Monday, 20 December 2010

HSPA and LTE carrier aggregation

Last week there were press releases about the Long Term HSPA Evolution. The only thing that got reported mostly is the 650Mbps peak rates. There are other interesting features in Release-11 that is covered in Nokia Siemens Networks presentation. Here is one of them:

The idea of aggregating multiple carriers to increase performance is included in both LTE and HSPA. A logical step to 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 3.

The aggregation of LTE and HSPA systems enables 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 devices 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.

Carrier aggregation is expected to have no impact on the core network.


Marcin Mikuszewski said...

Hi Zahid,
I have a question regarding new features in HSPA:
Where can I find information about new HSPA ehnacment in 3GPP?
I mean I follow your blog which is great source for such info.
I also follow vendors (i.e. NSN Ericsson, Qualcomm etc) web pages.
But sometimes I can find link to some 3GPP CR or similar doc which is describing new feature.
I would like to write some articles for HSPA evolution and hence would like to have the background from 3GPP.

Zahid Ghadialy said...

Hi Marcin,

There is no easy way to find this information on 3GPP website. The best way forward is whitepapers and books.

I have got some useful information on my website at but that section is not been updated for a while. I will add new information on it over the weekend.

Marcin Mikuszewski said...

Hi Zahid,

Thanks for the info.
I will wait then for your update - I will check if my library is complete.


BRosenbaum said...

does CA require the use of a quadplexer?

Θεόδωρος said...

Hi Zahid,

I am
interested in LTE+HSPA or LTE-WiFi carrier aggregation on PHY or MAC.. Do you know where I can find some bibliography/technical reports on the above?
Best Regards,


Zahid Ghadialy said...

For LTE+HSPA see:

For LTE-WiFi, I am not sure if anything concrete has happened yet. Qualcomm proposed LTE-U which is similar concept. See: