j111

Date of submission (month day, year): January 11,2019
Depar[mentStuden11D

HideyulduEHARA

D 149202

ELECTRICALAND ELECTRONIC
N山れber

INFORIVIATIONENGINEERING

Supervjsors

TakashioHIRA
ShuichilcH11【AWAPplica11t's nanw

MOCHAMN仏DZENSAMSONOHADI

Abstract (Doctor)
An Energy、E価Cient Adaptive Group clustering in 圦lireless sensor Netw01'ks for Mobile
Title ofThesis

GroupsApprox,80o words
A large number of sensor nodes create a 、Nh'eless sensor network.1t has components such as sensing,
Wireless communication, and data processing.圦lireless sensor networks (＼入ISNS) have many
applications, for example exploration, wildHfe protection, and health care application. other applications
t11at consider group mobility are search and rescue activity and the evacuation of people in a natural
disaster、 Regarding alese applications, a 、NSN needs to be designed considering mobile nodes. The main
goal of mobile 圦ISNs deployed in a network area is to delivel'1nore data 介om a mobile sensor node to abase station (BS)、Nitl) the li111itation of energy consumption. Then, the data 、Ni11 be analyzed at tl〕e BS,
D飢a c0Ⅱection and energy consunlption are important factors in designing and determining mobHe＼NSNS. To effectively perform u)ese tasks, this t11esis presents several protocols based on a clustering
System to tackle such issues

Firstly, this tl〕esis proposes a protoc01 、刃hich supports handover procedure 圦/ith el]tity mobility, i.e.,
Mobile Node LOW、Enel'gy Adaptive protoc01(入IN・LEACH). The 御'otocol reduces tl〕e dis{ance between
Cluster head and cluster member when t11e cluster m引nber lnoves out 介onl dle current clusfel' head

入4N、LEACH outperforms LEACH in terms of number of alive nodes and tl〕e energy dissipation perround. Then, to support the group movement and to achieve an energy・effici引lt protoc01, it proposesal)odler protoc01, nalnely a Group mobility based clustering (GC) scheme. Gc schemes apply a group asa cluster which consists of group leader and 合roup member.1hls protoc011'educes the contr01 0verheadin the setup phase of a clustering syst引n by introducing a concept of group leader and group member.1nUlis scheme, t11e communication with cluster・head is only done by t11e 即'oup leader to save the energy

Consumption. Based on dle simulation results, Gc single increases the lifetilne of tl}e networks and thenumber of packets received at a base station, compared with LEACH and MN・LEACH. From thisVie、Npoint, we study t11e characteristic of sensor nodes in nlobile environment 、vith entity mobility(入IN・LEACH) and group mobility (Gc sclwme).

Xve then tackle some problems of the existing protocols on tl〕e design of mobile group v、1SNs such as
high control packet and energy consumption as weⅡ as more frequent top010gy changes that reduce雫IV

network lifetime and the nulnber of data items received at the base station. To address these problems

and to respond to the chaⅡenge of group mobility based scheme, this thesis proposes a new protoc01
Considering group lnobility together 、Nith assigning an appropriate role to nodes, i.e. an Energy・efficient
Mobile Group clustering (ENIGC) PI'otocol for mobile ＼NSNS.1t makes a fixed group formation of aⅡSensor nodes to evaluate clearly dle effectiveness of the scheme. The sensor nodes are divided into t1ⅡeeCategories, i.e., a cluster head, a group leader and a group member node.1n our cluster formation andgroup handover scheme, group leaders and cluster heads do most of t11e comm山]ications to save onenergy conS山11Ption during 、Nhich group members are placed in the sleep condition. This scheme wiⅡreduce t11e n山ηber ofcontrol packets and 介equenttop010gy changes in the networks, n addition, ENIGC

Provides a 即'oup handover pl'ocedure when the group of sensor nodes moves out froln the cul'rent clusterand gets closerto another cluster. EMGc protoc010utperforms MN・LEACH, GMAC, MBc protocols interms ofenergy dissipation and d]e nulnber of data items received at a base station.

In mobile group enviromnents, there is a possible event occurring in a mobile group environment 、NI)ere
Some mobile nodes in the salne mobile group move to odler lnobile groups. This becomes a cha11enging

Problem in EMGc protocol because EMGc uses a fixed group formation which causes a longer distance
between GL and GM and requires lnore transmission power. Furthermore, this protocol fails to mahltainthe number of data delivery and network lifetilne as increasing the number of groups also i乃Creases dle

number of con11'ol packets and c011isions between GL and GM、 To address these 御'oblems, dlis thesis
Proposes a nove1 即'oup fonれation scheme which is integrated with an EMGc protoc01,i.e. an Adaptive
group formation 、¥ith ENIGC (AgEMGC) for mobile group wsNS.1t uses a link expiration time al〕dresidual energy to fonn a stable Hnk in a group、 1t also has a group merging procedure to decrease thenumber of groups. Fudhenηore, it develops two additional functions for tl〕e pl'otoc01, i.e., GL rotation
and a stay connection proced11re to diminiS11 energy consumption in the network. AgEMGc protoc01
Outperforms NIBC, EMGcwoh, and EMGc protocols in terms of data delivery, network Ⅱfetime, andenergy dissipation per round 、¥ith various group change probabHities and percentages of groups.