Cook explained why Apple does not support RCS enhanced SMS: users are not very vocal, just buy your mother an iPhone.

CTOnews.com Sept. 8, in today's Code Conference, Apple CEO Tim Cook was asked in an interview about iPhone's iMessage does not support RCS.

RCS, known as Rich Communication Services, or rich media communication service, can be understood as an "enhanced SMS" designed to replace the standard "SMS" (SMS).

Due to Apple's lack of support, the message will turn green when some content is sent between iPhone and Android. In recent months, Google has been publicly pressing Apple to adopt RCS on its iPhone.

In response to a question, Cook replied: "I don't see users asking us to put a lot of effort into this. I really want to turn your phone into an iPhone."

The questioner went on to explain that because his mother used an Android device and relied on text messages, he was unable to send some videos to his mother. Cook's response was simply to tell the person, "buy your mother an iPhone."

CTOnews.com has learned that Google has been promoting RCS over the past few years. In July, all three major operators in the United States pledged to adopt RCS. Compared with SMS, RCS supports higher quality photos, video and audio messages, higher security, and better group chat.

With RCS, Android-to-Android messaging will become "end-to-end" encryption. By contrast, communication between Android and iPhone is often referred to as a "green bubble", which is less secure because Apple is reluctant to adopt the RCS protocol.

For Apple, maintaining a good texting experience between iPhone helps keep users in the Apple ecosystem, while supporting RCS weakens the advantages of iMessage.