![]() ![]() ![]() The DoCoMo phones can be unlocked in a DoCoMo store for 3150yen. They sell DoCoMo & Softbank phones (locked), but also some factory unlocked phones. When browsing in these shops, make sure you DON'T buy any of the AU iphones/Samsung Galaxy/Experia/HTC/etc because these are special versions just for AU with ONLY CDMA, not 3G. This allows you to use your phone even when you are in the middle or no where far from any cell tower.You can get these phones at IOSYS at Akihabara. The Gateway processes and takes care of the switching of the calls rather than the satellite network. Any land-line or cellular network can call satellite phones. The call can be directed to a land-line or PSTN as well as a cellular network. When making a call the satellite signal goes to the satellites this it is directed down to a ground station or gateway where it is directed by the gateway the to the call destination. Globalstar has 48 satellites and Iridium has 66 that orbit the earth. When you turn on your satellite phone the signal goes up to any number of satellites in a compatible constellation where it is then registered with the constellation. The most popular hand held satellite telephones use Low Earth Orbiting or LEO satellites. Also it would be impossible to place towers out in the ocean far from land, again making your celullarl phone worthless when not close to a cell tower. That is because their phone is most likely using another cellular provider the uses a tower with a difference technology other than the technology compatible with your phone. There is also the issue where your friend's cell phone may work in an area or “cell” and yours does not. ![]() and other countries where a cellular phone does not have coverage because if you are not close to a cell tower your cell phone will not work. It is not cost effective for the cellular providers to put up cell towers in rural areas or many third world countries where there would be low usage. Imagine in a perfect world the cells or zones looked like a large honey bee cone that covered the planet. All the cell phones are registered with the control channel so the system knows where to find the cellular phone. The MTSO also controls all the cell sites. The Mobile Telephone Switching Office or MTSO connects the cellular calls with the Public Switched Telephone Network or (PSTN). The switch to the new cell is accomplished by the sending of a special signal to the mobile unit. As you move from one area or “cell” your call is “handed off” from the old to the new cell. The way cellular phones work they use zones or small base stations called “cells”. there are several cell phone that can receive but will not allow you to make a call - you will have to subscribe to their network (each country you visit). Regardless of international service you have with Docomo, only the satellite cell phone can receive & send. ![]()
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