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?

Saturday, 15 November 2014

Connectivity in the stadiums

I have recently been observing a lots of discussions around connectivity in the stadiums. I have used this picture above a few times to show different solutions available in different situations. You can see that in theory Wi-Fi, DAS, Micro and Pico would all be suitable for the connectivity in stadiums. In practice this is generally limited to DAS and Wi-Fi.

ThinkSmallCell have recently written an article on the stadium Wi-Fi experience of The Cloud here. Some very interesting choices were taken to keep things simple:

For the main stadium bowl, The Cloud designed for 50% concurrent access for the maximum 30,000 crowd, connecting 80 Wi-Fi access points using 1km of fibre and 9km of CAT6 ethernet cable.

Each access point can handle up to 250 concurrent users. Tightly focussed beams were used to segregate seating blocks, splitting these into distinct coverage sectors.

To simplify the design, the older 802.11b standard wasn't used/supported, VoIP was blocked and a maximum of 3 SSIDs assigned. Unlike a cellular system, there's no handoff as you move around the stadium – you'd need to reconnect and create another session. During peak usage, almost everyone is sitting down rather than moving about (if you ignore those jumping up and down on their seats).

Both Wi-Fi spectrum bands at 2.4GHz and 5GHz were used, with devices capable of the higher frequency prioritised to use it. 56% of clients used the 5GHz band, which has much more spectrum and many more channels available. The different propagation characteristics mean there are different coverage footprints, so planners are actually designing two networks rather than one.

The side lobes on the 5GHz coverage footprint were massive, limiting the number of Wi-Fi access points that could be deployed.

You can read the complete article on the ThinkSmallCell website here.

A question some people often ask is why bother with connectivity in the stadiums. There are many reasons and personally, I would rather have connectivity than don't, even if I am not going to use it.


Real Wireless has done substantial amount of work in this area and a slide from their recent presentation discusses the benefits for various parties very well. You can read their opinion on this topic on their website here.

No discussion on Stadium connectivity would be complete without mentioning the US operator AT&T. They regularly publish statistics and details of connectivity in various sports venues on their website here. A recent report from their new site on DAS connectivity in various stadiums as follows:

  • So far this season, there have been 119 pro football games and 214 college football games played across more than 75 different venues where we provide in-venue coverage via Distributed Antenna Systems (DAS). 
  • In total, across these 333 games our customers have used more than 104.9 Terabytes of mobile data on our in-venue cellular networks. That’s the same as 104,913 Gigabytes. Or more simply put, it is equivalent to more than 300M social media posts with photos. 
  • At this point in the year, pro football fans are edging college fans in average data usage per game by a 342GB to 293GB margin. Or a difference equivalent to about 140K more social media posts with photos per game on average.

Another recent report from the AT&T part in San Francisco where both Wi-Fi and DAS are present as follows:
Here are some of the record-breaking numbers we saw on our venue-specific mobile network at AT&T Park from the Giants’ three home games during the World Series:
  • Fans used more than 477GB of data on the AT&T cellular network during the game on 10/25. This is equivalent to more than 1.36M social media post with photos.
    • This marked the highest single game total for cellular data usage at AT&T Park in ballpark history.
  • Fans used an average of approximately 447GB of data per game over the weekend on the AT&T cellular network. This is equivalent to more than 1.27M social media post with photos.
    • It’s an increase of approximately 29% in cellular data usage compared to the average game during the League Championship series vs. St. Louis.
    • It’s an increase of approximately 109% in cellular data usage compared to the average game during the final home series of the regular season vs. San Diego (9/25-9/28).
  • The peak hour of data usage during three home games was on 10/25 was from 5-6pm PT, the hour in which the first pitch occurred. In this hour more than 83GB of data crossed our venue-specific cellular network.
  • On our AT&T Wi-Fi network we saw more than 1,626GB of data move across our network during the game on 10/25.
    • This is the highest single game Wi-Fi total in the history of AT&T Park.
    • 1,626GB is equivalent to more than 4.65M social media post with photos.
    • This showed an increase in Wi-Fi usage of approximately 302% compared to the average game during the 2012 World Series.
    • This showed an increase in Wi-Fi usage of approximately 163% compared to the average 2014 regular season game at AT&T Park.
    • This showed an increase in Wi-Fi usage of approximately 29% compared to the average game of the League Championship series vs. St. Louis.
  • The collective data usage equaled approximately 2.1TB of data across both our cellular and Wi-Fi networks at AT&T Park during the game on 10/25.
    • This marked the highest single game total for collective data usage (cellular and Wi-Fi) in AT&T Park history.
    • 2.1TB is equivalent to more than 6M social media post with photos.
Note: All cellular data is specific to only AT&T customers using the DAS network at AT&T Park.
AT&T DAS guru Paula Doublin was one of the most memorable speakers at this year’s HetNet Expo. The company’s AVP for antenna solutions, DAS and small cells did not shy away from questions about AT&T’s budget for heterogeneous networks, nor did she sugar coat the outlook for small cell deployments. A video of her presentation is embedded below and a writeup is available on RCR Wireless website here.




See Also: