[Networking] mdanh2002:
I posted this thread on the Windows Mobile Owners Circle forum but it seems that my thread does not haver enough attention (4 views after 2 day), so I posted it here again, hopefully some experts may help me figure out. :)

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I managed to set up an ad-hoc wireless network on my Windows XP laptop (open authentication, no data encryption) with Internet connection sharing. This wireless network is used by my 2 WM devices: a Dopod 838Pro PocketPC and a Dopod 577W Smartphone. Both are WM5. At a first glance, both the pocketPC and the smartphone can connect to the ad-hoc wireless network and surf the Internet smotthly and without any extra configurations. However, some problems are identified after several observations, listed below:

1. The PocketPC can always connect to the ad-hoc wireless network, even if there's no other devices/computers using the network. As soon as the PocketPC is connected, the connection status on Windows XP will change to Connected. This is expected.

2. If the PocketPC is on, the Smartphone can detect the wireless network and connect and surf the Internet. While the smartphone is using the network, e.g. watch streaming videos, if the PocketPC is disconnected from the network, the smartphone also loses its Internet connection. This behaviour is expected as this is a de-centralized ad-hoc network.

3. If the PocketPC is off, the Smartphone won't be able to detect the presence of my wireless network, e.g. the network name does not show up in the list. It, however, does detect other network (both access points and ad-hoc). Although it can connect to access points successfully, I don't have opportunity to see if it can really connect to other ad-hoc networks (and not just show their names in the list).

My conclusion is, for the smartphone to use my ad-hoc network, a necessary condition is that there must be at least one device using the network so the smartphone can establish connection to that device (since it can't connect directly to the laptop). I cannot verify the sufficient condition as I don't have any more devices to try.

This is very strange. Why does the smartphone refuse to be the first device on the network? As I am by no means a network expert, the only reason I can think of is the incompatibility between wireless standards supported by my device. The laptop has 802.11a/b/g, smartphone has 802.11b while pocketPC has 802.11g. Could this have prevented the smartphone to detect the signal from the laptop? Only after the PocketPC is connected and re-broadcoasts the signal as 802.11g can the smartphone hardware (802.11b) detect it.

Another possiblity is that the implementation of ad-hoc wireless network on the smartphone does not allow a device to act as broadcaster. As such if the smartphone was the first to be connected on the network, it would prevent other devices from connecting. If my assumption is true, is this perhaps why the smartphone refuses to detect the ad-hoc network when it sees no other active connections?

If it helps, the icon for my ad-hoc wireless network also looks different from other ad-hoc wiress networks. Although they both have a computer on the top left and a device on the bottom right, the icon for my network looks has a blue circle at the back. What does this difference indicate? On Windows XP, the icons look the same.

Anyone can give me any clues how to solve this problem? Thanks a lot.