Routing in Mobile Networks

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Routing in Mobile Networks

Professor Ching-Chi Hsu

Part I. Mobile IP on Network Layer

Part II. Routing in Mobile/Wireless Ad-hoc Networks

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Mobile IP on Network Layer

DNS based Name to Address resolution Network Layer Mobility Problem Illustration of Terms in Mobile IP Two Tier Addressing Mobile IP Architecture Components Address Translation Mechanisms Mobile IP Proposals

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DNS based Name to Address resolution

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Network Layer Mobility ProblemDirectory Service View

DNS didn’t handle dynamic updates.

DNS design attempts to optimize the access cost, and not the update cost.

There is no call back mechanism generally available from servers to clients in case the cached entries of the DNS clients become invalid.

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Network Layer Mobility Problem Internet View

TCP connection:<source IP address, source TCP port, destination IP address, destination TCP port>

If the mobile host acquires a new IP address, all TCP connections involving the mobile host will be broken.

If the mobile host retains its address, then the routing system cannot forward packets to its new locations.

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Illustration of Terms in Mobile IP

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Two Tier Addressing

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Mobile IP Architecture Components

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Address Translation MechanismsEncapsulation

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Address Translation MechanismsLoose Source Routing

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Mobile IP ProposalsColumbia Scheme

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Mobile IP ProposalsSony Scheme

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Mobile IP ProposalsLSR Scheme

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Mobile IP ProposalsIETF Scheme

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Routing in Mobile/Wireless Ad-Hoc Networks

Introduction Definitions of Dynamic Groups Routing Dynamic Groups Routing Algorithms Simulation and Analysis Conclusion Future Works

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Introduction

Ad-Hoc Networks Model

Previous Works on Routing in Ad-Hoc Networks

Motivations of Dynamic Groups Routing

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Ad-hoc networks Wireless communication Without fixed network interaction and centralized administration. Multi-hop routing style with no cheating of the forwarding nodes

mobile host

routing

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Why ad-hoc networks ? When the access base station are not set up due to low cost effect, p

oor performance or low usage Ad-hoc networks may be the extension of base stations

Applications of ad-hoc networks An outdoor conference Emergency situations of natural disasters Military deploys in battlefield

Ad-hoc networksBase station

Bridges

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Previous Works on Routing in Ad-Hoc Networks

On-demand dynamic source routing (D.B.Johnson et al.)

Cluster-based routing (P. Krishna et al.)

Zone routing (Z.J. Haas et al.)

Minimum connected dominating set routing (B. Das et al.)

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On-demand dynamic source routing

Loosely source routing while route requested Each node may overhear the routing information from the

neighbor nodes. Example: source routing and overhearing

sourcedestination

Route request messageRoute reply message

Overhearing range

Mobile node

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Cluster-based routing

The clustering method depends on the k-hop mutually reachable relation between any two nodes in a cluster.

A two-level network graph - cluster-level + node-level Example: 1-cluster(fully connected sub-graphs as clusters)

Mobile node

Cluster

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Zone routing

Zone - the nodes within the defined radius Radius - hop-count reachable from the central node Each node maintain the topology in its zone Example: zone with radius = 2

Mobile node

Zone

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Minimum connected dominating set routing

Minimum connected dominating set (MCDS) - construct a so-called virtual backbone in an ad-hoc network.

Routing through the virtual backbone by dominators. Example: virtual backbone construction

MCDS edge

Non-MCDS edge

MCDS(virtual backbone)

Mobile node

dominators

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Comparison

Routing methods Advantages Disadvantages

Zone Routing(cluster-based)

MCDS Routing

Infrastructure

Uniform cluster with the nodeas the center

MCDS virtualbackbone as routing trunk

Easy to maintainthe topology inzones

Frequent movingcausing heavy topology update

On-demand Routing

Only sense theneighbors

Less overhead tomaintain topology

Frequent routing make it mass routediscovery overhead

Simple to search routes by virtualbackbone

Network grownup make the virtualbackbone a heavyburden

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Motivations of Dynamic Groups Routing

Ad-hoc network topology maintenance Range Consideration

The whole network - inefficient and infeasible. Only neighbors - inefficient while frequent route requesting

Structure Consideration Relative conectivity Relative position

To propose an easy topology maintenance and good traffic isolation ad-hoc network routing system- Dynamic Groups Routing

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Definitions of Dynamic Groups Routing

Illustration of an ad-hoc network construction

Definitions Dominating value definition Routing groups definitions Definitions of attachable sets, bridge and peripheral clusters

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Illustration of an ad-hoc network construction

D

B

HC

RIE

A

JF G

Q

P

O

M

N

K

L

Routing group

Positive clusterNon-positive cluster

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Dominating value definition

Definition 1: DV(p) is the dominating value of a node p in an ad-hoc network. It is calculated as the following before the construction proceeds.

Initial DV(p) := 0

For each q which q in neighborhood of p

If deg(p) > deg(q)

then DV(p) := DV(p) +1

else if deg(p) < deg(q) DV(p) := DV(p) – 1

Theorem 1: In the initial constructed bi-directional connected network, the summation of all dominating values of nodes is zero.

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Routing groups definitions

Definition 2: A node p is positive while DV(p) > 0, otherwise non-positive.

Definition 3: In a constructed ad-hoc network, the cluster formed by all connected positive nodes is called positive cluster (P-cluster). The cluster formed by all connected non-positive nodes is called non-positive cluster (N-cluster).

Definition 4: A routing group (RG) is formed by one P-cluster with its adjacent N-clusters

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Definitions of attachable sets, bridge and peripheral clusters

Definition 4: An attachable set is a set of all the positive nodes in the same P-cluster with direct bi-directional links to the same adjacent N-cluster

Definition 5: A bridge cluster is the N-cluster belonged to more than one RG. On the other hand, the N-cluster belonged to one RG is called peripheral cluster.

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Dynamic Groups Routing Algorithms

Construction algorithm

Route discovery strategy

Route maintenance

Connection recovery

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Message propagating illustration in construction

D

B

HC

RIE

A

JF G

Q

P

O

M

N

K

LNote: <degree, DV>

<2,-2>

<5,+2>

<3,0>

<2,-1>

<5,+2>

<3,-2>

<5,+2>

<5,+2><3,-2>

<2,-1>

<3,0>

<2,-1> <2,0><2,-1>

<2,-2>

<2,0>

<2,-2>

<4,4>

Nlist(A),DV(A)

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Construction algorithm

{For each mobile node p in the ad-hoc network}

Broadcast message deg(p) to all neighbors

Receive message deg(q) from each neighbor q

Calculate DV(p) as definition 1

Broadcast message {List(N(p)) ,DV(p)} to each neighbor q

Receive message {List(N(r)) ,DV(r)} from each neighbor q

For each message {List(N(r)) ,DV(r)}

Case 1. DV(p) > 0 & DV(q) > 0

Propagate it to all positive neighbors excluding q

Case 2. DV(p) > 0 & DV(q) <= 0

Propagate it to all positive neighbors

Case 3. DV(p) <= 0 & DV(q) <= 0

Propagate to all neighbors excluding q

Case 4. DV(p) <= 0 & DV(q) > 0

Ignore the message

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Route discovery illustration

S

Intra-cluster

Intra-group

Inter-group

RG

P-cluster

N-cluster

Mobile node

Intra-cluster Inter-groupIntra-group

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Route discovery strategy

For a route request from the source node s to the destination node d

if (the node s is non-positive)

then it checks the local topology information of its N-cluster

if (the destination node d is found)

then it routes from the node s to the node d directly

else it multicasts intra-group route request message to all the nodes in its attachable sets and waits for reply message

if (all the reply message are failure)

then it issues inter-group route request message to all the nodes in its attachable sets

else it routes by the reply information from one of the nodes in its attachable sets

else it checks the local topology information of its routing group

if (the destination node d is found)

then it routes from the node s to the node d directly

else it multicasts inter-group route request message to all the nodes in the attachable sets of all its bridge clusters,which also belong to other routing groups

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Route maintenance(link variations)

Hm Hn

6 kinds of reactions to the variations

Reacting/Interactingnode

Interacting/ReactingnodeLink

N/P N/P

Connected/Disconnected

2 * 2 * 2 = 8

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Route maintenance(link variations)

Hm Hn Link(Hm,Hn) Action DescriptionP P Disconnect I Hm propagates "Delete link(Hm,Hn)" to the hosts in the

same P-cluster. If the P-cluster isn’t connected, the RG issplited.

P N Disconnect II Hm propagates "Delete link(Hm,Hn)" to the hosts in thesame P-cluster. Hm is detached the N-cluster of Hn fromHn .

NN

PN

Disconnect III Hm propagates "Delete link (Hm,Hn)" to the hosts in thesame N-cluster or in its ASET

P P Connect IV If Hn and Hm are the same P-cluster, Hm propagates"Insert link(Hm,Hn)" to the hosts in the same P-cluster.Otherwise Hm propagates "Insert RG topology of Hm" toHn and waits for the RG topology of Hn. Therefore, theaction joins two RGs.

P N Connect V Hm propagates "Insert link(Hm,Hn)" to the hosts in thesame P-cluster. If Hn and Hm are not the same RG, Hmwaits for the N-cluser+ASET topology of Hn.

NN

PN

Connect VI Hm propagates "Insert link (Hm,Hn)" to the hosts in thesame N-cluser or in its ASET. If Hn and Hm are not thesame RG, Hm propagates "Insert N-cluser+ASETtopology of Hm" to Hn.

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Route maintenance(connectivity dominating variations)

DV(E): +2

D E

I

H

G

F

C

A

B

-1

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The connectivity dominating v ariation of H m caused by the link variation of H n

Initial D V(H m ) D eg(H m )? deg(H n ) LinkHmHn variation U pdated D V(H m )

P > Connected→ disconnected P or NP = Connected→ disconnected PP < Connected→ disconnected PN > Connected→ disconnected NN = Connected→ disconnected NN < Connected→ disconnected N or PP > D isconnected→ connected PP = D isconnected→ connected PP < D isconnected→ connected P or NN > D isconnected→ connected N or PN = D isconnected→ connected NN < D isconnected→ connected N

Note: P: positive ; N : non-positive; → : link state transition from left to right

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The connectivity dominating variation of Hm caused by the conectivity dominating variation of Hn

Initial V(Hm) Deg(Hm)?deg(Hn) DV(Hn) variation Updated DV(Hm)P > Decrement PP = Decrement PP < Decrement P or NN > Decrement NN = Decrement N or PN < Decrement N or PP > Increment P or NP = Increment P or NP < Increment PN > Increment N or PN = Increment NN < Increment N

Note: P: positive ; N: non-positive

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Connection Recovery

Group-level backtracking to the last one

P-cluster P-cluster

N-cluster

N-cluster

N-clusterNew route

RG1 RG2

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Connection Recovery

Assume original discovered route from s to d. (s(a0)a1… an d(an+1))The corresponding attachable sets are A1,A2,….,AnFor node aiSearch the topology information in the routing group of aiIf the destination node d is found

Routing is successfulOtherwise

Checking the connection status of ai+1Case “Normal” Routing performs on the next node ai+1.Case “Broken” (Recovery process performs on node ai) Finding the other attachable sets from the routing group of ai. If there are other attachable sets excluding the routing group of ai-1 and ai+1 Rerouting starts from these attachable sets. Otherwise

Routing backtracks to ai-1 to find the other attachable sets excluding the routing group ofai. Rediscovery process performs on ai-1.

Case “Merged” Forwarding the routing process to ai+1.

Case “Attached” Forwarding the routing process to the attachable set excluding the routing group of ai.

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Simulations and Analysis

Simulation model

Simulation results

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Simulation model

N mobile nodes move randomly in a square area

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Simulation results

Connectionless Variant number of mobile hosts Variant moving frequency of mobile hosts Variant route query frequency of mobile hosts

Connection-oriented 32 mobile hosts in 800m*800m area 72 mobile hosts in 1200m*1200m area

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Total delay in route maintenance phase by increasing number of mobile hosts

Message Trip for Maintenance

0

10000

20000

30000

40000

50000

60000

70000

10 20 30 40 50 60 70 80 90 100

Number of mobiles

Tot

al h

op c

ount

DG Routing(mtc)Zone Routing(mtc)MCDS Routing(mtc)

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Message Propagation of Maintenance

0

500000

1000000

1500000

2000000

2500000

3000000

10 20 30 40 50 60 70 80 90 100

Number of mobiles

Num

ber of

mes

sage

pac

kets

DG Routing(mmc)Zone Routing(mmc)MCDS Routing(mmc)

Control traffic in route maintenance phaseby increasing number of mobile hosts

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Control traffic in route discovery phase byincreasing number of mobile hosts

Message Propagation of Route Discovery

0

2000000

4000000

6000000

8000000

10000000

12000000

14000000

16000000

18000000

20000000

10 20 30 40 50 60 70 80 90 100

Number of mobiles

Num

ber of

pro

paga

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mes

sage

pac

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DG Routing(rmc)Zone Routing(rmc)MCDS Routing(rmc)Flood Routing(rmc)

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Total control traffic by increasing number of mobile hosts

Message Propagation of Route Maintenance & Discovery

0

2000000

4000000

6000000

8000000

10000000

12000000

14000000

16000000

18000000

20000000

10 20 30 40 50 60 70 80 90 100

Number of mobiles

Num

ber of

pro

paga

ted

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sage

pac

kets DG Routing(tmc)

Zone Routing(tmc)MCDS Routing(tmc)

Flood Routing(tmc)

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Total delay in route maintenance phase by increasing moving frequency


0

5000

10000

15000

20000

25000

30000

35000

10 20 30 40 50 60 70 80 90 100

Frequency of movement(%)

Tot

al h

op c

ount

DG Routing(mtc)

Zone Routing(mtc)MCDS Routing(mtc)

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Control traffic in route maintenance phase by increasing moving frequency


0

100000

200000

300000

400000

500000

600000

10 20 30 40 50 60 70 80 90 100


Num

ber of

mes

sage

pac

ketsDG Routing(mmc)Zone Routing(mmc)

MCDS Routing(mmc)

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Control traffic in route discovery phase by increasing moving frequency


0

500000

1000000

1500000

2000000

2500000

3000000

10 20 30 40 50 60 70 80 90 100


Num

ber of

pro

paga

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sage

pac

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DG Routing(rmc)Zone Routing(rmc)

MCDS Routing(rmc)Flood Routing(rmc)

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Total control traffic by increasing moving frequency


0

500000

1000000

1500000

2000000

2500000

3000000

10 20 30 40 50 60 70 80 90 100


Num

ber of

pro

paga

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sage

pac

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DG Routing(tmc)

Zone Routing(tmc)MCDS Routing(tmc)Flood Routing(tmc)

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Total delay in route maintenance phase by increasing routing frequency


0

5000

10000

15000

20000

25000

30000

35000

10 20 30 40 50 60 70 80 90 100

Frequency of route request(%)

Tot

al h

op c

ount

DG Routing(mtc)Zone Routing(mtc)MCDS Routing(mtc)

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Control traffic in route maintenance phase by increasing routing frequency


0

50000

100000

150000

200000

250000

300000

350000

400000

10 20 30 40 50 60 70 80 90 100


Num

ber of m

ess

age p

ackets

DG Routing(mmc)

Zone Routing(mmc)

MCDS Routing(mmc)

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Control traffic in route discovery phase by increasing routing frequency


0

10000000

20000000

30000000

40000000

50000000

60000000

10 20 30 40 50 60 70 80 90 100


Num

ber of

pro

paga

ted

mes

sage

pac

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DG Routing(rmc)Zone Routing(rmc)MCDS Routing(rmc)Flood Routing(rmc)

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Total control traffic by increasing routing frequency


0

10000000

20000000

30000000

40000000

50000000

60000000

10 20 30 40 50 60 70 80 90 100


Num

ber of

pro

paga

ted

mes

sage

pac

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DG Routing(tmc)Zone Routing(tmc)MCDS Routing(tmc)Flood Routing(tmc)

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The message complexity comparison by connection time duration with area = 800m*800m, number of mobile

nodes = 32, moving frequency =50%

Message Complexity

0

5000

10000

15000

20000

25000

30000

35000

40000

10 20 30 40 50 60 70 80 90 100connection time duration(#clicks)

num

ber of

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kets DG without recovery

DG with recovery

Flooding routing

Zone routing

MCDS routing

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The message complexity comparison by mobile node moving frequency with area = 800m*800m, number of

mobile nodes = 32, connection duration = 50

Message Complexity

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

10 20 30 40 50 60 70 80 90 100

moving frequency %

num

ber of

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DG without recoveryDG with recoveryFlooding routingZone routingMCDS routing

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The message complexity comparison by connection time duration with area = 1200m*1200m, number of mobile

nodes = 72, moving frequency =50%

Message Complexity

0

20000

40000

60000

80000

100000

120000

140000

10 20 30 40 50 60 70 80 90 100

connection time duration(#clicks)

num

ber of

pro

paga

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The message complexity comparison by mobile node moving frequency with area = 1200m*1200m, number of

mobile nodes = 72, connection duration = 50

Message Complexity

0

20000

40000

60000

80000

100000

120000

140000

160000

10 20 30 40 50 60 70 80 90 100moving frequency %

num

ber of

pro

paga

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Conclusion

A two-type cluster scheme is proposed to form the routing groups structure, easily maintaining the routing environment in ad–hoc networks.

It seems that this approach is adaptive to such domain for reducing the control message propagation in ad-hoc networks

Upon the basic constructed model of ad-hoc networks, the route recovery method is developed for connection-oriented applications

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Future Works

Now a day many multicasting applications are applied in mobile/wireless ad-hoc networks.

The next research subject is developing efficient multicast routing methods in ad-hoc networks based on the constructed dynamic groups model.

Documents

Routing in Mobile Networks