[Ren Qian]

So I have a relatively new iMac, Macbook and old iBook all using a Wi-Fi internet connect. When I turn turn on or wake the laptops my internet is instant yet my iMac takes a while to get the signal. Now, it's only 30 secs or so but I find it annoying and if I try clicking on Safari etc before it's ready it ends up taking longer. I was just wondering if this is because I use a wireless keyboard and mouse. Would the signals interfere with each other? Does anyone else experience this? I know it's not a big deal but I'm considering going wired anyway because the batteries always seem to be dying on me. Basically if this is indeed the case it may be the extra reason I need to switch over. Thanks.

[ghporter]

Bluetooth and WiFi may share the same "spectrum," but they don't interfere with each other. My own, almost year-old iMac has NEVER had a problem with either of them or both together. On the other hand, when I wake the iMac, it takes a few seconds to find the WIRED network... I don't think it's your BT at all.

[mduell]

Yes, they share the same frequency range, so they can interfere with each other. Upgrade to a 5Ghz 802.11a or n network (assuming your iMac can support either) to avoid the interference.

[ghporter]

While a Bluetooth device may hop to a frequency in use by a WiFi device, and the WiFi device might step to a frequency in use by the BT device, both systems are built such that this should NOT cause interference. A loss of a small bit of data, sure, but not "interference." Bluetooth uses "frequency hopping," a method of multiple devices using a fixed span of frequencies, and it "hops" about 1600 times a second. WiFi uses direct sequence spread spectrum, another "frequency hopping" technology that, instead of bouncing around its span of frequencies in a pseudo-random manner as Bluetooth does, steps from one frequency to the next in a very predictable sequence. This sequence is what we call "channels" in WiFi. Both WiFi and Bluetooth are built to withstand loss of a packet or two here and there without the user even noticing.

The OP's problem is NOT a Bluetooth vs. WiFi issue. If it were, he'd notice that the keyboard and/or mouse gave him problems about as often as he noticed he had WiFi problems. Instead, I think it's something with how the various systems in the newer version of the iMac wake up. As I posted above, my wired connection takes several seconds to "wake up," and I've experienced the same sort of slow waking with the wireless as well.

[dimmer]

This is just FYI: Bluetooth radios come in three types of power -- type 1 (used in all Apple products) has a very low power output and is limited to around 10 feet of range; type 2 is more powerful and can hit around a 25 foot range; type 3 is the most powerful and can hit almost as far as 802.11b range (and mess that up damn well).

Given what you've shared, I doubt the problem is a WiFi / Bluetooth issue, but it may be worth taking the hardware in to a good tech repair place to make sure of that.

[Ren Qian]

Thanks 4 the info everyone.

[vmarks]

Originally Posted by mduell 

Yes, they share the same frequency range, so they can interfere with each other. Upgrade to a 5Ghz 802.11a or n network (assuming your iMac can support either) to avoid the interference.

They do share the same frequency range, but they do not interfere.

I wrote about this ages ago when the BT standard was just being introduced.

"Without going into a lot of
detail that belongs in an
article unto itself, Bluetooth
developers have begun to
research several methods for
getting around, or at least
lessening the worst of the
interference. Some of the
steps being considered are:
Driver-level switching
●
Adaptive frequency
hopping
●
MAC-level switching
●
"
-- me, in IBM's DeveloperWorks way back in 2001.

A better question is, what other signals are going on?
I've used MacStumbler in combination with AirTrafficControl widget to do a rudimentary wireless survey - see what channels other base stations in the area are operating on, and set yours in a channel with less overlap.