Today Docomo also announced a new pricing plan for Xi LTE service that will be introduced with the upcoming tablets. 7 GB will be available for ¥4,410 in a flat-rate plan if signing up during the campaign period (until 4/30/2012) for a 2-year contract. After exceeding 7 GB, it appears that you have a choice to either 1) live with 128 kbps data for the rest of the month, or 2) pay ¥2,625 per additional 2 GB.
In actuality, there will be very little change. The flat-rate plan will save a total of ¥525, over the stepped plan for 7 GB. The stepped plan is just stupid. Why Japanese carriers continue to structure stepped plans based on decade old data usage habits is beyond befuddling.
The minimum fee of the stepped plan will be raised from ¥1,000 to ¥2,500 which will include EXACTLY 9,524 KB. After which the the price will by ¥0.2625/KB until EXACTLY 24,800 KB are used. Then ¥4,935 will carry you to 7 GB.
LET'S ENJOY DOING MATH
Xi is theoretically capable of 75 Mbps. Of course we'd never get this in the real world, but since the carriers like to throw around their theoretical yet unattainable maximum throughput, let's use their numbers.
75 Mbps is 9.4 MegaBytes per second. Rounding to the same number of decimal places, the initial cost of ¥2,500 buys exactly 9.3 MB of data. So this means that the stepped plan is structured to give you exactly ONE SECOND of full-throttle usage before the price starts going up, theoretically. Realistically, you'd probably only get a quarter of that speed, so let's be generous and give 'em 4 seconds.
The full price for 7 GB is reached after consuming only 24 MB, easily done in a day with normal FOMA usage, or about THREE theoretical seconds with LTE (12 seconds, realistically). Unless you expect to not use your handset for an entire billing cycle, there is absolutely no reason whatsoever to even consider getting the stepped plan.