One primary barrier is the lack of support for legacy voice services within LTE, limiting the 4G network to data use for initial implementations, said Adam Leach, principal analyst at Ovum.
In a report he sent to ZDNet Asia, Leach said the lack of consensus within the industry regarding voice over LTE will likely result in early4G handset models being deployed over existing 2G and 3G network for voice, while data will be routed over LTE.
Voice can be delivered over LTE's IP-based network natively via IMS (IP Multimedia Subsystem), the older method of circuit switching that is currently used by 2G and 3G networks. Alternatively, operators can implement a VoIP (voice-over-Internet Protocol) application to tunnel voice traffic over LTE.
Daryl Chiam, Canalys senior analyst, said in a phone interview with ZDNet Asia that operators will also prioritize mobile broadband data usage with early LTE rollouts via devices, such as external modems.
"Several operators are prepping their LTE networks for initial rollout by the end of this year, but realistically we'd still have to wait another 12 to 14 months for commercial LTE network availability," Chiam said.
Leach said early adoption of LTE devices will likely come in the form of external modems such as dongles and PC cards, before users move to LTE-embedded devices such as laptops and mobile Internet devices (MIDs).
Ovum predicts voice-enabled LTE handsets will be a market reality only in the first half of 2012.
Once these handsets are available, Leach said shipments will grow at a CAGR (compound annual growth rate) of 163 percent between 2010 and 2014 to hit 75 million devices in 2014.
Chiam noted that it is "too early to tell" when 4G handsets would eclipse 3G handsets in sales.
Operators already on trial
Some telcos in the Asia-Pacific region have embarked on LTE pilots.
Singapore's three telcos MobileOne (M1), StarHub and SingTel announced their LTE trial networks earlier this year. M1 said last month it would be ready to unveil commercial services on its network by early 2011, according to reports.
Taiwan's Chunghwa Telecom announced in December last year it had embarked on a plan to set up a trial LTE network.
When contacted, two manufacturers--Nokia and HTC--preferred to keep mum on their LTE handset plans.
Last week, Samsung said it would release an LTE handset for trial in some U.S. cities by the end of the year.
According to a report posted in May last year, LTE chipset manufacturers will launch their first chips designed for portable modems and PCs. This means handset manufacturers will get dedicated chips only later--and certainly not in time for this year, it added.