Integrating UMTS and Mobile Ad Hoc Networks
description
Transcript of Integrating UMTS and Mobile Ad Hoc Networks
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Integrating UMTS and Mobile Ad Hoc Networks
MASc. Student: Jade Wu
Computer Networks,Department of Electrical and Computer Engineering,
Ryerson UniversitySupervisor: Dr. Muhammad Jaseemuddin
Sep 21, 2005
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Presentation Contents
BackgroundDesign DetailsSimulation & ResultsConclusionQ&A
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Wireless Communication Systems
2G – 2.5G 3G 4G
GSM – GPRS UMTS
WLAN
Integrating the existing wireless technologies
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Motivation
Hot Spot Coffee Shop
Email (PS)
Phone call (CS)
ExternalPacket Switched
Network
ExternalCircuit Switched
Network
Packet-Switched
Circuit-Switched
Node B
RNC
SGSN GGSN
MSC/VLR GMSC
Can we use this high-speed connection for PS services?
Different ISPs?
Different interfaces?
User moves to a hot spot.
Wide area coverage, but low data rate
Speed: hundreds kbps
Local area coverage, high data rate
Speed: ~ 54 Mbps
802.11 Router
UMTS Network
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Objective
Integrating UMTS and ad hoc network
Two interfaces UMTS interface: always on 802.11 interface: on when
MN detects 802.11 beacons
Integration point is located in UMTS CN. (operated by the same ISP)
Inter-system handover procedures occur when MN moves in or out of 802.11 local area.
802.11 ad hoc mode enhances flexibility (on-demand routing and multi-hop features)
UMTS Connection 802.11 Connection
UMTS BS Ad hoc Gateway
CN
Internet
UMTS Interface
802.11 InterfaceOFF
ONUMTS Interface
802.11 Interface!!!
ON
802.11 Beacon
UMTS Interface
802.11 Interface
ON
ON
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Presentation Contents
BackgroundDesign DetailsSimulation & ResultsConclusionQ&A
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Overview
Key Approaches Integration point: GGSN Apply SGSN signaling for
communication between UMTS CN and ad hoc netowrk
Inter-SGSN handover GTP tunneling
Apply MIP signaling for ad hoc mobility management
Gateway discovery Route discovery
UMTS Core Network
Ad hoc network
UTRAN
Gateway
GGSNSGSN
RNC
Node B
Internet
SGSN Signaling
MIP Signaling
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Signaling between UMTS and Ad hoc networks Why not IP Signaling?
Full MIP structure: HA (any GSN) FA (Gateway)+ MN
Modifying GSNs is costly and risky. No official standard for implementing MIP on GSNs.
SGSN Signaling Ad hoc gateway acts as SGSN. GGSN is the integration point. Apply inter-SGSN handover
signaling between new SGSN, old SGSN and GGSN. (standard by 3GPP)
Use GTP tunneling between GGSN and ad hoc gateway
Maintain 3GPP standard in UMTS CN with some minor modifications
Modifying ad hoc gateways is less expensive.
UMTS Core Network
Ad hoc network
UTRAN
Gateway/SGSN
GGSNSGSN
RNC
Node B
Internet
SGSN Signaling
UMTS Core Network
Ad hoc network
UTRAN
Gateway/FA
GGSN/HASGSN
RNC
Node B
Internet
MIP Signaling
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Ad Hoc Mobility Management
MIP signaling is used for ad hoc mobility management. Gateway acts as a FA. All the mobile nodes must register with the gateway. Registration procedure is simplified. No home registration. Gateway Discovery
Receive ad hoc beacons from neighbours Send out Gateway Query (Route Request for “All Mobility Agents”) Receive Gateway Reply from the neighbour who knows gateway or
gateway itself Send Registration Request to the gateway After Registration Reply is received, Mobile IP installs a default route to
the gateway. Receiving a Router Advertisement directly triggers registration process.
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Ad Hoc Mobility Management
Ad hoc forwarding is modified. Route Discovery:
Network ID: Carrying a different network ID means the destination must be located in the Internet.
Routing Table: Host route found means the destination is in ad hoc network.
Destination is unknown: Forward the packet to the gateway. Gateway determines whether or not this destination is in ad hoc network.
If so, gateway sends back error message to inform the sender to perform ad hoc route discovery.
If not , gateway tunnels the packet to GGSN.
Packet Ready to send. Determine Destination Add.
Same Network ID?
Routing Table Lookup.
Yes
Find Host Route?
Yes
Forward Packet via Next Hop
Forward Packet via Default Route
No
Perform Route Discovery in Ad
hoc Network
No
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Inter-System Handovers: UMTS-MANET Handover When MN moves in an area
where it receives ad hoc beacons from other ad hoc nodes
Perform gateway discovery in ad hoc network
Registration message triggers inter-system handover
Inter-SGSN handover between new SGSN (ad hoc gateway) and old SGSN (SGSN)
Buffering is enabled on SGSNs.
Receiving a Router Advertisement directly triggers the registration process.
MNx MN Gateway GGSNSGSN
Ad hoc Beacon
Gateway Query (unicast RREQ to MNx asking for mutlicast address
"All Mobility Agents")
Gateway Reply (unicast RREP with Gateway info back to MN)
Registration Request
Registration Reply
RARP
RARP Reply with IP@ of MNx
Update PDP Context Request
Update PDP Context Response
SGSN Context Request
Forward Packets
SGSN Context Response
SGSN Context Ack
Gateway Discovery
Inter-SGSN Handover
MIP Signaling
Buffer
Buffer
MN Gateway GGSNSGSN
Router Advertisment
Registration Request
Registration Reply
Update PDP Context Request
Update PDP Context Response
SGSN Context Request
Forward Packets
SGSN Context Response
SGSN Context Ack
Gateway Discovery
Inter-SGSN Handover
MIP Signaling
Buffer
Buffer
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Inter-System Handovers:MANET-UMTS Handover
When MN moves out of ad hoc network
Missing beacons causes registration entry to expire and triggers inter-system handover
Perform inter-SGSN handover procedure between new SGSN(SGSN) and old SGSN (ad hoc gateway)
MNx MN Gateway GGSNSGSN
Update PDP Context Request
Update PDP Context Response
SGSN Context Request
Forward Packets
SGSN Context Response
SGSN Context Ack
Inter-SGSN Handover
No Registration Request
No Ad hoc Beacon
Registration Entry Expires
Routing Area Update Request
Routing Area Update Accept
Routing Area Update Complete
Buffer
Buffer
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Addressing & Tunneling
UTRAN
UMTS Core Network
GGSN
RNC
SGSN
GTP Tunneling
GT
P T
unne
ling
MN
Addresses for Links to Internet:Assigned by ISP (public addresses)
Addresses in Core Network:Assigned by ISP
(private or public addresses)
Addresses for MNs in UTRAN: Assigned by GGSN(home addresses)
Packet Switched Network(Internet)
WLAN/Ad hoc
MN
Gateway
Addresses for MNs in Adhoc: Assigned by Mobile Agent
(care-of addresses)
GT
P T
unne
ling
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Presentation Contents
BackgroundDesign DetailsSimulation & ResultsConclusionQ&A
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Simulation Properties
Simulation tool: OPNET 10.5 Simulation area: 3km x 3km Simulation duration: 3,600 secs (1 hour) Ad hoc node transmission range: 200 meters No. of ad hoc nodes in MANET: 0, 2, 4, 6, 8, 10 Traffic:
CBR: Packet size: 128 bytes Packet arrival rate: 200, 400, 600, 800 packets/ sec
FTP: File size: 30000, 85000, 200000 bytes Inter-request time: 30 secs
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Simulation Timeline and Trajectory
UMTS CN
Ad hoc network
UTRAN
Gateway GGSN
SGSNRNCNode B
Internet
Power-up
Attach UMTS
0
Simulation Timeline (minute) 10 11 41 42 60
UMTS-MANET Handover
MANET-UMTS
Handover
Registration
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ResultsUMTS-MANET Handover Time
UMTS-MANET Handover Time
0
20
40
60
80
100
120
140
0 2 4 6 8 10 12
No. of MANET nodes
Han
do
ver
Tim
e (m
secs
)
SGSN Gateway
MN
GGSN
2 SGSN Context Requet
3 SGSN Context Response
4 SGSN Context Ack
5 U
pda
te PD
P
Co
ntext R
esponse
7 R
eqistration
Rep
ly
1 R
egistration
Req
uest
6 U
pda
te PD
P
Co
ntext R
eque
st
d2
d3
d1MN
321 232_ dddtimehandover
esrmedia_nodNo_of_inted1 where
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ResultsMANET-UMTS Handover Time
MANET-UMTS Handover Time
010
2030
4050
6070
8090
0 2 4 6 8 10 12
No. of MANET Nodes
Han
do
ver
Tim
e (m
secs
)
SGSN Gateway
MN
GGSN
2 SGSN Context Requet
3 SGSN Context Response
4 SGSN Context Ack
5 Update P
DP
C
ontext Response
7 Routing A
rea Update
Accepted
1 Routing A
rea Update
Request
6 Update P
DP
C
ontext Request
d2
d3d1
321 232_ dddtimehandover
where d1 is the transmission delay between SGSN and MN
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ResultsThroughput (file size = 30,000 bytes)
Max: 48,000
Average data rate: 8kbps
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ResultsThroughput (file size = 85,000 bytes)
2.8 times
Average data rate: 22.6kbps
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ResultsThroughput (file size = 200,000 bytes)
Buffer/Retransmission
6.8 times
Average data rate: 53.3 kbps > Max. bit rate 48kbps
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ResultsPacket Loss
200400
600800
10000 mobile nodes
2 mobile nodes
4 mobile node
6 mobile nodes
8 mobile nodes
10 mobile nodes
0
10
20
30
40
50
60
70
No
. of P
acket Dro
pp
ed
Packet Arrival Rate(packets/sec)
No. of MANET nodes
Total Packet Dropped During UMTS-MANET Handover
200400
600800
10000 mobile nodes
2 mobile nodes
4 mobile node
6 mobile nodes
8 mobile nodes
10 mobile nodes
0
10
20
30
40
50
60
70
80
No
. of P
acket Dro
pp
ed
Packet Arrival Rate (packets/sec)
No. of MANET nodes
Total Packet Dropped During MANET-UMTS Handover
Packets start to be dropped when buffer is overflow during handovers.
Default buffer size = 8172 bytes.
)(_)(__(sec)
)(___
sec packetbytespackets sizepacketratearrivalpacketmehandoverti
byteshandoverduringbyteoverflow
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Throughput (file size= 85,000) 2 mobile nodes move randomly.
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Throughput (file size= 85,000) 5 mobile nodes move randomly.
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Presentation Contents
BackgroundDesign DetailsSimulation & ResultsConclusionQ&A
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Conclusion
We assume that a mobile node is equipped with two interfaces – a UMTS interface and a MANET interface.
We consider MANET is connected to UMTS CN and integrated at GGSN.
We developed vertical handover scheme for a mobile node to move from UMTS to MANET and vice versa.
We addressed the issue of signaling and Quality of Service during the intersystem handover.
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Conclusion
We developed a simulation model of the integrated system in OPNET and evaluated the performance of the integrated system under variety of scenarios.
We analyzed the results and concluded as the following: Tolerable handover delays Significant throughput improvement Low packet loss rate
The purpose of this research relates to the idea of improving data transmission rates and mobility in existing wide area network (UMTS). For mobile hosts in an ad hoc network to enjoy the connectivity from both networks and be able to switch some types of services (i.e. packet data service) which require higher capacity to the 802.11 links.
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Presentation Contents
ObjectiveDesign DetailsSimulation & ResultsConclusionQ&A
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Thank you for attending my presentation.
Questions?
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THE END
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Why release buffer before Update PDP Context?
Distribute the packet load to both side buffers. Both SGSNs are enabled with buffering.
This way keep the packets in order. Packets can be forwarded from the GGSN and old SGSN during handover.
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Why early expiration?
Missing beacons means mobile node has left the ad hoc network. Therefore should perform handover immediately in order to minimize the packet loss or delay
Why not on gateway side? Gateway will be informed by new SGSN with
the SGSN context request during the handover. Could be a period of time gateway still sees
mobile node is reachable
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How buffer works?
In SGSN the packets will be assigned N-PDU before being sent.
When SGSN received a SGSN Context Request, the SGSN stop assigning N-PDU for the downlink PDUs toward this mobile node. Unsigned PDU will be put into buffer.
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How multicast address works for gateway discovery Multicast address 224.0.0.11 is reserved for all mobility
agents. Which mean Foreign Agents or Home agents for Mobile IP.
All the agent join this multicast group when it powers up in the network.
Every router acts as “multicast routers” which in charge of forwarding packets to the modes that related to this multicast address.
Multicast Routing enable Multicast address list Default Multicast address
IPC_ALL_MOBILITY_AGENT_MULTICAST_ADDR Interface Multicast enabled
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What are ad hoc parameters
Hello interval:1 secAllow hello loss = 3Route Request rate 10 packets/sec
0.1 sec / request
Retries: 5 Local repair TTL:
The hop count# to the destination + Local add TTL (default 2)
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WLAN interface parameters
Beacon interval 0.02sec 11 Mbps Max failed polls : 2 PHY: Direct Sequence Spread Spectrum
Chip Sequence: barker code XOR Robustness against interference
MAC: DFWMAC PCF Point Coordination function F , DCF Distributed coordination function. CTS/RTS CSMA/CA– no hidden node problem INTER-FRAME SPACING AND BACKOFF TIME DFIS PIFS
SIFS
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Mobile IP parameters
Agent: IRDP interval: 12-16 Hold time: 3x 16 = 48
Mobile nodes: Registration retries: 4 Registration interval: 4
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What if the network partition?
Trick: do not send out ad hoc beacons unless it registers with foreign agent.
Even it received beacons, then the intersystem handover starts. However, the handover will fail due to no way to get to the gateway. Therefore it will still be using UMTS connections.
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Gateway Discovery Repair3 beacon missing from neighbour A
neighbour A related to FA?
Delete this route from RT
Yes
Receive beacons from other nodes?
Yes
Local RepairPerform gateway discovery.
Send out gateway query
Delete this route from RT and send
out RERRs
No
Mark this registration entry invalid in FA list
Perform MANET-UMTS Handover
No
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RFC or internet draft
RFC 2002 IP Mobility Support
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How packets being forward by gateway to MNs?
MIP agent deliver packets to MNs through link-layer connectivity; however in ad hoc network, its multihop functionality need to use layer-3 identifier.
On gateway, the ad hoc routing protocol must be used instead of MIP forwarding.
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Delay – 2 mobile nodes
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Delay – 5 mobile nodes
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Why MANET-UMTS Handover doesn’t count Routing Area Update Complete
It’s on SGSN side.!!We measured on MN side.Received Accepted and send out
Complete is at almost the same time!
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Ad hoc beacon
Each node maintains its own timer for Beacon interval
Back off random time algorithmMedium busyOnly one beacon winsAdjust beacon interval with other nodes
when received beacons.