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In mobile ad hoc networks, mobile devices wander autonomously for the use of wireless links and dynamically varying network topology. AODV (Ad-hoc on-demand Distance vector routing) is a representative among the most widely studied on-demand ad hoc routing protocols. Previous protocols have shown some shortcomings on performance. AODV and most of the on-demand ad hoc routing protocols use single route reply along reverse path. Rapid change of topology causes that the route reply could not arrive to the source node, i.e. after a source node sends several route request messages, the node obtains a reply message, especially on high speed mobility. This increases both in communication delay and power consumption as well as decrease in packet delivery ratio. To avoid these problems, we propose a reverse AODV which tries multiple route replies. The extended AODV is called reverse AODV (R-AODV), which has a novel aspect compared to other on-demand routing protocols on Ad-hoc Networks: it reduces path fail correction messages and obtains better performance than the AODV and other protocols have. We design the R-AODV protocol and implement simulation models using NS-2. Simulation results show that the reverse AODV provides good experimental results on packet delivery ratio, power consumption and communication delay.

Currently, the IETF group is working on service differentiation in the Internet. However, in wireless environments such as ad hoc networks, where channel conditions are variable and bandwidth is scarce, the Internet differentiated services are suboptimal without lower layers’ support. The IEEE 802.11 standard for Wireless LANs is the most widely used WLAN standard today. It has a mode of operation that can be used to provide , but it has been shown to perform badly. In this paper, a new scheme of service differentiation to support QoS in the wireless IEEE 802.11 is proposed. It is based on a multiple queuing system to provide priority of user’s flow. Compared with the original IEEE 802.11b protocol, the proposed scheme increases overall throughput in the MAC layer.

We presents a power-aware routing protocol called Multi-Route Transmission Routing that utilizes multiple routes to transmit the data traffic simultaneously and leads to a balanced energy consumption. The proposed routing approach can extend the system lifetime of the network. A new routing decision index is also proposed for the route selection mechanism, which takes both the shortest-path and the maximum system lifetime into consideration and dynamically adjusts its weight between them according to the energy usage of the network. Experiment results show that, the proposed routing protocol provides a higher performance than other well-known power-aware routing protocols in terms of the energy-efficiency.

We propose a novel multicast scheme that can provide quality-of-service (QoS) to multicast service over IEEE 802.11 wireless LANs by utilizing medium access control (MAC) layer relay. It is well known that IEEE 802.11 provides a physical layer multi-rate capability in response to different channel conditions, and hence packets may be delivered at a higher data rate through a relay node than through the direct link if the direct link has low quality and low data rate. We develop the distributed relay node selection algorithm and the relay channel selection algorithm. The effectiveness of proposed scheme is examined by numerical method and simulation. Simulations show that the proposed relayed multicast significantly improves throughput and delay performance.

This paper presents the design of the adaptive concurrency control QOS agent, which is running on RCSM(Reconfigurable Context Sensitive Middleware) for ubiquitous networks. RCSM provides standardized commu-nication protocols to interoperate an application with others under dynamically changing situations. It describes a hybrid software architecture that is running on situation-aware middleware for a web based distance education system which has an object with a various information for each session and it also supports multicasting with this information. There are two approaches to software architecture on which distributed, collaborative applications are based. Those include CACV(Centralized-Abstraction and Centralized-View) and RARV(Replicated-Abstraction and Replicated-View). We propose an adaptive concurrency control QOS agent based on a hybrid software architecture which is adopting the advantage of CACV and RARV for situation-aware middleware.

This paper proposes an efficient end-to-end QoS supporting mechanism in Next Generation Network (NGN) with heterogeneous QoS capability to support ubiquitous and distributed applications. To address this, there should be proper admission control mechanism and adaptive provisioning to sustain end-to-end QoS and maximize network utilization. Resource and Admission Control Subsystem of NGN has unique feature of centralized network resource control rather than other network control protocol system in IP network. By showing optimal flows in heterogeneous QoS capability network, NGN can support average delay of end-to-end which the applications could receive proper Quality of Service over network.

Radio Frequency Identification (RFID) systems are increasingly becoming accepted for many EPC Network applications. However, RFID systems have some privacy problems. In this paper, a system for missing child location tracking in the EPC Network applications, is proposed. The proposed system improves security and privacy compared to existing applications, while also keeping in line with traditional procedures, commonly accepted by most industrial applications. The proposed MCLT (Missing Child Location Tracking) system can protect users’ privacy while providing location tracking of the RFID tag.

The ability to recognize many tags simultaneously is crucial for many advanced RFID-based applications. The tag anti-collision algorithm of an RFID system, which arbitrates collisions on the air interface among tags in the same reading range of a reader, makes a great influence on the speed and the reliability in multiple tag recognition. This paper presents a new memoryless tag anti-collision algorithm, QT-CBP (Query Tree with Collision Bit Positioning), which is designed based on QT (Query Tree) algorithm. QT-CBP is likely to make more concise tree traversal than QT by extracting and making use of detailed information on a collision condition, such as the number of collision bits and their positions. Basically QT-CBP is an enhanced algorithm for readers running QT, so no change is required at tags. Simulation study shows that QT-CBP outperforms QT, especially on the condition where tags have similar tag IDs by having the same company or product ID prefixes.

Grid computing and pervasive computing have rapidly emerged and affirmed as paradigms for high performance computing and for user-friendly computing respectively. These two separate worlds, however, can now interact each other in such a way that both pervasive and grid computing communities can benefit from integrating the two paradigms into a whole. This conjunction is already taking place to yield the model, and the present paper is focused on this approach. Purposely, it describes an Access&Location service for pervasive grid applications which uses RFID and WiFi technologies to grant access and locate mobile objects within a pervasive environment. Since this service is compliant to the OGSA specifications, it can be easily integrated into classic grid environments, therefore enhancing them with pervasive capabilities.

A framework for the autonomous management of large-scale ubiquitous sensor networks called SNOWMAN (SeNsOr netWork MANagement) is proposed in this paper. In large-scale ubiquitous sensor networks, a huge number of sensor nodes are deployed over a wide area and long distances and multi-hop communication is required between nodes. So managing numerous ubiquitous sensor nodes directly is very complex and is not efficient. The management of large-scale ubiquitous sensor networks therefore must be autonomic with a minimum of human interference, and robust to changes in network states. The SNOWMAN is responsible for monitoring and controlling ubiquitous sensor networks based on policy-based management paradigm. It allows administrators to simplify and automate the management of ubiquitous sensor networks. It can also reduce the costs of managing sensor nodes and of the communication among them using a new hierarchical clustering algorithm.