Cleon
Legend
If you just give different critters different broadcasting ranges, that would do the trick. Suppose robot A has broadcasting range 10 miles and B has range 5 miles and they're 8 miles apart. Maybe something like
Radiospeech (Ex): A creature with this ability can communicate verbally with any other creature that also has this ability within range. Any creature with this ability within range hears the radio speech, so it is possible to address many creatures at once using radiospeech, although maintaining a conversation with more than one creature at a time is just as difficult as simultaneously speaking and listening to multiple people at the same time. Radiospeech cannot penetrate 10 feet of stone or wood, three feet of water, or an inch of metal. Since radiospeech relies on words, two creatures must understand the same language to communicate by radiospeech. Some items can listen to or broadcast radiospeech, allowing creatures without this ability to participate in radiospeech conversations.
Then just list it in the SQ line as "radiospeech X miles."
Hmm, I'm not liking the first couple of sentences very much. The "with this ability" seems needlessly coy.
How about...
Radiospeech (Ex): A creature with this ability can broadcast a radio communication as an emanation with a radius up to the listed range (the creature can use less than its maximum range if it wishes to). All creature with radiospeech that are within range hears the communication, so it is possible to address many creatures at once using radiospeech, although maintaining a conversation with more than one creature at a time is as difficult as speaking with multiple people simultaneously. Radiospeech cannot penetrate 10 feet of stone or wood, three feet of water, or an inch of metal. Radiospeech relies on words, so two creatures must understand the same language to communicate by radiospeech. Some items can listen to or broadcast radiospeech, allowing creatures without this ability to participate in radiospeech conversations.