Location Based Web Search on GSM/GPRS Mobile Devices VVS. Nare sh, - PowerPoint PPT Presentation

Location Based Web Search on GSM/GPRS Mobile Devices VVS. Nare sh, Prasad Ping ali, Vasude va Varma I nte rnatio nal I nstitute o f I nfo rmatio n T e c hno lo g y, Hyde rabad, I ndia Murali K rishna Punag anti Ve nkata No kia Re se arc h Ce nte r, He lsinki, F inland

Agenda • So lutio n Outline nvo lve d ntro duc tio n ssue s • Ope n I • Ste ps I • I

Current search • Obtaine d fro m http:/ / mo bile se arc h.no kia.c o m

I ntroduction • Go al o f this pro je c t : Pro vide a L o c atio n B ase d S e arc h (L BS ) fo r GS M/ GPRS base d mo bile de vic e s. • GS M is a do minant mo bile pho ne syste m. • Mo bile de vic e s mo st suite d fo r lo c atio n base d se rvic e s, be c ause the y are “mo bile ” • L o c atio n base d se rvic e s we re trie d o n de skto ps using I P addre sse s fo r ano nymo us use rs. – e .g . URL re dire c tio n base d o n use r's I P addre ss

Solution Outline • T he so lutio n c an be se e n as two main ste ps Obtain Mo bile De vic e – L o c atio n – We b se arc h using L o c atio n. • Diffic ultie s I nvo lve d – Obtaining the lo c atio n string database – Re fining and re -ranking re sults • Ope n I ssue s – S tandardizatio n o f lo c atio n parame te rs – Privac y I ssue s – S e c urity Po lic ie s

Steps I nvolved • Displaye d lo c atio n string no t ac c e ssible fo r third-party applic atio ns • Mo bile De vic e L o c atio n ne e ds to be infe rre d – Ge t L o c atio n Co de s fro m De vic e – L o o kup L o c atio n Co de s to g e t L o c atio n Name s • We b S e arc h Using L o c atio n – Que ry E xpansio n – We b Me ta-S e arc h – Me rg e and Rank S e arc h Re sults using a We ig hte d Ranking func tio n. – De fault Ranking is base d o n Granularity o f L o c atio n.

Obtain Mobile Device Location � Inte r national Mobile Subsc r ibe r Ide ntity (IMSI) � use d fo r ide ntifying a mo bile pho ne subsc ribe r � Maximum le ng th o f c o de be ing 15 symbo ls � Co mpo se d o f thre e diffe re nt parts � MCC (Mobile Countr y Code ) � 3 digits fixe d le ngth � MNC (Mobile Ne twor k Code ) � 1-2 digits, var iable le ngth � MSIN or MIN (Mobile Station Ide ntific ation Numbe r ) � maximum 10 digits , var iable le ngth � L o c atio n Parame te rs o f I nte re st � T o tally 4 parame te rs � T wo fro m I MS I whic h are standardize d by IT U-T (T he I nte rnatio nal T e le c o mmunic atio n Unio n – T e le c o mmunic atio n S tandardizatio n S e c to r): � Mo bile Ne two rk Co de (MNC) � Mo bile Co untry Co de (MCC) � T wo fro m S e rvic e Pro vide r S pe c ific I nfo rmatio n � L oc ation Ar e a Code (L AC) and � Ce ll ID

Get Location I nform ation • T he S ymbian C++ (se rie s 60 ve rsio n-2.1) c o de snippe t to g e t all fo ur lo c atio n parame te rs fro m a mo bile de vic e lo o ks like this: RTelServer server; CleanupClosePushL(server); User::LeaveIfError(server.Connect()); User::LeaveIfError(server.LoadPhoneModule(_L("phonetsy.tsy"))); RTelServer::TPhoneInfo info; User::LeaveIfError(server.GetPhoneInfo(0, info)); RBasicGsmPhone phone; CleanupClosePushL(phone); User::LeaveIfError(phone.Open(server, info.iName)); MBasicGsmPhoneNetwork ::TCurrentNetworkInfo ni ; phone.GetCurrentNetworkInfo( ni ) ; TInt MCC = ni.iNetworkInfo.iId.iMCC; //Mobile Country Code TInt MNC = ni.iNetworkInfo.iId.iMNC; //Mobile Network Code TInt locationareacode = ni.iLocationAreaCode; //Location Area Code TInt cellId = ni.iCellId; //Cell ID

Query Expansion & Search • Que ry E xpansio n fo r e ac h L o c atio n Name I ndividually. • T hre e type s o f e xpansio n using – Co untry name (MCC) – City Name / Re g io n Name (L AC) – Re g io n Name within City (Ce llI D) • Re g io n be ing mo st g ranular, Co untry be ing le ast g ranular info rmatio n • S e arc h Re sults me rg e d, ranke d using g ranularity o f lo c atio n. • Ranking func tio n we ig hts are tunable .

Exam ple Location Based Search for “Chinese Restaurant”

Exam ple Location Based Search for “Chinese Restaurant”

Exam ple Location Based Search for “Chinese Restaurant”

Exam ple Location Based Search for “Chinese Restaurant” The above results are from a location in India-Hyderabad- Banjara Hills

MNC – 013 –Service Provider “C” Service Provider A Service Provider B Service Provider C

MCC – 404 - India

LAC – 2711 Hyderabad

CellID – 04BE Banjara Hills

Obtaining the Location Database • Diffic ulty in Obtaining L o c atio n Database be c ause – T hre e o f the fo ur L o c atio n parame te rs vary ac ro ss se rvic e pro vide rs e xc e pt MCC (Mo bile Co untry Co de ). • Use d c o mmunity e ffo rt to po pulate the database . • Applic atio n pro mpts use r to ide ntify any unkno wn lo c atio n c o de s. Use rs he lp po pulating the database .

I ssues • No t all lo c atio n parame te rs are standardize d. T he re fo re make s the task muc h mo re c o mplic ate d than I P addre ss to L o c atio n mapping in de skto ps. • Ope n issue s – Use r Privac y – S e c urity

Questions??