Nâng cao hiệu năng mạng MANET sử dụng kỹ thuật định tuyến cân bằng tải đảm bảo chất lượng truyền dẫn tt tiếng anh

The author focuses on study-ing the load balancing techniques, while ensuring QoT of data transmission routes to improve the performance of MANET... iiAnalyze and evaluate QoT in MANET n

MINISTRY OF EDUCATION VIETNAM ACADEMY

GRADUATE UNIVERSITY SCIENCE AND TECHNOLOGY

———————————-LE HUU BINH

IMPROVE THE PERFORMANCE OF MOBILE

AD HOC NETWORK USING LOAD BALANCING ROUTING TECHNOLOGY ENSURING

The thesis has been completed at Graduate University of Science and Technology, Vietnam Academy of Science and Technology

Supervisor 1 Assoc Prof Dr Vo Thanh Tu

Supervisor 2 Assoc Prof Dr Nguyen Van Tam

Review 1:

Review 2:

Review 3:

.on .

This thesis could be found at:

- National Library of Vietnam.

- Library of Graduate University of Science and Technology.

i

1 The necessity of this research

With the development trend of communication network technologies, the wirelesscommunications is one of the decisive solutions for the transmission technology ofthe telecommunications network in general, and the computer network in particu-lar In the era of the fifth generation wireless network (5G) and Internet of things(IoT), there are several wireless network models to provide the practical applica-tions such as MANET, wireless sensor networks (WSN), wireless mesh networks(WMN), and hybrid wireless networks Among these types, MANET is becomingmore and more widely used in many fields [66]

To be able to expand the scope of application of the MANET, it is necessary toimprove the transmission speed, increase the radio range, expand the area of thenetwork However, this can lead to some technical difficulties For example, if thetransmission speed and the radio range increase, the physical effects that happen onthe routes also increase, reducing the network performance [26,29,30,61,65] Toimprove the network performance, it is necessary to find solutions to ensure QoT inthe network The QoT of the channels depends on the route, meanwhile, the route

is determined by the routing algorithm Therefore, the study of QoT constraintrouting algorithms in MANET is very necessary This issue has been interested

by many research groups recently [5, 24, 33, 35, 46, 51, 53] These publishedworks have proposed routing algorithms that take into account the constraints ofsome QoT parameters, where the proposed algorithms attempt to find out the bestQoT route This therefore improves the QoT in the network However, for the meshtopologies such as MANET, the routing technique with the best QoT can increasethe bottlenecks due to unbalanced traffic load To reduce the bottlenecks in thenetworks, the load balancing routing is often used [34,39,41,44,67,70] However,

it can be the cause of the QoT impairment due to the route passing through manyintermediate nodes

We have the following comments based on the analysis above, it is necessary toinvestigate the routing algorithms that take into account both QoT and load bal-ancing, especially in the case of a wide MANET, high bit rate and heavy nodedensity This is the research motivation of this thesis The author focuses on study-ing the load balancing techniques, while ensuring QoT of data transmission routes

to improve the performance of MANET

2 Research purpose

The thesis focuses on the analyzing and evaluating QoT of the data transmissionroutes and its effect on the performance of MANET according to different routingalgorithms Thence, propose improved routing algorithms to balance the trafficload, meanwhile ensuring QoT on data transmission routes, improving the perfor-mance of MANET networks

3 Research scope and object

The research object of the thesis focuses on the load balancing routing algorithmsand QoT aware routing in MANET The research scope of the thesis is the DSRand AODV routing protocols

4 Research contents

The thesis focuses on studying the following contents: (i) Constructing and veloping QoT constraint conditions according to different routing algorithms (ii)Analyze and evaluate QoT in MANET network in the cases DSR, AODV routingprotocols and load balancing routing are used (iii) Proposing improved routingalgorithms of DSR and AODV protocols in order to balance traffic load in thenetwork, meanwhile ensuring QoT of the data transmission routes, improving theperformance of the MANET network

de-5 Layout of thesis:

The thesis consists of following sections:

The introduction section focuses on analyzing the necessity of the research topic,thence determining the research purpose, the object and scope of the research aswell as the research methods of the thesis Chapter 1 presents the overview ofMANET and the factors that affect on the network performance Chapter2focuses

on evaluating the quality of transmission of MANET network in the cases usingthe on-demand routing and load balancing routing protocols Chapter3proposes

a load balancing routing algorithm ensuring the quality of transmission based onthe traffic load that offers to each route Chapter4proposes the Source-based loadbalancing ensuring quality of transmission based on the characteristics of dynamicsource routing protocol in MANET The conclusions section presents the new con-tributions of the thesis and proposes the contents of studying for the future Finally,there are two appendixs Appendix A presents in detail the calculation for illustra-tive examples in the thesis Appendix B presents the source code of some mainmodules in the simulation software based on OMNeT ++

2

CHAPTER 1

OVERVIEW OF MANET AND FACTORS AFFECTING ON NETWORK

PERFORMANCE

1.1 The basics of MANET

This content presents the principles, characteristics of MANET network and thefactors affecting on the network performance

1.2 Routing in MANET

In MANET, the routing protocols need to perform two tasks, one is to create ing information, that is, discover the route from source node to destination node toupdate into the route cache The second is to maintain updated routing information

rout-to determine the route information in route cache is still fresh or not

1.3 Related researches in the fields of routing in MANET

1.3.1 QoS routing

QoS routing is the routing technique in which QoS parameters such as packetblocking probability, latency, and throughput are considered during the route dis-covery process to ensure QoS of the network system [1,14,62]

1.3.2 QoT routing

QoT routing is the routing technique in which QoT parameters are considered ing route discovery Recently, QoT routing technique has been implemented bysome research groups There are two methods currently used to determine theconstraint conditions of QoT in the routing algorithms Firstly, constraining QoTthrough the weight function This method is done by constructing weight functionsthat contain the parameters of QoT, the routing algorithm based on this weightfunction to select the route [46,35,29] Second, constraining QoT through controlpackets This method is done by using control packets such as RREQ and RREP

dur-to exchange QoT information between network nodes, thence determining the straint conditions of QoT for the route selection [5,24,51,58]

con-1.3.3 Load balancing routing

The load balancing routing technique in MANET has been implemented by severalresearch groups recently The authors of [44] have proposed a load balancing rout-ing protocol for MANET namely LMP-DSR (Load balanced Multi-Path DynamicSource Routing) LMP-DSR protocol is modified from original DSR protocol byusing multiple paths routing instead of single path routing In [39], a multi-levelrouting algorithm (MRA) has been proposed to balance the traffic load in wireless

ad hoc network MRA uses an efficient method of selecting the intermediate nodeswhich have the enough resources and capability to reach the destination node In[34], the authors have proposed a routing protocol called LBCAR This protocoluses two metrics, traffic load density and link cost associated with a routing path

in order to determine the congestion status, the route with low traffic load densityand maximum life time will be selected for data transmission

1.3.4 Some comments and evaluations

• Proposing routing algorithms taking into account QoT has been implemented.However, most of the proposed algorithms check the QoT constraint conditionsafter the route set has been found Therefore, there are some cases where thefound route is not the best route with QoT, even does not satisfy the constraintconditions of QoT

• Regarding the network models are used for the performance evaluation, most

of works only evaluate the network models with low bit rate, using the channelswith the bandwidth of 20 MHz In the case of a broadband network, the effects

of physical effects need to be considered, because the wider the bandwidth, thegreater the interference on the channel

• Load balancing routing in MANET has also been devoloped by some researchgroups The results have demonstrated that network performance improves interms of the packet blocking probability and network throughput However, theconstraints of QoT have not been considered in the balanced routing algorithms

1.4 The new contributions of the thesis

(i) The thesis has proposed a new method to determine the constraint conditions

of the quality of transmission based on the cross-layer model This method isused for discovering the route of the on-demand routing protocols in MANET.(ii) Based on traffic load offers each route, the thesis has proposed Load BalancingRouting algorithm ensuring Quality of Transmission (LBRQT) for MANET.(iii) Based on the characteristics of DSR protocol, the thesis has proposed Source-based Load Balancing ensuring Quality of Transmission in DSR for MANET

1.5 Conclusion of chapter 1

Chapter 1 has presented the basics of MANET and the factors affecting on thenetwork performance, in which routing techniques were analyzed in depth Theauthor also carefully analyzed the published works related to routing techniques

in the MANET Thence the author determines the research problem and the newcontributions of the thesis

4

CHAPTER 2 EVALUATE QoT OF MANET IN THE CASE USING ON-DEMAND ROUTING

AND LOAD BALANCING ROUTING PROTOCOLS

2.1 Physical effects happen on the data transmission routes

2.1.1 Related technical factors

The physical effects happen on the data transmission routes depend on the technicalsolutions used at the physical layer and data link layer, such as modulation formats,wireless communication standards

2.1.2 Path loss [ 20 ]

Lf =

4πdλ

2

=

4π fcdc

2

(2.2)

where fcis the frequency of the carrier, c is the speed of the light and d is distance

2.1.3 Noise accumulates on the transmission routes

There are four noise components generated during data transmission, thermal noise,interference noise, crosstalk and impulse noise For MANET, the noise componentthat most affects on QoT is thermal noise with the power is given by:

where K is Boltzmann constant, T is temperature and B is channel bandwidth

2.2 Performance of MANET

In a general sense, the network performance is the efficiency, capacity and quality

of a network The evaluation of the network performance is the determination ofmeasures that reflect the effectiveness, capacity and quality of a network system

by methods of simulation, analytical or experimental In MANET, metrics monly used to evaluate performance include packet blocking probability, delay,throughput, signal-to-noise ratio and error bit rate

com-2.2.1 Blocking Probability of Data packet (BPD)

where Ngand Nbare number of data packets are generated and are blocked, tively Nbincludes blocking due to congestion and QoT constraint unsatisfactory

respec-2.2.2 Delay end to end

Delay end to end is the summation of time taken by a data packet to travel fromsource to destination

2.2.3 Signal to Noise Ratio (SNR)

In MANET, SNR depends on the relay type of the intermediate nodes There aretwo relay types which are amplify and forward (AF) and decode and forward (DF).SNR of a route depends on these forward types, is determined by [9,65]:

where βnis the SNR at the destination node and βh i is the SNR of the i hop

2.2.4 Bit Error Ratio (BER)

BER is the number of bit errors per number of transmitted bits Dependence ofBER versus SNR according to modulation formats is determined by [11]

2.3 QoT of the routes when using on-demand routing protocol

2.3.1 The basic principle of on-demand routing protocol

The principle of on-demand routing protocol is that routes will be discovered cording to the requirement [3] When a node requests a new route, it must initiate

ac-a route discovery process This process is only completed when ac-a new route isfound or all possible routes have been checked There are two on-demand routingprotocols in common research, which are DSR [22] and AODV [16]

2.3.2 QoT of the routes when using on-demand routing protocols

using AODV routing protocol

According to the principle of

on-demand routing protocols, there are

some cases that the route found

does not satisfy the constraints of

QoT Considering an example as

shown in Figure2.16 with AODV

protocol is used Assuming that A

want to discover a route to H For

AODV, the found route is A → E

→ C → H Assuming the relay type

of the nodes is AF According to

→ G → I → H Although hopcount of this route is 4, SNR of that is 24.1 dB Thisvalue is better than SNR of the route A → E → C → H that AODV found.

2.4 QoT of the routes when using load balancing routing protocols

2.4.1 The principle of load balancing routing technique

32

28

RREQ is continued to broadcast RREQ is discarded RREP is replied to source node

balancing routing in MANET network

Load balancing routing is the routing

tech-nique in which the route selection

crite-rion is the uniform load traffic distribution

across all connections in the network

2.4.2 QoT of the routes

Consider an axample of the route

discov-ery as shown in Figure2.17with the FMLB

load balancing routing algorithm [70] used,

K is set to 3 Considering case A wants to

transmit data to H According to the

princi-ple of route discovery by broadcasting the

RREQ packets, three routes found are A →

E → C → H, A → E → G → I → H and

A → B → D → H SNR of the routes are

23.86, 24.04 and 20.2 dB, respectively Thus, only the second route satisfies QoTconstraint Meanwhile, all three routes are used Therefore, data packets are trans-mitted on the first route and the third route with non-guaranteed QoT

2.5 Evaluate QoT and network performance using simulation method

2.5.1 Simulation scenarios

To evaluate QoT of the data transmission routes and its effect on the MANETperformance, the author has simulated based on OMNeT++ [10]

2.5.2 Simulation results of DSR protocol

The result in Figure2.19shows the SNR at the receiver of the destination node.There are many routes that does not satify the constraint of QoT since its SNR isless than required SNR This is the cause of the increasing BPD in the network

Figure 2.19 SNR of the routes in case of

DSR protocol

21.00 22.00 23.00 24.00 25.00

DSR

21.00 22.00 23.00 24.00 25.00

0.00 0.01 0.02 0.03 0.04 0.05 0.06

Tải lưu lượng (Erlang)

BPD toàn phần BPD do QoT

Traffic load (Erlang)

BPD overall BPD due to QoT

in case of DSR protocol

The existence of many routes that do not

sat-isfy QoT constraint has increased BPD as

shown in Figure2.24 BPD due to QoT is not

satisfied to account for nearly 50% of the

to-tal BPD

2.5.3 Simulation results of AODV

For AODV, SNR of the routes as shown in

Figure2.29 There are many routes that does

not satify the constraint of QoT (is less than

23.5 dB) This is the cause of increasing

BPD, this is clearly visible from Figure2.31

AODV protocol

0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08

Tốc độ di chuyển (m/s)

BPD toàn phần BPD do QoT

0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08

Mobility speed (m/s)

BPD overall BPD due to QoT

speed of AODV protocol

2.6 Conclusion of chapter 2

Chapter2 presents the research results about the physical effects happening on

the data transmission routes and its impact on MANET network performance The

simulation results have proved that, these effects is the cause of BPD increase,

lead-ing to the reduction of network performance Therefore, it is essential to improve

routing algorithms to ensure QoT and improve network performance

8

CHAPTER 3 LOAD BALANCING ROUTING ENSURING QUALITY OF TRANSMISSION

BASED ON TRAFFIC LOAD OFFERS TO EACH ROUTE

3.1 Introduction

The research results in Chapter2have shown that, load balancing routing can be solved traffic bottleneck in the network However, it can decrease QoT because theroutes may pass through multiple hops To ensure the QoT of the data transmissionroutes, several works have proposed routing algorithms that take into account theconstraints of some QoT [5,24,46,58], where the proposed algorithms attempt

re-to find out the best QoT route This therefore improves the QoT in the network.However, for the mesh topologies such as MANET, the routing technique with thebest QoT can increase the bottlenecks due to unbalanced traffic load

Thus, one problem to consider is how to combine harmony between QoT constraintrouting and load balancing routing, to find a set of routes that load traffic distributebalancedly for all links, while satisfying the constraint of QoT as shown in Figure3.2 For this idea, the author proposes a load balancing routing algorithm, while en-suring QoT of the routes The load balancing route is chosen based on informationabout probability of blocking packets from source to destination The proposedalgorithm is called LBRQT (Load Balancing Routing ensuring QoT)

Decreasing QoT

Load balancing routing under constrain of QoT

Load balancing

routing

3.2 Relevant theory

3.2.1 Analyze the blocking probability of data packet using queue theory

Considering a hop j (hi j), assume that the data packet arrivals follow Poisson tributions, the packet transmission times are exponentially distributed Thus hi jismodeled as M/M/1/L queuing [6,63] By solving the steady-state balance equation,

L+ 1 if ρi j= 1

(3.4)

where λi jand µi j are the arrival and service rates of data packets, ρi j= λi j/µi jistraffic density distributed to hi j Let B(r)sd is BPD of route rsd, we have

B(r)sd = 1 − ∏

∀hi j∈rsd

3.2.2 Analyze end-to-end delay based on the queue theory

End-to-end delay (EED) of a route is determined by:

determined based on the queue mechanism at the network nodes As analyzed inSection3.2.1, M/M/1/L queue mechanism is used, so τq(i) is determined by [19]:

where L is the average length of the queue, determined by [19]

3.3 The idea of the proposed algorithm

3.3.1 Analytical model

The idea of proposing LBRQT algorithm is to combine balancing routing and QoTconstraint routing To implement this idea, the objective function is to minimizeBPD on each route The constraint are defined including QoT and EED

In order to formulate LBRQT routing algorithm, the author defines a matrix Xsd=

Thence, LBRQT algorithm is modeled to nonlinear programming problem:

conser-3.3.2 The idea of implementing LBRQT algorithms ussing cross-layer model

3.3.2.1 Modify the node structure using cross-layer model

Update the database of traffic density

SA: Stationary Agent

Data RREQ

Node j

LBRQT algorithm

To be able to use information about

QoT for routing constraints, the

net-work layer must be able to directly

access to the information of the

physical layer This can only be

per-formed by using cross-layer model

[2, 5, 26] In LBRQT algorithm,

the cross-layer model is proposed as

shown in Figure 3.6, where an

sta-tionary agent (SA) is used for the

exchange of the information of QoT

between physical and network

lay-ers The tasks if the SA includes: (i)

updating traffic load for the connections in the network, and (ii) predicting the formance parameters which include the blocking probability of the data packets,SNR of a route and EED The information of QoT and EED are used for routingconstraints according to (3.21) and (3.22) The information of BPD is used for the