We really did open our gates to Brics VIPs: Sandton residents suspect signal jammers to blame for disruptions

Residents of Parkmore and parts of Sandhurst in Sandton had to endure several days of disruption in their suburbs this week when home alarms went off and gates and garage doors opened randomly.

Johannesburgers also had the novelty of a South African Air Force Gripen plane protecting the airspace over the Sandton Convention Centre where delegates were attending the Brics summit.

WhatsApp groups were abuzz and security guards were on the hop.

It's highly likely signal jammers used by security teams for visiting dignitaries were to blame for the unusual phenomenon affecting home security systems, according to a defence expert and residents.

“As much as everyone enjoyed having a fighter jet flying over and all the police around, it wasn’t enjoyable from the security risk of tampering with radio transmitters or frequency,” said Parkmore Community Association security oversight manager Lori Klein.

Different types of garage doors and gates opening willy-nilly were affected so it was not a specific manufacturer's fault.

“It started going crazy on Tuesday. Gates and garage doors were randomly opening and closing. Security companies received more than 100 calls of this type. Some people also have sensors on the gate so when it opens a few times it sends a signal to the security company [for a call-out],” she said.

“People are at work and the next minute, security is calling you, saying your garage or gate is open and asking what is going on. It is a concern when these types of things are going on and no one is around,” she said. 

Guy Martin, editor of DefenceWeb, said jammers are designed to jam signals commonly used in communications, such as cellphones, and to detonate explosive devices from a remote location. Security forces use broad-spectrum signal jammers to disable all nearby frequencies.

“It is common practice for security personnel to jam a range of frequencies to interrupt radio and cellphone communications, as well as devices that could be used to trigger explosives,” he said.

“Brics security details on the ground would have jammers covering a large number of frequencies that could certainly affect house alarms and remote controls that operate gates.”

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