Ericsson's next-generation Radio Dot picocell base stations will be able to flexibly send data over licensed LTE or unlicensed 5GHz WiFi bands.
Swedish telecoms equipment vendor Ericsson is using this week’s International Consumers Electronics Show (CES) in Las Vegas to showcase its latest product and technology that it says will offer data hungry smartphone users concurrent access to both licensed and unlicensed spectrum.
Set to be part of its small cells line-up, the company is readying a device in its 6402 series of Radio Dot picocells to which it has added a technology dubbed Licensed Assisted Access (LAA). This is a sub-set of LTE-Advanced technology aimed at allowing carriers to aggregate and “fairly share” the public 5GHz band with the unlicensed WiFi spectrum. The proposition is that 5GHz services will handle the mobile data heavy lifting, particularly in indoor locations where it would be deployed on the picocells alongside 3G and LTE. For now, the signalling will still be the job of the conventional cellular network, but when required, could flip the LTE payload over to the public band, thus taking advantage of the higher capacity available there.
The set up “would significantly improve app coverage for all smartphone users, increasing speeds on LAA-enabled devices, reducing wireless network congestion and ensuring fair sharing between LTE and WiFi,” suggests Ericsson.
According to its calculations, using just 4% of the 5GHz band, LAA can provide up to a 150Mbit/s data rate increase to smartphone users. An even more mouth-watering prospect is the suggestion that each additional 4% of available spectrum used would increase data speeds even further. “One of the great things about LAA is its ‘rising tide’ effect, increasing system capacity and making way for better service to all users in the area, whether they have an LAA-enabled device, or are using WiFi or cellular access,” notes Thomas Noren, VP, head of Radio Product Management at Ericsson.
This is a clear sign that Ericsson sees such a combination of licensed and unlicensed frequencies as yet another potential path to the much vaunted 5G networks of beyond 2020, in whose development and standardization the Swedish group is playing a major role. The company plans to have its first small cell product ready by the fourth quarter of this year -- with indications that it will retail at about $2000- and, in a coordinated announcement at the CES, said it has teamed with T-Mobile in the US to trial the technology over the coming months.
“Currently, there is approximately 550MHz of under-utilized spectrum in the 5GHz Unlicensed National Information Infrastructure (UNII) band, which is available for any use within the FCC’s rules for the UNII band,” wrote Neville Ray wrote Neville Ray, chief technical officer, T-Mobile US Inc., in a blog earlier this week.
The word ‘various’ used by Ray clearly suggests that neither T-Mobile on the carrier side, nor Ericsson amongst the equipment makers, will have the field to themselves in all this. Indeed, there is a very closely allied initiative also under way, LTE-Unlicensed (LTE-U), first suggested by Qualcomm and Ericsson in late 2013, that also focuses on the use of LTE in the 5GHz unlicensed frequency band. This has already been vigorously debated within the 3rd Generation Partnership Project (3GPP) as, like LAA, has the potential to cause interference if LTE ‘takes over ‘ the WiFi it is riding on.
Although not specifically noted, one of the most important considerations of the T-Mobile/Ericsson trials will be to assess in real operating conditions the impact of such potential interference. We have had little feedback on this aspect from trials such as those conducted last year by Huawei and Japanese carrier NTT DoCoMo that did demonstrate LTE-U technology works. Nokia and Samsung are also known to have developments around LAA. There are, not surprisingly, downsides to using LAA. For example, some have noted that it could degrade the performance of 5GHz WiFi networks. Network operators will also be wary as they may lose the ability to monitor, and thus charge, subscribers once they enter the unlicensed world.
As an aside, it seems strange Ericsson decided to use CES to grab what it hopes will turn out to be first mover advantage for its LAA-enabled picocells. Yes, the Las Vegas extravaganza is no longer a show just about traditional consumer electronics products, but a more obvious venue for such a product announcement might have been the Barcelona gig that is the World Mobile Congress, taking place during March 2-6 this year, rather than the usual mid-February slot.
Perhaps the Swedish group has some intelligence that others involved in developing LAA small cell devices or trialing them was gearing up for a similar announcement. That would not be a surprise, as this aggregation technology is definitely one to watch.