Direct meassure 3G or WiFi signal

view story

http://androidforums.com – Hi Is it possible to direct measure the signal strength (in DBm) of one phone from another phone (for 3G or WiFi, not a tower or AP)? There are a lot of apps on the Play measuring nearest tower or AP strength, but I wish to detect if there is another phone in the room just based on its transmitting signal. For example it is possible for BT, but is it for 2G/3G.. or WiFi? Tnx (General)