How are you seeing the networks you are trying to connect to? The networks may (or may not) be using any security protocols (WEP-64, WEP-128, WPA-PSK, WEP/TKIP, etc.). If you are using the software on the TX to browse for available networks and you see a padlock icon on the line with the identified network, those are running encryption of some sort and require a passphrase or shared key. Unless you have that little tid bit of info, you can't connect to the locked nets (without using hacking tools).
If you are roaming around a neighborhood, a business area, or in a coffee shop and can't connect to a network that does not have the padlock icon next to it, then you may still have one of the following problems:
1. Weak signal in one or both directions. The design of wi-fi is to drop the tranmit speed as the signal attenuates. As a result, you may time out your connection tries/re-tries. And without any logs of the activity to inspect, it may look like you never connect even though your TX repeatedly attempts to do so, it just doesn't get a resonse from the server before a timeout occurs. Transfer rates drop in order as 54Mbps, 48Mbps, 36Mbps, 24Mbps, 18Mbps, 12Mbps, 11Mbps, 9Mbps, 6Mbps, 5.5Mbps, 2Mbps, 1Mbps.
2. The hotspot is forcing all connections at a rate higher than the TX can handle. The TX uses 802.11b protocol (11Mbps). The hotspot may be allowing only 802.11g (54Mbits). So you may see it but cannot connect.
3. The hotspot you are seeing in the browser may appear to be open (has
no padlock icon next to it) but the administrator validates the MAC address of the client through an access list. If the MAC address on your TX is not on the list of allowed devices you won't be allowed to connect (unless you do some hacking).
The last choice, while most people think configuring their router/WAP like this is the easiest way to do things, it is pretty simple to break into and therefore is the least secure (next only to an open link). All you need is to use a sniffer and capture a few packets to get some MAC addresses and then set your PC/laptop to use one of these addresses, refered to a Locally Administered Address (LAA). Pretty simple for even the greenest of amatures. Similar techniques are often used for man-in-the-middle attacks even on a secure network, although it requires some more advances tools.
There may be some other technical isues, so if you are trying to connect to a hotspot/WAP legitimately, then you should ask the owner what the requirements are. There are a few local places here that allow FREE connectivity, but they frequently change the passphrase/shared key. Others allow you to connect, but you must register or pay for the service before they issue the passphrase/shared key.
To get more details and see the "browser" I'm refering to see
T|X User's Guide - Chapter 14 .
Hope this helps.
Cheers,
John
