A straightforward loanword for a mobile phone. In everyday Japanese, 携帯電話 (けいたいでんわ) or スマホ are more common, but モバイルフォン is understood, especially in tech or business contexts.
I bought a new mobile phone.
Life has changed with the spread of mobile phones.
Variant with interpunct; less common in running text but seen in some contexts.
Borrowed from English 'mobile phone'.