HSPA and LTE carrier aggregation

The idea of aggregating multiple carriers to increase performance is included in both LTE and HSPA. A logical step fully leverage existing HSPA deployments and future LTE deployments is to aggregate the capacity of both systems and tie them together into a single mobile system. The concept is illustrated in Figure.

The aggregation of LTE and HSPA systems enable the peak data rates of the two systems to be added together. It also allows for optimal dynamic load balancing between the two radios. A small number of active LTE and HSPA aggregation capable devices is sufficient to exploit this load balancing gain, since the network can schedule these devies to carry more data on the radio that has lower instantaneous loading and less data on the radio with the higher load at any given moment.

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According to Sony Ericsson, smartphones are the perfect business companions. Apparently, the business world has greatly benefitted from smartphone technology. Their ability to perform multiple business functions such as email, networking and internet browsing has enabled them to become a major factor in the efficiency of travelling businessmen and women, according to Sony Ericsson.

The vast majority of business executives now possess a smartphone, such is their need to be in constant touch with various clients and colleagues whilst on the move. The functionality of a business smartphone which allows users to receive, browse and reply to emails has been a particularly helpful solution to business travel, enabling users to continue to conduct their work to a much greater degree regardless of their location.

Applications for the various models of touchscreen phone available, such as Sony Ericsson’s Xperia™ range, also facilitate greater connectivity for business executives, allowing them to engage with their online communities within social networks such as Twitter and LinkedIn, as well as making the most of their travelling time by catching up with more personal contacts on other networks like Facebook.

Ben Padley, Head of Digital and CRM, said: “Businessmen and women all over the world are now reliant upon smartphone technology to keep them connected with their working world, irrespective of where they are or where they are going at any given time. The ability to do this has had a positive effect on the way that business is conducted all over the world, improving efficiency and helping people make the most of their time.”

Sony Ericsson creates innovative, sophisticated and inspirational phones and accessories, designed with each individual's fun and entertainment in mind. Sony Ericsson seeks to help each user see things differently, to be at the centre of countless everyday moments and make them extraordinary, to create an inspiring friend for everyone so that they can find beauty in the unexpected.

Multicarrier and multiband HSPA aggregation

HSPA Release 10 with 4-carrier HSDPA provides a peak downlink data rate of 168 Mbps using 2x2 MIMO (Multiple Input Multiple Output) over the 20 MHz bandwidth. This matches the LTE Release 8 data rates obtained using comparable antenna and bandwidth configurations. A natural next step for the HSPA Release 10 downlink is to further extend the supportable bandwidths to 40 MHz with 8-carrier HSDPA, doubling the Release 10 peak rate to 336 Mbps.

8-carrier HSDPA coupled with 4x4 MIMO doubles the peak rate again to reach 672 Mbps, see Figure 1. The evolution of HSPA beyond Release 10 will push the peak data rates to rival those provided by LTE Advanced.

In addition to increased peak rates, the aggregation of a larger number of carriers improves spectrum utilization and system capacity owing to inherent load balancing between carriers. Additional capacity gains from trunking and frequency domain scheduling will also be seen.

Typical spectrum allocations do not provide 40 MHz of contiguous spectrum. To overcome spectrum fragmentation, HSDPA carrier aggregation allows carriers from more than one frequency band to be combined. 3GPP Release 9 already makes it possible to achieve 10 MHz allocation by combining two 5 MHz carriers from different frequency bands, such as one carrier on 2100 MHz and another on 900 MHz.

The 4-carrier HSDPA of Release 10 extends this further, allowing the aggregation of up to four carriers from two separate frequency bands. Long Term HSPA Evolution allows eight carriers. Typical cases of HSDPA multiband aggregation are shown in Figure 2.

参考：3g and 4g wireless blog