Ericsson, SK Telecom eliminate inter-cell handovers for faster rates, higher capacity

Infrastructure vendor Ericsson (NASDAQ:ERIC) and Korean operator SK Telecom have taken advantage of an LTE Advanced (LTE-A) capability to enable mobility without the need for an inter-cell handover between base stations.

The approach, called handover-free cell, uses adaptive coordination between base stations and mobile terminals.  "When a terminal is located in a cell edge, multiple base stations adjacent to the terminal jointly transmit the same signal to it, thus removing the need for inter-cell handover," SK Telecom explained.

The result is a 1.5x to 2x increase in voice and data transmission rates and a boost in cell system capacity of five to 10 percent, the carrier added.

Key to the approach's development is the use of LTE-A's transmission mode 9 (TM-9), which defines transmissions between mobile devices and base stations. Ericsson and SK Telecom demonstrated TM-9 for the first time during January 2013, and the two began working on handover-free cell technology in March. SK Telecom said it will apply the handover-free technology to its mobile network in the first half of 2014.
Ericsson and SK Telecom also developed a technology they call reduced-power sub-frame (RPS), which is an upgrade to enhanced inter-cell interference coordination (eICIC), also a core LTE-A technology. The carrier said although eICIC reduces inter-cell interference, it also has the unattractive side effect of decreased cell system capacity.

RPS is said to reduce interference to terminals within small cells located inside of a macro cell by reducing transmission power without compromising capacity. "Compared to eICIC, RPS improves cell system capacity by as much as 62 percent," SK Telecom said.
The technology advances made with Ericsson tie into SK Telecom's Super Cell concept, announced in February at Mobile World Congress 2013. The notion is aimed at eliminating inter-cell boundaries and making multiple numbers of small cells and/or macro cells act as one by allocating identical cell IDs.

Earlier this month, SK Telecom also announced a partnership with Intel to develop vRAN, a virtualized intelligent base station that will run on universal hardware. SK Telecom said the vRAN system will reduce development time and support new technologies simply software upgrades running on standard high-volume servers.

For more:
- see this SK Telecom release

Related articles:
SK Telecom not shy about marketing LTE Advanced
SK Telecom: Take a closer look at its LTE Advanced rollout
LTE Advanced is the next competitive battleground for operators
SK Telecom rolls out LTE Advanced with carrier aggregation
SK Telecom CTO dishes on small cells, LTE-Advanced and RCS