Look back and forecast of Small Cells

Going through 'End of Year Report' by ThinkSmallCell. A good summary of what happened in 2016 and what we can see in 2017. This picture above from the same report is interesting. As you can see that the average speeds of 3G have decreased while that of 4G has increased significantly. I suspect what has happened is that the newer devices with more advanced 3G capabilities now have access to 4G while the older devices with basic HSDPA support have stayed on 3G, decreasing the average speeds.

You can also read the top 5 posts from this blog here.

Coming back to forecasts, another ThinkSmallCell Analyst Spotlight webinar where Caroline Gabriel from Rethink research and Kyung Mun from Mobile experts provide their insight into where small cells are headed in 2017 and beyond.

Personally, I think with VoWiFi becoming common in our devices, the market for residential and enterprise eventually will decrease. I hear you say what about QoS, well see my 3G4G blog post here.

Here are the slides and video from ThinkSmallCell webinar:

LTE-A, Hetnets and Phase Timing

I was going through my old presentations looking at frequency and phase requirements for LTE-A and HetNets. The slide above is some years old but it does summarise the requirements well. There is also an interview by Martin Kingston & Andy Sutton of EE on this topic which is available here. I would think that with 5G latencies often quoted as less than 1ms (but in practice it may be up to 10ms) would have very critical frequency and phase timing requirements.

ThinkSmallCell recently held a webinar on this topic. The write-up is available here and slides/video is embedded below. Here is something I found interesting:

In the past, a central Grand Master supplied a common signal that was hardwired throughout the network. Today, we now see distributed master clocks appearing almost everywhere. Typical requirements are for 50ppb frequency and 1.5us phase timing over the air, driven from 16ppb and 1.1us into the base station.

Frequency sync requires a Primary Reference Clock (PRC), whereas Timing sync requires a Primary Reference Time Clock (PRTC). The latter must come from a satellite GNSS source, such as GPS, and be traceable to Universal Co-ordinated Time (UTC).

The end-to-end Inter-Cell time error budget of 1.5us (1500nanoseconds) is split into three parts:

• A time source, with an error of up to 100n
• The transmission network, with up to 1000ns
• The small cell (eNodeB), with up to 400ns

The transmission network may have up to 10 boundary clocks with a combined total of 500ns error. The remaining allowance is split equally between dynamic time errors and network asymmetry. It is especially important that packets travelling in each direction (uplink/downlink) incur similar amounts of delay variation – if the time taken to send and receive packets varies differently, then phase timing errors would mount up rapidly.

It is this asymmetry of packet delay variation which is the biggest problem with engineering phase timing throughout a large network.

The ITU has defined two different time profile standards related to transmitting the phase sync signal.

G.8275.1, which relies on full on-path support. Each node in the backhaul transmission network must be fully aware of the phase timing component and actively support its transmission. Each router or node would have its own boundary clock that synchronises and re-generates the timebase locally. This may be feasible for new product but would otherwise require replacement or upgrade for existing routers and backhaul transmission equipment.

G.8275.2 was recently consented and only requires partial on-path support. One or more boundary clocks are installed at the most effective points in the backhaul path, with many legacy routers/nodes being unaware of the special importance of the PTP packets.

It is crucial to take into account the existing technical infrastructure and also cost for deployment. As part of this effort, it is critical to engineer the network so that asymmetry correction can be considered.

In cases where full on path support is deployed, the mitigation of uplink versus downlink asymmetries are extremely important and usually requires a manual calibration of each link which is extremely costly.

Here are the slides with Video in the end. Video can also be directly viewed on Youtube here.

*** Edited 11/04/16 - 10.30 ***

RTT has just published an article on related topic titled 'A second look at time', available here.

Small Cells Forecasts...

Small Cell Forum published a report last year titled 'Crossing the Chasm: Small Cells Industry 2015' in which draws on the findings of three very different pieces of research to show that, in 2015, for the first time outside the residential segment, small cells moved from trials and smaller deployments, to large-scale roll-outs, and this process of densification will accelerate from 2016 through to the end of the decade. The three studies each targeted a different base of respondents and so the plans and opinions of three key stakeholder groups – mobile operators, the component ecosystem, and enterprises – are all brought together to create a uniquely multidimensional view of the state of the market today. The report is available here to download.

ThinkSmallCell held their annual analyst forecast with Caroline Gabriel of Rethink Technology Research and Joe Madden of Mobile Experts. Their slide deck (with Video at the end) is embedded below. The webinar could also be viewed directly on Youtube here.

Feel free to add your opinion in the comments section on if you agree or disagree with these forecasts and statistics.

In-Building Options: Facts, fiction, Architecture and Solutions

In-building solutions are still a big topic of discussion. While there are neutral solutions like Wi-Fi will become more common, does it mean that cellular is no longer a necessity? To answer these questions and to make everyone familiar with the options here are a couple of videos of recent webinars.

The first one is from Alcatel-Lucent titled "Fact vs. Fiction – The Debate on In-Building Architecture Options". It discussed the three architectures (as seen in the picture above) DAS, Distributed Radio Systems (DRS) and Small Cell. Here is the video:


The other webinar (actually 2) is from ThinkSmallCell.

"Choosing the right In-Building Cellular Solutions" is a high level webinar that discusses the needs and available solutions. It also shows the decision process in selecting the right solution. The video is embedded at the end of the slides below but can also be seen directly from Youtube here.

The other older webinar and presentation by ThinkSmallCell that goes more in-depth of these In-building solutions has already been covered in an earlier blog post here.

In-building Wireless Solutions Webinar

Last month, David Chambers from ThinkSmallCell held a webinar exploring available In-building solutions and comparing the advantages and disadvantages of each solution, also looking at the approach taken by different vendors. Worth a look. The presentation and Youtube video are both embedded below.

HetNet Strategies with Oi Brazil

Brazil has been in limelight since the beginning of the year. Initially, the focus was on how the FIFA World Cup may fail but later on for the way everything came together at the last minute and everything worked. From a technology point of view, WiFi was a big saviour in the stadiums, allowing good connectivity for everyone wishing to add the things they liked on social networks as soon as they can.

An example was this chart tweeted by Ruckus Wireless to proudly show what their achievement was with stadium WiFi.

Recently, Maravedis-rethink conducted a webinar with the Brazilian operator Oi, regarding their HetNet strategies. The video for the relevant part is embedded in the end. Two slides caught my attention. The first was about the different technologies and their concerns (above). For example for a HetNet to be successful, all components should synchronised and have a strict time accuracy requirements. The Backhaul & Fronthaul requirements are equally interesting for different cases.

The second interesting slide is the final one where they have their wish list to what they would like to do in near-term and long-term. WiFi features in all the scenarios except for the rural case (as expected). Anyway, here is the video:



You can download the slides from Slideshare here.

Case Study: Deployment scenarios with DAS, RRH, Small Cells and Wi-Fi

I attended an interesting webinar (details in the end) from Infonetics Research, EXFO and ExteNet Systems where one of the areas of discussion was around which technology for which scenario. The four main technologies being considered was DAS, RRH, Small Cells and Wi-Fi. There was some interesting deployment examples that I have embedded below:

How to Get the Best Out of DAS, Small Cells, and WiFi from Zahid Ghadialy

NOTE: If the slides are not working, please view it on Slideshare - slides 21 to 24

To watch the webinar recording and download slides, please follow this link: http://w.on24.com/r.htm?e=783410&s=1&k=CD70E2F6D98C3E67A3B5A1936E23DB13

DAS or 'Small Cells' for Indoor Location

There was a recent webinar by Maravedis-Rethink & EJL. The slides are available on Slideshare here. I think there were some good points made about using DAS or Small Cells for the Indoor environment. Here is the youtube clip. You can drag the pointer to the beginning, to listen from the start.

Small Cells and WiFi Forecast 2012 - 2018

I have been following and having some interesting discussions on a Linkedin group where the main argument is that Small Cells may never really take off as its not a good solution and doesn't make a good business case. I think that kind of discussion is best left to do on Linkedin.

ThinkSmallCell held a webinar recently inviting couple of leading experts to discuss their forecasts for Small cells. The webinar slides and videos are embedded below. Here is a quick comparison of what these independent leading experts had to show:

The main point to note above is that we will hopefully hit 1 million public access small cells probably around/after 2015. My view on why operators have been slow in deploying small cells have been mainly to do with interference management. As we know, Small cells are deployed for Coverage and Capacity and is mainly deployed in Co-channel (same carrier as Macro). If there is no or little coverage, Small cells deployment is not an issue. With higher frequencies, the reception in the houses goes down so deploying Femtocells make sense. With public access small cells, interference (especially on 3G) has to be managed. Surprisingly the practical results for co-channel public access outdoor small cells deployed for capacity purpose is not too bad but there is a no coverage area created as a result of interference at the edge of the small cell. This can cause handover issues.

In LTE-A, Interference techniques like (f)eICIC will help handle these situations so I wont be surprised if there are lots of deployments next year with this interference management capability.

The main thing to note is that WiFi will play a huge part for the connected devices of the future. Most of the small cells deployed with also have a WiFi capability so operators can use that to offload traffic from the cellular on Wi-Fi.

My understanding is that in future we will see Macro cells mainly serve high-mobility connections (including connected cars) and Small cells and WiFi will be used for low mobility and fixed access. I guess the real advantage of cellular over Wi-Fi in this low mobility scenario is that since Wi-Fi is unlicensed, there could be interference from many unpredictable sources. Licensed cellular bands dont generally have this issue.

Anyway, the presentation and video from webinar is embedded below:

New opportunities in Carrier Wi-Fi & Wi-Fi offload

Interesting webinar from Maravedis-Rethink exploring the new opportunities with Carrier-WiFi and Offloading. Embedded below is the video and presentation:

Carrier Wi-Fi & Wi-Fi offload from Zahid Ghadialy

Enterprise Small Cell Architectures

Deployment in enterprise is a challenging task for the operators but it has many benefits hence this is one of the areas they have been working very hard to get it right.