Mijeong Hoh

Bio-Inspired Routing Protocol Based on Pheromone Diffusion in Mobile Ad Hoc Networks

Bio-inspired routing protocols use the principle of swarm intelligence, which finds the optimal path to the destination in a distributed and autonomous way in dynamically changing environments; therefore, they can maximize the routing performance, reduce the control overhead, and recover a path failure quickly according to the change in the network topology. In this paper, we propose a bio-inspired routing protocol for mobile ad hoc networks. The proposed protocol uses a technique of overhearing for obtaining routing information without additional overhead. Through overhearing, a pheromone is diffused around the shortest path between the source and the destination. On the basis of this diffused pheromone, a probabilistic path exploration is executed and the useful alternative routes between the source and the destination are collected. Therefore, the proposed routing protocol can gather up-to-date effective routing information while reducing the control overhead. The simulation results show that the proposed routing protocol outperforms the typical ad hoc on-demand distance vector (AODV) and AntHocNet protocols in terms of the delivery ratio and the end-to-end delay and significantly decreases the routing overhead against AntHocNet.

Tactical MANET architecture for Unmanned Autonomous Maneuver Network

A MANET is a self-configuring ad hoc network that could be very useful for battlefield communication. Because of its versatility, Tactical Mobile Ad-hoc NETwork (MANET) is also widely used by modern military units especially for the autonomous maneuvering of unmanned vehicles and robots. But Quality of Service in Tactical-MANET is difficult because the network topology changes dynamically. The resource allocation scheme of MAC layer and load balancing of network layer can be critical factors in Tactical MANET. Without a QoS scheme, users might have difficulties in getting their service in Tactical MANET. In this paper we present the architecture of the MAC and Network layers of tactical MANET for Unmanned Autonomous Maneuver Network in order to provide better communication support in battlefield. It aimed to provide real-time streaming over a multi-hop ad hoc network with QoS support. The simulation results are presented to demonstrate the effectiveness of proposed scheme.

Traffic-aware adaptive routing metrics for tactical ad hoc networks

In tactical environment, MANET (Mobile Ad Hoc Network) has the network characteristics which make highly dynamic nodes, self-organized in fully-distributed style. Also, it has a harsh wireless channel environment compared to the commercial networks. In these channel environments, optimal path decision suited for Quality of Service (QoS) of transmitted tactical traffics must be performed by recognizing various environmental factors of wireless channels and the status of tactical mobile radio nodes autonomously to construct reliable communication links. In this paper, we newly define the required QoS features of tactical traffics and the characteristics of routing metrics in tactical network environment. We also propose a new ad hoc routing algorithm to ensure an efficient communication in tactical environment by calculating the optimal path using adaptive selection of routing metrics according to traffic characteristics. Simulation results show that the proposed algorithm outperforms existing ad hoc routing schemes, especially when tactical network has a high mobility and a high traffic load.

Active buffer management algorithm for silence suppressed voice applications

This paper proposes silence drop first algorithm(SDF) for the active buffer management. This algorithm finds and drops silence packet rather than talkspurt packet in the queue for resolving buffer overflow of queue. This algorithm can serve more simultaneous user while maintain voice service quality with same link capacity. Simulations with voice codec of G.711 and G.729a are performed in this paper. The simulation results shows that SDF can serve more users than drop-tail and drop-head, whose are general active buffer management algorithms for voice application used in commercial and military router. By using proposed SDF algorithm, the voice capacity is increased by 84.21% with G.729a and 38.5% with G.711. Also, SDF algorithm loosens the silence packet inter-arrival time limit to service target number of users.