WITN: Collaborative research in Location Dependent Data Management

该研究项目是南卫理公会大学Margaret Dunham（IIS-9979458）和密苏里州大学堪萨斯城分校Vijay Kumar（IIS-9979453）的合作成果，并得到了无线信息技术和网络（WITN）计划NSF 99-68的支持。本研究的目标是开发计划，用于处理数据，强烈相关的地理位置，在移动的计算平台。与传统的数据处理系统不同，在无线移动的计算环境中，数据的价值可以取决于位置，并且在一个站点处的交易处理可以给出与在另一站点处的交易处理不同的结果。这种情况标识了一种新类型的数据，我们将其称为位置相关数据（LDD）。因此，LDD是一类数据，其值由（a）数据存储的地理位置和（B）发起查询的移动的单元（MU）的地理位置确定。例如，当来自MU的查询想要找出关于当地酒店的信息时，它将在达拉斯得到与在堪萨斯城不同的答案。从达拉斯驾驶到堪萨斯城的旅行者甚至可以在途中询问相同的问题，但是具体地使用堪萨斯城数据而不是基于他请求查询的位置的数据来请求响应。虽然查询可能以完全相同的方式陈述，但它是在位置相关的上下文中解释的。本研究的目的是进一步探讨LDD的概念，其对交易处理的影响，并制定有效的方案，其管理。作为该研究的结果，将产生便于在移动的单元处存储位置相关数据的方法以及有效地处理访问这种类型的数据的事务的技术。建立一个试验台是该项目的一个主要目标。它将用于实施和比较研究期间提出的各种战略。

This research project is a collaborative effort of Margaret Dunham, Southern Methodist University (IIS-9979458) and Vijay Kumar, University of Missouri at Kansas City (IIS-9979453) and is supported under the Wireless Information Technology and Networks (WITN) initiative, NSF 99-68. The goal of this research is to develop schemes for processing data that are strongly related to geographical locations, on a mobile computing platform. Unlike conventional data processing systems, in a wireless mobile computing environment the value of data may depend on location, and processing of a transaction at one site may give different results than that at another. This situation identifies a new type of data, which we refer to as Location Dependent Data (LDD). Thus, LDD is a class of data whose value is determined by (a) the geographical location of data storage and (b) the geographical location of the Mobile Unit (MU) where the query originated. For example, when a query from a MU wants to find out information about local hotels, it will get a different answer in Dallas than in Kansas City. It would even be possible for a traveler driving from Dallas to Kansas City to ask the same question en route but specifically request the response using Kansas City data rather than data based on the location from which he requests the query. Although the query may be stated in exactly the same way, it is interpreted in a location-dependent context. The objective of this research is to further explore the concept of LDD, its impact on transaction processing, and develop efficient schemes for its management. As a result of this research, methods will be produced which facilitate the storage of location dependent data at Mobile Units and techniques to efficiently process transactions which access this type of data. The creation of a testbed to is a major objective of the project. It will be used to implement and compare the various strategies proposed during the research.