On Wed, May 11, 2011 at 11:39 AM, George Bonser <gbonser@seven.com> wrote:
There are other things to take into account. If you increase the time it takes a mobile device to complete a transaction by only a couple of seconds, if you multiply those couple of seconds by all of the users in a large metro area, you end up with devices increased use of network resources (and increased battery drain on the devices themselves). Anything that can be done to speed transactions up and get those transmitters shut off as quickly as possible is a win.
I agree that seconds sometimes matters, but the latency of a transaction doesn't have a linear relationship with radio or battery usage on a mobile device. Because of the timers involved in the state transitions (eg CELL_FACH -> CELL_DCH), a few seconds of extra latency often is inconsequential because there is a minimum duration for which the radio will stay awake anyways. Coalescing techniques like Android's setInexactRepeating method of the Alarm Manager also optimize radio access across multiple apps. And if I'm not mistaken, it's the transition to/from CELL_DCH which is the most expensive resource-wise for network operators, not the duration of keeping this state. The argument that IPv6-induced latency is going to affect mobile devices disproportionally doesn't seem especially compelling. -Nick