Seamless Infrastructure independent Multi Homed NEMO Handoff Using Effective and Timely IEEE 802.21 MIH triggers

Handoff performance of NEMO BS protocol with existent improvement proposals is still not sufficient for real time and QoS-sensitive applications and further optimizations are needed. When dealing with single homed NEMO, handoff latency and packet loss become irreducible all optimizations included, so that it is impossible to meet requirements of the above applications. Then, How to combine the different Fast handoff approaches remains an open research issue and needs more investigation. In this paper, we propose a new Infrastructure independent handoff approach combining multihoming and intelligent Make-Before-Break Handoff. Based on required Handoff time estimation, L2 and L3 handoffs are initiated using effective and timely MIH triggers, reducing so the anticipation time and increasing the probability of prediction. We extend MIH services to provide tunnel establishment and switching before link break. Thus, the handoff is performed in background with no latency and no packet loss while pingpong scenario is almost avoided. In addition, our proposal saves cost and power consumption by optimizing the time of simultaneous use of multiple interfaces. We provide also NS2 simulation experiments identifying suitable parameter values used for estimation and validating the proposed mode

STUDY OF MOBILITY AND QoS OF 802.11 AND 802.11e WIRELESS LAN STANDARDS

Quality of service (QoS) is a key problem in wireless environments where bandwidth is scarce and channel conditions are time varying and sometimes implies highly packet losses. IEEE 802.11b/g/a wireless LAN (WLAN) are the most widely used WLAN standards today, and the IEEE 802.11e QoS enhancement standard exists and introduces QoS support for multimedia applications. This paper presents a class based admission control algorithm for 802.11e based wireless local area networks . The strengths of our admission control is dynamicity and flexibility of the algorithm, which adapts to the situation of the BSS, like global load, number of best effort AC, and position of QSTA by report of QAP. Thus it achieves higher throughput than other admission control for 802.11 e. A summary of many good solutions on admission control for 802.11e is be done, and the model of our admission control is presented. The 802.11e standard starves the low priority traffic in case of high load, and leads to higher collision rates, and did not make a good estimate of weight of queues, so there is an unbalance enters the flows with high priorities. A discussion is presented in detail using simulation-based evaluations, with an aim of comparing results of our admission control algorithm, with the 802.11e standard and the FHCF algorithm. Results reveal an improvement of the network load and a decrease of the number of collisions

Securing vehicular cloud networks

Vehicular Cloud Networks (VCN) is the network that ensures mobility and availability of resources allowing new services and applications like Network as a Service (NaaS), STorage as a Service (STaaS), Computation as a Service (CompaaS) and Cooperation as a Service (CaaS). In this paper, we propose a solution to secure the Vehicular Cloud Network (VCN). Our challenge in this work is to adapt the PKI architecture, which is mainly used in wired networks to be used in VCN. To propose a security solution for Vehicular Cloud Networks (VCN), our work is based on three steps; the first one is to make network architecture study, where we tried to highlight the main network components. The second step is to propose the security solution architecture. Finally, the last step is to program a test and validate the solution using a simulation

QoS Routing RPL for Low Power and Lossy Networks

Energy conservation, while ensuring an adequate level of service, is a major concern in Low power and Lossy Networks (LLNs), because the nodes are typically deployed and are not replaced in case of failure. Several efforts have recently led to the standardization of a routing protocol for LLNs. The standard provides several criteria that can be used as a routing metric. The working group RoLL of the IETF developed a routing protocol for 6LoWPAN sensor network (IPv6 over IEEE 802.15.4) (Ko et al., 2011), RPL, recently standardized. Using this protocol could become common and standard in IPv6 sensor networks in the future. Most implementation of the protocol makes use of the transmission rate successfully (ETX) as metric and focuses on the reliability of links. In this paper we present the use of the residual energy and the transmission delay as routing metric in the next hop selection process for the RPL protocol. We design an objective function for this metric based on ant colony optimization (ACO), and then we compare the results of experiments realized with the RPL based on ETX