1768220
A biologically inspired QoS routing algorithm for mobile ad hoc networks
This paper presents EARA-QoS, a improved version of swarm-intelligence inspired ad hoc routing algorithm EARA introduced in (Z. Liu et al., 2004). In this algorithm, we use the principle of swarm intelligence to evolutionally maintain routing information. The biological concept of stigmergy is used to reduce the amount of control traffic. A light-weight QoS scheme is proposed to provide service-classified traffic control. The simulation results show that this novel routing algorithm performs well in a variety of network conditions.
8433230
A biologically inspired congestion control routing algorithm for MANETs
This paper presents EARA-CG, an improved version of a swarm-intelligence ad hoc routing algorithm EARA introduced in the work of Z. Liu et al. (2004). Based on the understanding of the evolutionary cooperation in the biological swarm, we use the principle of swarm intelligence to reinforce good quality routes with only local communication. The concept of stigmergy is adopted to reduce the amount of control traffic. By locally monitoring the network transmission queue and other MAC layer information, this algorithm can forward data traffic through paths that avoid network hotspots. The data traffic influences routing table updates at each node. We also discuss an evaluation methodology to simulate ad hoc networks, and the simulation results show that this novel routing algorithm scales well to a variety of network conditions.
6908345
A swarm intelligence routing algorithm for MANETs
This paper presents a novel swarm intelligence inspired routing algorithm (EARA) for mobile ad hoc networks. Based on the understanding of the evolutionary cooperation in the biological swarm, which provides an alternative solution resilient against changes in the dynamic environment, We use the principle of swarm intelligence for the reinforcement of optimal routes with only local communication (here, local communication is defined as neighbourto-neighbour one only). The data traffic is influenced at each node, and the communicating nodes observe this influence to update their tables. We also include an evaluation, and the simulation results show that this routing algorithm scales well to a variety of network conditions.
9219349
Flexible Secure Multicasting in Active Networks
In this paper we describe an alternative, flexible approach to multicast security in active networks. Traditional schemes for securing multicast communication have key management and scalability problems for many typical applications. In addition, traditional mechanisms are not capable of expressing flexible, situational security policies for multicast sessions and participants. Our scheme exploits the computational power of active networks to provide dynamic, flexible security for multicast applications. One of the main advantages of our scheme is the low communication and key distribution overhead associated with multicast group management. Our approach is based on the Seraphim security architecture implementation, which uses active capabilities for access control. Seraphim is an extensible, reconfigurable security architecture that is flexible and accommodates a wide variety of security policies and mechanisms. It also provides applications and users the ability to create dynamically and enforce highly customized and situational policies. Using these policies we have developed several secure multicast applications that demonstrate the flexible nature and low overheads associated with our architecture.
2853015
On the capacity of hybrid wireless networks
This paper involves the study of the throughput capacity of hybrid wireless networks. A hybrid network is formed by placing a sparse network of base stations in an ad hoc network. These base stations are assumed to be connected by a high-bandwidth wired network and act as relays for wireless nodes. They are not data sources nor data receivers. Hybrid networks present a tradeoff between traditional cellular networks and pure ad hoc networks in that data may be forwarded in a multihop fashion or through the infrastructure. It has been shown that the capacity of a random ad hoc network does not scale well with the number of nodes in the system. In this work, we consider two different routing strategies and study the scaling behavior of the throughput capacity of a hybrid network. Analytical expressions of the throughput capacity are obtained. For a hybrid network of n nodes and m base stations, the results show that if m grows asymptotically slower than √n, the benefit of adding base stations on capacity is insignificant. However, if m grows faster than √n, the throughput capacity increases linearly with the number of base stations, providing an effective improvement over a pure ad hoc network. Therefore, in order to achieve nonnegligible capacity gain, the investment in the wired infrastructure should be high enough.
15986830
A formal semantics of UML sequence diagram
We present a formal semantics of UML sequence diagram. In abstract syntax form, a well-formed sequence diagram corresponds to an ordered hierarchical structure tree. The static semantics of a sequence diagram is to check whether it is consistent with the class diagram declaration as well as with its well-formed tree structure. Meanwhile, the dynamic semantics is defined in terms of the state transitions that are carried out by the method invocations in the diagram. When a message is executed, it must be consistent with system state, i.e., object diagram and the state diagrams of its related objects. The semantics clearly captures the consistency between sequence diagram with class diagram and state diagram. Therefore, it is useful to develop the model consistent checking functions in UML CASE tools. And it also can be used to reason about the correctness of a design model with respect to a requirement model.
14922920
A dynamic trust model for mobile ad hoc networks
This paper introduces a trust model for mobile ad hoc networks. Initially each node is assigned a trust level. Then we use several approaches to dynamically update trust levels by using reports from threat detection tools, such as intrusion detection systems (IDS), located on all nodes in the network. The nodes neighboring to a node exhibiting suspicious behavior initiate trust reports. These trust reports are propagated through the network using one of our proposed methods. A source node can use the trust levels it establishes for other nodes to evaluate the security of routes to destination nodes. Using these trust levels as a guide, the source node can then select a route that meets the security requirements of the message to be transmitted. This paper demonstrates important concepts for establishing a collaborative, dynamic trust model and for using this model as an example to enhance the security of message routing in mobile ad hoc networks.
7323063
rCOS: Refinement of Component and Object Systems
We present a model of object-oriented and component-based refinement. For object-orientation, the model is class-based and refinement is about correct changes in the structure, methods of classes and the main program, rather than changes in the behaviour of individual objects. This allows us to prove refinement laws for both high level design patterns and low level refactoring. For component-based development, we focus on the separation of concerns of interface and functional contracts, leaving refinement of interaction protocols in future work. The model supports the specification of these aspects at different levels of abstractions and their consistency. 
 
Based on the semantics, we also provide a general definitional approach to defining different relational semantic models with different features and constraints.