The paper introduces a new secure power aware many-to-many routing protocol for wireless sensor and actuator networks. Actuators register for sensing data and sensor nodes send data directly to actuators using the proposed protocol. The protocol has two versions. The first version is designed for networks where every node transmits at the same power level. The second version is for the case where nodes can individually adjust the transmission power according to the channel conditions and communications distance. The protocol increases energy efficiency and prolongs network life-time while still keeps the communications secure. Copyright © 2012 John Wiley & Sons, Ltd.

A new scheme of service oriented architecture for federating services provided by multiple clouds as one application is introduced. Service federating inter-cloud application configuration requires selecting a set of services from various clouds such that the user preferences and constraints are satisfied. This configuration process is defined as a multi criteria design problem with posterior articulation of preferences. An efficient scheme for the configuration of a service federating inter-cloud application is also presented. The experimental results prove the feasibility of our new scheme.

Wireless sensor networks (WSN) have many security and safety applications. Wireless sensor networks for pipeline security, border security and blue force tracking are among the emerging WSN security applications. These are heterogeneous systems where various kinds of sensing, surveillance, networking and command/control (C2) technologies are integrated. They are based on the deployment of a large number, i.e., hundreds of thousands, of unattended nodes for extended time periods. The nodes can be in a distance of several hours from physical reach. Some parts need to be deployed and redeployed rapidly, and rely on battery power on board. Therefore, scalability, fault tolerance and power awareness are critical factors influencing their design.

A new secure power aware many-to-many routing protocol for wireless sensor and actuator networks is introduced. The protocol has two versions. The first version is designed for networks where every node transmits at the same power level. The second version is for the case where nodes can individually adjust the transmission power according to the channel conditions and communications distance. In both versions, actuators are registered for sensed data, and every intermediate node that relays registration messages authenticates them through an efficient and secure protocol. When sensor nodes have data, they are sent directly to the actuators registered for that type of data by using a secure many to many routing protocol.

The quarantine region scheme (QRS) is introduced to defend against spam attacks in wireless sensor networks where malicious antinodes frequently generate dummy spam messages to be relayed toward the sink. The aim of the attacker is the exhaustion of the sensor node batteries and the extra delay caused by processing the spam messages. Network-wide message authentication may solve this problem with a cost of cryptographic operations to be performed over all messages. QRS is designed to reduce this cost by applying authentication only whenever and wherever necessary. In QRS, the nodes that detect a nearby spam attack assume themselves to be in a quarantine region. This detection is performed by intermittent authentication checks. Once quarantined, a node continuously applies authentication measures until the spam attack ceases. In the QRS scheme, there is a trade-off between the resilience against spam attacks and the number of authentications. Our experiments show that, in the worst-case scenario that we considered, a not quarantined node catches 80 percent of the spam messages by authenticating only 50 percent of all messages that it processes

Anti-nodes deployed inside a wireless sensor network can frequently generate dummy data packets that make the nodes relaying them deplete their energy. Especially the nodes closer to the sink fail sooner, because they convey more data packets. This causes the sink to be disconnected from the sensor network. The counter-measures for this type of attacks, namely spam attacks, should consider that the sensor nodes have limited energy, computational power and memory. In this paper, we propose detect and defend against spams (DADS) scheme. In DADS the vicinity of the detected malicious node is notified about the quarantine region, and nodes do not relay unauthenticated messages coming from a node in the quarantine region. Our experiments show that our scheme fits the requirements of the sensor network.

A new group of end-to-end reliable event transfer schemes is introduced for sensor networks. In these schemes, reliable event delivery is considered rather than reliable delivery of data packets, since the ultimate goal is the detection of events in sensor networks. Reliable event transfer is critical in many applications. Therefore, the need for transferring the events in a reliable way coerced us to introduce a new group of end-to-end event transfer schemes, in sensor networks end-to-end reliable event transfer schemes can be categorized into two broad classes, as acknowledgement based and non-acknowledgement based. Our new schemes introduced in this paper are in acknowledgement based class. The performance of the proposed schemes is also evaluated for various application areas by simulation.

A new scheme is developed for optimal location area design in wireless systems. New algorithms based on intercell traffic prediction and traffic-based cell grouping are used to select the optimal set of cells for location areas (LAs). The expected intercell movement patterns of mobiles are determined by using the new intercell traffic prediction algorithm. Further, the cells are partitioned into LAs by applying the new traffic-based cell grouping algorithm where the cell pairs with higher intercell mobile traffic are grouped into the same LA. Hence, the inter-LA mobile traffic is decreased by increasing the intra-LA mobile traffic. Experimental results show that this cell grouping algorithm reduces the number of location updates by 27 percent to 36 percent on average compared to proximity-based cell grouping schemes.

The user mobility pattern (UMP) scheme is introduced for location update and paging in wireless systems where mobile terminals (MTs) maintain their history data in a database called user mobility history (UMH). During a location update, a UMP is derived from UMH and registered to the network. Unless the MT detects that it has moved out of the registered UMP, it does not perform any other location update. On the other hand, cells are paged selectively according to the cell entry times in the registered UMP upon a call arrival for the MT. The related data structures and the protocols for the UMP scheme are presented in the paper. The experimental results show that the UMP scheme outperforms the time-based and movement-based location update schemes as well as the blanket, selective, and velocity paging schemes.

Personal mobility and terminal mobility which are viable through wireless access to communication networks are the most fundamental goals of personal communication services (PCS). The technology needed for the wireless access in PCS networks is generally provided by the cellular networks and intelligent networks (IN). In cellular networks, the wireless mobile terminals (WMT) communicate with base stations (BS) which convey the messages among the WMTs and switching centers (SC). SCs and BSs are usually wired to the upper layers of the communication network. In this paper, we briefly review PCS and then propose an algorithm which determines the number of SCs and the BSs attached to the determined SCs in a network for which BS information together with the traffic requirements are given. While the algorithm produces these solutions, it also satisfies some constraints determined by the network designers such as the maximum capacities and the minimum utilization for the SCs.