Structured Peer-to-Peer Overlay Deployment on MANET: A Survey

There are many common characteristics between Peer-to-Peer (P2P) overlay networks and Mobile Ad-hoc Networks (MANET). Self-organization, decentralization, dynamicity and changing topology are the most shared features. Furthermore, when used together, the two approaches complement each other. P2P overlays provide data storage/retrieval functionality, and their routing information can complement that of MANET. MANET provides wireless connectivity between clients without depending on any pre-existing infrastructure. The aim of this paper is to survey current P2P over MANET systems. Specifically, this paper focuses on and investigates structured P2P over MANET. Overall, more than thirty distinct approaches have been classified into groups and introduced in tables providing a structured overview of the area. The survey addresses the identified approaches in terms of P2P systems, MANET underlay systems and the performance of the reviewed systems

A one hop overlay system for Mobile Ad Hoc Networks

Peer-to-Peer (P2P) overlays were initially proposed for use with wired networks. However, the very rapid proliferation of wireless communication technology has prompted a need for adoption of P2P systems in mobile networks too. There are many common characteristics between P2P overlay networks and Mobile Ad-hoc Networks (MANET). Self-organization, decentralization, a dynamic nature and changing topology are the most commonly shared features. Furthermore, when used together, the two approaches complement each other. P2P overlays provide data storage/retrieval functionality and MANET provides wireless connectivity between clients without depending on any pre-existing infrastructure. P2P overlay networks can be deployed over MANET to address content discovery issues. However, previous research has shown that deploying P2P systems straight over MANET does not exhibit satisfactory performance. Bandwidth limitation, limited resources and node mobility are some of the key constraints. This thesis proposes a novel approach, OneHopOverlay4MANET, to exploit the synergies between MANET and P2P overlays through cross-layering. It combines Distributed Hash Table (DHT) based structured P2P overlays with MANET underlay routing protocols to achieve one logical hop between any pair of overlay nodes. OneHopOverlay4MANET constructs a cross-layer channel to permit direct exchange of routing information between the Application layer, where the overlay operates, and the MANET underlay layer. Consequently, underlay routing information can be shared and used by the overlay. Thus, OneHopOverlay4MANET reduces the typical management traffic when deploying traditional P2P systems over MANET. Moreover, as a result of building one hop overlay, OneHopOverlay4MANET can eliminate the mismatching issue between overlay and underlay and hence resolve key lookups in a short time, enhancing the performance of the overlay. v In this thesis, we present OneHopOverlay4MANET and evaluate its performance when combined with different underlay routing protocols. OneHopOverlay4MANET has been combined with two proactive underlays (OLSR and BATMAN) and with three reactive underlay routing protocols (DSR, AODV and DYMO). In addition, the performance of the proposed system over OLSR has been compared to two recent structured P2P over MANET systems (MA-SP2P and E-SP2P) that adopted OLSR as the routing protocol. The results show that better performance can be achieved using OneHopOverlay4MANET

Performance evaluation of OnehopMANET

When used together, Peer-to-Peer overlays and MANET complement each other well. While MANET provides wireless connectivity without depending on any pre-existing infrastructure, P2P overlays provide data storage/retrieval functionality. However, both systems face common challenges: maintaining connectivity in dynamic and decentralized networks. In this paper we evaluate the performance of OnehopMANET[1] as a structured P2P over MANET system that uses cross-layering with a proactive underlay. We compare the performance of OnehopMANET with two recent structured P2P over MANET systems (MA-SP2P and E-SP2P) that use the same underlay protocol (OLSR) and that have been shown to outperform other proposals. Through simulation we show that OnehopMANET achieves a better performance in terms of file discovery delay, lookup fail rate and total traffic load for all the simulated scenarios

Airborne Network Data Availability Using Peer to Peer Database Replication on a Distributed Hash Table

The concept of distributing one complex task to several smaller, simpler Unmanned Aerial Vehicles (UAVs) as opposed to one complex UAV is the way of the future for a vast number of surveillance and data collection tasks. One objective for this type of application is to be able to maintain an operational picture of the overall environment. Due to high bandwidth costs, centralizing all data may not be possible, necessitating a distributed storage system such as mobile Distributed Hash Table (DHT). A difficulty with this maintenance is that for an Airborne Network (AN), nodes are vehicles and travel at high rates of speed. Since the nodes travel at high speeds they may be out of contact with other nodes and their data becomes unavailable. To address this the DHT must include a data replication strategy to ensure data availability. This research investigates the percentage of data available throughout the network by balancing data replication and network bandwidth. The DHT used is Pastry with data replication using Beehive, running over an 802.11 wireless environment, simulated in Network Simulator 3. Results show that high levels of replication perform well until nodes are too tightly packed inside a given area which results in too much contention for limited bandwidth

Design and evaluation of a peer-to-peer MANET crosslayer approach: OneHopOverlay4MANET

Peer-to-Peer overlay networks can be deployed over Mobile Ad hoc Networks (MANET) to address content discovery issues. However, previous research has shown that deploying P2P systems straight over MANET do not exhibit satisfactory performance. Bandwidth limitation, limited resources and node mobility are some of the key constraints. OneHopOverlay4MANET exploits the synergies between MANET and P2P overlays through cross-layering. It combines Distributed Hash Table (DHT) based structured P2P overlays with MANET underlay routing protocols to achieve one logical hop between any pair of overlay nodes. In this paper, we present OneHopOverlay4MANET and evaluate its performance when combined with different underlay routing protocols. We evaluate OneHopOverlay4MANET with two proactive underlay (OLSR and BATMAN) and with three reactive underlay routing protocols (DSR, AODV and DYMO). Through simulation we show that the use of OLSR in OneHopOverlay4MANET yields the best performance. In addition, we compare the performance of the proposed system over OLSR to two recent structured P2P over MANET systems (MA-SP2P and E-SP2P) that adopted OLSR as the routing protocol. As simulation result shows, better performance can be achieved using OneHopOverlay4MANET

Cross-layer Peer-to-Peer Computing in Mobile Ad Hoc Networks

The future information society is expected to rely heavily on wireless technology. Mobile access to the Internet is steadily gaining ground, and could easily end up exceeding the number of connections from the fixed infrastructure. Picking just one example, ad hoc networking is a new paradigm of wireless communication for mobile devices. Initially, ad hoc networking targeted at military applications as well as stretching the access to the Internet beyond one wireless hop. As a matter of fact, it is now expected to be employed in a variety of civilian applications. For this reason, the issue of how to make these systems working efficiently keeps the ad hoc research community active on topics ranging from wireless technologies to networking and application systems. In contrast to traditional wire-line and wireless networks, ad hoc networks are expected to operate in an environment in which some or all the nodes are mobile, and might suddenly disappear from, or show up in, the network. The lack of any centralized point, leads to the necessity of distributing application services and responsibilities to all available nodes in the network, making the task of developing and deploying application a hard task, and highlighting the necessity of suitable middleware platforms. This thesis studies the properties and performance of peer-to-peer overlay management algorithms, employing them as communication layers in data sharing oriented middleware platforms. The work primarily develops from the observation that efficient overlays have to be aware of the physical network topology, in order to reduce (or avoid) negative impacts of application layer traffic on the network functioning. We argue that cross-layer cooperation between overlay management algorithms and the underlying layer-3 status and protocols, represents a viable alternative to engineer effective decentralized communication layers, or eventually re-engineer existing ones to foster the interconnection of ad hoc networks with Internet infrastructures. The presented approach is twofold. Firstly, we present an innovative network stack component that supports, at an OS level, the realization of cross-layer protocol interactions. Secondly, we exploit cross-layering to optimize overlay management algorithms in unstructured, structured, and publish/subscribe platforms

Mobile P2Ping: A Super-Peer based Structured P2P System Using a Fleet of City Buses

Recently, researchers have introduced the notion of super-peers to improve signaling efficiency as well as lookup performance of peer-to-peer (P2P) systems. In a separate development, recent works on applications of mobile ad hoc networks (MANET) have seen several proposals on utilizing mobile fleets such as city buses to deploy a mobile backbone infrastructure for communication and Internet access in a metropolitan environment. This paper further explores the possibility of deploying P2P applications such as content sharing and distributed computing, over this mobile backbone infrastructure. Specifically, we study how city buses may be deployed as a mobile system of super-peers. We discuss the main motivations behind our proposal, and outline in detail the design of a super-peer based structured P2P system using a fleet of city buses.Singapore-MIT Alliance (SMA

Exploiting epidemic data dissemination for consistent lookup operations in mobile applications

This paper presents a general-purpose distributed lookup service, denoted Passive Distributed Indexing (PDI). PDI stores entries in form of (key, value) pairs in index caches located at mobile devices. Index caches are filled by epidemic dissemination of popular index entries. By exploiting node mobility, PDI can resolve most queries locally without sending messages outside the radio coverage of the inquiring node. For keeping index caches coherent, configurable value timeouts implementing implicit invalidation and lazy invalidation caches implementing explicit invalidation are introduced. Inconsistency in index caches due to weak connectivity or node failure is handled by value timeouts. Lazy invalidation caches reduce the fraction of stale index entries due to modified data at the origin node. Similar to index caches, invalidation caches are filled by epidemic distributions of invalidation messages. We evaluate the performance of PDI for a mobile P2P file sharing a mobile instant messaging application. Simulation results show that with the suitable integration of both invalidation mechanisms, up to 80% of the lookup operations return correct results and more than 90% of results delivered by PDI index caches are up-to-date

Priority Based Routing for Mobile Peer-To-Peer Communications

In a Mobile Peer-to-Peer (MP2P) network, mobile nodes share their resources among one another in a mobile wireless environment. Communication among nodes in MP2P network has become an important area for research due to the significance of its applications. The success of these MP2P applications depends on the number of users in the network, popularity of services offered, quick response and faster access to services. Some services offered could be more popular than others and some peers may contribute more to the network by catering to more requests compared to other peers. In priority based routing mechanism, there is an increase in the priority of a peer with the increase in the number of times it provides services to other peers. The priority of a shared service also increases as the number of requests for that service increases. Also, the mechanism of priority based mobile peer-to-peer routing provides higher priority for traffic destined to high contributing peers and the traffic of popular services, during routing. This would provide high contributing peers quicker response and faster access to services. Hence, this mechanism motivates more users to join the MP2P network and contribute more to the network

Effects of Data Replication on Data Exfiltration in Mobile Ad hoc Networks Utilizing Reactive Protocols

A swarm of autonomous UAVs can provide a significant amount of ISR data where current UAV assets may not be feasible or practical. As such, the availability of the data the resides in the swarm is a topic that will benefit from further investigation. This thesis examines the impact of le replication and swarm characteristics such as node mobility, swarm size, and churn rate on data availability utilizing reactive protocols. This document examines the most prominent factors affecting the networking of nodes in a MANET. Factors include network routing protocols and peer-to-peer le protocols. It compares and contrasts several open source network simulator environments. Experiment implementation is documented, covering design considerations, assumptions, and software implementation, as well as detailing constant, response and variable factors. Collected data is presented and the results show that in swarms of sizes of 30, 45, and 60 nodes, le replication improves data availability until network saturation is reached, with the most significant benefit gained after only one copy is made. Mobility, churn rate, and swarm density all influence the replication impact