Recently MIIT issued a circular, approving China Unicom to refarm 900MHz, 1800MHz and 2100MHz bands for LTE.
Though policy obstacle is removed, China Unicom faces huge challenges in market and technology of spectrum refarming and Carrier Aggregation (CA).
Due to lots of 2G subscribers being on the 1.8GHz network and the 2.1GHz network, China Unicom's main 3G carrier network, China Unicom can't clear the two bands. The company can't obtain new frequencies in a short time or realize LTE FDD Carrier Aggregation nationwide. In the aspect of low-frequency band, China Unicom just get 6M spectrum in GSM900 band.
The operator is restricted because only a small amount of spectrum is available compared with the other two giants, China Telecom & China Mobile.
China Unicom should also consider rapidly driving the migration of 3G/2G subscribers to 4G and spectrum release.