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—In this paper, the IEEE 802.16 protocol is investigated with respect to the bandwidth provision problem arising at the Medium Access Control (MAC) layer. The aim is to optimally tune the resource allocation to match QoS requirements. Traffic flows are originated at network layers overlying the 802.16 protocol stack. This leads to the investigation of a(More)
SUMMARY Designing efficient transmission mechanisms for advanced satellite networks is a demanding task, requiring the definition and the implementation of protocols and architectures well suited to this challenging environment. In particular, transport protocols performance over satellite networks is impaired by the characteristics of the satellite radio(More)
—This paper considers a packet-based telecommunica-tion network architecture suited to be used as an Environmental Monitoring System (EMS) over wide areas. It can be employed to retrieve the measures of physical quantities, such as temperature, humidity, and vibrations intensity (physical information) together with the geographical position where the(More)
The paper proposes two alternative bandwidth allocation schemes suited for the Ka-band satellite environment. The aim is to provide a control mechanism to compensate rain fade. The main idea is considering the effect of the attenuation as a reduction of the bandwidth 'seen' by a single land station and using a supplementary portion of bandwidth to guarantee(More)
| Satellite communications are characterized by long delays, packet losses, and sometimes intermittent con-nectivity and link disruptions. The TCP/IP stack is ineffective against these impairments and even dedicated solutions, such as performance enhancing proxies (PEPs), can hardly tackle the most challenging environments, and create compatibility issues(More)
The paper contains a proposal about the design and implementation of an on-board satellite packet-switching emulator. The paper lists the requirements of the emulator that have been followed for the design and that will represent the guidelines for the implementation of the features not yet concluded. The characteristics of the emulator architecture are(More)
—The letter contains the formulation of an analytical expression of the Transmission Control Protocol (TCP) packet loss probability over geostationary satellite channels on the basis of the state-of-the-art in the field. The expression obtained is function of the bandwidth available and is suited to be used in control mechanisms. It is compared with the(More)
—Two criteria are proposed to characterize and improve suboptimal coordinate-convex (c.c.) policies in Call Admission Control (CAC) problems with nonlinearly-constrained feasibility regions. Then, a structural property of the optimal c.c. policies is derived. This is expressed in terms of constraints on the relative positions of successive corner points.
—This paper presents a performance enhancing transport architecture for the satellite environment. This solution improves the network transport performance by overcoming the limits imposed by a transmission control protocol/Internet protocol (TCP/IP)-based stack suite, while maintaining the interfaces offered by it. This is an important issue since TCP/IP(More)