ROUTING IN OPTICAL MESH NETWORKS-A
QOS PERSPECTIVE
International Journal of Ad hoc, Sensor & Ubiquitous Computing (IJASUC), 09 (2):
13 (2023)Abstract
Wireless Ad-Hoc Mesh Networks are characterized by static nodes connected in a mesh topology. A routing
protocol discovers and maintains the route for successful transmission of data in a network. The routing
protocol should also provide load balancing and fault tolerance for improved network performance. In
Free Space Optical networks (FSO) line of sight (LOS) should be maintained between the two
communicating nodes. In a multihop scenario maintaining LOS during routing is a challenge. In this paper
we propose a routing protocol Quality of Service-Directional Routing Protocol (QDRP) - which assures a
certain level of performance to a data flow in terms of delay and implemented on FSO MANET. Through
simulations it is observed that QDRP chooses the path with the least delay and performs satisfactorily
under varying node densities and transmission rates achieving end to end delay of .14 s and packet delivery
percentage of 96% when simulated for an area of 1300 m *1300 m for 100 nodes. This work explores the
potential of the proposed routing protocol for free space optical mesh networks. QDRP is compared with
ORRP (Orthogonal Rendezvous Routing Protocol) and AODV (Ad-Hoc on Demand Distance Vector), a
reactive protocol which is also implemented in free space optical environment. We support our conclusions
that QDRP gains in terms of packet delivery percentage, end to end delay and goodput.
Description
The radio frequency part of the electromagnetic spectrum is classified into licensed and
unlicensed bands, the existing unlicensed bands are already saturated thus the research is shifting
towards using the optical part of the spectrum. This technology is referred to as “optical
communication without the fiber” and also defined as “optical communication at the speed of
light”[1].Environmental conditions such as fog, scattering, absorption affect FSO communication.
An optical mesh network is equipped with optical transceiver nodes. A mesh network is very
robust to link failure. For dense networks finding out the connectivity and best path in terms of
QoS is a very cumbersome task. Destination Sequenced Distance Vector (DSDV) [2] is a
proactive routing approach whereas Dynamic Source Routing (DSR) [3] and Ad-Hoc on Demand
Distance Vector (AODV) [4], protocols explored reactive routing methods which used the
flooding technique during the course of finding the path from source to destination. Flooding
causes additional overhead on the network and thus reducing the throughput. Directional form of
data communication can be very promising because of directional nature of the FSO transceivers.
In this work a routing protocol with directional perspective is proposed for the optical mesh
networks to satisfy QoS requirements. Out of multiple paths between source to a destination, the
path with the least delay is selected for data transmission. Through comparative evaluation we
provide conclusions for the “metrics” packet delivery percentage, delay, number of hops and
International Journal of Ad hoc, Sensor & Ubiquitous Computing (IJASUC) Vol.9, No.2, April 2018
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goodput. Section 2 presents the literature related to free space optical networks. Section 3
discusses the methodology of existing work Orthogonal Rendezvous Routing Protocol
(ORRP).Section 4 discusses proposed routing protocol QDRP. Section 5 presents NS-2.34
implementation of the protocol. Section 6 provides details of the results obtained after
implementation. Conclusion and future scope is presented in section 7.