Sony chairman Nobuyuki Idei says the potential of third-generation mobile phones is overestimated.
Mr Idei said people had overestimated the potential of 3G.
He said in the short term, they would have to be realistic as 2G and 2.5G phones would meet most of the needs of users.
"Instruction manuals for i-Mode terminals are already as big as telephone directories. It will take users time to adapt."
Mr Idei said Sony still intended to reinforce its position in the mobile sector, and he was confident about the company's position in spite of the economic crisis affecting Japan.
"During the last three years, we have seen our sales rise 69%, due to PlayStation 2, Vaio portable computers and our mobile phones.
"It is not a miracle that we have been less affected than other technology companies. We do not have business customers, and we do not sell manufacturing tools."
Mr Idei said part of the company's competitive edge came from manufacturing in-house items like computer chips, instead of relying on sub-contractors.
He said he thought buy-outs were an inefficient way for a company to grow, saying he preferred "soft alliances" or joint ventures, like those Sony had with Vivendi Universal. "Tomorrow, we could work with AOL or Yahoo. They have the networks and need material and content, which we have."
Mr Idei concluded by saying the reorganisaiton Sony launched last week would let young managers gain experience and allow for more alliances.