Horas and konnichiwa untuk semua

Almost a year passed since last year posting and I am now much more knowledgeable about world’s cellular systems. I have since found ways to roam outbound and inbound between GSM and W-CDMA networks. The following summary about Indonesian GSM SIM card roaming in Japan something that not even Indonesian operators’ customer support staffs know.

Official data

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In Japan there are two networks that accepts inbound roamer with GSM SIM cards: DoCoMo and Vodafone. Both are W-CDMA (3G) operators. While in Indonesia there are at least three GSM operators: Telkomsel, Indosat and Excelcom (See GSM World’s listing).

Here are officially published roaming partners of the Indonesian operators:

	Indosat			Telkomsel		Excelcom
	Matrix	Mentari	IM3	Halo	Simpati	Xplor	Jempol
DoCoMo	-	-	-	Partner	Partner	-	-
Vodafone	Partner	Partner	-	Partner	Partner	Partner*)	Partner*)

*) On Excelcom’s website, J-Phone (Vodafone Japan’s former name) is described as partner, but card type is not stated.

Here are officially published roaming partners of the above Japanese operators:

	DoCoMo	Vodafone
Indosat	Partner (IM3 only)	Partner
Telkomsel	Partner	Partner
Excelcom	-	Partner

Actual results

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After rigorous web research, numerous calls to customer support staffs and actually trying roaming in Japan, I found the following conclusions for Telkomsel’s Halo/Simpati, Indosat’s Matrix and Excelcom’s Jempol:

	Indosat	Telkomsel		Excelcom
	Matrix	Halo	Simpati	Jempol
DoCoMo	No access*)	Complete access**) with Motorola W-CDMA/GSM handset	Partial access***) with Motorola W-CDMA/GSM handset	No access*)
Vodafone	Complete access**)	No access*)	No access*)	No access*)

*) Signal detected by handset, but network access is forbidden
**) Voice and SMS work for both sending and receiving
***) SMS sending/receiving works, but voice is barred.

The reason why Motorola W-CDMA/GSM handset is necessary for successful roaming with DoCoMo networks is because DoCoMo’s W-CDMA network originally set up with revision 99 of 3GPP specification, and now many parts of the networks are still using this. Revision 99 is an older specification that is not common. Currently all other W-CDMA networks are using revision 2000, so all handsets except Motorola’s are built for revision 2000.

SIM card preparation for international roaming

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In order to get the above results, the SIM card must be activated for international roaming, as follows:
-Satelindo Matrix: activation is automatic
-Telkomsel Halo: go to Telkomsel Grapari and ask for activation (payment by credit card is necessary for activation, or if approved credit card is not available deposit 1,000,000 rupiahs for activation)
-Telkomsel Simpati: send activation message by SMS

Testing environment

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I did testing with my Sony Ericsson 802SE and Motorola A1000 handsets, as well as with Vodafone Rental’s Nokia 6650.

Sony Ericsson 802SE	Nokia 6550	Motorola A1000
Best 3GSM Handset Natively supports Japanese	First W-CDMA/GSM handset English only and bulky	Symbian-based smartphone Smart enough and displays Japanese through font install

The conclusion is:
-802SE is fully tested (countless times) and found to work on Vodafone network only
-Nokia 6550 is tested a few times and found to work on Vodafone network only
-Motorola A1000 is fully tested (countless times) and found to work on both Vodafone and DoCoMo network, given the right SIM card is inserted.

Notes:
-802SE and Motorola A1000 are not generally available through official channels, as they are sold by operator exclusively (802SE by Vodafone, A1000 by 3) and SIM locked.
-Nokia 6550, being the first dual W-CDMA/GSM handset, is rather old
-Both 802SE and Motorola A1000 are unlockable. 802SE needs a special cable for unlocking, while Motorola A1000 requires subsidy code to unlock.
-Though not tested by myself, the following Motorola handsets should work with revision 99 network (DoCoMo’s network): A835, A920, A925, E1000.