Mesh topology definition
In a network based on mesh topology, all the network nodes, in this case – IoT devices, work together to distribute and transmit data to the destination in the network. Mesh topology is typically used for massive IoT applications, including facility management, industrial automation and smart metering.
How does mesh topology work?
A Mesh IoT network is a local network topology, in which the connected devices, including the end-points and Edge devices connect directly, dynamically and in a non-hierarchic way to multiple devices to co-operate, according to a pre-defined protocol to route data across the network. Ideally, none of the devices in a Mesh IoT network is dependent on only one other device. This allows for each device to participate in the relay of data.
What is full mesh topology?
In Full Mesh Topology, all the devices are connected to the other devices in the network.
What is partial mesh topology?
In Partial Mesh Topology, some of the devices can be connected in a full-mesh setup, however, some devices can be connected to only one or two other devices.
Routing vs. Flooding mesh techniques
Mesh networks can relay messages by using – either a routing technique or a flooding technique. In mesh routing, which is the most used technique, a message is propagated along a path by hopping from device to device, until it reaches the edge device, or other destination. However, not all routing techniques are created equally.
To ensure that all its paths are available, the network must allow for continuous connections and must reconfigure itself around broken paths, done by using self-healing algorithms such as Shortest Path Bridging. Self-healing allows a routing-based network to operate when a device becomes unavailable. This means that, a Mesh IoT network is typically very reliable, as there are more paths between a source and a destination in the network.
In flooding, instead of using a specific route for sending a message from one node to another – the message is sent to all the devices in the network, including those to whom it was not intended.
Mesh topology – advantages and disadvantages
The most of the commonly-used Mesh IoT network protocols can dynamically self-organize and re-configure, which reduces deployment overheads, simplifies network planning and ultimately, saves costs.
The self-configuration capability enables for the dynamic distribution of data transmission and computing load, especially if a device should fail or overload. Mesh IoT networks are fault-tolerant systems with low maintenance costs.
Unlike star and point-to-point topologies, which are well established, standardized IoT protocols with compatibility between vendors; Mesh IoT protocols do not provide common standards, or interoperability between devices of different vendors. This can be considered as a disadvantage of Mesh Topology.
List of the four most popular mesh iot protocols
Here is a list of the most commonly used Mesh IoT Protocols.
Wirepas Mesh Networking
Wirepas wireless mesh protocol is developed for low-power IoT applications. Wirepas is a fully decentralized meshed technology and network architecture. All the devices in a Wirepas network are homogenous and make the routing decisions locally based on the present radio circumstances. An unlimited number of Wirepas enabled devices can be connected in a network. Wirepas can be licensed for many commercial off-the-shelf radio SOCs (System on a Chip) and can use standard LPWA radio technologies, such as Bluetooth Low Energy. Find out more about Wirepas Mesh at our IoT Connectivity Garage.
Zigbee Mesh Topology
Zigbee mesh topology allows the relaying of data between the Zigbee devices to carry data over long distances.
There are three types of nodes in a Zigbee mesh network: they are coordinators, routers and end devices. Each Zigbee network requires one coordinator; which is a device responsible for forming the network and routing traffic. After a network is formed, the coordinator adopts the capabilities of a Zigbee router, which acts as an intermediate node relaying data from other devices. A router never goes into a sleep mode. Routers can also be a Zigbee end device
End devices can only communicate with parent nodes, i.e. the coordinator or routers. Zigbee end devices are very power-efficient devices, and can enter Sleep mode to save energy. Each parent node can serve up to 20 Zigbee end devices.
Zigbee is an open standard with interoperability between vendors. Find out more about Zigbee protocol at our IoT Connectivity Garage.
Google Thread Mesh Network
Google’s Thread is a mesh networking protocol designed to universally connect Smart home devices. Unlike Mesh IoT protocols Zigbee and Z-Wave, Thread doesn’t require a hub device. Thread enabled devices connect to each other without a single point of failure. The system is capable of automatically re-configuring, should a device become unavailable. Thread technology is aimed to become an open, vendor-agnostic and interoperable Mesh technology. It uses open standards like IPv6 and a 6LoWPAN foundation. Details about Google Thread protocol can be found at our IoT Connectivity Garage.
Bluetooth Low Energy mesh networking is based on the Flooding technique. The simple and reliable message relay technique is optimized for low-power wireless mesh networks, which requires high scalability to carry large amounts of multicast data traffic. Bluetooth LE devices talk to each other using messages and a publish/subscribe mechanism. Bluetooth LE mesh networking scales to cover very large areas by allowing some of the devices in the network to be designated “relays”. These Relay devices retransmit messages that they receive from other devices. A message can be relayed over up to 127 hops. Details about Bluetooth Low Energy protocol can be found at our IoT Connectivity Garage.