HAMNET Report 13 January 2019

Here’s something I’ll bet you never thought you would hear about on a HAMNET Bulletin. The Japan News carried a post this week about frogs! Apparently, regularities seen in the calls of frogs can be used to improve radio communications systems, according to the findings of a Japanese scientific team led by Ikkyu Aihara, an assistant professor at the University of Tsukuba.

The findings were published in the British science journal Royal Society Open Science issued on Wednesday. The mechanism of the behaviour is expected to help avoid so-called packet collisions, a data communication failure in smart-phones and other devices, and could eventually contribute to energy savings.

Packet collisions occur when multiple devices simultaneously emit radio waves that interfere with each other, preventing the sending and receiving of data. The reduction of such collisions is key to improving telecommunication technology.

According to the team’s announcement, the scientists recorded and analyzed the sounds of three Japanese tree frogs. They found that a group of frogs delays, or “trolls,” the timing of their calls so as not to interfere with each other, and the group overall regularly switches between calling together and resting together.

Aihara, who specializes in mathematical biology, noticed the state of frogs’ singing can be likened to the transmissions of wireless communication equipment, and re-created the patterns of their trolling in mathematical formulas. The team used a computer to install the formulas into 100 devices and had them correspond with each other in a simulation.

Devices set next to each other began delaying the timing of their transmissions and avoiding packet collisions, just like the frogs’ trolling. Furthermore, the mechanism of calling in chorus, involving the repetition of simultaneous transmissions and rests, was seen among the devices as a whole. The team also found that the mechanism helped reduce power consumption.

“The sudden increase in IoT [internet of things] devices will cause packet collisions and massive power consumption,” said Keio University Prof. Satoshi Kurihara, who specializes in complex network science. “Many of the mechanisms possessed by living creatures are efficient, and can be useful for developing equipment that is inexpensive and has better energy-saving performance.”

I wonder whether this technique could not be employed by hasty users of our repeaters, to prevent doubling!

News from the medical front concerns the World Health Organisation’s drive to eradicate Polio throughout the world. In that Polio only occurs in humans, and can only be spread from human to human, all that has to be done is to isolate the last human case of Polio on earth, prevent any further spread, and the disease will be eradicated. Who’s Director General, Dr TA Ghebreyesus spent 4 days recently in Afghanistan and Pakistan, the last two countries where Polio cases were reported last year, and he highlighted Who’s commitment to its final eradication.

He said: “We must all give our best on this last mile to eradicate polio once and for all. My wish for 2019 is for zero polio transmission. You have full WHO’s support to help reach every child and stop this virus for good.”

Smallpox was declared eradicated in this way in 1980, after the last case was identified and isolated in Somalia in 1977. Like Polio, Smallpox occurs only in humans, and is transmitted from hand to mouth or by droplet infection from an infected person’s exhaled air. Polio immunisation in children is still given, but Smallpox vaccination is no longer required.

If you’d like to ogle stations of other radio amateurs around the world, consider logging in to the Facebook group called “Ham Radio Show and Tell” launched by Kevin Duplantis W4KEV in Tennessee. As you’d expect, it is a site to show off your shack, mobile installation, or anything ham radio that you’re proud of. So let’s see who’s going to be the first South African to feature the station he is proud of.

On Friday evening, the Southern Coast of the Western Cape was suddenly faced with three massive and very fast-moving fires. From videos seen, it even looked as though the intensity of the fire had generated firestorms, intense winds which further fanned the flames. There was a forecast for strong South-Westerly winds, and the fire and the wind seemed to combine to worsen the disaster.

Fires had been burning around the Southern tip of Africa ever since New Year’s eve, and fire-fighters have been fighting and monitoring hotspots ever since. Suddenly, on Friday evening, three fires flared up, and within hours, about 50 houses had been destroyed, countless vehicles burnt out, and entire coastal villages evacuated. Franskraal was badly affected, as well as Betty’s Bay, and suburbs of Hermanus ordered to be evacuated, as the flames neared them.

Grant Southey ZS1GS, Regional Director for HAMNET Western Cape ordered a net to be established amongst available operators in the Peninsula, and along the coast as far as Hermanus, in case help was required. Some areas consumed in the fires had lost power due to damage to wiring, and the possibility of no communications was rearing its head.

Very swiftly, some ten amateurs were to be heard on the 145.600 MHz repeater on Sir Lowry’s Pass, and HF comms were established on 80m. By about 21h00 on Friday evening, the chatter on the repeater had died down, and so had the fires a bit, thanks to some life-saving rain along the coast, which helped to dampen the strength of the fire.

Unfortunately the 145.725MHz  repeater outside Hermanus is not within range of the Peninsula operators, and the UHF link with the 145.600MHz repeater is unserviceable at present, so no contact was directly possible with Hermanus amateurs. Callsigns heard on 80 and 2 metres included ZS1DDK, ZS1SBM, ZS1KP, ZS1PDE, and ZR1FR, and ZS1OR and ZS1TR were also heard on 2 metres. Thank you to you all for being available. Thankfully, you were not needed.

Saturday’s social media were full of pictures and videos of the raging inferno. So far, no lives have been lost and the Overstrand Fire Authorities are reporting that the fires are under control and being monitored.

This is Dave Reece  ZS1DFR  reporting for HAMNET in South Africa.