A Strategy to Share Documents in MANETs using Mobile Devices Andres Neyem, Sergio F. Ochoa, Jose A. Pino Computer Science Department, Universidad de Chile, ITCC Chile-Corea Av. Blanco Encalada 2120, Santiago, Chile /aneyem, sochoa, Jpino}@dcc. uchile. cl Sharing information on mobile networks using computers is Abstract - Since long time ago, information sharing has been the not a new challenge; it has been studied by distributed base to support collaboration in several scenarios. Advances in systems researchers for many years, and several interesting mobile technology have extended such collaboration scenarios solutions have been proposed [18;9]. However, most of these including one-hop and multi-hop wireless networks. Traditional strategies to share information in wired networks are not soltos dobnot c oner theu hn-eld devices, suitable for mobile scenarios because they do not consider the as PDAs, mobile phones or other wireless devices. disturbing networking aspects such as high disconnection rate, Furthermore, these solutions do not take into account the dynamic topology and the low bandwidth. The use of hand-held instability of communication services, which is a particular devices to share documents. This paper presents a strategy feature of MANETs. The use of PDAs as collaboration based on XML to share information in MANETs (Mobile Ad- supporting devices and the instability of communication hoc NETworks) using hand-held devices, considering services in MANETs bring new challenges for sharing disconnections and instability of the network bandwidth. This information for collaboration. strategy is currently implemented in PASIR (service Platform PDAs typically limit groupware applications mainly in for Ad-hoc Sharing Information Resources) and it can be terms of screen size, processing power, memory capacity and considered by other middleware products when design the data networking services provided by the operating systems. sharing support. In addition, many groupware applications v b v could be designed using this strategy, i.e.: distributed technical These services allow notebooks and PDAs be integrated in presentations, casual interactions, brainstorming, meetings for the same workgroup scenario [5]. The more restrictive these decision making and software technical reviews. resources are, the more need there is to find new strategies to support sharing information and to integrate these devices in Keywords - Sharing Information, Design Aspects, Groupware a MANET. Applications, Mobile Collaboration, MANETs. Communication services in MANETs are unstable and with tight bandwidth. However, collaborative systems should exhibit high availability to avoid jeopardizing the 1. Introduction collaborative process. These restrictions also show the need for new solutions able to keep high availability of shared For many years the CSCW and CSCL communities have information even in that unstable scenario. used shared information as a way to support or enhance This paper presents a strategy based on XML to share collaboration among people [17; 19] and also to develop information in MANETs (Mobile Ad-hoc NETworks), software solutions that support key design aspects of considering disconnections and instability of the network groupware applications [4; 16]. The most common strategy to bandwidth. This strategy is currently implemented in PASIR share information among collaborators involves centralizing (service Platform for Ad-hoc Sharing Information Resources) data and services. Many groupware platforms were designed [14] and it can be considered by other middleware products following this strategy [2;15], and showing good results in when design the data sharing support. In addition, many stable communication scenarios, such as fixed computer groupware applications could be designed using this strategy, networks. However, the strategy to centralize data and i.e.: distributed technical presentations, casual interactions, services to facilitate sharing information is limited when brainstorming, meetings for decision making and software collaborators are communicated through an unstable network technical reviews. like a MANET [1;5]. Every centralized resource represents a Next section presents the problem statement. Section 3 vulnerable point for collaborative solutions in term of presents and discusses similar research initiatives focused on availability, because of the typical communication instability sharing information over MANETs. Section 4 describes the in these networks. Moreover, the collaborators' mobility strategy proposed to share data in MANETs. Finally, Section increases that communication instability. Consequently, a 5 presents the conclusions and future work. low availability of the collaborative system jeopardizes the collaboration process. ISBN 89-5519-129-4 - 1400 - Feb. 20-22, 2006 ICA0T2006