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In future wireless ad hoc networks, transactions are expected to become one of the primary types of flows. Transactions require only a small number of packets to complete. Hence, providing optimal (shortest path) routes to such transactions consumes more energy than the actual data transfer. Conventional shortest path routing protocols are, thus, unsuitable for routing transactions. In this paper, we present a novel architecture, called TRANSFER, for transactions routing in large-scale wireless ad hoc networks. In our approach, we aim to reduce the total energy consumption by transactions as opposed to finding shortest path routes. Our architecture uses a hybrid approach, in which each mobile node obtains information about nodes in its proximity (zone), up to R hops away, using a proactive link-state protocol. Beyond the proximity, we introduce the novel notion of contacts that act as shortcuts to reduce the degrees of separation between the source of the transaction and the destination. We propose an efficient on-demand protocol for contact selection that does not assume knowledge of location information. Contacts are used during transactions and queries to discover valid routes in an energy-efficient manner. Extensive simulations are used to evaluate the performance of our protocol in terms of energy consumption and success rate. We compare our architecture to flooding, dynamic source routing (DSR), zone-routing protocol (ZRP), and two power-aware schemes. Our results show substantial power savings for our contact-based protocol, especially for large ad hoc networks. Index Terms--Adhoc networks, contact-based architecture, energy efficiency, network simulation, routing protocol.

A novel hybrid routing protocol - the Two-Zone Routing Protocol (TZRP) as a non-trivial extension of Zone Routing Protocol is proposed. TZRP uses two different zones to decouple the protocols ability to adapt to traffic characteristics from the ability to adapt to mobility.

The ATM VP-based leased line network communication demands varied combination of configurations that link the routes to the actual facilities. An integer programming formulation of the problem and an algorithm to solve it are proposed. It is proved that an algorithm can be used to solve problems with small computing lines.

A novel, efficient and low cost start-up and restart synchronization approach for TDMA environments is presented by focusing on bus-based communication protocols. The approach utilizes information about a node's message length that forms a unique sequence to achieve synchronization such that communication overhead can be avoided.

Different static and dynamic schemes are explored to select the virtual lanes for outgoing messages and mix the load among them without restricting any particular type of message to be carried only by a particular virtual network. In addition, the network latency, the number of message buffers per virtual lane, and the depth of network interface output queues affect the relative performance of various virtual lane selection algorithms are examined.

A self-stabilizing asynchronous phase synchronization protocol for uniform unidirectional rings is presented. Provided that K and b satisfy the limitation K x b > n(b-1), the proposed protocol is correct under the parallel model and takes at most 2(K x b) rounds to stabilize.

There was generally a significant relationship between the hypothesized mediators and perceived learning for online courses. Studies indicate that outcomes of online courses improved when professors structured them to support the growth of a learning community, by being available online to interact with students, and by using collaborative learning strategies.

A new transmission protocol that uses a joint lossless-source and channel coding scheme (JARQ) is introduced. The protocol is evaluated by analyzing its throughput, and simulation results are presented that compare the throughput achieved with this protocol with that of conventional ARQ protocols.

Negotiation protocols almost define simple contracts consisting of one or a few independent issues. A simulated annealing-based approach, a refined version based on a parity-maintaining annealing mediator and an unmediated version of the negotiation protocol is presented.

The bulk synchronous task-scheduling problem (BSSPO) is known as an effective task scheduling problem for distributed-memory machines. A proof of NP-completeness of the decision counterpart of BSSPO is presented.

Protocols are proposed to achieve mutual anonymity in a peer to peer (P2P) file-sharing environment.

The correct operation of the CANopen protocol relies on the assumption that each node in the network be identified uniquely. To this extent, the CANopen specifications provide a means to remotely configure the addresses of the slave devices attached to the CAN bus. This technique, however, requires that each device has to be connected separately to a configuration tool. CANopen, in fact, does not have a mechanism to identify, in an efficient and reliable way, the nodes that do not have an associated address when they have already been connected to the network. In this paper, we present a new automatic node discovery protocol, which is able to eliminate such drawbacks. Our technique can be used to identify the nonconfigured nodes directly in the final system and is conceived as an extension of the basic layer setting services of CANopen, so as to provide a very good degree of compatibility with the existing devices. Index Terms--Communication protocols, Controller Area Network (CAN), field buses, industrial control, manufacturing automation.

An energy-efficient routing protocol for the single-channel, p-station Broadcast Communication Model (BCM) is described.

This paper describes a lab project in computer communications and networks for senior undergraduate students in computer science and engineering. Given detailed specifications, students are asked to implement a data link layer (DLL) that integrates correctly with other provided layers to obtain a complete working network stack. This lab gives the students the opportunity to learn how to read formal specifications for a network project and write a complete piece of source code. It provides a comprehensive environment for students to write software for a network protocol, test and debug it, and observe its working behavior. In this paper, the authors present a technical description of the project and a discussion of related educational issues. Index Terms--Computer communications and networks education, data link layer (DLL), network architecture, network protocols, open systems interconnection (OSI) reference model.

Users interested in high-end microcomputers should become familiar with the ever-flowing river of acronyms in order to keep abreast of technological developments. Both the original modified frequency modulation (MFM) and the newer run length limited (RLL) data coding sequences are compatible with the IBM ST-506 hard disk system (HDS), for instance. Both MFM and RLL became obsolete with the advent of the small computer systems interface (SCSI) and enhanced small device interface (ESDI). Other terms, such as seek time, explain the various measures of hard disk performance.