Comparison of Linux and Symbian Based Implementations of Mobile Peer-to-Peer Environment Arto Hämäläinen, Petri Hiirsalmi, Jari Porras Lappeenranta University of Technology P.O. Box 20 53851 Lappeenranta, Finland {Arto.Hamalainen, Petri.Hiirsalmi, Jari.Porras}@lut.fi Abstract: In this paper two software implementations of a mobile peer-to-peer communication environment (PeerHood) are compared. The basic properties of the environment are first identified and then the implementations are presented. First one of the implementations is based on Linux operating system and is implemented on HP/Compaq iPAQ devices. This implementation is compared to the PeerHood implementation on Symbian OS based mobile phones. Due to limitations of the Symbian environment and devices some properties has been left out in mobile phone environment, but it still has certain similarities with the Linux implementation. 1. INTRODUCTION Mobile communications has increased its popularity for the last 20 years. In the early days the development happened in the area of communication technologies. NMT, GSM, GPRS are all results of the need for mobility. Currently we are in a situation where we have several mobile communication technologies available. Bluetooth, WLAN and GPRS are all supported by the modern mobile devices. If considering the usage of devices there are not too many differences between mobile phones and PDAs. It seems that they are evolving into a single personal trusted device (PTD) that the user uses for different purposes. What is more important than the actual device at the moment is how the users are using those devices. Mobile phone manufacturer Nokia announced their Linux based networking device few months ago. This device and simultaneously announced development platform, Maemo [1], reflect how not only the devices and their usage but also the development for mobile devices is evolving. Mobile devices has traditionally been proprietary systems. Recent years have brought some changes. A significant step in opening up the mobile device development has been the introduction of Symbian OS in smart phones, and open source platform takes the idea further. Linux is a strong candidate for future mobile phones, if certain shortcomings and requirements for mobile phone use can be satisfied [2]. The rapid development and wide utilization of the fixed Internet based services has led into a situation where Internet access is the key factor in mobile devices as well. Fixed Internet has seen development in personal communications in form of instant messaging, presence and peer-to-peer communications. All these will eventually find their way to mobile Internet as well. Our vision is that the next step will be the true peer-to-peer type of communication in mobile environment. This could be referred as ubiquitous or pervasive computing / communication where devices are communicating directly with each other. This is very logical step as short-range technologies like Bluetooth have been implemented on almost all new mobile devices. Therefore in this paper we are studying the peer-to-peer type of communication in mobile environment. We have implemented PeerHood, a mobile peer-to-peer environment, for Linux based PDA devices and Symbian OS based mobile phones. In this paper we want to compare the software issues of these implementations. 2. PEERHOOD ENVIRONMENT PeerHood is an implementation of a personal area network (PAN) based on mobile peer-to-peer paradigm. There exist several approaches for the personal networking ranging from proximity based approaches, e.g. PeerHood [3][4] and Digital Aura [5], to approaches based on personal interests, e.g. Personal Networking [6], I-centric communications [7] and Personal Distributed Environment [8]. Our approach is based on the need of local services (proximity) and the use of them through different networking technologies (Bluetooth, WLAN and GPRS). The goal of the PeerHood system is to provide a communication environment where devices act and communicate in a peer-to-peer manner. This means that devices communicate directly with each other without any centralized servers. In order to enable fast creation of required ad-hoc type networks the immediate neighbors of a device are monitored and the gathered information is stored for possible future usage. The second goal is to create a library that enables usage of any supported networking technology via a unified interface so that the underlying networking structure is hidden from the applications point of view. As a direct consequence the application development time should be reduced because complex tasks like device discovery, connection establishment and error checking are handled by the PeerHood system.