More Wireless Woes: Ideas, Readers?

Following up on last month’s wireless interference writeup, I’ve got a baffling situation to run by you all. Several months back, I installed two 802.11b-supportive webcams, a DCS-1000W and a DCS-5300W (both made by D-Link), at our weekend getaway. Until a few weeks ago, I had no problem reliably pairing them with the router, which originally was also made by D-Link (a DI-524). The DCS-1000W is at the front of the house, a few dozen feet and two wooden walls away from the router. The DCS-5300W is also a few dozen feet from the router but in the opposite direction and, being in the same room, has line-of-sight connectivity to it.

As I noted at the end of May, a month-plus back I swapped out the DI-524 for a Linksys WRT54GC (in the same location as its predecessor) in order to gain access to a DynDNS- and TZO-supported and -blessed DDNS client. At that same time, I also swapped out the Rocketfish 2.4 GHz wireless speaker kit for a 5.8 GHz-based Amphony Model 1520 wireless transmitter-and-receiver set. Again, all seemed to be well….until mid-June, when I added several more seemingly innocuous pieces of gear to the mix: four Black and Decker EX410-2P-TP1 ultrasonic pest repellers (yes, we have mice), installed at various locations in the lower (where the networking gear is also located) and upper floors of the premises.

Now, in spite of supplementing the router with an external antenna and converting the webcams from DHCP to static IP address assignments, I can’t achieve a sustained connection between the router and either webcam for more than a few hours’ duration. After I power-cycle a webcam, it’ll come up fine at first, but inevitably it’ll eventually drop the link. My first thought was that even though the Amphony 1520 operated on 5.8 GHz, and even though webcam link drops occurred even when audio wasn’t playing (and therefore the wireless speaker transmitter shouldn’t be broadcasting), a 5.8 GHz frequency harmonic might be causing problems. But pulling the plug on the Amphony gear hasn’t helped one bit (and a 5.8 GHz frequency harmonic shouldn’t reside within the 2.4 GHz band, anyway).

The most obvious remaining culprits are the Black & Decker pest control units, but here again I’m skeptical. Product documentation suggests that "the frequency ranges from 26-74Khz at 105 decibels in a constant fluctuation", therefore the fundamental frequencies should be nowhere near the 2.4 GHz ISM band where the webcams reside. Could harmonics from the EX410-2P-TP1s really be interfering with the 802.11b webcams? I haven’t noticed any Wi-Fi service degradation between my laptop and the router with the EX410-2P-TP1s plugged in, which further increases my skepticism. But then what else could explain my webcam woes?

Neighbors’ Wi-Fi access points’ signal strengths are weak-to-nonexistent at my premises and don’t broadcast on or overlap with the 802.11b/g channel that my system’s using. And there’s nothing else at my home on the 2.4 GHz band, at least that I can think of, aside from the occasional microwave oven session….I have intentionally installed 900 MHz cordless phones there (and here at the primary home office, as well). I’m probably going to just bite the bullet and convert the webcams to operate on a powerline network, since they both also offer CAT5 connections. And frankly it’s not clear that the ultrasonic pest repellers are having a meaningful effect on our resident rodent population. Regardless, I welcome your insights and suggestions.