Schoolar: LTE Advanced may just be carrier aggregation, and that is OK

Daryl Schoolar ovum

Daryl Schoolar

We have had commercial LTE Advanced (LTE-A) networks since mid-2013 launches by LGU U Plus and SK Telecom in South Korea. Both of these mobile operators made their LTE-A claims based purely on deploying carrier aggregation (CA). None of the other technology advances coming with LTE-A were used.  Those features include coordinated multipoint (CoMP), higher orders of MIMO, enhanced inter-cell interference coordination (eICIC), and relay nodes.

Now some market observers questioned if just having carrier aggregation was enough to be an LTE-A network. Some thought true LTE-A networks had to support multiple LTE-A features to hold that distinction. In the year plus since the first commercial LTE-A networks there are now around 20 operators claiming commercial service. All of those claiming commercial LTE-A services are doing so based purely on carrier aggregation. The debate over how many different features a mobile operator has to deploy before declaring it has an LTE-A network is over. Carrier aggregation is enough, and that isn't a bad thing.

The LTE-A focus on carrier aggregation makes sense. It is a sellable feature.  Mobile operators know how to market 150Mbps versus 75Mbps.  People understand network speeds and they want faster performance. The other advancements that come with LTE-A are harder to market.  How exactly does an operator sell cell edge improvement due to reduce spectrum interference.  That doesn't exactly flow during a 15 second commercial spot. Furthermore focusing marketing too much on a more consistent network experience reminds the consumer that promised high-speeds aren't available every within the operator's footprint.

Another thing to consider when thinking about LTE-A, carrier aggregation looks to be the only ubiquitous feature. All operators deploying LTE-A will have carrier aggregation, but it is doubtful they will use all the other features. In fact from my observations I doubt relay nodes will be deployed at all. 8x8 MIMO could take a long time to become a reality due to the difficulty of putting all of those antennas into a smartphone. 8X8 MIMO for now could end up being limited to just larger devices like laptops and tablets.

Even with an operator deploying multiple LTE-A features, it is doubtful that other than carrier aggregation operators will deploy those features throughout their network footprint. There just isn't the need to do so.  Cell edge conditions in some areas may not be such they require CoMP or eICIC.  This doesn't make this part of the operator's network any less LTE-A then those areas where they are deployed.

In the debate of what is and isn't real LTE-A, there has never been any official definition saying an operator has to deploy a certain amount of features to qualify as a legitimate LTE-A. While a network deploying carrier aggregation, eICIC, and 8x8 MIMO might be more advanced than a network just deploying carrier aggregation, that doesn't make an operator's claim of LTE-A based solely on CA any less LTE-A than one deploying three features.  Both are LTE-A.  This isn't the case of marketers winning out over engineers, as was the case when the 4G label was applied to HSPA+.

For RAN vendors this obviously doesn't mean they should limit their LTE-A development to carrier aggregation. As stated before, operators will deploy other features, but without the fanfare or ubiquity of CA. This means RAN vendors need to provide a road map to their clients of the features they will be supporting and when. This really needs to be done at the initial LTE engagement. As LTE-A is an enhancement of the existing LTE network, I seriously doubt mobile operators will be swapping out incumbent LTE macro vendors as they deploy LTE-A.  Those LTE-A upgrades will be beneficial to vendors as I suspect they will be more profitable than the original LTE build. This is due to much of the LTE-A upgrade will have a higher software component than the initial LTE buildouts.

Daryl Schoolar is Principal Analyst of Wireless Infrastructure for Ovum. Daryl's research includes not only what infrastructure vendors are developing in those areas, but how mobile operators are deploying and using those wireless networking solutions. Contact him at [email protected] and follow him at @DHSchoolar.

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