A qualitative comparison evaluation of the greedy forwarding strategies in Mobile Ad Hoc Network

Abstract

The Mobile Ad Hoc Network (MANET) is wireless network which provides communication among wireless mobile hosts without the need of any standing network infrastructure. In such networks, and to facilitate communication between participating nodes, every node has to offer routing services. Routing in MANET is responsible for selecting and forwarding packets along optimal paths. Finding an optimal route is a crucial task in MANET where routes tend to be multi-hop. Many routing protocols have been proposed in literature. However, few of them are efficient when the network is sparse and highly dynamic. Position-based routing and forwarding provides the opportunity for improving the efficiency and performance of the existing MANET routing strategies. This research work presents an extensive overview of geographic forwarding techniques in MANET. In particular, it focuses on the presentation of the basic operation mode of geographic forwarding, which is greedy forwarding. Meanwhile, this research work presents a qualitative evaluation of the most current and popular greedy forwarding strategies used with position based routing protocols. Furthermore, the findings have been used to conclude the most appropriate unicast forwarding policy for future research efforts.

Introduction

Mobile Ad Hoc Networks (MANETs) are composed of wireless mobile devices (nodes) equipped with portable radios but without the aid of any centralized management or existing infrastructure such as base-station. MANETs are used in battlefield environments, disaster relief, and for commercial issues (Ambhaikar Sharma). MANETs have received significant attention due to their easy deployment for such usages. In MANETs, each node must act as a router and host at the same time. These mobile nodes themselves must be able to cooperate to allow communication among each other. Moreover, a routing protocol for MANET runs on every node and is affected by the limited resources at each Mobile Node (MNs). Hence, each MN takes a part in data packets forwarding process (Qadri and Liotta, 2009).

Nodes in such a network move in a freely and arbitrarily manner, thus a MANET topology changes frequently and unpredictably (Chlamtac et al., 2003). Moreover, MANET is limited in its resources (bandwidth and power). Meanwhile, it is expected to perform efficiently with such limitations. These constraints in combination with the MANET dynamics topology make the designing of routing in such networks a challenging task. This means that we need a more dynamic routing protocol that not only finds an optimal route between the communicating MNs, but also responds quickly to the topology changes, and optimally using limited recourses (Qadri and Liotta, 2009, Chlamtac et al., 2003, Ghosekar et al., 2010). To solve the addressed problems of routing in MANET, many routing protocols that are compatible with the characteristics of MANET have been proposed in the literature. However, few of them are efficient when the network is sparse and highly dynamic.

For the sake of classification of routing protocols in MANET, there are several approaches that have been adopted. One of those approaches is in regards to the required routing information that will be used in packet forwarding. As is pointed out in (Rubinstein et al., 2006), within the framework of the Internet Engineering Task Force (IETF), routing in MANET can be broadly classified into two main categories. These categories are position-aware (position-based), and position-unaware (topology-based) routing protocols.

Position-unaware routing protocols use information about links that exist in the network to perform packet forwarding. Position-aware routing protocols use the position information of nodes to make routing decisions (Mauve et al., 2001, Liu and Kaiser, 2005, Rajaraman, 2002). Position-based routing and forwarding approaches provides the opportunity for improving the efficiency and performance of the existing MANET routing strategies over topology-based protocols.

In this work, an extensive overview of geographic forwarding techniques for the position-based routing protocol introduced is presented. It focuses on the presentation of the basic operation mode of geographic forwarding, which is greedy forwarding. This work introduces in depth the basic principles involved and describe the classical techniques as well as the latest advances in this area. These techniques are the most current and popular greedy forwarding strategies used with position-based routing protocols.

Furthermore, the techniques under study have been analyzed and evaluated in terms of several qualitative characteristics. These criteria are transmission range, path strategy, deployed criterion, optimization criteria, optimization objective, memorization, communication complexity, implementation complexity, robustness, scalability, optimal path, guarantee delivery, and lastly, are they loop-free. The protocols that have been selected for analyses are; Greedy Forwarding Strategy, (GFS) (Finn, 1987), Most Forward within Transmission Range, (MFR) (Takagi and Kleinrock, 1984), Nearest with Forward Progress, (NFP) (Hou and Li, 1986), Compass Routing, (CR) (Kranakis, 1999), Random Progress, (RPF) (Nelson and Kleinrock, 1984), Angular Routing protocol, (ARP) (Giruka Singhal), Maximum by Conventional Geographic Routing, (MAGF) (Li and Shatz, 2008), Normalized Advance, (NADV) (Lee et al., 2010) and lastly, Greedy-based Backup Routing (GBR) (Yang et al., 2010).