S. Louvros

An Alternative Queuing Technique to Optimize the Performance of TDMA Based Mobile Communication Systems

This paper analyses an alternative traffic queuing model for the quality of service (QoS) optimization in mobile communications systems. According to the proposed model, the queue of handover attempts is separated to each of the used transceivers of a base transceiver station that covers a particular area. Fixed channel assignment and TDMA are considered, while the proposed technique is compared to the classic queuing model. The comparison results show that the QoS of the proposed model is fully optimized, especially if large queue sizes are chosen.

Handover Optimization in Wireless Microcellular ATM Networks

Microcellular solutions in wireless ATM networks increase the network traffic control as a result of frequent handover requests. The blocking probability or the forced termination probability presents a quality of service criterion for evaluation of certain handover techniques. This paper presents a handover protocol that can avoid cell loss and guarantee cell sequence, and a two layer wireless call admission control is studied, using Markov state diagrams, in order to optimize the performance of wireless ATM networks.

Study of LED response in optical telecommunication networks using DPWM access technique

Light emitting diodes (LED) are usually the second choice optoelectronic devices for optical communications with moderate bandwidth efficiency and bit rates, compared to semiconductor lasers. Laser applications dominate the long distance communication networks. However considering the cost efficiency, LED seems to be a very good solution, especially in short distance communication networks. From the LEDs response in applied electrical signals, obviously there is a limit in maximum transmitted bit rate, posing an upper boundary in the available amount of information transmitted by LED. The idea of multiple access technique using Digital Pulse Width Modulation (DPWM) is needed in order to cure the weakness of LEDs bit rate efficiency. Combining multiple access with source coding allows the transmission of 4 Mb/s using normal 2 Mb/s PCM line over short distance communication links.