Mobility through Heterogeneous Networks in a 4G Environment

Serving and Managing users in a heterogeneous environment. 17th WWRF Meeting in Heidelberg, Germany, 15 - 17 November 2006. [Proceeding presented at WG3 - Co-operative and Ad-hoc Networks]The increase will of ubiquitous access of the users to the requested services points towards the integration of heterogeneous networks. In this sense, a user shall be able to access its services through different access technologies, such as WLAN, Wimax, UMTS and DVB technologies, from the same or different network operators, and to seamless move between different networks with active communications. In this paper we propose a mobility architecture able to support this users’ ubiquitous access and seamless movement, while simultaneously bringing a large flexibility to access network operators

Seamless integration of unidirectional broadcast links into QoS-constrained broadband wireless mesh access networks

Proceeding of: International Conference for Internet Technology and Secured Transactions ICITST 2009, London, U.K., 9-12 Nov. 2009Wireless Mesh Networks (WMNs) have matured in recent years. They allow two nodes to communicate via multiple hops when no direct connectivity exists. This allows community networks such as Freifunk [3] to provide affordable Internet access to their communities by sharing a few gateway nodes. Increasing demand for multi-media content poses a challenge for the typical WMN routing protocols such a Optimised Link State Routing (OLSR) which lack Quality of Service (QoS) support. Although, numerous solutions have been proposed to introduce QoS awareness such as [4], those WMNs fail to meet commercial operator requirements in term of reliability and QoS guarantees. In this paper we propose the seamless integration of Broadcast technologies such as Digital Video Broadcast (DVB) to introduce support for high-bandwidth multi-media services.European Community's Seventh Framework ProgramPublicad

Energy Efficient Minimum Broadcast Routing in ASN

Routing in a symmetric sensor network brings many challenges in wireless sensor network. As wireless sensor network works in infrastructure less environment. In asymmetric network it is a challenging to choose path at runtime to send packet from source to destination. In literature we discussed that most of the work is done in symmetric network only and routing in asymmetric network and related challenges are left uncovered. In our proposed work we have proposed a shortest path energy efficient routing in a asymmetric network. We extended the work to incorporate the energy with the shortest path routing. We simulated the performance of the proposed protocol in terms of PDR, PLR, Overhead and number of hops used. We compared the proposed system with Egyhet, Layhet and Prohet routing protocol and proved to be more efficient

Current Development: SOIASIA Project: A New and Effective Distance Learning Environment for Internet Developing Area Utilizing the Satellite Link

This paper describes a distance learning environment using the Internet via satellite in Asian regions where Internet infrastructure is insufficient. The merit of distance learning is that students can receive cutting edge lectures from professors all over the world. For those areas with sufficient Internet infrastructure, there would be no problem receiving these kinds of lectures. However, it is difficult for countries with insufficient Internet infrastructure to receive them. The SOI (School of Internet) ASIA project proposes and demonstrates a distance learning environment utilizing satellite links as an Internet infrastructure that can be quickly installed with low cost for those areas

Protocol Independent Multicast and Asymmetric Routing

Originally all links in the Internet were assumed to operate bidirectionally. Like many other routing protocols, PIM (protocol independent multicast) is based on this assumption: as will be explained, PIM's concept of using the routers' unicast RIBs (routing information bases) for reverse-path-forwarding is not applicable in networks with uni-directional links. If an additional bidirectional link such as a dial-up connection exists, link-layer tunnelling can overcome these basic routing deficiencies. But in order to achieve a more efficient routing and sustain scalability we argue that multicast and unicast traffic should be distinguished either by an extended link-layer tunnelling or dual RIBs

On the Scaling of Feedback Algorithms for Very Large Multicast Groups

Feedback from multicast group members is vital for many multicast protocols. In order to avoid feedback implosion in very large groups feedback algorithms with well behaved scaling-properties must be chosen. In this paper we analyse the performance of three typical feedback algorithms described in the literature. Apart from the basic trade-off between feedback latency and response duplicates we especially focus on the algorithms' sensitivity to the quality of the group size estimation. Based on this analysis we give recommendations for the choice of well behaved feedback algorithms that are suitable for very large groups

A Cross-System Approach for Multimedia Services with IP Multicast in 4G Networks

The increased demand for multimedia services by mobile end users in recent years have driven both Broadcast and Wireless Network operators to develop new systems and architectures for the deployment of such services. The proposed solutions are nonetheless limited either in terms of QoS or Capabilities to deliver new interactive services. This paper highlights strengths and drawbacks of the existing technologies in terms of QoS, Security and Mobility. In order to fill the gap between current solutions we propose a new architecture that builds itself on the synergies created by a heterogeneous network made of existing delivering technologies, such as 3GPP/MBMS and DVB, where services can be delivered to end-users in the most appropriate way for end-users and operators alike. A prototype implementation is further described.EU project - IST-2002- 506997 Daidalos I

Enhancing Performance by Salvaging Route Reply Messages in On-Demand Routing Protocols for MANETs

Researchers prefer on-demand routing protocols in mobile ad hoc networks where resources such as energy and bandwidth are constrained. In these protocols, a source discovers a route to a destination typically by flooding the entire or a part of the network with a route request (RREQ) message. The destination responds by sending a route reply (RREP) message to the source. The RREP travels hop by hop on the discovered route in the reverse direction or on another route to the source. Sometimes the RREP can not be sent to the intended next hop by an intermediate node due to node mobility or network congestion. Existing on-demand routing protocols handle the undeliverable RREP as a normal data packet - discard the packet and initiate a route error message. This is highly undesirable because a RREP message has a lot at stake – it is obtained at the cost of a large number of RREQ transmissions, which is an expensive and timeconsuming process. In this paper, we propose the idea of salvaging route reply (SRR) to improve the performance of on-demand routing protocols. We present two schemes to salvage an undeliverable RREP. Scheme one actively sends a one-hop salvage request message to find an alternative path to the source, while scheme two passively maintains a backup path to the source. Furthermore, we present the design of two SRR schemes in AODV and prove that routes are loop-free after a salvaging. We conduct extensive simulations to evaluate the performance of SRR, and the simulation results confirm the effectiveness of the SRR approach