“Three blocks that way,” Alan said, pointing. “Hanging off my house. The network name is ‘walesave.’”
“Shit, that’s you?” the kid said. “Goddammit, you’re clobbering our access points!”
“What access point?”
“Access points. ParasiteNet.” He indicated a peeling sticker on the lapel of his cut-down leather jacket showing a skull with crossed radio towers underneath it. “I’m trying to get a mesh-net running though all of the Market, and you’re hammering me. Jesus, I was ready to rat you out to the radio cops at the Canadian Radio and Television Commission. Dude, you’ve got to turn down the freaking gain on those things.”
“What’s a mesh-net?”
The kid moved his beer over to Alan’s table and sat down. “Okay, so pretend that your laptop is the access point. It radiates more or less equally in all directions, depending on your antenna characteristics and leaving out the RF shadows that microwaves and stucco and cordless phones generate.” He arranged the coffee cup and the beer at equal distances from the laptop, then moved them around to demonstrate the coverage area. “Right, so what happens if I’m out of range, over here—” he put his beer back on his own table—"and you want to reach me? Well, you could just turn up the gain on your access point, either by increasing the power so that it radiates farther in all directions, or by focusing the transmissions so they travel farther in a line of sight.”
“Right,” Alan said, sipping his coffee.
“Right. So both of those approaches suck. If you turn up the power, you radiate over everyone else’s signal, so if I’ve got an access point here"—he held his fist between their tables—"no one can hear it because you’re drowning it out. It’s like you’re shouting so loud that no one else can carry on a conversation.”
“So why don’t you just use my network? I want to be able to get online anywhere in the Market, but that means that anyone can, right?”
The crusty-punk waved his hand dismissively. “Sure, whatever. But what happens if your network gets shut down? Or if you decide to start eavesdropping on other people? Or if someone wants to get to the printer in her living room? It’s no good.”