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Mario Gerla

Bio: Mario Gerla is an academic researcher. The author has contributed to research in topics: Ad hoc wireless distribution service & Optimized Link State Routing Protocol. The author has an hindex of 1, co-authored 1 publications receiving 14 citations.

Papers
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01 Jan 1998
TL;DR: This dissertation proposes a new routing approach for ad hoc wireless network: Global State Routing (GSR), similar to link state routing, GSR maintains a global view of network topology and uses the fisheye technique to keep the control message small, thus reducing the consumption of bandwidth by control overhead.
Abstract: One feature that distinguishes the ad hoc wireless network from traditional wired networks and PCS (personal communication network) is that all hosts in an ad hoc wireless network are allowed to move freely without the need for static access points. This distinct feature, however, presents a great challenge to the design of the routing scheme and the support of multimedia services, since the link quality and the network topology may be fast changing as hosts roam around. In this dissertation, we investigate the behaviors of existing routing algorithms. None of them satisfies the stringent requirements of ad hoc wireless networks. These requirements include: high accuracy, low overhead, scalability in a large network, the possibility of providing QoS routing, etc. Therefore, we propose a new routing approach for ad hoc wireless network: Global State Routing (GSR). Similar to link state routing, GSR maintains a global view of network topology. But unlike link state routing, GSR uses the fisheye technique to keep the control message small, thus reducing the consumption of bandwidth by control overhead. As a result, GSR can be scaled for use in networks with large populations. GSR can also be extended with QoS parameters to perform QoS routing for multimedia applications. In order to validate the results in our investigation, all schemes are simulated and/or implemented in our testbed at UCLA. The implementation of our testbed also involves the creation of several new features in the operating system to provides QoS support in wireless networks, and the creation of new applications which fully utilize this QoS information. With the integration of these features across various layers, we can realize a truly mobile, multimedia, multihop wireless network.

14 citations


Cited by
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Proceedings ArticleDOI
21 Sep 1999
TL;DR: A novel soft state wireless hierarchical routing protocol-Hierarchical State Routing (HSR) is proposed, which keeps track of logical subnet movements using home agent concepts akin to Mobile IP.
Abstract: In this paper we present a hierarchical routing protocol in a large wireless, mobile network such as found in the automated battlefield or in extensive disaster recovery operations. Conventional routing does not scale well to network size. Likewise, conventional hierarchical routing cannot handle mobility efficiently. We propose a novel soft state wireless hierarchical routing protocol-Hierarchical State Routing (HSR). We distinguish between the "physical" routing hierarchy (dictated by geographical relationships between nodes) and "logical" hierarchy of subnets in which the members move as a group (e.g., company, brigade, battalion in the battlefield). HSR keeps track of logical subnet movements using home agent concepts akin to Mobile IP. A group mobility model is introduced and the performance of the HSR is evaluated through a detailed wireless simulation model.

371 citations

Dissertation
Scott F. Midkiff1, Tao Lin1
01 Jan 2004
TL;DR: This dissertation summarizes all the aforementioned methodologies and corresponding applications the authors developed concerning MANET routing protocols and shows that reactive protocols may only be suitable for MANETs with small number of traffic loads and small link connectivity change rates.
Abstract: A mobile ad hoc network (MANET) is a wireless network that uses multi-hop peer-to-peer routing instead of static network infrastructure to provide network connectivity. MANETs have applications in rapidly deployed and dynamic military and civilian systems. The network topology in a MANET usually changes with time. Therefore, there are new challenges for routing protocols in MANETs since traditional routing protocols may not be suitable for MANETs. For example, some assumptions used by these protocols are not valid in MANETs or some protocols cannot efficiently handle topology changes. Researchers are designing new MANET routing protocols and comparing and improving existing MANET routing protocols before any routing protocols are standardized using simulations. However, the simulation results from different research groups are not consistent with each other. This is because of a lack of consistency in MANET routing protocol models and application environments, including networking and user traffic profiles. Therefore, the simulation scenarios are not equitable for all protocols and conclusions cannot be generalized. Furthermore, it is difficult for one to choose a proper routing protocol for a given MANET application. According to the aforementioned issues, my Ph.D. research focuses on MANET routing protocols. Specifically, my contributions include the characterization of different routing protocols using a novel systematic relay node set (RNS) framework, design of a new routing protocol for MANETs, a study of node mobility, including a quantitative study of link lifetime in a MANET and an adaptive interval scheme based on a novel neighbor stability criterion, improvements of a widely-used network simulator and corresponding protocol implementations, design and development of a novel emulation test bed, evaluation of MANET routing protocols through simulations, verification of our routing protocol using emulation, and development of guidelines for one to choose proper MANET routing protocols for particular MANET applications. Our study shows that reactive protocols do not always have low control overhead, as people tend to think. The control overhead for reactive protocols is more sensitive to the traffic load, in terms of the number of traffic flows, and mobility, in terms of link connectivity change rates, than other protocols. Therefore, reactive protocols may only be suitable for MANETs with small number of traffic loads and small link connectivity change rates. We also demonstrated that it is feasible to maintain full network topology in a MANET with low control overhead. This dissertation summarizes all the aforementioned methodologies and corresponding applications we developed concerning MANET routing protocols.

64 citations

Proceedings ArticleDOI
16 Oct 2000
TL;DR: A LOcation Trace Aided Routing (LOTAR) protocol is proposed, which utilizes the mobile nodes' location information to assist in routing and reduce the disruption of a flow.
Abstract: A Mobile Ad hoc NETwork (MANET) is a collection of wireless mobile computers forming a temporary network without any existing wire line infrastructure. Due to the dynamic nature of the network topology, the established routes in a MANET may be disconnected because of node mobility. It is difficult to support real-time traffic if the routes are broken and re-constructed frequently. In this paper, we propose a LOcation Trace Aided Routing (LOTAR) protocol, which utilizes the mobile nodes' location information to assist in routing and reduce the disruption of a flow. The performance of LOTAR is studied and compared to other routing approaches in MANET.

26 citations

Book
01 Jan 2003
TL;DR: This chapter presents the basic concepts of quality of service support in ad hoc networks for unicast communication, reviews the major areas of current research and results, and addresses some new issues.
Abstract: Wireless mobile ad hoc networks consist of mobile nodes interconnected by wireless multi-hop communication paths. Unlike conventional wireless networks, ad hoc networks have no fixed network infrastructure or administrative support. The topology of such networks changes dynamically as mobile nodes join or depart the network or radio links between nodes become unusable. Supporting appropriate quality of service for mobile ad hoc networks is a complex and difficult task because of the dynamic nature of the network topology and generally imprecise network state information, and has become an intensely active area of research in the last few years. This chapter presents the basic concepts of quality of service support in ad hoc networks for unicast communication, reviews the major areas of current research and results, and addresses some new issues. The principal focus is on routing and security issues associated with quality of service support. The chapter concludes with some observations on the open areas for further investigation.

13 citations