The "active radar" tagging gadgets are being designed to help staff control children on class trips and stop them leaving school grounds.
Each pupil is tagged and teachers have a pager-style device which tells them how far away they are. The tracking radar beeps if children go beyond a set distance, though the first devices will not tell staff on trips exactly where the children have gone.
However, when the devices are set up in schools they could be used to stop tagged children walking out of the grounds or into restricted areas.
A prototype has been developed by the High Wycombe-based technology company Microwave Designs, which is consulting schools on the system.
Nigel Gaylard, the company's technical director, said he hoped to trial the technology in a Birmingham school in April 2004 and begin selling next summer.
The tags were mainly for primary and nursery-aged children, he said, and staff would be alerted if pupils removed them. Mr Gaylard said the system was partly inspired by recent press stories about deaths on school trips.
"I am a parent and I think most reasonable parents would like that extra security," he said.
"In schools you can set up different zones so, for instance, you could receive alerts if children in Year 3 walked into the laboratory when they were not supposed to be there."
Mr Gaylard said he had been pleased by early feedback from schools on the devices, which are expected to cost around pound;10 for the tags and around pound;20 to pound;30 for the teachers' units.
But Chris Keates, deputy general secretary of the National Association of Schoolmasters Union of Women Teachers, said she could not see how the device would prevent accidents or indicate if pupils were in danger.
Meanwhile the civil rights group Liberty said it feared that such radar systems could become a part of everyday life in the classroom.
Barry Hugill, Liberty spokesman, said: "I can see why the devices might be useful on a school trip. What is much more scary is if they become part of schools' policy."
Schools can take part in online consultation on the devices, and enter a prize draw to win pound;500, by visiting the website.