21.   For example, says Warwick, could doctors use neural signals from a healthy person to help someone learn to walk again after an injury that damaged motor functions?

22.   Governments could track innocent people, while criminals hacking into the system could use the signals to home in on targets.

23.   GPS devices use signals from satellites to pinpoint a location anywhere on the globe.

24.   Hackers find it easy to infiltrate wireless networks because they use radio signals that are transmitted at the same frequency as most cordless telephones.

25.   He added the upcoming measurements could help influence debates over the safety of other technologies, like mobile phones, that may soon use phased signals as well.

26.   He plans to lend an infrared accessory to friends so their calculators can communicate using invisible signals.

27.   If the call is being made to another cell phone user, the MTSO contacts the other cell phone using microwave signals.

28.   In addition to cutting prices, the new wireless companies plan to build systems that use digital signals -- the ones and zeros that computers read.

29.   Israel television aired much of the attack live, using a signal from the Arab satellite channel Al-Jezira.

30.   It uses infrared signals to communicate.