Mobile cards have been introduced for international roaming, but they are still not available in the Netherlands. If there is no signal, colleagues can use it, but the operator's manual selection ment

Mobile cards have been introduced for international roaming, but they are still not available in the Netherlands. If there is no signal, colleagues can use it, but the operator's manual selection mentioned by colleagues can't be used, so it is disabled. There are three GSM bands, one is 800MHZ, the other is 1800MHZ and the other is 1900MHZ. Many domestic mobile phones do not support 1900MHZ. Personally, I guess your local roaming contract operator uses 1900MHZ, and your colleagues can use it. Maybe he is a WCDMA mobile phone or he is roaming in CDMA.