Giuseppe Razzano

Wireless LANs: an adaptive algorithm to reduce power consumption

A novel radio modem architecture is proposed for a single-hop ad hoc networks (WLAN) providing wireless access to Internet. The system works at 17 GHz, employs OFDM modulation and provides very high bit rate (up to 160 Mbit/s at physical layer) using TDMA access scheme. Network control is centralized and handled by a device (master), which is run-time selected among all the active devices (slaves). The main focus of the paper is to address the power consumption issue, which is a crucial requirement for portable devices. In particular, the paper described the developed MAC procedures and algorithms concerning the interface with physical layer. Simulation trials show that a considerable power saving can be attained without decreasing system performance.

Performance comparison of three call admission control algorithms in a wireless ad-hoc network

Three connection admission control (CAC) algorithms are described and compared via computer simulations by referring to the novel WIND-FLEX wireless LAN, recently developed in the framework of a European IST project. The three CAC solutions employ different strategies to estimate the link utilization, thus giving different performance in terms of number of refused connections and network throughput. The first solution is characterized by reduced complexity by unsatisfactory performance. The other two methods, exhibit much better performance at a reasonable complexity increase. So, they are good candidates for practical applications.

Wireless LANs: an advanced control system for efficient power saving

This paper proposes a novel radio modem architecture for wireless telecommunication networks. The main focus is to reduce the power consumption, which is a crucial requirement for portable devices. In particular, the paper describes a new control architecture which is in charge of properly adapting the transmission power to the links condition by controlling the transmission bit rate and the capacity request scheme. By using fuzzy logic and internal model control, the scheme manages to adapt the bit rate, granting at the same time the reduction of the power consumption and the satisfaction of the Quality of Service requirements.

An efficient power saving mechanism for wireless LAN

In this paper, a novel radio modem architecture for a wireless local area network is proposed. The main focus is to reduce the power consumption, which is a crucial requirement for portable devices. In particular, the paper describes a new control architecture which is in charge of properly adapting the transmission power to the links condition by controlling the transmission bit rate and the capacity request scheme. By using fuzzy logic and internal model control, the scheme manages to adapt the bit rate, granting at the same time the reduction of the power consumption and the satisfaction of the quality of service requirements.

17 GHz wireless LAN: performance analysis of CAC algorithms

The paper deals with measurement-based CAC alternatives applicable to the novel WIND-FLEX architecture, a 17 GHz wireless LAN recently developed in the framework of an European 1ST project. We first present some existing CAC algorithms based on traffic stream measurement. Afterwards, we develop a novel CAC algorithm which is based on queue state measurement. The performance of the different CAC algorithms is then evaluated by extensive simulations. One of the main conclusions from simulative investigations is that our novel CAC algorithm is superior to other ones from the aspects of achievable utilization and parameter robustness. Moreover the proposed solution requires no additional signaling overhead and demands low implementation complexity.

A reduced complexity MAP receiver for digital ISI channels, with application to HF radio links

A reduced-complexity MAP equalizer (RMAP) is proposed, together with an associate channel estimator, where only H channel states having largest probability are adaptively retained over the total of N states, with H/spl Lt/N. For a channel length L, RMAP reduces the complexity from LN to LH. Channel estimator complexity is LH/sup 2/ + HL/sup 2/ instead of LN/sup 2/. Performance analysis shows that P-MAP allows practical applications using state-of-art low-cost DSP devices: this is the case of a HF digital modem recently developed at Marconi Mobile laboratories.

Wireless LANs Systems: An Advanced Resource Assignement Algorithm

The paper describes the design and simulation of a radio modem architecture, which provides wireless access to Internet in a single-hop, ad hoc network.The main emphasis is on the Medium Access Control (MAC) and Dynamic Link Control (DLC) layer’s design, and in particular on the adopted innovative scheduling algorithm, which has been developed to satisfy the system requirements of the WIND-FLEX radio modem. The algorithm is presented and compared to the Earliest Deadline First (EDF) solution.Several software simulation tests have been executed on the network, to test the performance of the system, in order to verify the capability of the scheduler algorithm to satisfy the expected requirements and the efficiency of the implemented solutions.

17 GHz wireless LAN: performance analysis of ARQ based error control schemes

The paper presents the development of ARQ schemes applied to a 17 GHz single-hop ad hoc network, providing very high bit rate. In particular, the paper aims to analyze and compare the performances of different ARQ protocols, in order to outline the most suitable one for a very high bit rate wireless system. Simulation trials show that a reliable error control protocol, realized by means of a proper retransmission strategy, can sensibly reduce the number of transmission errors, thus improving the wireless network overall performances.