An ant-based algorithm for distributed routing and wavelength assignment in dynamic optical networks

Abstract

Abstract-Future optical communication networks are expected to change radically during the next decade. To meet the demanded bandwidth requirements, more dynamism, scalability and automatism will need to be provided. This will also require addressing issues such as the design of highly distributed control plane systems and their associated algorithms to respond to network changes very rapidly. In this work, we propose the use of an ant colony optimization (ACO) algorithm to solve the intrinsic problem of the routing and wavelength assignment (RWA) on wavelength continuity constraint optical networks. The main advantage of the protocol is its distributed nature, which provides higher survivability to network failures or traffic congestion. The protocol has been applied to a specific type of future optical network based on the optical switching of bursts. It has been evaluated through extensive simulations with very promising results, particularly on highly congested scenarios where the load balancing capabilities of the protocol become especially efficient. Results on a partially meshed network like NSFNET show that the ant-based protocol outperforms other RWA algorithms under test in terms of blocking probability without worsening other metrics such as mean route length.

Topology analysis of auto load-balancing RWA in optical burst-switched networks

“…And finally, with respect the parameterizations of ALBA, unless otherwise noted, the following values have been used: ρ 1 = 0.001, β = 3.0, α 1 = 0.001, r 0 = 0.9 and ω = 0.75. These values have been demonstrated to offer good performance [10]. Fig.…”

QoS‐aware ant‐based route, wavelength and timeslot assignment algorithm for optical burst switched networks

“…Thus, the forward and backward processing of the ant in the proposed algorithm adds a complexity of O (2 V 2 ). We observe that time complexity of the proposed algorithm is similar to that of Ant Colony Route and Wavelength Assignment Algorithm (ACRWA) with improved burst loss ratio and delay.…”

“…In Equations and , variables h , j and d denote current node, current output port in consideration and the destination node, respectively. It should be noted that the desirability factor η that depends on f ( y ) does not contain the distance parameter as is the case in . This is a major difference between our work and that work.…”

Blocking performance of a burst-outputted model considering different service rates and different output port-selected probabilities in an optical burst switching core node

“…Such an assumption makes it easy to establish the burst-outputted model in an OBS core node, but it ignores the difference of the service rates of network interface units (NIUs) 2,3 and the difference of output ports-selected rules based on optimal routing algorithms. 4 In fact, according to the general rule of an optimal routing, if there is enough remaining wavelength in a network, it should select a shortest path; it should also increase the probability of selecting a low-load or shortdelay path. The wavelength indicates that a burst will use different probabilities to select output ports that lead to the same destination in an OBS core node.…”