Costas C. Constantinou

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In this paper, on-body propagation modelling has been investigated applying various numerical computational techniques. Propagation measurements with body-worn antennas have been carried out at 2.4GHz inside and outside an anechoic chamber respectively for narrowband communication channel characterisation. Both simulation and measurement results have been(More)
This paper presents EARA-QoS, a improved version of swarm-intelligence inspired ad hoc routing algorithm EARA introduced in (Z. Liu et al., 2004). In this algorithm, we use the principle of swarm intelligence to evolutionally maintain routing information. The biological concept of stigmergy is used to reduce the amount of control traffic. A light-weight QoS(More)
This paper presents EARA-CG, an improved version of a swarm-intelligence ad hoc routing algorithm EARA introduced in the work of Z. Liu et al. (2004). Based on the understanding of the evolutionary cooperation in the biological swarm, we use the principle of swarm intelligence to reinforce good quality routes with only local communication. The concept of(More)
In this paper a review of recent research in characterizing on-body wireless channels is presented. Path gain random variations caused by body movements in various environments have been investigated at several frequencies, including 2.45 GHz and 5.8 GHz. In a scattering environment, such as an office, the fading of on-body channels was found to undergo a(More)
This paper presents a novel swarm intelligence inspired routing algorithm (EARA) for mobile ad hoc networks. Based on the understanding of the evolutionary cooperation in the biological swarm, which provides an alternative solution resilient against changes in the dynamic environment, We use the principle of swarm intelligence for the reinforcement of(More)
The two-dimensional (2-D) parabolic equation (PE) is widely used for making radiowave propagation predictions in the troposphere. The effects of transverse terrain gradients, propagation around the sides of obstacles, and scattering from large obstacles to the side of the great circle path are not modeled, leading to prediction errors in many situations. In(More)
A natural hierarchical framework for network topology abstraction is presented based on an analogy with the Kadanoff transformation and renormalisation group in theoretical physics. Some properties of the renormalisation group bear similarities to the scalability properties of network routing protocols (interactions). Central to our abstraction are two(More)
Existing routing and broadcasting protocols for ad-hoc networks assume an ideal physical layer. In reality, an accurate representation of physical layer is required for analysis and simulation of multi hop networking in sensor and ad-hoc networks. This paper describes the model for the lognormal correlated shadow fading loss from the first principles of(More)
The connectivity of the Internet at the Autonomous System level is influenced by the network operator policies implemented. These in turn impose a direction to the announcement of address advertisements and, consequently, to the paths that can be used to reach back such destinations. We propose to use directed graphs to properly represent how destinations(More)