One of the major challenges faced by MANET researchers is the deployment of end-to-end quality-of-service support mechanisms for streaming media services over a group of MANET users. Group-oriented services over large, dynamically changing MANET networks has a big impact on the needs of streaming services communication in terms of mobility, quality of service (QoS) support and multicasting.
In MANET networks, where such features are not embedded with its architecture, it is necessary to develop QoS multicasting strategies. The research work focuses on the basic building blocks of an mobile ad hoc group communication scheme, which achieves multicasting optimal QoS efficiency OptiQ by tracking resource availability in a node’s neighborhood based on resource reservations, which announces the required QoS before each session initiation.
The primary quality of service (QoS) issues such as required bandwidth, message delay, traffic type and hop count per route improves the efficiency of streaming services over ad-hoc network. Streaming services support voice, data and video traffic by assessing and adjusting for various levels of QoS. The performance analysis is performed on functional prototype of OptiQ in mobile / wireless ad-hoc network with emphasis on service satisfaction for multiple group conference sessions.
The performance of OptiQ scheme is well compared with QoS-aware versions of AODV and TORA, well-known ad-hoc routing and limited QoS protocols. Using the SPRUCE bandwidth traffic gathering tool, with a set of C++ modules an extensive set of performance experiments were conducted for these protocols with OptiQ on a wide variety of mobility patterns and reservation strategies. The results shows the performance analysis of OptiQ is better than AODV or TORA protocol in minimizing end-to-end delay and controlling loss.
Table of Contents
Abstract
I. INTRODUCTION
II. RELATED WORK
A. Review Stage
B. Challenges
III. QASAN Architecture
.A. QASAN Group Create / Modify
B. Route Discovery
C. Routing Table Update
D. Alternate Route on Repair
E. Route Deletion
IV. QASAN Policy Manager (OPTIQ_Policy)
V. QoS Simulation Evaluation Metrics
A. Capacity estimation
B. Delay estimation
C. Admission control and resource reservation
VI. Experimental Test Bed Preparation
A. Hardware Setup Used
B. Performance & Evaluation
VII. Summary
Objectives and Research Focus
This paper presents the QASAN (Quality of Services for Media Streaming in Group Communication Over Mobile Ad Hoc Networks) scheme, which addresses the challenges of providing reliable end-to-end Quality of Service (QoS) for multimedia streaming in highly dynamic ad hoc environments.
- Development of a QoS-aware multicasting strategy for ad hoc networks.
- Implementation of the OptiQ_Policy algorithm for optimal resource tracking and reservation.
- Identification of an integrated approach for route discovery and bandwidth provisioning.
- Performance evaluation through a functional prototype in comparison with AODV and TORA protocols.
Excerpt from the Book
B. Route Discovery
Supporting QoS in an ad hoc environment entails the coordination of several system activities. The first is route discovery and route repair. Since ad hoc network topologies are highly dynamic, routes between two nodes often need to be produced or discovered upon demand, at the time of connection establishment in the case of a QoS connection, since previous routes may no longer exist.
When a source node needs a route to a destination, it transmits a neighbor broadcast query for Node Identification and Status request (REQS) packet. Nodes which receive the query check to see if they are the destination, if not, the protocol appends the receiving node’s information to the packet and rebroadcasts to the neighboring node Ni. The appended information includes identification, associativity with all its neighbors, route-relaying load, link-propagation delay, remaining power life, route hop count. The succeeding node erases its upstream node’s associativity information with other neighbors, retaining only the portion that concerns itself and the upstream node. When nodes join a session with available QoS, this information is updated to all the neighboring most appropriate routes.
Summary of Chapters
Abstract: Provides an overview of the challenges in deploying end-to-end QoS for media streaming in ad hoc networks and introduces the QASAN scheme.
I. INTRODUCTION: Discusses the requirements for QoS in ad hoc networks, defining the objectives of QASAN and the importance of optimal QoS routing decisions.
II. RELATED WORK: Reviews existing multimedia transmission approaches, degradation mechanisms, and highlights the specific challenges addressed by QASAN.
III. QASAN Architecture: Details the multi-cast request and reply query process, including group creation, route discovery, and session maintenance.
IV. QASAN Policy Manager (OPTIQ_Policy): Explains the algorithm used to monitor and negotiate optimal QoS parameters such as bandwidth, delay, and packet loss.
V. QoS Simulation Evaluation Metrics: Defines evaluation metrics for ad hoc protocols, specifically introducing Bandwidth Efficiency Ratio (BWER) and Normalized Overhead Load (NOL).
VI. Experimental Test Bed Preparation: Describes the hardware setup and traffic generation parameters used to evaluate the QASAN model.
VII. Summary: Concludes that QASAN outperforms traditional protocols like AODV and TORA in specific mobility scenarios by offering a source-initiated, on-demand QoS scheme.
Keywords
Quality of Service, Media Streaming, Mobile Ad Hoc Networks, Group Communication, QASAN, Multicasting, OptiQ_Policy, Bandwidth Estimation, Route Discovery, Admission Control, Network Topology, QoS Routing, Ad Hoc Wireless Network, Performance Evaluation
Frequently Asked Questions
What is the primary purpose of this research?
The paper aims to develop a specialized QoS strategy called QASAN to support media streaming in ad hoc networks, where traditional routing protocols often fail to provide consistent service quality.
What are the main components of the QASAN architecture?
The architecture integrates on-demand route discovery, signaling functions for resource reservation, and an optimal path selection mechanism to maintain group communication sessions.
What is the significance of the OptiQ_Policy algorithm?
OptiQ_Policy is the core module that tracks resource availability in a node's neighborhood and negotiates parameters like bandwidth and delay to ensure session-specific QoS requirements are met.
How is network performance measured in this study?
Performance is measured using specific metrics including the Bandwidth Efficiency Ratio (BWER), Normalized Overhead Load (NOL), and packet delay, tested against established protocols like AODV and TORA.
What hardware was used for testing?
The researchers used a test bed consisting of 40 laptops running Linux, equipped with wireless cards, configured to act as nodes in a controlled ad hoc environment.
Which protocols is QASAN compared against?
QASAN is compared against QoS-aware versions of the AODV and TORA routing protocols to demonstrate its efficiency in managing bandwidth and routing overhead.
How does the "Node Associativity" process function?
Node Associativity measures the stability of links between nodes over time and space, using beacon signals to determine the most reliable route based on connectivity and battery life.
What happens when a link breaks in a QASAN network?
The protocol performs a localized, real-time partial route repair by selecting an alternative route, which avoids the need for a global route discovery process and reduces signaling overhead.
- Arbeit zitieren
- Dr. Arunkumar Thangavelu (Autor:in), 2007, Delivering Quality Of Services For Media Streaming Networks, München, GRIN Verlag, https://www.hausarbeiten.de/document/72844
