Is it feasible to connect some devices to Android or Iphone smartphone through Wifi?

I'm doing a research because I want to develop an app to which different devices connect.

The app can be an Android or iPhone smartphone. It will be for mountain equipment devices and sensors, so no wifi router is availabe. It needs long range, so Bluetooth is not an option.

I'm thinking on creating a hotspot in the smartphone and connect the devices to this hotspot. In this case, I'm thiking of this way of doing it:

• Programatically create the hotspot in the smartphone. In Android, like this: http://www.whitebyte.info/android/android-wifi-hotspot-manager-class
• Set up the name of the hotspot in the devices so they know where to connect. Pressing a button, they connect to the hotspot.
• The android device broadcasts its IP, so devices know where to connect.
• Devices connect and send the data.

I think this could be a real scenario, but I'm worried about:

• Maybe there's a design flaw in my scenario that I'm not seing.
• Batteries on the devices: how do batteries behave through "intensive" use of WIFI? (sending small amount of bytes of data every five minutes, e.g.).
• The ability to replicate this scenario on an iPhone. Can it be done, or should the user manually create the hotspot to do this?
• Any other feedback that I couldn't be thinking of.

Thanks.

Yes, on Android all of that can be done and should work fine.

Yes, you can programatically configure the hotspots info in the client.

Another way to make the connection (other then hotspot broadcasting its IP) is for the hotspot to reads it ARP cache, i.e. parse the cache to find the IP of all of the clients connected.

Battery could be a problem. That doesn't really sound like 'intensive' use of the wifi, but it will still consume a fair bit of battery (I find that even just having the hotspot enabled draws the battery).

I don't know the answer for iPhone.