Reliable network connectivity is one of the major design issues in the context of wireless sensor networks. These networks have diverse communication patterns due to non-uniform sensing activities at various locations in the environment being monitored. In such scenarios, some nodes lying in high-traffic zones may consume more energy and eventually die out resulting in network partitioning. This gives rise to a situation in which alive nodes are trapped in a disconnected cluster, and they do not have enough radio range to communicate their data to the destination (i.e. a sink or a relay node connected to the main part of the network). This phenomenon may deprive a large number of alive nodes of sending their important time-critical data to the sink. In this article, we propose a virtual antenna–based cooperative beamforming approach for retrieving valuable data from these disconnected nodes. In the proposed approach, the sensor nodes in an isolated partition work together to form a directional beam. This directional beam significantly increases their overall communication range to reach out to a distant relay node which is connected to the main part of the network. The proposed approach of cooperative beamforming–based partition connectivity is more effective when a cluster with a favorably large number of nodes gets partitioned. Furthermore, a beamforming-based mechanism is proposed for a disconnected cluster to locate the nearest relay node which is still connected to the sink and to reconnect itself to the main part of the network via the most adjacent relay node for time-critical data transmission. The proposed mechanism is then evaluated through simulation results.

中文翻译：

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在分区无线传感器网络中连接断开的集群以进行时间关键数据收集

可靠的网络连接是无线传感器网络环境中的主要设计问题之一。由于被监测环境中不同位置的非均匀传感活动，这些网络具有不同的通信模式。在这种情况下，一些位于高流量区域的节点可能会消耗更多能量并最终消亡，从而导致网络分区。这会导致出现以下情况：活动节点被困在断开连接的集群中，并且它们没有足够的无线电范围将其数据传送到目的地（即连接到网络主要部分的接收器或中继节点）。这种现象可能会导致大量活动节点无法将其重要的时间关键数据发送到接收器。在本文中，我们提出了一种基于虚拟天线的协作波束成形方法，用于从这些断开连接的节点中检索有价值的数据。在所提出的方法中，隔离分区中的传感器节点一起工作以形成定向波束。这种定向波束显着增加了它们的整体通信范围，以到达连接到网络主要部分的远程中继节点。当具有大量节点的集群被分区时，所提出的基于协作波束成形的分区连接方法更有效。此外，提出了一种基于波束成形的机制，用于断开连接的集群定位最近的中继节点，该中继节点仍连接到接收器，并通过最相邻的中继节点将自身重新连接到网络的主要部分，以进行时间关键的数据传输。