A Survey of Routing Techniques for Mobile Collaborative Virtual Environment Applications <s> Proactive Routing Scheme <s> Mobile wireless computing devices such as cellphones, pagers, per- sonal digital assistants, pocket PCs, and tablet computers are all potential plat- forms for participating in small group, wireless, many-to-many distributed appli- cations. The networking technology needed to support such applications is readily available. However, almost all existing middleware infrastructure for distributed applications was designed for central servers and wired connections. The Anhinga Infrastructure described here runs entirely on the wireless mobile devices and so does not require any central server support. The Anhinga Infrastructure provides a message broadcast ad hoc networking protocol and a distributed computing plat- form based on lightweight versions of Java, Jini Network Technology, and tuple spaces. <s> BIB001 </s> A Survey of Routing Techniques for Mobile Collaborative Virtual Environment Applications <s> Proactive Routing Scheme <s> Mobile ad-hoc networks are a growing research topic. Much effort has been put into providing a technical basis for such networks. However, up to now, there has been very little work on how to facilitate integrated usage of the resources available in such a network. In this paper, we give an insight into our research on developing concepts to use the services of an ad-hoc net in an integrated, effective, and efficient manner. Our main focus lies on information services supporting e-learning applications. <s> BIB002 </s> A Survey of Routing Techniques for Mobile Collaborative Virtual Environment Applications <s> Proactive Routing Scheme <s> In this paper we present an experimental evaluation of a full ad hoc network architecture with particular attention to routing and middleware layers. In particular we set up a MANET prototype on which we performed a large set of experiments: in a first phase, we analyzed performances of a proactive and a reactive routing protocols in case of low mobility scenarios in small-medium scale ad hoc networks; then we studied the performances of a first prototype of an optimized p2p system for ad hoc networks (CrossROAD), based on a cross-layer interaction with a proactive routing protocol. Our analysis shows that the use of a proactive routing protocol does not negatively influence system performances, furthermore it allows the optimization of a structured p2p system on ad hoc networks, providing a complete and timely updated knowledge of the network topology. In this way, the overlay network is completely self-organizing and correctly manages network partitioning and topology changes. <s> BIB003 </s> A Survey of Routing Techniques for Mobile Collaborative Virtual Environment Applications <s> Proactive Routing Scheme <s> Developing and evaluating protocols and applications for mobile ad-hoc networks requires significant organisational effort when real mobile ad-hoc networks with several mobile terminals are considered. For fine tuning and optimizing ad-hoc protocols, network simulators like the OpNet Modeller, NS2, or GloMoSim are most suitable. However, for the comprehension of the mode of operations of adhoc network mechanisms and their effects on the communication flow of applications a real-time experiment environment is more preferable. In this paper, an emulation environment for mobile ad-hoc networks is presented, which operates within existing local area networks utilizing virtual overlay structures reflecting the characteristics of mobile ad-hoc networks. Routing protocols and applications are able to communicate in real-time over emulated mobile infrastuctures using the unmodified IP protocol stack. The emulator provides an extensible interface for specifying mobility patterns in order to define and to evaluate diverse mobile scenarios. Several ad-hoc specific mobility patterns have been integrated and evaluated. <s> BIB004 </s> A Survey of Routing Techniques for Mobile Collaborative Virtual Environment Applications <s> Proactive Routing Scheme <s> In the research area of mobile ad hoc network, ZRP which integrates advantages of proactive routing protocols and on-demand routing protocols has been the crucial research now. In this paper, the principle and the cache mechanism of ZRP are analyzed. In allusion to the problems of late-deletion and early-deletion in ZRP, the optimized A-ZRP which associates the routing information priority with the latest access time is proposed. It improves information store format of cache in the routing table. Finally, the simulation experiment shows that A-ZRP shows advantages to ZRP in terms of the radius of routing zone, routing overhead, delivery fraction and packet delay based on the same transmission load and node movement. In A-ZRP, the processing of path discovery is reduced, the routing overhead is decrease and the performance of the delivery fraction and the packet delay are improved. The routing protocol performance of mobile ad hoc ZRP is improved. <s> BIB005 </s> A Survey of Routing Techniques for Mobile Collaborative Virtual Environment Applications <s> Proactive Routing Scheme <s> One of the popular wireless network architectures is mobile ad hoc network (MANET) which can be deployed easily in almost any environment, without any underlying backbone and infrastructure support. In this paper, an efficient DSDV (Eff-DSDV) protocol is proposed for ad hoc networks. Eff-DSDV overcomes the problem of stale routes, and thereby improves the performance of regular DSDV. The proposed protocol has been implemented in the NCTUns Simulator and performance comparison has been made with regular DSDV and DSR protocols. The performance metrics considered are packet-delivery ratio, end-end delay, dropped packets, routing overhead, route length. It has been found after analysis that the performance of Eff-DSDV is superior to regular DSDV and sometimes better than DSR in certain cases. <s> BIB006
This section describes some relevant works that uses Proactive scheme as ad-hoc routing protocols. In Cross-ROAD BIB003 Delmastro present an extended version of OLSR with structured overlay functionality by hashing the IP addresses in the routing table. In this work authors compared CrossROAD's performance with the Pastry overlaid on OLSR. Simulations results show that the proposed cross-layer modification eliminate the network overhead required for the overlay maintenance. Cramer and Fuhrmann  have evaluated the behaviour of Chord lookup protocol in MANET using the network simulator GloMoSim  . Various routing protocols Ad hoc On-Demand Distance Vector (AODV) routing  , Dynamic Source Routing (DSR)  , and Optimized Link State Routing (OLSR)  are used in the simulation scenarios. Experimental results show poor performance and unpredictable behaviors when we increase the network size. MobiGrid  address the problem of information sharing using an interplay scheme between structured peer-to-peer system and MANET. This architecture is unique in that it allows nodes to negotiate the key space in order to build a sophisticated binary search tree. In this section we present some significant approaches used in this area that uses proactive ad-hoc routing protocols. Guettier et al  propose an approach in an ad-hoc network to support multiple collaborative services. The protocol relies on OLSR  routing to address mobile tactical communications, and to provide proactively a route always available between any two nodes. The key concept of this protocol is the use of specific parameter MPR-COVERAGE to deal with the unnecessary network overhead. Received message is checked based on the parameters to decide about it's state (Drop or Forward). Simulation results reveal better performance in term of network latency, and dropped network packets. Ready et al BIB006 Christopher et al  present an extended version of ZRP BIB005 protocol in order to improve the service discovery in MANETs. The approach implements a service discovery in the routing layer by piggybacking the service information into routing message, in doing so we decrease communication network overhead and save battery power. Based on their simulation results, extended ZRP provides better performance compared to ZRP. Halgo et al BIB004 describe an emulation environment tool called MASSIVE (MAnet Server Suite Incorporating Virtual Environments) for mobile ad-hoc networks to perform a system analysis. The main focus lies on; analyze the interaction between of the ad-hoc network and the applications itself. As an example authors incorporate an enhanced routing protocol TORA with an E-Learning in ad hoc network application BIB002 . 3.2.7 One Hop Routing Scheme Face-to-Face This is a very commune technique used by researches to design face-to-face collaboration system. In this technique nodes should be close enough in order to communicate and collaborate with each other. What follows is a description of some of these schemes in order to improve the routing performance. Alf et al.  designed a framework to support ComputerSupported Cooperative Work (CSCW) on mobile phones using J2ME and Personnel Area Network (PAN). The developed scheme is not suitable because CVE systems are expected to enable user interaction, and collaboration with the environment and other participants regardless of their proximity. CSCW is still under progress; simulation scenarios are very limited (only three users). iCoulds [52] is a simple peer-to-peer information-sharing system for mobile networks. It was developed mainly for J2ME (Java 2 Micro Edition). The communication layer in iClouds architecture is based on a simple one-hop exchange message. Proximity limitation and information sprinklers are the limitations of this project. Anhinga et al BIB001 , propose an approach that does not make use of an ad hoc routing protocol. Instead it technology is based on proximity and community systems to support face-to-face collaboration in mobile ad hoc networks. The system design relies on lightweight Java Version, Jini Network, and tuple spaces. The proposed solution runs on groups of proximal mobile devices characterized by many-to many communication patterns.