Base Stations in Wireless Sensor Networks
Wireless sensor networks are playing a more significant role in daily life, sending data from different locations of wireless and wired communications networks. Of course, all of these different sensor nodes require power, and the efficient use of network energy requires a delicate balance between sending and receiving sensor data and switching times to and from the various parts of the wireless network.
Fortunately, work is being done on how to effectively accomplish data transmissions in these wireless sensor networks without compromising energy efficiency, at the same time following the guidelines set by the IEEE 802.15.4 standard. The novel handover approach was modeled with commercial mathematical simulation software. It has been found to provide the necessary performance for timely switching and data transfer while also saving power compared to conventional handover schemes.1. The diagram shows an edge node beacon frame.
All wireless sensor networks suffer some node switching delays; the challenge in improving performance is to reduce power consumption while also diminishing those delays. Unfortunately, a great deal of energy is consumed when switching sensor data among different Personal Area Networks (PANs), and an effective and efficient handover scheme must handle multiple-node systems while reducing power consumption.
The proposed new handover scheme takes advantage of the fact that cellular base stations can manage over PAN in a wireless network and use the cellular network to control the handovers of wireless sensors. By managing the PANs in the larger cellular network—and setting “edge nodes” at the edges of the PANs in order to send signals to associated user equipment when handovers occur—mobile wireless sensors need only scan a target channel to realize efficient handovers.
Edge nodes are static sensor nodes which distribute data in overlapping areas between two PANs (Fig. 1). They are used for mobile nodes to provide warnings at these edges of a network, and they are equipped with strong communication capabilities (such as routing nodes). When edge nodes are determined by a cellular base station, they will send a special beacon frame to notify mobile nodes located in PAN edge areas. The beacon frame is defined in part by the selection of the edge node.
When a wireless sensor network is established, every PAN coordinator in the network has access to the locations and topologies of the nodes and can send related messages to a cellular base station controlling the network. The base station saves the information and determines which are edge nodes for the PANs in the full network. If changes are made to the network or PANs, a PAN coordinator can send new channel and topology information to help base stations stay current with the network conditions.2. This flow chart depicts an efficient handover scheme for wireless sensor networks.