IoT in Africa - Signaling traffic burning up mobile radio resources

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Today in Africa, IoT technology is already being used to help farmers increase their yields, reduce water wastage and prevent overuse of pesticides. Through accurate measurements of insect monitoring, weather and soil moisture, farmers have powerful control over production throughout the growing season. For example, South African farmer Cobus van Coller can view on his computer screen in his cab the precise yield and moisture levels on each part of his field, as his harvester mows down corn stalks.

Other applications such as Silent Herdsman and Moo Monitor can be used by dairy farmers to track cows’ ovulation cycles to ensure that they are inseminated at exactly the right moment to produce as much milk as possible. Cows are not the only animals that are monitored. As part of an effort to protect threatened species, black rhinos in eastern and central Africa are relaying their movements back to anti-poaching teams through signals transmitted from their ankle collars.

Infrastructure needs to keep pace

As the number of rapidly-growing connected devices increases, African operators will need solutions that will enable them to connect more devices using the same infrastructure.

IoT requires that each device send small amounts of data periodically. When the signaling messages related to these data transmissions are added up and multiplied by the number of devices connected to the network, the impact on network congestion is even greater than the increase in data traffic caused by the plethora of mobile devices.

Network applications need to communicate with their devices to determine network status including key information on which parts of the network are congested, the location of the device, its wake-up times, and who has authorised access. The increasingly large number of messages due to state changes on the radio spectrum can result in the inefficient use of resources in both the network and the device, for example:

• Push notifications can be sent to a large number of devices within a small time window, creating huge spikes in signaling and congestion on the radio spectrum.
• Devices can send frequent “keep alive” messages just to ensure the network address translation (NAT) port remains open
• Devices can ping the network every few minutes when unable to connect to the application server

When each of these inefficiencies is multiplied by thousands of devices the extra load on the network can have a negative impact on performance.

Streamlining signaling

The best option is to support more intelligent signaling in order to reduce congestion. Using this approach, inefficiencies with signaling can be eliminated by streamlining and orchestrating the data traffic to reduce the number of signaling messages related to state changes. The sending of unnecessary data control messages can be managed or delayed until there is a more opportune time for transmission.

Signaling can be tweaked to improve network performance. For example, data control messages can be delayed, queued and then transmitted in batches and signaling messages can be balanced over time to prevent bursts.

These optimisation techniques can reduce data signalling events by 5%-15%, reduce RF state changes and save battery life. By influencing traffic flows at the network core the increased efficiency is automatic and all signaling traffic is optimised.

IoT will most likely continue to be used in Africa to better manage water and electricity consumption and to improve agricultural yields. As the number of connective devices grows operators will need to manage the increase in signaling traffic, and orchestrating at the core could be the most practical solution.