Open Shortest Path First (OSPF), a link state routing protocol, is a popular interior gateway protocol (IGP) in the Internet. Wide spread deployment and years of experience running the protocol have motivated continuous improvements in its operation as the nature and demands of the routing infrastructures have changed. Modern routing domains need to maintain a very high level of service availability. Hence, OSPF needs to achieve fast convergence to topology changes. Also, the ever-growing size of routing domains, and possible presence of wireless mobile adhoc network (MANET) components, requires highly scalable operation on part of OSPF to avoid routing instability. Recent years have seen significant efforts aimed at improving OSPF's convergence speed as well as scalability and extending OSPF to achieve seamless integration of mobile adhoc networks with conventional wired networks. In this paper, we present a comprehensive survey of these efforts.

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Improving Convergence Speed and Scalability in OSPF: A Survey

Mobile ad hoc networks have very attractive intrinsic qualities. However they will be adopted only if they are able to support applications with QoS requirements. They should provide a route providing the QoS requested by a flow. The OLSR routing protocol can be extended for that purpose. OLSR relies on multipoint relay (MPR) selection that has an important effect on the routing protocol's performances. Indeed, the overhead generated by the OLSR protocol and more particularly the flooding efficiency depend on MPR selection. Moreover, MPRs are used as intermediate nodes in the routes. The analysis of MPR selection presented in this paper, gives quantitative results and also takes QoS support into account. Simulations on large and dense networks show that our analysis is highly accurate.

Analysis of MPR Selection in the OLSR Protocol

In this paper we consider the problem of distributed fault diagnosis in Wireless Sensor Networks (WSNs). The proposed Fault Diagnosis Algorithm (FDA) aims to handle both permanent and intermittent faults. The sensor nodes with permanent communication faults can be diagnosed by using the conventional time-out mechanism. In contrast, it is difficult to detect intermittent faults due to their inherent unpredictable behavior. The FDA is based on the comparison of sensor measurements and residual energy values of neighboring sensor nodes, exploiting their spatial correlations. To handle intermittent faults, the comparisons are made for $$r$$ r rounds. Two special cases of intermittent faults are considered: one, when an intermittently faulty node sends similar sensor measurement and similar residual energy value to some of its neighbors in all $$r$$ r rounds; another, when it sends these values, either or both of which deviates significantly from that of some neighbors in all $$r$$ r rounds. Through extensive simulation and analysis, the proposed scheme is proved to be correct, complete, and efficient to handle intermittent faults and hence, well suited for WSNs.

Diagnosis of Wireless Sensor Networks in Presence of Permanent and Intermittent Faults

Recent trends have suggested convergence to Wireless Sensor Networks (WSNs) becoming IPv6-based. To this effect, the Internet Engineering Task Force has chartered a Working Group to develop a routing protocol specification, enabling IPv6-based multi-hop WSNs. The current effort of this working group is development of a unicast routing protocol denoted RPL. RPL constructs a “DAG-like” logical structure with a single root, at which the majority of the traffic flows terminate, and assumes restrictions on network dynamics and traffic generality, in order to satisfy strict constraints on router state and processing. This paper investigates the efficient network-wide broadcast mechanisms in WSNs, using the logical structure already established by RPL. The aim hereof is to impose minimal additional state requirements on WSN routers, beyond that already maintained by RPL. This paper presents a selection of such broadcast mechanisms for RPL routed WSNs, and evaluates their performances. As part of this evaluation, the paper compares with MPR Flooding - an established efficient flooding optimization, widely used in MANETs.

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Comparative study of RPL-enabled optimized broadcast in Wireless Sensor Networks

In this paper, a new Controlled Vehicular Internet Access protocol with QoS support (CVIA-QoS) is introduced. CVIA-QoS employs fixed gateways along the road which perform periodic admission control and scheduling decisions for the packet traffic in their service area. The CVIA-QoS protocol is based on Controlled Vehicular Internet Access (CVIA) protocol that was designed only for the best-effort traffic. The most important contribution of the CVIA-QoS protocol is providing delay bounded throughput guarantees for soft real-time traffic, which is an important challenge especially for a mobile multihop network. After the demands of the soft real-time traffic is met, CVIA-QoS supports the best-effort traffic with the remaining bandwidth. Simulation results confirm that in CVIA-QoS protocol, the real-time throughput is not affected from the best-effort load and its delay is much smaller than CVIA delay when both the real-time and best-effort load exist in the channel. It has been observed that, unlike, CVIA-QoS, IEEE 802.11e with multi-hopping suffers from lower throughput and high number of real-time packet drops.

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Supporting real-time traffic in multihop vehicle-to-infrastructure networks

This document specifies an OSPFv3 interface type tailored for mobile
ad hoc networks. This interface type is derived from the broadcast
interface type, enhanced with MANET techniques based on multi-point
relaying (MPR).

OSPF Multipoint Relay (MPR) Extension for Ad Hoc Networks

OSPF MPR Extension for Ad Hoc Networks

Solutions for mobile ad hoc routing have matured. Building atop these foundations, new challenges are set for MANETs, such as integration in the Internet core. On this topic, this paper designs and evaluates MPR-OSPF, an extension of the OSPF protocol enabling its operation on networks that may include both MANET nodes and usual fixed routers. Automatic integration of different types of vehicular ad hoc networks (VANETs) in the IP infrastructure is then possible using the classic OSPF framework. Techniques used therefore are derived from OLSR, the MANET routing protocol that is the most compatible with traditional IP environments.

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Dang-Quan Nguyen

Papers

OSPF Multipoint Relay (MPR) Extension for Ad Hoc Networks

OSPF MPR Extension for Ad Hoc Networks

Integrating VANETs in the Internet Core with OSPF : the MPR-OSPF Approach