After I got my Asus RT-N16, I flashed it with Tomato USB right away. All of its functions work as expected but I found its wireless signal is not stable. My X61 shows its signal strength jumps around from 40% to 80% and my wife became to complain the voice quality of my IPEVO Skype phone. But it works under daily use and I can't find any solution other than some one brought up this issue a while ago. Therefore, I just ignore this problem and try to live with it because I need QoS and Access restriction badly and don't want to switch back to my old wireless router (AximCom) that I got from Taiwan three years ago.
I have a Brother 4040CN with Ethernet port, my PC without wireless adapter and some Cisco gears for my own lab. In order to access them with my other computers, I used an old Buffalo WHR-HP-G54 running Tomato as the Wireless Ethernet Bridge. They are located in another room with some interferences from my neighbors. Overall, everything works fine until I got a recertified Netgear WRN3500L. I hope the 802.11n with WDS or Wireless Ethernet Bridge between RT-N16 and WNR3500L can deliver better throughput. When the WNR3500L runs in WDS mode, the connection is extreme unstable. Whenever I changed any wireless parameters to see any difference, I found I have to reboot WNR3500L to make WDS work. Therefore, I decide to switch their roles. I moved WNR3500L to living room with cable modem and moved RT-N16 to the room to run WDS. It got worse. The connection failed to setup between them with WDS configuration and Wireless Ethernet Bridge works but it is not stable. BUT I found, my X61 shows me very stable and strong the wireless signal. That is why I began to wonder how bad the weak wireless signal of RT-N16 and what is the possible cause.
Anyway, I did a lot of tests and google without any progress. I decide to flash back to the original Asus firmware and study their WL configuration because the wireless signal of RT-N16 is much better than the wireless signal running tomato. After one or two days testing, there are three WL parameters in Asus firmware caused my attention:
1. txpwr. Its value is more than 1000mW. I guess it is larger than regulation and the system will use default. I found the wireless signal got a little better if I change it to 60 directly. But it is not related to weak signal of Tomato.
2. The values of antdiv and txant are all "0" in Asus firmware. The default values are "3" in Tomato. After I found these differences, I changed the Receive Antenna to be "A" and Transmit Antenna to be "B" (of course, I tried other combination and even with WL CLI commands). Then, my X61 shows 100% wireless signal of Asus RT-N16 after the change!!
Since I don't know how driver does with value 3 of antdiv and txant but they do cause weak and unstable wireless signal in my home. If you suffer the same issue, it might be a possible and easy fix for your problem.