GA application with hybrid encoding for QoS routing

Abstract

The search of routes with multiple Quality of Service (QoS) constraints from sources to destinations connected by networks is a Non Polynomial (NP) problem, which can be approached using Genetic Algorithms (GAs). These are heuristic algorithms that simulate the natural evolution process to solve optimization problems. In this paper we elaborate on tree-based GAs which represent the set of paths from source to destination as a tree. While existing GA applications use m-ary or binary encoding representing single paths and classes of paths in chromosomes, respectively, we propose a GA application with hybrid encoding which uses both of them. This application uses binary encoding from the first iteration until good classes of paths are found and later encodes the best paths of these classes with m-ary encoding. Its objective is taking advantage of the fast convergence due to the per class-processing of binary chromosomes and the lower computational cost of the single path processing of m-ary chromosomes. Simulation results show the performance, in terms of convergence speed, of the proposed GA application with hybrid encoding.

Research on Quality of Service Based Routing Protocols for Mobile Ad Hoc Networks

“…GAMAN has better performance in small-sized MANET topologies in which the nodes have lower mobility. GAMAN is an example of how genetic algorithms may be applied to QoS-based routing protocols for MANETs [20].…”

“…Hierarchy improves scalability of the network and reduces message overhead by giving group leadership to some nodes. According to network topology, QoS routing protocols classified under the hierarchical category are: ACMP [5], CEDAR [12], CQMP [13], EHMRP [17], GAMAN [20] HQMRP [23], QMRPD [33] and QOLSR [34]. Nodes can be location aware to retrieve location information of other nodes in the network.…”

“…A hybrid routing protocol is a combination of a proactive and a reactive protocol, taking the best features from each. There are various protocols in the literature that fall under the hybrid routing protocol category: BEQR [11], CEDAR [12], EHMRP [17], GAMAN [20] and PLBQR [32].…”

“…They perform resource reservation and guarantee QoS requirements. AQOR [10], BEQR [11], CEDAR [12], EBR [16], GAMAN [20], HMCOP [21], NSR [31] and TDR [40] are dependent QoS routing protocols.…”

“…Mobility is a big challenge for multi-constrained protocols due to finding the best path with multiple constraints at the same time. Multiconstrained routing protocols are: AAQR [3], ACMP [5], AQOR [10], DSARP [14], EHMRP [17], GAMAN [20], HMCOP [21], HQMRP [23], PLBQR [32], QMRPD [33], QOLSR [34] and TBR [39]. Figure 7 provides a schematic representation of the relations between QoS metrics and QoS-based routing protocols.…”