899 MOBILE DATA SHARING AND COLLABORATION Martin Klima Czech Technical University in Prague Karlovo nam. 13, Praha 2, Czech republic Zdenek Mikovec Czech Technical University in Prague Karlovo nam. 13, Praha 2, Czech republic Pavel Slavik Czech Technical University in Prague Karlovo nam. 13, Praha 2, Czech republic ABSTRACT Problems of data retrieval and collaborative work in mobile environment are introduced. System architecture of a system solving these problems is introduced and described. A short analysis of the system requirements and possible architecture is given and a result solution (with respect to the use case) is introduced. Finally technique of optimizing the network traffic using a message queue reduction is described. KEYWORDS Collaboration, mobile, network, traffic, PDA, data sharing, optimization 1. INTRODUCTION In the framework of the Mobile Data Sharing and Collaboration System project we are designing and implementing a system for supporting rescue actions in mobile environment. The goal is to provide support for fast decision-making and coordination in situations where it is impossible to use stationary technologies and where voice communication is not sufficient. The mobile environment is specific in many aspects. We have to deal with special set of mobile devices, namely PDAs (Personal Digital Assistant) that are limited in many ways. The size of the display, processor power, limited memory, absence of keyboard, special user interaction model and unreliable network connection are all factors that have to be taken into account when designing a mobile application. 1.1 Goals Our goal is to design and implement a system for instant data sharing and collaboration in mobile environment. We are especially concentrated on sharing of XML (Extended Markup Language) based data formats like SVG (Scalable Vector Graphics). The SVG is a vector format for two dimensional plans and blueprints. The system will also support multimodal communication, i.e. beside sharing the SVG the users will also have voice connection over wireless network. 1.2 Scenario First step in our project was identification of the target users and creation of a scenario. The targeted users of the system are rescue teams like firefighters, railway emergency squads, gas and electrical emergency squads etc. Once the team is called to the emergency event, the members of the team often have to make fast and skilled decisions. To do so they need appropriate information delivered to their current location and usually have to consult and coordinate their rescue actions with other team members. The team members are using PDA devices equipped with wireless technology (UMTS in the near future). Users can request data from the central database. The data are stored in a SVG format. Thanks to the nature of this format (vector based) it can be browsed and zoomed on the limited device easily. If needed, the users can communicate to each other and simultaneously share the 2D plans. The application offers a list of