Balazs Bakos

Peer-to-peer protocol evaluation in topologies resembling wireless networks. An experiment with Gnutella query engine

Peer-tepeer (P2P) protocols implemented in wireless networks and mixed scenarios would generate new applications and value added services. In order to analyze the performance of such protocols the specific topologies of current and future wireless networks should be taken into account. In our paper we analyze the performance of a Gnutella-type protocol query engine on random mesh (Random), semi-random mesh (Semi), connected stars (ConStan) and connected mesh (ConMesh) application layer network topologies. In addition we discuss and simulate for the considered topologies the effect of adaptive time-twlive (TTL) techniques. We take into account in our analysis the document replication phenomenon. Within this paper we limit ourselves to the simulation of static network topologies. The results of this study show that Semi and ConStan are the most useful topologies. Semi is the hest topology for heterogeneous devices, e.g. all of the nodes are mobile phones. ConStars is useful when the network consists of devices with dilferent capabilities, e.g. mobile phones and PC-s. If the node degrees are chosen appropriately the bandwidth needs can reasonably small making content sharing peer-twpeer applications feasible in pure wireless networks and mixed scenarios.

P2P applications on smart phones using cellular communications

In this paper we describe four P2P applications developed for smart phones, ranging from distributed computing to content sharing and search in closed and open user groups. Their common feature relies in the communication interface which has been cellular data transmission (SMS, HSCSD, respectively GPRS). Through our examples we highlight various aspects that application development on smart phones has to take into account, such as traffic efficiency, CPU load and social awareness. We discuss our main observations related to the experiments and highlight some promising directions for future mobile P2P applications. The discussed set of applications developed by us in the period between 2001-2005 cover the areas of distributed computing, large-scale content sharing in open communities, content sharing in closed groups, respectively keyword search in a social network of phones

Search engine for phonebook-based smart phone networks

Search engines generally lack the trust and personalization dimension. The outcomes of the search are not socially relevant: they often reflect only the content popularity based on lookup tables gathered by search robots. In order to obtain personalization and social relevance, in other words, to bring the search outcome closer to a common human perception of value and reliability, the search database itself could be personalized. One possible method to obtain personalization is through the social neighborhood of the searcher. An enabler for the personalization is the phonebook stored in mobile phones. The group of mobile phonebooks can create an infrastructure for a peer-to-peer search network with a social dimension. In order to demonstrate this concept our work introduces a novel search and recommender engine and application for phonebook-based smart phone networks. The concept has been implemented on the Symbian Series 60 platform over GSM using short message exchange. The efficiency of the search and recommendation system is also analyzed.

A practical approach to multicasting in Bluetooth piconets

This work studies a special multicasting problem in Bluetooth networks supporting point-to-point connections and piconets. The reason for the topic choice relies in the fact that Bluetooth, a de-facto proximity communication technique widely available in smart phones today, supports piconets, but sending content to more than 7 nodes is cumbersome. It turns out that by using a non-standard approach, that of parallel piconets of two nodes each, we can obtain a more efficient multicasting than through the legacy multicasting approach

Hybrid Peer-to-Peer Content Sharing in Mobile Networks

As the capabilities of mobile phones are increasing and they are able to consume different type of multimedia contents, it is important to provide an efficient content sharing solution for them. Since people usually store their content on their personal computer, we need architecture for content sharing which supports mobiles and personal computers as well. In this paper we propose an innovative content sharing solution, called Swarm, which offers the following benefits to service providers: cost efficient, mobility support, necessary control points to prevent misuse of the service and backend for the stored information. Swarm is a hybrid solution, it combines the advantages of peer-to-peer and client-server systems and it also considers the special abilities of mobile phones by enabling local cooperation. During the paper we introduce the proposed architecture with the main features, discuss our experience with the reference implementation, demonstrate calculations about the cost efficiency of Swarm and propose future plans for further improvements. Index Terms

Local Connectivity Solution over Bluetooth and Wi-Fi

In this paper a local connectivity solution is presented in which smart phones and PDA-s can connect to the enterprise intranet using either Bluetooth or Wi-Fi proximity networking via access points. The contribution highlights the differences at various levels of the implementation between the Bluetooth-based and Wi-Fi based components in our attempt to create a unified service level for Bluetooth-based, Wi-Fi based and both Bluetooth- and Wi-Fi based terminals (newer generation smart phones). Finally use cases and a list of applications are presented that can benefit from our solution in the enterprise segment.