Consumers could pay more, expect slower services and face difficulties in making phone calls if an overhaul of the 3G mobile market went ahead, technical experts warned.
Dr Cheung Sing-wai, an associate professor at the University of Hong Kong, said data services, such as internet browsing and video streaming, were most likely to be affected by the changes because they consumed significantly larger amounts of bandwidth than other activities.
An independent consultant said subscribers would have to pay HK$5.4 billion in total to upgrade to 4G services; if they did not, they faced losing the ability to make calls in some locations.
The government says a 3G overhaul - in which the available spectrum could be split among more operators than the existing four - HKT (PCCW); SmarTone; CSL (one2free), and 3 Hong Kong (Hutchison Telecom) - will cause a degradation in service of about 9 per cent.
But British firm Plum Consulting, hired by the 3G operators to provide a parallel report, said the weighted impact across the four operators would be 27 per cent on network services. In the worst-case scenario, the operator that relied the most on 3G faced a 39 per cent cut in mobile data capacity. This would, in turn, lead to a two-thirds increase in download times during peak periods, with voice calls prone to dropping out.
Plum Consulting said the overhaul also ran the "risk of complete loss of voice communications on the MTR and at some outdoor locations".
Chinese University information engineering associate professor Lau Wing-cheong said: "Whether you lose 27 per cent or 9 per cent, it could have a substantial impact … if the system is already running near to capacity for that particular location."
If the government granted more competition within the market by seizing one-third of each existing operator's allotted 3G spectrum, any disruption to mobile services could be long-term as less bandwidth would be allocated to any one operator.
HKT, the city’s biggest telecommunications network operator, estimated individual bills would rise by up to HK$360 a year.