The number of mobile phone users happy with their mobile devices has declined significantly over the last three years, a survey released this week showed.

A poll of 1000 mobile phone users in the US found only 20 percent "very satisfied" with their devices in 2003, compared with 39 percent in 2001, market researcher Strategy Analytics said.

The introduction of higher quality, feature-rich devices, including clamshells, slider formats, color screens and cameras, have raised consumers' expectations and caused increasing discontent with older cellular phones, Strategy Analytics said. Such displeasure is expected to be a boost for replacement sales.

Among cellular phone manufacturers, Asian companies Samsung Corporation, LG Electronics Incorporated and Kyocera Corporated have done an "exceptional job" improving handset features, while Nokia Corporation and Motorola Incorporated have fallen behind.

"Asian manufacturers have really increased the benchmark for handsets," Strategy Analytics analyst Eddie Tapiero said. "Those vendors are trying to capture market share with new features, and consumers are comparing their handsets with others, and are saying they want those capabilities."

Indeed, leading manufacturer Nokia suffered a dramatic drop in market share in the first quarter of 2004 to 28.9 percent from 34.6 percent a year ago, according to Gartner Incorporated. The drop occurred despite a 34 percent increase in global shipments in the quarter to 153 million phones.

Tapiero said consumer dissatisfaction should be a "wake up call" for vendors that have been slow to roll out new cellular phone features.