Download Integrating UMTS and Ad Hoc Networks

Integrating UMTS and Mobile
Ad Hoc Networks
MASc. Student: Jade Wu
Computer Networks,
Department of Electrical and Computer Engineering,
Ryerson University
Supervisor: Dr. Muhammad Jaseemuddin
Sep 21, 2005
1
Presentation Contents
Background
Design Details
Simulation & Results
Conclusion
Q&A
2
Wireless Communication Systems
2G – 2.5G
3G
4G
GSM – GPRS
UMTS
WLAN
Integrating the existing
wireless technologies
3
Motivation
Packet-Switched
External
Packet Switched
Network
SGSN
GGSN
UMTS Network
External
Circuit Switched
Network
Wide area coverage,
but low data rate
Speed: hundreds kbps
MSC/VLR
RNC
GMSC
Circuit-Switched
Email (PS)
Phone call (CS)
Node B
Hot Spot Coffee Shop
Local area coverage,
high data rate
Speed: ~ 54 Mbps
802.11 Router
User moves to a hot spot.
Can we use this high-speed
connection for PS services?
Different ISPs?
Different interfaces?
4
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 (ondemand routing and multihop features)
Internet
UMTS Connection
802.11 Connection
CN
UMTS BS
Ad hoc Gateway
802.11 Beacon
ON
UMTS Interface
OFF
802.11 Interface
ON
UMTS Interface
ON
!!!
802.11 Interface
5
Presentation Contents
Background
Design Details
Simulation & Results
Conclusion
Q&A
6
Overview
 Key Approaches
UMTS Core Network
Internet
SGSN
GGSN
SGSN Signaling
RNC
Ad hoc network
Node B
Gateway
UTRAN
PS
MI
ig
li
na
ng
 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
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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
UMTS Core Network
Internet
Internet
SGSN
SGSN
GGSN/HA
GGSN
MIP
SGSN
Signaling
Signaling
RNC
RNC
Node B
Node
B
Gateway/SGSN
Gateway/FA
Ad hoc network
UTRAN
Ad hoc network
UTRAN
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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?
No
Yes
Routing Table
Lookup.
Find Host
Route?
Forward Packet
via Default Route
No
Yes
Forward Packet
via Next Hop
Perform Route
Discovery in Ad
hoc Network
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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
MN
Gateway
Gateway
SGSN
SGSN
GGSN
GGSN
Ad hoc Beacon
Gateway
Discovery
Router Advertisment
RARP
RARP Reply
Registration Request
with IP@ of MNx
Gateway
Discovery
Gateway Query
SGSNaddress
Context Request
(unicast RREQ to MNx asking for mutlicast
"All Mobility Agents")
SGSN Context Response
Gateway Reply
Buffer
(unicast RREP with Gateway info back to MN)
Inter-SGSN
Handover
SGSN Context Ack
Registration Request
MIP Signaling
Forward Packets
Buffer
SGSN Context Request
Update PDP Context Request
SGSN Context Response
Inter-SGSN
Handover
Buffer Response
Update PDP Context
MIP Signaling
SGSN Context Ack
Registration Reply
Forward Packets
Buffer
Update PDP Context Request
Update PDP Context Response
Registration Reply
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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 intersystem handover
 Perform inter-SGSN
handover procedure
between new
SGSN(SGSN) and old
SGSN (ad hoc gateway)
MNx
MN
Gateway
SGSN
GGSN
No Ad hoc Beacon
No Registration Request
Registration
Entry Expires
Routing Area Update Request
SGSN Context Request
SGSN Context Response
Inter-SGSN
Handover
Buffer
SGSN Context Ack
Forward Packets
Buffer
Update PDP Context Request
Update PDP Context Response
Routing Area Update Accept
Routing Area Update Complete
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Addressing & Tunneling
Packet Switched
Network
(Internet)
Addresses for Links to Internet:
Assigned by ISP (public addresses)
n
Tun
GTP
elin
g
GGSN
GTP Tunneling
UMTS Core Network
RNC
UTRAN
GTP Tunneling
SGSN
Addresses in Core Network:
Assigned by ISP
(private or public addresses)
Gateway
WLAN/
Ad hoc
MN
Addresses for MNs in Adhoc:
Assigned by Mobile Agent
(care-of addresses)
MN
Addresses for MNs in UTRAN:
Assigned by GGSN
(home addresses)
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Presentation Contents
Background
Design Details
Simulation & Results
Conclusion
Q&A
14
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
Attach UMTS
Power-up
Node B RNC
MANET-UMTS
UMTS-MANET
Handover
Handover
SGSN
UMTS CN
UTRAN
Registration
Internet
Gateway
GGSN
Ad hoc network
Simulation
Timeline
(minute)
0
10 11
41
42
60
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Results
UMTS-MANET Handover Time
GGSN
2 SGSN Context Requet
3 SGSN Context Response
SGSN
Gateway
4 SGSN Context Ack
120
100
80
60
40
20
0
0
2
4
6
8
10
12
d1
MN
7 Reqistration Reply
handover _ time  2d1  3d 2  2d 3
1 Registration Request
d2
Handover Time (msecs)
140
d3
5 Update PDP
Context Response
6 Update PDP
Context Request
UMTS-MANET Handover Time
No. of MANET nodes
MN
where
d1  No_of_intermedia_nodes
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Results
MANET-UMTS Handover Time
GGSN
5 Update PDP
Context Response
6 Update PDP
Context Request
d3
2 SGSN Context Requet
3 SGSN Context Response
SGSN
Gateway
4 SGSN Context Ack
7 Routing Area Update
Accepted
1 Routing Area Update
Request
d1
MN
d2
Handover Time (msecs)
MANET-UMTS Handover Time
90
80
70
60
50
40
30
20
10
0
0
2
4
6
8
10
12
No. of MANET Nodes
handover _ time  2d1  3d 2  2d 3
where d1 is the transmission delay between SGSN and MN
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Results
Throughput (file size = 30,000 bytes)
Max: 48,000
Average data rate: 8kbps
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Results
Throughput (file size = 85,000 bytes)
2.8 times
Average data rate: 22.6kbps
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Results
Throughput (file size = 200,000 bytes)
Buffer/Retransmission
6.8 times
Average data rate: 53.3 kbps > Max. bit rate 48kbps
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Results
Packet Loss
Packets start to be dropped when buffer is overflow during handovers.
Default buffer size = 8172 bytes.
Total Packet Dropped During MANET-UMTS Handover
Total Packet Dropped During UMTS-MANET Handover
70
80
60
70
40
10 mobile nodes
30
8 mobile nodes
20
6 mobile nodes
10
4 mobile node
0
2 mobile nodes
0 mobile nodes
200
400
600
800
1000
60
No. of MANET nodes
50
10 mobile nodes
30
40
8 mobile nodes
20
6 mobile nodes
10
4 mobile node
0
2 mobile nodes
0 mobile nodes
200
Packet Arrival Rate(packets/sec)
No. of Packet Dropped
No. of MANET nodes
No. of Packet Dropped
50
400
600
800
1000
Packet Arrival Rate (packets/sec)
overflow _ byte _ during _ handover(bytes)
 handovertime(sec)  packet _ arrival _ rate( packets sec)  packet _ size (bytes packet )
22
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
Background
Design Details
Simulation & Results
Conclusion
Q&A
25
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
Objective
Design Details
Simulation & Results
Conclusion
Q&A
28
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.
31
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
32
How buffer works?
In SGSN the packets will be assigned NPDU 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.
33
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
34
What are ad hoc parameters
Hello interval:1 sec
Allow hello loss = 3
Route 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
37
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 Repair
3 beacon missing
from neighbour A
neighbour A
related to FA?
No
Yes
Delete this route
from RT
Receive
beacons from
other nodes?
Delete this route
from RT and send
out RERRs
No
Yes
Local Repair
Perform gateway discovery.
Send out gateway query
Mark this registration entry
invalid in FA list
Perform MANET-UMTS
Handover
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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
42
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!
44
Ad hoc beacon
Each node maintains its own timer for
Beacon interval
Back off random time algorithm
Medium busy
Only one beacon wins
Adjust beacon interval with other nodes
when received beacons.
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