Geographic random forwarding (geraf) for ad hoc and sensor networks: multihop performance

Abstract

In this paper, we propose a novel forwarding technique based on geographical location of the nodes involved and random selection of the relaying node via contention among receivers. We focus on the multihop performance of such a solution, in terms of the average number of hops to reach a destination as a function of the distance and of the average number of available neighbors. An idealized scheme (in which the best relay node is always chosen) is discussed and its performance is evaluated by means of both simulation and analytical techniques. A practical scheme to select one of the best relays is shown to achieve performance very close to that of the ideal case. Some discussion about design issues for practical implementation is also given.

Cost Efficient Localized Geographical Forwarding Strategies For Wireless Sensor Networks

“…3, we report both the success probability curve P s (x) and Γ (x) as a function of the normalized distance x/R. Clearly, P s (x) drops as x → R and this is the reason for which the often considered [6,18] maximum advancement within radius metrics does not represent the optimal relay node selection criterion when fading is taken into account. It shall be observed that our derivation is an extension of previous results.…”

“…In this section, we report some preliminary performance results by comparing our new approach with the GeRaf scheme proposed in [6]. The GeRaf framework consists of an integrated practical MAC/routing scheme based on pure advancements: its capacity of approaching the maximum possible advancements toward the destination makes GeRaf a good candidate for our investigation.…”

“…Further results on this issue are one of the main objectives of our future research. For the pure geographical routing scheme, we consider the version of the GeRaf protocol proposed in [6], by subdividing F into a given number N r of priority regions, according to the advancement toward the destination provided by the nodes therein. For the relay election, we consider the probabilistic contention as in [6], where the nodes in the non-empty region with the highest priority are the ones contending to act as relay.…”

“…For the pure geographical routing scheme, we consider the version of the GeRaf protocol proposed in [6], by subdividing F into a given number N r of priority regions, according to the advancement toward the destination provided by the nodes therein. For the relay election, we consider the probabilistic contention as in [6], where the nodes in the non-empty region with the highest priority are the ones contending to act as relay. 11 For what concerns the performance metrics, we consider the normalized advancement (z relay ) provided by the relay node, the number of contention rounds (n rounds ) needed to elect a relay as well as the total number of packets transmitted (n tx ) within the entire relay election procedure, including the transmission of REQ/REPLY messages, collided packets and the final packet transmission from the forwarder to the relay node.…”

“…Many routing solutions, in fact, exploit the concept of maximum advancements toward the destination [3][4][5][6] to effectively route packets in a best effort (greedy) manner. However, recent empirical measurements [7][8][9] have proved that the unit disk connectivity model [10], on which these solutions are based, often fails in real settings.…”