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Wireless sensor networks (WSN) including large quantity of small sensor nodes with low-power energy consumption can effectively extend its life-span. However, the performance of WSN is affected by the environment. In this paper, we devise a new multi-hop routing algorithm clustering sensor nodes into groups to minimize the total energy consumption of the WSN. The proposed algorithm optimizes the intensity distribution of the cluster-heads(CHs) when introducing the model of Voronoi-Structure trees. The results of the simulation indicate that our algorithm using optimal parameter is able to prolong the life-span of the networks around 16% compared with low-energy adaptive cluster hierarchy (LEACH) and the whole networks obtain high performance on effective energy consumption.

To conquer the problems existing in access control mechanisms available nowadays, such as how to manage the access authorities of the users and the protected resources, and how to keep the confidential data from visiting and modifying illegally, a new access control mechanism called Multi-Device TBPM-RBAC (MD-TBPM-RBAC) is proposed in this paper. According to the demand for unified users management in the network management system (NMS), MD-TBPM-RBAC uses Role-Based Access Control (RBAC) for the center, and expands the TBPM-RBAC. In MD-RBPM-RBAC, the users, resources and permissions are stored in the remote server, when a user lands, the device will communicate with the server to authenticate and authorize. As the MD-TBPM-RBAC implements the users' unified authentication and authorization, it manages the users centralized, protects the resources effectively, prevents the important resources from visiting illegally, and protects the critical processes from stopping illegally.