Optimization of an Underwater Wireless Sensor Network Architecture with Wave Glider as a Mobile Gateway

This paper presents an original probabilistic model of a hybrid underwater wireless sensor network(UWSN),which includes a network of stationary sensors placed on the seabed and a mobile gateway.The mobile gateway is a wave glider that collects data from the underwater network segment and retransmits it to the processing center.The authors consider the joint problem of optimal localization of stationary network nodes and the corresponding model for bypassing reference nodes by a wave glider.The optimality of the network is evaluated according to the criteria of energy efficiency and reliability.The influence of various physical and technical parameters of the network on its energy efficiency and on the lifespan of sensor nodes is analyzed.The analysis is carried out for networks of various scales,depending on the localization of stationary nodes and the model of bypassing the network with a wave glider.As a model example,the simulation of the functional characteristics of the network for a given size of the water area is carried out.It is shown that in the case of a medium-sized water area,the model of“bypassing the perimeter”by a wave glider is practically feasible,energy efficient and reliable for hourly data measurements.In the case of a large water area,the cluster bypass model becomes more efficient.

A Novel Approach to Reduce Handover Latency in Proxy Mobile IPv6 Based on Multi-Homing

Proxy Mobile IPv6 (PMIPv6) is a network based mobility management protocol. It is proposed by the Internet Engineering Task Force. In PMIPv6 the Mobile Node (MN) need not participate in signalling of mobility. PMIPv6 is a layer 3 protocol. In this paper the issue of layer 3 mobility is resolved by the Enhanced Open Flow Technique (EOFT). Generally, the open flow protocol makes functions on network devices, routers, switches. Open flow controller act as server for network devices to make communication between them. In the proposed EOFT-PMIPv6, the control signalling and mobility is managed by EOFT controller. In PMIPv6, the Mobility Access gateway (MAG) has the responsibility of the control signalling. But in the EOFT-PMIPv6, the responsibility of MAG is done by the EOFT-Controller. In the proposed technique, the mobility management function is isolated from PMIPv6 mechanisms. These isolated mechanisms are combined in the EOFT-Con- troller. This EOFT-Controller satisfies the responsibility of the mechanisms which are separated from PMIPv6. The eminent mobile environment must provide the efficient multi-homing protocols. The proposed technique overcomes the problem of multihoming in PMIPv6. The EOFT-Controller takeover the responsibility of Layer 3 functions. Also, the proposed technique combines with Modified Mobility Access Gateway (M_MAG) and it handles the handover session dynamically. This paper provides the extended architecture of EOFT-PMIPv6 and provide unbeaten handover scheme for multi-homing. The result is provided by systematic analysis based on comparison with PMIPv6 and EOFT-PMIPv6 is obtained.

AN ADVANCED DYNAMIC FEEDBACK AND RANDOM DISPATCHING LOAD-BALANCING ALGORITHM FOR GMLC IN 3G

Based on the system architecture and software structure of GMLC (Gateway Mobile Location Center) in 3G (third generation), a new dynamic load-balancing algorithm is proposed. It bases on dynamic feedback and imports the increment for admitting new request into the load forecast. It dynamically adjusts the dispatching probability according to the remainder process capability of each node. Experiments on the per- formance of algorithm have been carried out in GMLC and the algorithm is compared with Pick-KX algorithm and DFB (Dynamic FeedBack) algorithm in average throughput and average response time. Experiments re- sults show that the average throughput of the proposed algorithm is about five percents higher than that of the other two algorithms and the average response time is four percents higher under high system loading condi- tion.