Kinetic wireless mesh networks for mining and process operations

March 14th, 2014, Published in Articles: EngineerIT

 

Kinetic wireless mesh networks enable communications and data acquisition in mobile environments such as mining operations, which are constantly changing and expanding. This wireless infrastructure is able to maintain reliable and seamless communication.

Typical services required in mobile mining environments are dispatch systems, fatigue monitoring, ground probe radar, condition monitoring, fleet management, drill management system, global positioning system (GPS), vital information management system (VIMS), 2-way radio communication repeater site and video streaming. When considering the technology and product selection for wireless mobile networks, the following has to be taken into consideration: mobility (changing environment); capacity (throughput); reliability (network uptime); adaptability (tolerant of change); sustainability (effort needed to maintain); extensibility (ability to scale and upgrade, future proof); integration (insure applications play nice with one another); data security (keep intruders out); quality of service (prioritise data traffic).

Fig. 1: Rajant kinetic wireless mesh network with multiple wireless radios on different frequencies, all active and all forwarding traffic with a fully connected mesh topology – (not just backhaul and access point node – but all haul).

Fig. 1: Rajant kinetic wireless mesh network with multiple wireless radios on different frequencies, all active and all forwarding traffic with a fully connected mesh topology – (not just backhaul and access point node – but all haul).

There are typically different ways to provide wireless mesh networks and there has to be a clear distinction on what a wireless mesh network has to provide. The definition of mesh networks according to Wikipedia: “A mesh network is a network topology in which each node (called a mesh node) relays data for the network. All nodes cooperate in the distribution of data in the network.”A mesh network can be designed using a flooding technique or a routing technique. When using a routing technique, the message is propagated along a path, by hopping from node to node until the destination is reached. To ensure all its paths’ availability, a routing network must allow for continuous connections and reconfiguration around broken or blocked paths, using self-healing algorithms.

A mesh network whose nodes are all connected to each other is a fully connected network. The self-healing capability enables a routing based network to operate when one node breaks down or a connection goes bad. As a result, the network is typically quite reliable, as there is often more than one path between a source and a destination in the network.”

Fig. 2: Rajant can utilise the LAN on any number of connections to send traffic as soon as possible from wireless networks across high speed LAN networks to assist in traffic flow and congestion of wireless networks.

Fig. 2: Rajant can utilise the LAN on any number of connections to send traffic as soon as possible from wireless networks across high speed LAN networks to assist in traffic flow and congestion of wireless networks.

The other type of wireless network technology works on the principle of a wireless distribution system (WDS) is a system enabling the wireless interconnection of access points in an IEEE 802.11 network. It allows a wireless network to be expanded using multiple access points without the traditional requirement for a wired backbone to link them.

A wireless distribution system (WDS) access point can be either a main, relay, or remote base station.

  • A main base station is typically connected to the (wired) Ethernet.
  • A relay base station relays data between remote base stations, wireless clients, or other relay stations; to either a main, or another relay base station.
  • A remote base station accepts connections from wireless clients and passes them on to relay stations or to main stations. Connections between “clients” are made using media access control (MAC) addresses.

WDS may also be considered a repeater mode because it appears to bridge and accept wireless clients at the same time (unlike traditional bridging). However, with the repeater method, throughput is halved for all clients connected wirelessly.

Fig. 3: Coal mine in South Africa with a self-sustained solar mobile  repeater node fitted with four-radio kinetic mesh node  to extend the coverage for open pit area.

Fig. 3: Coal mine in South Africa with a self-sustained solar mobile
repeater node fitted with four-radio kinetic mesh node
to extend the coverage for open pit area.

Each technology works on a different form of system to do the calculation and establishment of the links, and is typically controlled by a controller. The controller manages and calculates the different paths, to either form a per-hop-based calculation to the controller, and so creates a tree structure and not a true mesh structure. Wireless manufactures have typically adopted this approach due to the technology available, and have had to redesign it be like a mesh network. Some vendors also create radios with dedicated backhaul link and then use the other radios for client access. This is why not all systems and technologies provide a true fully connected mesh network.

Technology provider Rajant has designed the complete technology from the ground up for mobility and is a true fully connected mesh network as described above. The company also uses the term kinetic wireless mesh, as this refers not only to the mobility or any physical change in a true fully connected mesh network, but has to provide for a constantly changing environment in mining operations, such as where multi devices can be in motion; new nodes can be added; nodes can be removed or switched off due to shift changes, maintenance or power failure; there is no single point of failure, nor single controller. Each node has to be able to change on the function required, i.e. it has to accomplish all roles required (main base station, bridge, router, Gateway, backhaul, access point, client – and with all radios performing this function simultaneously without loss of data). The local area network (LAN) should be utilised so as to load balance mesh traffic across, making use of the bigger pipe of the LAN and for changing from one LAN node to another LAN node for redundancy.

Fig. 4: First Quntime Mineral mines in Zambia. Lieber shovel loading Hitachi truck, both fitted with four-radio kinetic mesh node operating in open  pit area that covers over 27 km2. Response time below 10 ms.

Fig. 4: First Quntime Mineral mines in Zambia. Lieber shovel loading Hitachi truck, both fitted with four-radio kinetic mesh node operating in open pit area that covers over 27 km2. Response time below 10 ms.

The following are changes or motions that can occur in the mining operation: changing radio frequency environment due to noise or interference; change in LAN environment; congestion in wireless mesh network; and tracking of mobile equipment with GPS connected to the radio – hence the term “kinetic wireless mesh network”.

Sectors that could benefit from the kinetic wireless mesh network include: mobile haul trucks, drills, shovels etc.; stackers and reclaimer; slope monitoring systems and spreaders; railway carts and container movement areas; military, public health and safety; public transport; shipping yards; oil and gas; and any area where there is mobile wireless communication and data acquisition is a requirement.

Contact Raine Sadie, Scanrf Projects, Tel 012 665-5020, rajant-ee@scanrf.co.za

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