A senior executive at NTT DoCoMo said on Thursday the Japanese mobile carrier is in crisis over subscriber losses in the last year.

DoCoMo, which is No. 1 in Japan, has lost about 1 million subscribers in the last year since number portability was introduced allowing subscribers to switch carriers without losing their telephone number.

"We have a sense of crisis," said Kiyoyuki Tsujimura, executive vice president and managing director of the carrier's products and services division. "In some months we had a net decline in subscribers."

Customers have been switching to KDDI's Au brand and Softbank Mobile. Au is well known for innovative and well-designed handsets while Softbank has been winning customers with low prices and Japan's first free mobile calls scheme.

Despite the subscriber losses NTT DoCoMo isn't in danger of losing its top spot anytime soon. With 53 million subscribers at the end of September it had a 53 percent share of the market. But executives at the carrier are conscious that the days when they could rest on their laurels are gone.

As part of a push to keep subscribers and appeal to new ones DoCoMo introduced 23 new cell phones on Thursday -- the largest launch it has ever staged. The complete overhaul of its handset range includes models that can warn of impending earthquakes, help with language translation and show TV programming.

Among the new phones is the L705iX from South Korea's LG Electronics. The phone is notable because it supports 7.2Mbps HSDPA (high-speed downlink packet access) data transmission. DoCoMo plans to offer the service, which is double the speed of its current 3.6Mbps service, from April next year.

Also next year DoCoMo will begin a severe weather and earthquake warning service using the cell broadcast service. Data from the meteorological agency will be broadcast to phones from cell towers. Included will be earthquake warnings that should flow from a new system introduced earlier this year that attempts to gives a heads-up to people in the few seconds between an earthquake striking and the strong shaking waves reaching people.

The new translation service works in English, Japanese, and Chinese. Users say simple phrases into the phone, and the audio data is sent back to a translation server where it is processed and delivered back in text form.

Well-known consumer electronics brand names are among the new lineup too. Panasonic and Sharp have labeled their new TV phones with the same brands they use in Japan for flat-panel TVs: Viera and Aquos. And Sony's new phone carries the Cybershot name and offers an impression 5-megapixel image quality.

None of the handsets will be offered overseas but some features might make their way into the manufacturers' foreign models next year. Prices will depend on retailer discounts, incentives, and the length of service contract signed.