Design and Implementation of Mobile P2P Collaboration Framework for Spatial Data

Abstract

A map is one of the most useful media in disseminating spatial information. As mobile devices are becoming powerful and ubiquitous, people increasingly want spatial information to be available anywhere and anytime. Google Maps for Mobile is one of the most popular mapping applications on mobile devices delivering location aware information since mobile map services are introduced a few years ago. When it is used in Mobile Collaboration in which sharing of information is focused, sharing of location is realized by means of real-time transfer of spatial data between mobile devices. In the perspective of map based communication, the mobile maps used to share information on spatial properties can play an important role in wireless environment. This research describes a practical approach to designing spatial data sharing framework for efficient interactions between mobile devices. There are just a few studies on the interaction of spatial data between mobile devices while researches on standards based spatial data interchange in the wired Internet has been widely conducted. General collaboration technologies applied to spatial data can provide facilities for spatial data delivery but in is hardly applicable for real world data on mobile devices because of unacceptable performance and lack of research effort addressing limitations of mobile environment. To overcome the limitations in mobile collaboration with spatial data mentioned above, an approach based on a peer-to-peer standard protocol which initiates and maintains sessions between mobile in introduced. Peer-to-peer based approach has benefits such as improved scalability and elimination of the need for costly infrastructure by enabling direct communication among clients. Among several protocols for peer-to-peer communication on mobile devices, SIP is unique, flexible and stable enough to be used in designing new framework. The main contribution of this work is to design new framework based on standard peer-to-peer technologies enabling spatial data transfer between mobile devices. Prototype applications for several typical scenarios are also designed and implemented to prove feasibility of the framework. This research proposed extensible components by extending basic features of SIP protocol and it means that it is compatible to SIP standard. The new framework accelerates and facilitates sharing of spatial data transfer and essential components consisting of the new framework are designed based on them. the first scenario is to share destination and current location in navigation system and the second one is to send and receive hazardous area for emergency cases in forest fire. Spatial data types such as point, polyline and polygon need to be transferred as primitive data types to support immediate notification and display on mobile devices after updating current location or target region to meet the requirements of the above scenarios. In implementing prototype applications, user agents on mobile devices play an important role for seamless integration of mapping modules and communication modules. Immediate notification and display is verified as an important and necessary function for a mobile client that is designed on a user agent because real-time delivery of spatial objects is assumed. The performance of lightweight mobile libraries for the user agent is good enough to be used in real world applications. Open API for the integration of existing mobile applications dealing with spatial data is also proposed to facilitate loose coupling between the proposed framework and existing mobile applications. Finally, the results of this research show SIP based mobile collaboration system architecture can be implemented with spatial features by incorporating open standards in the design and by resolving notification services using our proposed framework for mobi1e devices. The framework can also be applied in many emergency cases such as criminal investigation and in fieldwork for the monitoring of land resources.