Sunday, 22 March 2015

10 million small cells and growing?

There were some good news that was announced in MWC 2015. Here are some interesting points from Total Telecom:

  • Operators around the globe have purchased more than 10 million small cells
  • In excess of 75 operators worldwide are using small cells in their networks
  • The majority of these to date have been deployed in residential scenarios, but we have also seen a significant step upward in the enterprise and urban sectors.
  • 17,000 small cells have been deployed in rural or remote applications

While this all sounds good, Small Cells are facing many challenges. The biggest among them being WiFi. With the introduction of VoWiFi, many operators are starting to play a waiting game rather than deploy more small cells.

I blogged back in 2013 that AT&T planned to deploy 40,000 small cells by 2015 but it looks like they have now abandoned their goal. The reason being cited is that they acquired another small operator (Leap Wireless) which gave them additional macro sites, hence removing the need for small cells.

As per a report by the analyst firm ThinkSmallCell, TalkTalk, a UK based "thick" MVNO is trying to deploy an "Inside-out" Femtocell network. They have also been experimenting with 3MHz bandwidth in LTE and surprisingly, it works fine on most devices.

TalkTalk Future Network
Another option could be to have LTE-LAA/LTE-U along with this and they could provide good speeds not only to the people indoor but also outdoor.

In any case, we will have to wait and see if operators continue rolling out small cells and if they do why, how, where and in which situations.

Sunday, 22 February 2015

Flying Small Cells for Rural Coverage using Drones and Balloons

Image: Google Loon Balloon

"We will begin exploring 'Air Masts'," EE CEO Olaf Swantee wrote. These are "essentially aerial small cells positioned in the sky above a hard-to-reach area, using either tethered balloons or unmanned craft, bridging the UK's transmission gap.

While this would be interesting and challenging, it wouldn't be the first time. Google has been trying something similar with its 'Loon' project. In fact its partnered with the Australian operator Telstra to bring connectivity in hard to reach places.

Another possible approach is to have small cells via drones. A prototype can be seen above in the embedded tweet. In fact one of the articles have been nicely worded "EE Plots Drones to Blanket UK for 4G"

Daily mail has a picture of the drone as well.

Back in 2012, Daily Wireless ran an article on Unmanned Aerial Vehicles (UAVs) to be used as 'Flying Cell Towers'.

The main challenge for these deployments is the backhaul. One approach is to have satellite backhaul which may be possible for balloons but may not be easy. For the drones, they would have to create a mesh network among themselves with at least one of them receiving signal from the ground.

This nice conceptual diagram from Inmarsat shows how backhaul is provided to the planes. Using a combination of satellite and complemented by a fully integrated air-to-ground network. I am assuming a similar approach for the balloons/drones.

Anyway, we will hopefully learn a lot more in the coming months and years.

Sunday, 1 February 2015

LTE-LAA updates - Jan 2015

There has been quite a few updates on LTE LAA in the past month. First, there is this good video from Ericsson explaining what it is:

The 3GPP chairman recently presented a status update about developments on unlicensed spectrum at an IEEE 802 meeting last month. His presentation is embedded below:

IEEE 802 group have their own presentation on the co-existence lessons learned. This is embedded below:

Ericsson has also got a recent presentation on this topic. As can be seen, they expect a solution to be available in 2016-17. Presentation embedded below (download link here)

Finally, if you watched the video by Ericsson, they mention that one of the key milestones of 5G is to be able to combine licensed and unlicensed technology. One of the technologies being proposed in 5G is called Multi-Stream Aggregation (MSA). MSA allows multiple access technologies over licensed and unlicensed bands effectively. The picture above shows how it would work in theory. It may be more difficult in practise though. 

Monday, 19 January 2015

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.

Monday, 12 January 2015

Case study of WLAN and Small Cells by China Unicom

China is a huge and most populated country. Many people do not realise that the number of mobiles in China is more than combined USA and Europe. There are challenges that come along with this huge subscriber base. That is why its not enough to have just cellular connectivity. Small cells and WiFi has a big role to play. A news article last year boldly stated that 'Wi-Fi to be new battleground in China's internet sector'.

According to this article by ThinkSmallCell last year, China Unicom is the second largest operator in China with 251 million subscribers and $21 Billion in revenues. They have only 40MHz available for 4G cellular as compared to 130MHz for the leader China Mobile.

This presentation from Small Cells World Summit 2014 is a good case study of how China Unicom is working on deploying Wi-Fi hotspots and Small cells to meet their customers needs. The complete presentation is below and available from Slideshare.

Tuesday, 6 January 2015

Small Cells Backhaul & Coordination

An interesting presentation from the Small Cells Backhaul Summit in June 2014. Time synchronization between Macro and Small cells are becoming very important for new features like eICIC, CoMP, etc. This presentation provides some insights into this.

Friday, 19 December 2014

Small Cells Network Sharing

Network sharing makes sense for the operators in this day and age when ARPU keeps going down and users expect more from their networks. The picture above shows the different components that can be shared to increase the cost savings.

Small cells sharing has been on agenda for a long time and it is starting to be deployed in the networks. I an interview with the new Small Cell Forum chariman, Alan Law, ThinkSmallCell covered this as a question:

What's your view on multi-operator Small Cell solutions?

Historically, there were a number of factors holding back adoption of multi-operator Small Cells, ranging from commercial aspects to technical aspects such as managing how the available capacity is shared between operators.
However, two 3GPP standards (MORAN and MOCN) have been defined which allow the same Small Cells to be shared between networks.
A few vendors and operators have implemented these features today demonstrating that there is no reason why Small Cells must be tied to a single operator
In another article featuring Radisys:

Can't Small Cells support multi-operator without DAS?

There are two existing 3GPP standards which do make this technically feasible. Both are already in commercial use today.
MOCN (Multiple Operator Core Network) is a network sharing concept that is fairly straightforward to implement, similar to network roaming. MORAN (Multiple Operator Radio Access Network) is more involved, providing a deeper integration and requiring more software within the small cells.
Some of our key customers are already using MOCN, but I see MORAN being the long term future – sharing the RAN as an end-to-end resource rather than just connecting through the core network. I can see a major challenge as we move outdoors to the streets where practical deployment constraints won't allow multiple small cells to be strung from the same lamp-posts.

I covered this RAN sharing in the 3G4G blog earlier here.

While the above picture is for the UMTS network, the LTE network sharing would be similar. Embedded below is a research paper that discusses the various approaches and to small cells network sharing and also features some case studies.

Here are some additional links on this topic that would make an interesting reading:

Thursday, 11 December 2014

Small Cells and WiFi Forecast 2013 - 2019

We had this last set of forecasts back in February, here is a new one up to 2019/20.

The slides and the video is embedded below but I want to mention few things here. The first being that in the last year (or since the beginning of this year) the main change that has occurred is the availability of Voice over WiFi (VoWiFi), either as native or as an app, has become a commonplace. What this means that some small cells deployments are no longer high priority and has been pushed back.

On the other hand some operators are conscious that small cells can provide a better QoS than WiFi hence they are going ahead with Small cells deployments.

Anyway, Slides and Video as follows:

Please feel free to leave your opinions in the comments below.

Saturday, 29 November 2014

'Inside-out' or 'Outside-in'

Going through my old presentations, I came across this prestigious lecture delivered by Dr. Tim Whitley of BT. The main argument of that lecture was, The future of mobile is fixed and the future of fixed is mobile. During the ending of the presentation there is a discussion on Outside-in v/s Inside-out. Lets look at those slides here:

Qualcomm is a big fan on Inside-out as can be seen here. Other small cell manufacturers support the inside-out approach too.

The question is, does inside-out approach matters any more. By next year many operators and devices will support VoWiFi in native client. Which means that even if your coverage is poor or non-existant inside, you will still receive voice calls and text messages. Data will continue over WiFi as normal.

An argument in favour of cellular is better/guaranteed QoS as in VoLTE and maybe new services can be available faster but private WiFi best (or no) effort is not bad generally.

What are your thoughts on this topic?