iPhone & network load.

One of the main reasons, other than too many people are overloading networks, that iPhone is causing such headache for operators (esp AT&T)is that the paging channel is not implemented. In order to save battery life, smartphones completely drop off from the connection when data is done and reconnect when data is needed. This requires the re-establishment to the network again and eating up the channel bandwidth rather than using the paging channel and using keep alive message.