On 02/15/2011 05:04 PM, Timothy Murphy wrote: > I'm having terrible problems with my modem/router at the moment. > The WiFi connection on my Thinkpad laptop drops every 10 minutes or so. > I have to restart the network service to get the connection back. > > I'm not sure what exactly wakes the modem/router up when I do this? > I presume some packet my WiFi driver sends has this effect? > > I haven't found anything similar with NetworkManager; > when I restart the NetworkManager service it just says it is re-starting, > but I'm still not connected. > > Windows XP is even worse, as the same thing happens there > and I don't know of any way to re-start the network. > > At least, there is a way with Lenovo's ThinkVantage tools, > which offer a crude map showing visible access points; > and if you click on an access point it tries to connect to that. > > This seems a great idea to me. > Under Fedora, "iwlist scan" lists the access points that are within range; > surely it wouldn't take a guru much time to convert this into a map, > and add an option to click on an access point to connect to it? > > I'm not sure, incidentally, what the position of the AP on the map conveys. > The nearer points correspond to stronger signals, I think, > but I don't know if the position on the circle of that diameter means, > if anything. > > The wireless device on my present Thinkpad T60 laptop is > Intel Corporation PRO/Wireless 3945ABG, with the iwl3945 driver. > > If anyone can throw any light on my problem, I would be eternally grateful. > I assumed the problem was in the outside line to the modem, > but my ISP assures me the line is perfect. > > I tried using another modem (Billion), but it needs a password > and the password my ISP sent me does not seem to work. > (It is their modem.) I work on the IEEE 802.11 standards, so know what follows from working closely with the engineers that build the products. I am a major contributor to 802.11i, and am now working on 802.11ai. I am a security protocol wonk, but am quite conversant with MAC issues, though only know how to filter PHY talk... A VERY common problem with WiFi is channel selection. If 2 APs have overlapping coverage and on the same channel, this can cause a station to drop its connection. You need to use the discovery tools to see what channels are active in your coverage area. Then you need to work with your neighbors so that you are not stepping on each other. Each country has its own specific allowed channels and with 802.11j (or was that 11h? ARGH!) we got smart and it is now table driven. 2.4Ghz has wider coverage, slower speeds, and fewer channels than 5.4Ghz that has more channels, smaller coverage, and higher speeds. Choose your poison. Many users just use the default channel and never change it and are always complaining about lost connections. -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines
