On Cross-Layer Routing in Wireless Multi-Hop Networks

International audienc

Mobile Networks

The growth in the use of mobile networks has come mainly with the third generation systems and voice traffic. With the current third generation and the arrival of the 4G, the number of mobile users in the world will exceed the number of landlines users. Audio and video streaming have had a significant increase, parallel to the requirements of bandwidth and quality of service demanded by those applications. Mobile networks require that the applications and protocols that have worked successfully in fixed networks can be used with the same level of quality in mobile scenarios. Until the third generation of mobile networks, the need to ensure reliable handovers was still an important issue. On the eve of a new generation of access networks (4G) and increased connectivity between networks of different characteristics commonly called hybrid (satellite, ad-hoc, sensors, wired, WIMAX, LAN, etc.), it is necessary to transfer mechanisms of mobility to future generations of networks. In order to achieve this, it is essential to carry out a comprehensive evaluation of the performance of current protocols and the diverse topologies to suit the new mobility conditions

Experimental evaluation of the usage of ad hoc networks as stubs for multiservice networks

This paper describes an experimental evaluation of a multiservice ad hoc network, aimed to be interconnected with an infrastructure, operator-managed network. This network supports the efficient delivery of services, unicast and multicast, legacy and multimedia, to users connected in the ad hoc network. It contains the following functionalities: routing and delivery of unicast and multicast services; distributed QoS mechanisms to support service differentiation and resource control responsive to node mobility; security, charging, and rewarding mechanisms to ensure the correct behaviour of the users in the ad hoc network. This paper experimentally evaluates the performance of multiple mechanisms, and the influence and performance penalty introduced in the network, with the incremental inclusion of new functionalities. The performance results obtained in the different real scenarios may question the real usage of ad-hoc networks for more than a minimal number of hops with such a large number of functionalities deployed

Transporting audio over wireless ad hoc networks: Experiments & new insights

Current efforts on ad hoc wireless network research are focused more on routing and multicasting protocols. However, there is an increasing need to understand what sort of media could be transported over wireless ad hoc networks other than data. Existing research on multimedia wireless communications often addresses broadband wireless networks with a connection-oriented backbone. In this paper, we address the possibility of transporting audio traffic over wireless ad hoc networks. We examine the impact of wireless multi-hop links on audio data relay and how the audio quality at the receiver is affected. In particular, we examine communication parameters such as latency, jitter, packet loss, and their impact on perceived audio quality. ©2003 IEEE.published_or_final_versio

Quality Of Service Enabled Cross-Layer Multicast Framework For Mobile Ad Hoc Networks.

Rangkaian ad hoc bergerak merupakan suatu rangkaian tanpa wayar yang boleh dibentuk secara bebas, dinamik serta disusunatur dan ditadbir dalam bentuk topologi rangkaian sementara dan arbitrari. Mobile ad hoc networks (MANETs) are wireless networks that can freely and dynamically be created, organized and administered into arbitrary and temporary network topologies

Localization of nodes in wired and wireless networks

This thesis focuses on the implementation of algorithms for localization of nodes in wired and wireless networks. The thesis is organized into two papers. The first paper presents the localization algorithms based on time of arrival (TOA) and time difference of arrival (TDOA) techniques for computer networks such as the Internet by using round-trip-time (RTT) measurements obtained from known positions of the gateway nodes. The RTT values provide an approximate measure of distance between the gateway nodes and an unknown node. The least squares technique is then used to obtain an estimated position of the unknown node. The second paper presents localization of an unknown node during route setup messages in wireless ad hoc and sensor networks using a new routing protocol. A proactive multi-interface multichannel routing (MMCR) protocol, recently developed at Missouri S&T, was implemented on the Missouri S&T motes. This protocol calculates link costs based on a composite metric defined using the available end-to-end delay, energy utilization, and bandwidth, and it chooses the path that minimizes the link cost factor to effectively route the information to the required destination. Experimental results indicate enhanced performance in terms of quality of service, and implementation of this protocol requires no modification to the current IEEE 802.11 MAC protocol. Received signal strength indicator (RSSI) values are recorded from the relay nodes (gateway nodes) to the unknown node during route setup messages. The location of the unknown node is estimated using these values with some a priori profiling and the known positions of the relay nodes as inputs to the least squares technique --Abstract, page iv