Proposal of Terminal Self Location Estimation Method to Consider Wireless Sensor Network Environment

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1 1 2 2 GPS (SOM) Proposal of Termnal Self Locaton Estmaton Method to Consder Wreless Sensor Network Envronment Shohe OHNO, 1 Naotosh ADACHI 2 and Yasuhsa TAKIZAWA 2 Recently, large scale wreless sensor networks are amed to apply to envronmental montorng system. The montorng system requres the locaton where data s montored. The conventonal locaton estmaton method, s GPS, however GPS s sutable for wreless sensor network because of ts cost and power consumpton. Therefore, many locaton estmaton methods wthout GPS are proposed. However, they need a large number of anchor nodes for hgh accuracy on the locaton estmaton. To solve the problem, we have proposed the node locaton estmaton method usng Self-Organzng Map (SOM). Our proposed method can estmate hgh accurate locaton wth mnmzed number of anchor nodes. In ths report, the omsson of range functon from our method s nvestgated to apply our method to any sensor networks. 1. GPS(Global Postonng System) 1) GPS GPS RFID Centrod 2) DV-Hop 3) () SOM(Self Organzng Maps) 1 Graduate School of EngneerngKansa Unversty 2 Faculty of Envronmental and Urban EngneerngKansa Unversty 1 c 2011 Informaton Processng Socety of Japan

2 4) SOM T.Kohonen SOM SOM SOM 2 3 SOM 4 SOM 5 2. GPS GPS(Global Postonng System) 1) 4 GPS TOA(Tme of Arrval) Actve Bat 5) Crcket 6) TDOA(Tme Dfference of Arrval) Centrod 2) DV-Hop 3) Centrod 2) () GPS DV-Hop 3) 1 3 Centrod GPS 3. SOM SOM(Self Organzng Maps ) 4) GPS TOATme Of ArvalTDOATme Deference Of ArrvalRTOFRoundtrp 2 c 2011 Informaton Processng Socety of Japan

3 1 Fg. 1 Constructon of self-locaton estmaton functon. w V 1 ( t) w j d j 2 Fg. 2 Input vector and correcton vector byneghbor node. Step.1 w t t = 0 Step.2 j j d j j w j d j m m m m w V 1 2 V {1} = Tme Of Flght SOM T.Kohonen ) SOM Bonabeau SOM 8) Bonabeau 4) d j w w j (w w j ) (1) w w j j k j d j j 2 k d jk 3 V {2} = d j + d jk w w k (w w k ) (2) w w k (1)(2) 2 k j w w j w w k (2) j 4 V {2} = 3 c 2011 Informaton Processng Socety of Japan

4 & > <? = < ( 4 > A? > *,+ ')( 0,1./ - MONOPRQS TOU? = > #%$!" A EGFH Ï JLK 9;: Fg. 3 Postonal correcton wth 2 hop neghborhood node /10. +-, )%*!! % & ' #%$ " GIHJ K LNM ;=< 8:9 DBFE? B Fg. 4 Postonal correcton wth 2 hop neghborhood node 2. w j w + d j d jk (w j w k ) (3) V 1 w (t + 1) = w + α (V {1} + V {2} k ) k t τ w + α V {1} t > τ τ α t α = { 1 θ E E (t 1) η α (t 1) otherwse E = 1 N (d j w w j ) N 2 (6) j=1 E t N (4) (5) t θ η Step.3 Step.2 Step.2 Step SOM SOM 4) 9) CSMA/CA IEEE802.11b SOM 4 c 2011 Informaton Processng Socety of Japan

5 10) SOM Qualnet SOM SOM SOM 3.1 dj w j w j f(x) d j = f( w w j ) (7) SOM 5 Fg. 5 locaton estmaton and dstance estmaton. 5 SOM 2 2 w j w j 2 k w k 2 k j ( w w j w w k ) m CSMA/CA IEEE802.11bW-F 1Mbps 500m c 2011 Informaton Processng Socety of Japan

6 500m 500m CSMA/CA IEEE802.11b () r j r j = dj/d j (8) dj j () d j j () r j r j r j 1 r j 1 6 Fg. 6 locaton estmated result r j r j SOM () 6 c 2011 Informaton Processng Socety of Japan

7 () 7 Fg. 7 orgnal topology on network. 1) B.Hofmann-Wellenhof, H.Lchtenegger, and J.Collns : Global Postonng System; Theory and Practce, 4th ed. (1997). 2) N.BulusuJ.Hedemannand D.Estrn : GPS-less low cost outdoor localzaton for very small devcesieee Personal Communcatons Magazne (2000). 3) D.Nculescu and B.NathDV-based postonng n ad hoc networkstelecommun.systvol.22,pp (2003). 4) Vol.46, No.12 (2005). 5) A.HarterA.HopperP.StegglesA.Wardand P.Webstar : The anatomy of a context-aware moble applcatonsmobicom1999 (1999). 6) N.PryanthaA.MuH.Balakrshmanand S.Teller : The crcket compass for context-aware moble applcatonsmobicom2001 (2001). 7) T.KohonenSelf-Organzng Maps3rd edtonsprner (2001). 8) E.Bonabeau and F.HenauxGraph Parttonng wth Self-Ogrganzng MapsPrvate Communcaton (1998). 9) DPS144 No.2 (2010). 10) DPS146 No.21 (2011). 8 Fg. 8 Smlar verfcaton. 7 c 2011 Informaton Processng Socety of Japan