Meanwhile ... back at the server Meanwhile ... back at the server

Managing Server-Based Data in Support of Managing Server-Based Data in Support of the Location-Based the Location-Based mm-Business Applications of -Business Applications of

Location-Variant Mobile UsersLocation-Variant Mobile Users

Jim WyseJim Wyse

77thth World Congress on the Management of World Congress on the Management of ee-Business (2006)-Business (2006)

mm-Business Environment-Business Environment

Mobile Business (Mobile Business (mm-Business)-Business)

• transactions through communication channels that permit a high degree of mobility by at least one of the transactional parties.

• m-business with location-referent transactions: transactions in which the geographical proximity of the transactional parties is a material transactional consideration.

• Critical capability: location awareness.

• Yuan and Zhang (2003): “location awareness … is a new dimension for value creation” in a wide variety mobile business applications.

Location-Based Location-Based mm-Business-Business

Location Aware CapabilityLocation Aware Capability

• The capability to obtain and use the geo-positions of the transactional parties to perform one or more of the CRUD (create, retrieve, update, delete) functions of data management (Butz, Baus, and Kruger 2000) in support of location-referent transactions.

The Data Management ProblemThe Data Management Problem

• Location-referent transactions are supported by proximity queries: What is my proximity to a goods-providing (or service-offering) location in a selected category?

• A proximity query bears criteria that reference static attributes (e.g., hospital) and dynamic attributes (e.g., nearest).

• Proximity queries are burdensome to conventional query resolution approaches (Nievergelt and Widmayer, 1997).

Proximity Query Resolution: Proximity Query Resolution: Proximity PortalsProximity Portals

The The ii-DAR Prototype-DAR Prototype

The Problem (. . . and a Solution?)The Problem (. . . and a Solution?)

LinkcellsLinkcellsGeographical Space Geographical Space Relational Space Relational Space

Location-Aware Linkcell MethodLocation-Aware Linkcell Method

• Transforms Transforms mumu’s’s position (47.523 position (47.523° N, ° N, 119.137° W) into a linkcell (N47W119).119.137° W) into a linkcell (N47W119).

• Initiates search sequence at Initiates search sequence at mumu’s linkcell ’s linkcell {N48W119, N48W118, N47W118, {N48W119, N48W118, N47W118, N46W118, ….}N46W118, ….}

• Permits large numbers of locations to be Permits large numbers of locations to be excluded as proximity portal candidates.excluded as proximity portal candidates.

• Requires an appropriate linkcell ‘size’ to give Requires an appropriate linkcell ‘size’ to give superior performance.superior performance.

Figure 4Figure 4

nn-effect-effect cc-effect-effect

100,000-Location SCR – Brute Force Results100,000-Location SCR – Brute Force Results

Solve ….

PTC(S) = 1 – (1 – nTC/N)N/CS 0.6 . . . (A)

. . . . for Linkcell “Name Increments”

nTC is the number of locations in category, TC,

N is total number of locations, and

CS is the number of linkcells of size, S, created from the N locations.

Optimal Linkcell SizeOptimal Linkcell Size

MCRs and SCRsMCRs and SCRs

• Multiple Category Repositories (MCRs)Multiple Category Repositories (MCRs)

• Single Category Repositories (SCRs)Single Category Repositories (SCRs)

• Equation (A) applies to MCRs but not to SCRsEquation (A) applies to MCRs but not to SCRs

• For SCRs, nFor SCRs, nTCTC = N = N P PTCTC(S) = 1, for all S.(S) = 1, for all S.

Single Category Repositories Single Category Repositories (SCRs)(SCRs)

• For For SCRs, it is hypothesized thatSCRs, it is hypothesized that

P (S) = 1 – (1 – S2/4A)N 0.6 . . .

(B)will yield optimal values, where

A is the entire geographical area covered by the repository,

S is the linkcell size, andN is the number of locations.

• Some preliminary results ……Some preliminary results ……

Figure 6

Critical Area for Further WorkCritical Area for Further Work

• Uniform locational distributions assumedUniform locational distributions assumed

• Businesses often locate or co-locate in non-Businesses often locate or co-locate in non-uniform ways:uniform ways:

-- pharmacies next to medical clinicspharmacies next to medical clinics-- law firms in legal ‘districts’law firms in legal ‘districts’-- retail petroleum outlets near highway retail petroleum outlets near highway

intersections.intersections.- - etc.etc.

Jim WyseJim Wysewww.busi.mun.ca/jwyse

Conference PaperConference Paper

Data Management for Location-Based Data Management for Location-Based Mobile Business Mobile Business Applications: :

The Location-Aware Linkcell MethodThe Location-Aware Linkcell Method