A key consideration when designing IoT networks is the topology of the networks. There are two principal types of networks that are used in design of IoT related networks: star and mesh.
In a star network topology, all nodes are connected to one central node, which is typically the gateway to the Internet. A commonly used Wi-fi network is where the central node is called the access point and the connected nodes are called stations. Star networks are characterised by transfer of large data blocks, fast interconnect speeds, and quick response times.
On the other hand, a star network that uses Bluetooth for example, can only support a limited number of nodes. The cost of scaling and building redundancy within a star network is relatively expensive.
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In a mesh network, every node is connected to each other. Out of the multiple nodes inside such local networks, a few of them act as Internet Gateways and relay data into and out off, the local proprietary network to the Internet. Since the process of communication is a large number of small hops, the speed of communication into and out of a local mesh network is relatively slow. They are also more complex to design than star networks.
On the other hand, mesh networks provide multiple internal paths for movement, require small amounts of power to transmit and compute, and can add nodes relatively easily. Hence, they are relatively less expensive to build, highly scalable and also highly redundant.