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The performance of a Mobile Ad hoc Network (MANET) is closely related to the capability of the implemented routing protocol to adapt itself to unpredictable changes of topology network and link status. The Optimized Link State Routing (OLSR) protocol is a one key of the proactive routing protocols for MANETs. It is based on the multi-point relays (MPRs) technique to reach all nodes in the network with a limited number of broadcasts. In this paper, we propose new versions of the original OLSR protocol based on a new mobility parameter, in the goal to enhance and adapt it in the presence of the mobility. For this objective we define new three criterions for MPRs selection. The first criteria take for selection, just the mobility of nodes at one-hop. The two others criterions are based on both mobility of nodes at one-hop and two-hops

Purpose – This paper aims to demonstrate that a policy-based middleware solution which facilitates the development of context-aware applications and the integration of the heterogeneous devices should be provided for ubiquitous computing environments. Ubiquitous computing targets the provision of seamless services and applications by providing an environment that involves a variety of devices having different capabilities. These applications help transforming the physical spaces into computationally active and smart environments. The design of applications in these environments needs to consider the heterogeneous devices, applications preferences and rapidly changing contexts. The applications, therefore, need to be context-aware so that they can adapt to different situations in real-time. Design/methodology/approach – In this paper, we argue that a policy-based middleware solution that facilitates the development of context-aware applications and the integration of the heterogeneous devices should be provided for ubiquitous computing environments. The middleware allows applications to track items and acquire contextual information about them easily, reason about this information captured using different logics and then adapt to changing contexts. A key issue in these environments is to allow heterogeneous applications to express their business rules once, and get the preferred data once they are captured by the middleware without any intervention from the application side. Findings – Our middleware tackles this problem by using policies to define the different applications’ rules and preferences. These policies can specify rules about the middleware services to be used, type of data captured, devices used, user roles, context information and any other type of conditions. Originality/value – In this paper, we propose the design of a flexible and performant ubiquitous computing, and context-aware middleware called FlexRFID along with its evaluation results.

Radio Frequency Identification (RFID) has been used since the Second World War to identify “friend or foe” aircrafts. It has become an enabling wireless technology that is widely used in a number of application areas, such as product tracking through manufacturing and assembly, inventory control, and supply chain management (SCM). By 2006, Wal-Mart used RFID for all of its suppliers. The use of RFID in supply chain networks has allowed Wal-Mart to create value through greater visibility in its networks, higher product velocity, reduce human error and labor cost, and more efficient inventory management, which led to the achievement of Quick Response (QR) and improved Customer Relationship Management (CRM) in the supply chain. However, RFID system challenges and uncertain Return-On-Investment (ROI) must be overcome to fully achieve these objectives. This paper introduces RFID technology and its key components and concepts, and presents an RFID middleware solution called FlexRFID that achieves the maximum benefits of RFID technology independently of the interested backend applications. This paper illustrates how RFID technology is used to solve the main problems in SCM, the advantages and key issues when implementing RFID in SCM networks, and the relationship between RFID and the main SCM processes.