingbutIP is not Changing
IP Net Prefix IF ID from MAC2
IP Net Prefix IF ID from MAC1
IP Net Prefix IF ID from MAC1
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Automatic Changing - Procedure (contd.)
BCE list
13
LMA
15
ACR (pMAG)
14
Router (nMAG)

• lt Networks actions gt
• As soon as LMA receives Ack. from pMAG, LMA
  updates BCE list.
• LMA sends Confirm_BU to nMAG
• LMA changes forwarding path

802.16 BS (RAS)
802.11 AP
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Automatic Changing - Procedure (contd.)

• After finishing IP configuration of MN, nMAG
  sends Handover_Complete message to pMAG and LMA
• nMAG releases the packes cached
• Previous connection is closed
• pMAG LMA clears binding information of MN

LMA
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ACR (pMAG)
16
Router (nMAG)
16
802.16 BS (RAS)
802.11 AP
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802.11 gt 802.16
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802.11 gt 802.16

• When the MN detects that the signal from AP
  becomes weaker
• Signal strength
• Link_Going_Down
• How to decide a valid threshold
• MN triggers HO

LMA
ACR (pMAG)
Router (nMAG)
802.16 BS (RAS)
802.11 AP
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Procedure

• MN detects that the signal becomes weaker
• MN starts detecting another network If MN finds
  another 802.11s network?...
• MN tries to establish the L2 connection with
  802.16 BS
• MN sends Prepare_Handover message to nMAG

LMA
ACR (pMAG)
Router (nMAG)
802.16 BS (RAS)
4
802.11 AP
2
3
1
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Procedure contd.

• Next steps are same with the step3step17 of the
  automatic changing procedure of 802.16 to
  802.11
• Only one difference
• In this case, changing policy does not follow
  network priority
• At step 8
• When nMAG receives Change_Network message, nMAG
  already knew that HO must be performed.
• Because of step 4

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The Biggest Problem of 802.16 network

• It takes very long time to detect and to register
  BS
• P19 of this ppt
• Before completing connection procedure, previous
  connection with WLAN will be closed.

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How to Solve

• If detecting procedure begins early?
• In spite of good signal strength
• Is it efficient?
• Maintaining L2 connection of previous 802.16
  network continuously, while MN is being attached
  to 802.11 network
• HO is performed very quickly
• But it causes resource waste

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Second Solution
LMA
ACR (pMAG)
Router (nMAG)

• MN detects that the signal becomes weaker
• MN sends Prepare_Handover message to nMAG

802.16 BS (RAS)
2
802.11 AP
1
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Second Solution
BCE list
4
LMA
5
ACR (pMAG)
3
Router (nMAG)
6

• nMAG sends Change_Network message to LMA
• LMA updates BCE list.
• LMA changes forwarding path
• LMA sends Confirm to nMAG

802.16 BS (RAS)
802.11 AP
1
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Second Solution
LMA

• At nMAG
• nMAG starts forwarding packets destined for MN to
  pMAG
• nMAG sends Ack. To LMA
• nMAG sends Confirm to MN
• MN changes layer2 interface.
• Next steps are same with previous case..

ACR (pMAG)
Router (nMAG)
802.16 BS (RAS)
8
802.11 AP
1
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Agenda

• Why Vertical Handover
• Wireless technologies
• Handover between 802.11 and 802.16
• Procedure
• 802.16 gt 802.11
• 802.11 gt 802.16
• Remaining Problems
• Comments

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Remaining Problems

• Adjusting the link Going Down threshold to allow
  enough time to perform full network entry in
  802.16 would require the MN to trigger an event
  while the connectivity to the 802.11 AP is still
  good.
• Some solutions to optimize the handover between
  802.11 and 802.16 include
• Keep the 802.16 interface on
• Use sleep mode
• Speed up the network entry by providing
  heterogeneous information through the 802.11
  interface (Information Service)
• 802.16 synchronization phase plays a key role in
  the handover latency
• Any prior knowledge for synchronization (channel
  descriptor messages) is critical in speeding up
  the handover.
• Reducing the synchronization time by increasing
  the frequency of the channel descriptor messages
  comes generally at the cost of a higher bandwidth
  overhead (less bandwidth available for user
  traffic).
• Keeping the 802.16 interface turned on is
  beneficial at the cost of additional power
  consumption and reduced battery life.
• The use of 802.16e mechanisms including neighbor
  advertisement, BS synchronization, and sleep mode
  may prove to be helpful.

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Remaining Problems

• To apply IPv6 to 802.16 Network, additional
  technique is needed
• Convergence Sublayer (CS)
• IP CS/ Ethernet CS
• Keeping the 802.11 interface turned on always?
• To reduce battery consumption, 802.11 interface
  is turned on only at the coexistence area of
  802.16 and 802.16
• Using extra information system

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Agenda

• Why Vertical Handover
• Wireless technologies
• Handover between 802.11 and 802.16
• Procedure
• 802.16 gt 802.11
• 802.11 gt 802.16
• Remaining Problems
• Comments

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Comments