Saturday, February 12, 2011

How to Minimize Wi-Fi Problems With the iPad

I’ve only had the iPad since launch day, but I have logged hundreds of hours on the little slate. I have been exploring the device and its capabilities, along with determining how to best use its strengths. There have been reports from some iPad owners concerning problems with Wi-Fi connectivity, especially with some routers and mobile modems. I have seen those problems first-hand, and I have tested the iPad extensively to isolate Wi-Fi connectivity problems. I have determined the problems can be minimized with just a few simple steps. Note that I am not addressing the problems that have been reported by some universities that have prohibited the iPad from use on their networks.
The first problem I had with Wi-Fi on the iPad was exposed while using it with the Sprint Overdrive 3G/4G modem. This modem connects to the Sprint network and dishes the connectivity out over Wi-Fi. This would be the perfect solution for using the iPad over Wi-Fi to get mobile broadband connectivity. What I was immediately confronted with was the iPad was constantly disconnecting from the Sprint connection, and often having trouble reconnecting. The session would be working as it should and the iPad would suddenly disconnect and then I would have no connectivity at all.


I researched this and tested it and came to the conclusion that the iPad has a tendency to let the Wi-Fi connection go dormant very quickly. A brief lull in data transmission results in the iPad shutting the Wi-Fi down. This is probably by design and likely is an attempt to save on battery life, something the iPad is very good at doing. Unfortunately, while the iPad should automatically reconnect to the Wi-Fi network after such a dormancy, it wasn’t able to using the Sprint Overdrive modem.
I didn’t have this reconnect problem with any other router or network, just the Sprint Overdrive connection. That led me to do some investigation, and I determined that the Sprint Overdrive was using 64-bit WEP encryption for security on the Wi-Fi network connection. The iPad can handle this fine, but it was different than the newer (and better) WPA2 encryption used on all the other networks I use that had no problem reconnecting with the iPad.
I changed the Sprint Overdrive settings to WPA2, and the reconnect issue disappeared. Apparently the iPad was failing to reconnect properly over the WEP encryption, but it has no problem with WPA2. This matches what I see on other modems and routers, so I recommend changing it if you are having a similar problem with your iPad dropping connections and failing to renegotiate a reconnection. It’s easy to do and it worked for me; I haven’t seen a single failure to reconnect since making this change, and using two different Sprint Overdrive units.
The other problem I have encountered has to do with the Wi-Fi radio in the iPad. Let me set the scene for how I discovered this problem and the solution. The big comfy easy chair in my living room is as far from the router in my office as can be. The chair is right on the fringe of the range the router can dish out Wi-Fi, and out of all the mobile devices I have tested I’ve seen several that cannot see the network at all. Some get intermittent signal from the chair, and others none at all. It comes down to how powerful the Wi-Fi radio is in the given device, as that determines if it can see the network consistently.
The iPad is one of those devices that is right on the fringe of the ability to see the router from this spot in the house. This led me to do extensive testing to determine what factors under my control could minimize the bad signal strength the iPad reported, and thus get better bandwidth. In normal circumstances the iPad shows at most one bar on the Wi-Fi signal meter, and it occasionally drops the connection entirely.
My testing indicated that when I hold the iPad in portrait orientation in my two hands, like a book, the signal drops immediately. I can set the iPad in my lap with no hands holding it on the sides, and the signal meter immediately jumps to over 50% and the bandwidth increases accordingly. I verified this by running speed tests in a number of configurations. I can consistently set the iPad in my lap with no hands holding it, fire up the speed test, and see outstanding connection speeds from this remote location. If I do the same while holding it as a book, the speeds are abysmal, if the network is available at all.
I can run the speed test with the iPad in my lap, and after it starts running with fast connection speed I can pick it up and watch the speed drop to near nothing immediately. There is no question in my mind that holding the iPad in the hands interferes with the internal Wi-Fi radio somehow, and setting the device down is a simple solution. It is important to note that it is only holding the iPad in portrait mode that interferes with Wi-Fi. I can hold it in both hands in landscape orientation and the signal strength is not impaired. I’m not sure where in the iPad the Wi-Fi is physically located, but it must be near one of the sides in portrait orientation.
The iPad is a very small, slim gadget, and it doesn’t surprise me that Apple used what looks to be a low-power Wi-Fi radio. The point is now that you know how to maximize the network performance with the radio, you will get better results as I do.
So to recap, change your router settings to WPA2 if possible. This will minimize any problems the iPad has reconnecting after going dormant. How you hold the iPad can interfere with the Wi-Fi radio in fringe areas. If your signal strength goes really low and speed suffers, try setting the iPad down. You may see the signal meter jump back up, along with the connection speed.

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