Inter-cluster Routing Research Articles

An Information Management Protocol to Control Routing and Clustering in Sensor Networks

In this paper, we develop and analyze a novel clustering protocol, Decentralized Energy Efficient cluster Propagation (DEEP), that attempts to manage the communication of data while minimizing energy consumption across the sensor networks. We also develop an Inter-Cluster Routing protocol (ICR) that is compatible with the proposed clustering technique. DEEP takes advantage of the multi-rate capabilities of 802.11a, b, g technologies by elevating the data rate to higher levels for shorter transmission ranges. This approach reduces the energy consumption by lowering the transmission time. Protocol DEEP starts with an initial cluster head and gradually forms clusters throughout the network by controlling the geographical dimensions of clusters and distribution of cluster heads in order to conserve energy and prolong network lifetime. Furthermore, due to the balanced load, protocol overhead caused by unnecessary frequent re-clustering is eradicated. Our simulation results demonstrate that DEEP distributes energy consumption approximately 8 times better than an existing clustering scheme, LEACH. In addition, DEEP substantially reduces total data communication and route setup energy consumption in the network compared to LEACH.

Providing interoperability between IEEE 802.11 and Bluetooth protocols for Home Area Networks

We present a cluster-based low-complexity routing algorithm for self-organizing networks of mobile nodes called FRANCA. The proposed algorithm allows mobile nodes to autonomously create clusters to minimize the power consumption. We maintained our proposal as simple as possible also providing it with robustness and auto-recoverability properties to allow nodes reconfiguration to be simple and fast. FRANCA is implemented as two separate protocols: the intra-cluster data-dissemination protocol and the inter-cluster routing protocol. These protocols allow integrating IEEE 802.11 and Bluetooth networks providing interoperability among mobile devices. We present a sensitivity analysis of the overall protocol architecture by varying the critical factors related to protocol behavior and we show that, in general, FRANCA implementation allows up to 25% of energy saving while keeping the overhead extremely low.

A Link-cluster Route Discovery Protocol for Ad Hoc Networks

In MANETS, node mobility induces structural changes for routing. We propose a route discovery algorithm for MANET based on the link-cluster architecture. The algorithm selects the clusterheads and gateway nodes, and then builds routing tables for nodes both inside and outside the cluster. The algorithm attempts to minimize the number of clusterheads and gateway nodes to avoid storing redundant data. For intra-cluster routing, the shortest paths are maintained. For inter-cluster routing, we implement routing on-demand (the shortest paths are maintained only for the nodes that need to send packets). The proposed algorithm adapts to arbitrary movement of nodes, and joining and/or leaving of existent nodes.

Non-uniform cellular packing of the stratum corneum and permeability barrier function of intact skin: a high-resolution confocal laser scanning microscopy study using highly deformable vesicles (Transfersomes).

Novel, functional skin staining with fluorescent, ultradeformable lipid vesicles (Transfersomes, IDEA, Munich, Germany) was developed and combined with confocal laser scanning microscopy. This revealed the structural and barrier characteristics of intact skin to a resolution of > or = 0.2 micron, that is, to the limit of light microscopy. Different routes of penetration into the stratum corneum were visualized and new details in the skin anatomy and barrier were unveiled. Most prominent was the lateral inhomogeneity of the stratum corneum, where three to 10 neighbouring corneocyte 'columns' were found to form a cluster. Corneocyte edges inside each cluster intercalated extensively, but adjacent clusters were separated by 'gorges' a few micrometers deep; lipid packing was also less regular and tight in the intercluster region. Two quantitatively different hydrophilic pathways were found in the horny layer: an intercluster route with low penetration resistance comprising < or = 1% of the total or < or = 20% of the pathway area in the skin, and an intercorneocyte pathway that resists penetration better and is more abundant (> or = 3% of the skin or > or = 80% of the pathway area). This latter route is strongly tortuous, as it goes between all the corneocytes in a cluster. It traces the irregularities between the intercellular lipid lamellae and/or the adjacent corneocyte envelopes which may act as virtual channels in the skin. It was inferred that such channels coincide with the route of water evaporation through the skin and exhibit the permeability barrier maximum in the stratum corneum conjunctum.

WICI: an efficient hybrid routing scheme for scalable and hierarchical networks

Many recent supercomputers employ either a cluster-based design or a highly scalable network. Clustering is built-in in a hierarchical system, while highly scalable networks like mesh or torus could be easily partitioned into modules to form several clusters. This paper first specifies a self-routing connection method in a recently introduced class of hierarchical topology called de Bruijn-Cube (dBCube) network, and presents a deadlock-free routing scheme using virtual channels. A new switching method called Wormhole Intracluster Cut-through Intercluster (WICI) routing is also introduced to improve the network performance fairly close to the virtual cut-through and to maintain the buffer cost as compared to prevalent routing schemes of wormhole. Usefulness of WICI routing has been demonstrated for the hierarchical network of dBCube and large networks like mesh and torus, and simulation results for WICI routing are compared with wormhole and virtual cut-through routings.