-level simulations, we examine various performance and design issues in such protocols. Our analysis leads to a new protocol, MACAW, which uses an RTS-CTS-DS-DATA-ACK message exchange and includes a significantly different backo algorithm.

Network protocols are usually tested in operational networks or in simulated environments. With the former approach it is not easy to set and control the various operational parameters such as bandwidth, delays, queue sizes. Simulators are easier to control, but they are often only an approximate

Questions of belief are essential in analyzing protocols for the authentication of principals in distributed computing systems. In this paper we motivate, set out, and exemplify a logic specifically designed for this analysis; we show how various protocols differ subtly with respect to the required

Mobile devices are battery powered device. But battery is a limited source of energy depend upon their shape .in this paper various protocols and different power management techniques aiming to reduce power consumption mobile devices are describe. Static techniques, applied at design time, have

topology changes. Many protocols have been proposed for MANETs for efficient routing. The primary goal of routing protocols is to establish route with a minimum of overhead and bandwidth consumption. This paper analyses the performance of various protocols for efficiency (in terms of packet loss

T occurs. Fault-tolerant consensus protocols are given for various cases of partial synchrony and various fault models. Lower bounds that show in most cases that our protocols are optimal with respect to the number of faults tolerated are also given. Our consensus protocols for partially synchronous

collection of linear equations for calculating the energy consumed in sending, receiving and discarding broadcast and pointto -point data packets of various sizes. Some implications for protocol design and evaluation in ad hoc networks are discussed. Keywords---energy consumption, IEEE 802.11, ad hoc

Recent advancement in wireless communica- tions and electronics has enabled the develop- ment of low-cost sensor networks. The sensor networks can be used for various application areas (e.g., health, military, home). For different application areas, there are different technical issues

to incorporate individual entities into various information structures, such as aggregate directories that support a variety of different query languages and discovery strategies. These protocols can also be combined with other Grid protocols to construct additional higher-level services and capabilities

indicate that different mobility patterns affect the various protocols in different ways. In particular, the ranking of routing algorithms is influenced by the choice of mobility pattern. 1