Wireless network refers to any type of computer network that uses wireless infrastructure (usually, but not always radio waves) for network connections. It needs network components such as Wi-Fi adapter, wireless router / modem, etc.,
Wireless PAN (Personal Area Network)
Wireless LAN (Local Area Network)
Wireless Mesh Network
Wireless MAN (Metropolitan Area Network)
Wireless WAN (Wide Area Network)
Cellular Network (Mobile Network)
Wireless Sensor Network
A wireless sensor network (WSN) consists of spatially distributed autonomous sensors to monitor physical or environmental conditions, such as temperature, sound, pressure, etc.
The WSN is built of "nodes" – from a few to several hundreds or even thousands, where each node is connected to one (or sometimes several) sensors.
Each such sensor network node has typically several parts: a radio transceiver with an internal antenna or connection to an external antenna, a microcontroller, an electronic circuit for interfacing with the sensors and an energy source, usually a battery or an embedded form of energy harvesting.
The topology of the WSNs can vary from a simple star network to an advanced multi-hop wireless mesh network.
WSN Network Topologies:
WSN nodes are typically organized in one of three types of network topologies.
Star topology- star topology, each node connects directly to a gateway.
Cluster tree network- cluster tree network, each node connects to a node higher in the tree and then to the gateway, and data is routed from the lowest node on the tree to the gateway.
Mesh networks- mesh networks feature nodes that can connect to multiple nodes in the system and pass data through the most reliable path available.