This paper presents Virtual Ring Routing (VRR), a new network routing protocol that occupies a unique point in the design space. VRR is inspired by overlay routing algorithms in Distributed Hash Tables (DHTs) but it does not rely on an underlying network routing protocol. It is implemented directly on top of the link layer. VRR provides both traditional point-to-point network routing and DHT routing to the node responsible for a hash table key. VRR can be used with any link layer technology but this paper describes a design and several implementations of VRR that are tuned for wireless networks. We evaluate the performance of VRR using simulations and measurements from a sensor network and an 802.11a testbed. The experimental results show that VRR provides robust performance across a wide range of environments and workloads. It performs comparably to, or better than, the best wireless routing protocol in each experiment. VRR performs well because of its unique features: it does not require network flooding or translation between fixed identifiers and location-dependent addresses.

Abstract. Various peer-to-peer (P2P) architectures for ad-hoc networks have been proposed over the last few years. Most of them are unstructured and use some form of flooding to locate content, because the physical constraints of the underlying network make the construction of arbitrary application-layer overlays impractical. In this paper, we study the problem of applying distributed hash tables (DHT) to ad-hoc networks. Our approach to efficiently lookup content in such networks exploits physical proximity of peers when establishing and maintaining the DHT based routing tables. The efficiency of our method is demonstrated by simulation of large networks. 1

Abstract — Social networking is increasingly becoming a popular means of communication for online users. The trend is also true for offline scenarios where people use their mobile phones to network with nearby buddies. In this paper, we propose a distributed tuple space for social networking on ad hoc networks. We describe the tuple space model and its operations, and give evidence of its advantages for ad hoc social networking through several applications. I.

In recent years the popularity of multi-hop wireless networks has been growing. Its flexible topology and abundant routing path enables many types of applications. However, the lack of a centralized controller often makes it difficult to design a reliable service in multi-hop wireless networks. While packet routing has been the center of attention for decades, recent research focuses on data discovery such as file sharing in multi-hop wireless networks. Although there are many peer-to-peer lookup (P2P-lookup) schemes for wired networks, they have inherent limitations for multi-hop wireless networks. First, a wired P2P-lookup builds a search structure on the overlay network and disregards the underlying topology. Second, the performance guarantee often relies on specific topology models such as random graphs, which do not apply to multi-hop wireless networks. Past studies on wireless P2P-lookup either combined existing solutions with known routing algorithms or proposed tree-based routing, which is prone to traffic congestion. In this paper, we present two wireless P2P-lookup schemes that strictly build a topology-dependent structure. We first propose the Ring Interval Graph Search (RIGS) that constructs a DHT only through direct connections between the

Efficient group communication within the Internet has been implemented by multicast. Unfortunately, its global deployment is missing. Nevertheless, emerging and progressively establishing popular applications, like IPTV or large-scale social video chats, require an economical data distribution throughout the Internet. To overcome the problem the limitations of multicast deployment, we introduce and analyze BIDIR-SAM, the rst structured overlay multicast scheme based on bi-directional shared prefix trees. BIDIR-SAM admits predictable costs growing logarithmically with increasing group size. We also present a broadcast approach for DHT-enabled P2P networks. Both schemes are integrated in a standard compliant hybrid group communication architecture, bridging the gap between overlay and underlay as well as between inter- and intra-domain multicast.

Mobile phones have become a basic commodity and smartphone devices claim a continuously increasing market share. Modern smartphone devices are equipped with powerful processing units and high speed mobile internet capabilities. Mobile operators in turn are offering a wide variety of data plans. These developments will lead to an increase of internet access from mobile devices. At the same time the internet is not solely used anymore for displaying data but collaborative editing, evaluation and distribution of data in any form has become widely popular, as can be seen in the socalled “Web 2.0 ” services. Suppliers are offering versions of these services that are especially designed for mobile devices. Today Peer-to-Peer networks are responsible for a considerable amount of the total internet traffic. Although Peer-to-Peer networks mainly gained attention in the media for copyright infringement cases Peer-to-Peer networks offer many positive characteristics. Peer-to-Peer networks are decentralized, self-organizing, scalable and offer no single point of failure. This makes Peer-to-Peer networks an ideal candidate for deploying mobile web services. The MobP2P base system is a foundation for developing Peer-to-Peer based applications for collaborative data processing developed for the Android platform. Applications built on top of the

The vision of pervasive computing is one of a personalized space populated with vast amounts of data that can be exploited by humans. Such Personalized Networked Spaces (PNetS) and the requisite support for generalpurpose spatiotemporal search of the “here ” and “now ” have eluded realization, due primarily to the complexities of indexing, storing, and retrieving relevant information within a vast collection of highly ephemeral data. We present the Gander search engine, founded on a novel conceptual model of search in PNetS that connects formal notions of sampling asearchspaceto expressive, spatiotemporal-aware protocols that perform distributed query processing in situ.