LTE has been considered as the mainstream technology evolving to the next generation of mobile communication networks in the past few years. However, the effect of the international financial crisis and the unclear economic environment in the near future, as well as the too much larger cost, prohibit the operators to upgrade the entire networks to some degree. As the evolution version of HSPA system, HSPA+ networks are being supported by the operators globally. Before 2010, 37 HSPA+ commercial networks in 24 countries have been deployed and additionally, 29 more HSPA+ networks are under the construction or the plan. HSPA+ has been the selection of the main operators on the world, including Telstra, Vodafone, O2, EMOBILE, Telus&Bell and China Unicom.
HAPA+ is the evolution version of the current HSPA networks, which is able to be smoothly evolved by updating the software for the WCDAM and TD-SCDMA systems. It aggregates multiple HSPA carriers to provide higher data transfer speed on both uplink and downlink and increase the network capacity obviously. The peak rate of HSPA+ can be 21Mbit/s, 28Mbit/s, 42Mbit/s and 84Mbit/s according to the different used technologies, such as downlink 64QAM high-order modulations, MIMO and Dual Carrier techniques. From the viewpoint of rate and user experience, it has some difference compared with the current LTE trail networks; however, HSPA+ can fulfill the market requirements without any problem currently. Since HSPA+ can be evolved smoothly, it makes more practical sense to the operators. In contrast, although LTE has more advantages in techniques, it requires too much investment and frequency resources, as well as the developed technical version. Therefore, LTE will appear as the complement for the 3G networks for a long time in most regions on the world. After deploying the HSPA and the HSPA+ networks, the operators in some European countries have found that the data rate can satisfy the user requirement basically, When the urgent demand on LTE is reduced, the indoor distribution of diversified options on handset terminals such as Femto and WLAN, to some degree, makes an effective supplementation to the 3G network in some hot regions. The pressure on 3G capacity was released as the whole system capacity was greatly improved by involving a great amount of services. So the operators are holding different market requirement on whether to deploy HSPA+ network. In the future LTE/4G age, HSPA+ is quite capable of being a complementary part for LTE/LTE-A so as to realize the transition and upgrade of the networks.
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