Monday, 27 November 2017

5G and CBRS Hype?

The dissenting voices on 5G and CBRS are getting louder. While there are many analysts & operators who have been cautioning against 5G, its still moving ahead with a rapid pace. In the recent Huawei Mobile Broadband forum for example, BT's boss admitted that making case for 5G is hard. Bruno Jacobfeuerborn, CTO of Deutsche Telekom on the other hand is sitting on the fence. Dean Bubley's LinkedIn post is interesting too.

Anyway, we have storified most of the tweets from Huawei Mobile Broadband Forum here.

Signals Research Group recently published their Signals Flash report, which is different from the more detailed Signals Ahead reports looking at 5G and CBRS, in addition to other topics. I have embedded the report below (with permission - thanks Mike) but you can download your own copy from here.

The summary from their website will give a good idea of what that is about:

CBRS – Much Ado About Not Very Much.  The FCC is heading in the right direction with how it might regulate the spectrum. However, unless you are a WISP or a private entity looking to deploy a localized BWA service, we don’t see too many reasons to get excited.

Handicapping the 5G Race.  Millimeter wave networks will be geographically challenged, 600 MHz won’t scale or differentiate from LTE, Band 41 may be the most promising, but this isn’t saying much. Can network virtualization make a winner?

It makes no Cents! Contrary to widespread belief,  5G won’t be a new revenue opportunity for operators – at least in the near term. The vertical markets need to get on board while URLLC will lag eMBB and prove far more difficult to deploy.

This Fierce Wireless article summarises the issues with CBRS well.

“While (some) issues are being addressed, the FCC can’t solve how to carve up 150 MHz of spectrum between everyone that wants a piece of the pie, while also ensuring that everyone gets a sufficient amount of spectrum,” the market research firm said in a report. “The 150 MHz is already carved up into 7- MHz for PAL (Priority Access License) and 80 MHz for GAA (General Authorized Access). The pecking order for the spectrum is incumbents, followed by PAL, and then by GAA…. 40 MHz sounds like a lot of spectrum, but when it comes to 5G and eMBB, it is only somewhat interesting, in our opinion. Further, if there are multiple bidders going after the PAL licenses then even achieving 40 MHz could be challenging.”

Signals said that device compatibility will also be a significant speed bump for those looking to leverage CBRS. Manufacturers won’t invest heavily to build CBRS-compatible phones until operators deploy infrastructure “in a meaningful way,” but those operators will need handsets that support the spectrum for those network investments to pay dividends. So while CBRS should prove valuable for network operators, it may not hold as much value for those who don’t own wireless infrastructure.

“The device ecosystem will develop but it is likely the initial CBRS deployments will target the more mundane applications, like fixed wireless access and industrial IoT applications,” the firm said. “We believe infrastructure and devices will be able to span the entire range of frequencies—CBRS and C-Band—and the total amount of available spectrum, combined with the global interest in the C-Band for 5G services, will make CBRS more interesting and value to operators. Operators will just have to act now, and then wait patiently for everything to fall into place.”

While many parts of the world are focusing on using frequencies around and above 3.5GHz for 5G, USA would be the only country using it for 4G. I suspect that many popular devices may not support CBRS but could be good for Fixed Wireless Access (FWA). It remains to be seen if economy of scale would be achieved.

Thursday, 23 November 2017

5G NR Radio Protocols and Tight Inter-working with LTE

Osman Yilmaz, Team Leader & Senior Researcher at Ericsson Research in Finland gave a good summary of 5G NR at URLLC 2017 Conference (see summary here). His presentation is embedded below:

Osman, along with Oumer Teyeb, Senior Researcher at Ericsson Research & member of the Ericsson 5G standardization delegation has also published a blog post LTE-NR tight-interworking on Ericsson Research blog.

The post talks about how how signalling and data will work in LTE & New Radio (NR) dual connected devices. In control plane it looks at RRC signalling applicable for this DC devices whereas in user plane it looks at direct and split DRB options.

Further details here.

Tuesday, 21 November 2017

A practical use of MOCN in ESN

Just came across this slide from recent DAS & Small Cells Congress where EE talked about their ESN network development. Found this particular example interesting as they talk about how the commercial user and ESN user would use the same RAN but a different core.

This ties nicely with a recent tutorial that I did on Mobile Network Sharing options. If you would like to learn more, see here.

Thursday, 16 November 2017

Ultra Reliable Low Latency Communications (URLLC) 2017 Conference summary

Picture Source: Martin Geddes

It was a pleasure to attend this conference this week. Not only was the topic of interest but I am always impressed by how well EIE organizes their events. Instead of writing my own summary, here is a story created from tweets, 'The Mobile Network' live blog and a summary write-up from Martin Geddes. I have my takeaways below.

My takeaway from the conference is that:

  • URLLC is going to be challenging but its achievable.
  • Ultra-reliable (UR) may have different use cases then low latency communication (LLC). Lumping them together in URLLC is not helpful.
  • Extremely low latency may not be achievable in every scenario. In some cases it would make more sense to continue with existing or proprietary solutions.
  • URLLC may not happen when 5G is rolled out initially but will happen not long after that. 
  • There are many verticals who may be able to take advantage of both the higher data rates that would come as part of eMBB and the low latency and high reliability as part of URLLC. 
  • The operators would have to foot the bill for upgrading the networks as there is a relucatnce from the verticals to invest in something they cant see or play with
  • There are verticals who invest heavily in alternative solutions that 5G may be able to solve. Some operators believe that this will bring new revenue to the mobile operators
  • Slicing has a lot of open questions including Security and SLAs - nobody has a clear cut answer at the moment
  • The industry is in a learning phase, figuring things out as they go along. There should be much more clarity next year.
  • #URLLC2018 is on 13 & 14 Nov. 2018 in London. Plenty of time to find all the answers 😉

Further reading:

Wednesday, 15 November 2017

Couple of quick interviews from URLLC 2017 Conference

I tried the Facebook Live feature yesterday at the URLLC 2017 conference and recorded a couple of quick interviews with Martin Geddes and Prof. Andy Sutton. Hope you find them useful.


Further Reading:

Friday, 10 November 2017

5G Research Presentation on URLLC

Dr.Mehdi Bennis from Centre for Wireless Communications, University of Oulu, Finland recently did a keynote at The International Conference on Wireless Networks and Mobile Communications (WINCOM'17), November 01-04, 2017, Rabat, Morocco. He has shared his presentation with us. Its embedded below and available to download from Slideshare.

Picture Source: Ericsson

For those who may not be aware, there are 3 main use cases defined for 5G. As shown in the picture above, they are enhanced Mobile BroadBand (eMBB), Ultra-Reliable Low Latency Communications (URLLC) and massive Machine Type Communications (mMTC). You can read the requirements here.

Further Reading:

Thursday, 9 November 2017

Quick tutorial on Mobile Network Sharing Options

Here is a quick tutorial on mobile network sharing approaches, looking at site/mast sharing, MORAN, MOCN and GWCN. Slides with video embedded below. If for some reason you prefer direct link to video, its here.

See also:

Sunday, 5 November 2017

RRC states in 5G

Looking back at my old post about UMTS & LTE (re)selection/handovers, I wonder how many different kinds of handovers and (re)selection options may be needed now.

In another earlier post, I talked about the 5G specifications. This can also be seen in the picture above and may be easy to remember. The 25 series for UMTS mapped the same way to 36 series for LTE. Now the same mapping will be applied to 38 series for 5G. RRC specs would thus be 38.331.

A simple comparison of 5G and LTE RRC states can be seen in the picture above. As can be seen, a new state 'RRC Inactive' has been introduced. The main aim is to maintain the RRC connection while at the same time minimize signalling and power consumption.

Looking at the RRC specs you can see how 5G RRC states will work with 4G RRC states. There are still for further studies (FFS) items. Hopefully we will get more details soon.

3GPP TS 22.261, Service requirements for the 5G system; Stage 1 suggests the following with regards to inter-working with 2G & 3G Legacy service support
The 5G system shall support all EPS capabilities (e.g., from TSs 22.011, 22.101, 22.278, 22.185, 22.071, 22.115, 22.153, 22.173) with the following exceptions:
- CS voice service continuity and/or fallback to GERAN or UTRAN,
- seamless handover between NG-RAN and GERAN,
- seamless handover between NG-RAN and UTRAN, and
- access to a 5G core network via GERAN or UTRAN.