Global Roaming

Back to Contents of Issue: October 2005

Can I use my mobile phone in Japan? That depends. Read on for an update on roaming in Japan.

by Arjen van Blokland

For a long time Japan has been a place where foreign business travelers and tourists could not use their mobile phones, on account of incompatible networks. This was because rather than adapt the GSM standard, the Japanese Government promoted the homegrown PDC system. Consequently, phone rental shops at Narita Airport and major overseas hubs flourished. This situation is about to change.

The worldwide introduction of third generation (3G) systems (W-CDMA and CDMA 1X) has enabled foreign travelers to use their phones on Japanese networks and for Japanese to use their phones abroad.

A recent customer survey published by NTT DoCoMo revealed that Japanese bring their mobile phones abroad for more reasons than just calling. The travelers use their phones as an alarm clock, MP3-player, and for playing games rather than just for roaming.

Can I use my phone in Japan?
JI readers often ask, "Does it make sense to bring my own phone to Japan?" The answer depends on your carrier, type of phone and type of subscription.

If you are a Vodafone subscriber and a proud owner of a 3G-phone, you can roam on Vodafone Japan's network without changing your mobile number. This is the most convenient roaming service at the moment, but requires a Vodafone subscription in your home country. You will be directly billed on your Vodafone account.

If your home network has a roaming agreement with NTT DoCoMo, you can roam with your own handset if it works on the 3G network. According to NTT DoCoMo, most Nokia and Motorola 3G handsets are compatible with their network.

In case your phone does not work on the 3G network, you can use a rental phone. NTT DoCoMo offers this service for subscribers of their international roaming partners. By inserting your SIM card into the rental handset, you won't miss any calls. Do not expect to get hold of the latest 3G handsets with the latest gadgets -- DoCoMo rents out the uninspired A835 Motorola for JPY525 per day. This service is available for subscribers to most European and Asian carriers and for subscribers to US carriers T-Mobile and former AT&T carriers with the exception of Cingular. The rental shops can be found at the international airports of Narita, Kansai and Nagoya. Vodafone offers phone rental services similar to DoCoMo's but for almost double rates.

I recommend checking your carrier's international roaming plans for the latest updates because the situation is frequently changing. Most carriers also require you to register before you can use the global roaming services. Buying a prepaid phone in a local convenience store is not an option if you are not a resident of Japan, as you have to register the phone using your alien registration card.

Using Japanese phones outside Japan
Vodafone and DoCoMo have W-CDMA/GSM handsets that work in most countries worldwide. Global roaming and technology-handset compatibility are pillars of Vodafone's strategy. I have been using Vodafone's global roaming for some time and am satisfied with its coverage in Europe and major US cities. Browsing mobile Japanese sites and checking mail are smoothly accomplished with Vodafone. The only problem is sending SMS -- still the main messaging technology -- because Vodafone Japan's global service only supports SMS interoperability with a limited number of carriers.

The NEC N900iG is the only handset in DoCoMo's line-up with dual-mode functionality. The features are similar to those of the 900i FOMA-series and are thus one generation behind state-of-the art phones. KDDI Global Passport service supports handsets with technologies like GPS, stereo chaku-uta (real music ring- tones), BREW, barcode reader and QVGA screen -- all of which are sure to impress your overseas friends or business partners. Because KDDI operates the Qualcomm CDMA 1X network, overseas usage is mainly limited to the US, Korea, China, Taiwan, Thailand, Indonesia, Australia and New Zealand. Global Passport does not cover Europe, however, because KDDI does not offer dual-mode handsets supporting both CDMA 1X and GSM. While it would not be a major technical challenge for Qualcomm to develop dual-mode chipsets, there are perhaps valid commercial reasons not to introduce handsets of global utility.

KDDI announced a new service for their Japanese subscribers -- an international service that roams between KDDI's CDMA and GSM networks. These two networks' standards are technically incompatible. By using Syniverse's solutions, KDDI subscribers can use their existing phone number to make and receive calls while roaming. Syniverse provides the necessary signaling and translation, number mapping between the networks, as well as billing data conversion. KDDI needs to provide their subscribers with an activated SIM-card to use this service and a GSM phone. Still not an easy solution but their subscribers can now use their own number, even in GSM countries.

The price sticker -- still an issue for consumers
Our main concern with global roaming services is the pricing. In particular, phone calls between different countries outside Japan will cause price-sticker shock for most users. Rates vary between JPY150 and JPY280 per minute. Phone charges are rounded up to whole minutes -- a rip off. We were used to paying these rates 15 years ago, when we called abroad from Japan using KDDI fixed-line long-distance service; but we will not pay such rates today.

International roaming rates are already under investigation by European authorities, but I do not expect the outcome to have an impact anytime soon on rates charged by Japanese carriers. Market competition should drive down prices. Until it does, I will continue using convenient global roaming services -- at a high price though. JI

Arjen van Blokland

International Business Development Manager, Class Technology Co., Ltd.; author of "Wireless Watch," a newsletter about Japan's wireless world (

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