Thursday, 25 August 2016

Small Cells vs Macro Cells Densification

Here is a presentation by KPN from Small Cells World Summit 2016 explaining how densification using small cells makes more sense than using macro cells. They have presented case study of Rembrandtplein to explain this. Feel free to add your views as comments.

Related posts:

Wednesday, 17 August 2016

Drone cells are becoming a reality

Back in early 2015, the then EE CEO Olaf Swantee said, "We will begin exploring 'Air Masts', 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."

The vision has not changed a lot. I recently blogged about 'EE's vision of Ultra-Reliable Emergency Network'. If you look at the slide above you will notice temporary solutions include Air masts, UAV's and Network in a box (NIB).

Nokia recently did a trial with EE where they used a drone to carry a tiny base station to remote areas around Inverness. Weighing in at only 2 kg, the Nokia Flexi Zone Pico cell has all the punch of LTE in a very compact package, allowing 4G services to be provided wherever a drone can reach. High quality LTE voice calls between responders, video streaming and up to 150 Mbps data throughput were all achieved, with no need for a connection to an external core network.

While it doesn't exactly say the area that was covered, I would expect it to be able to do at least 1 km diameter to be effective in an emergency scenario.

According to a recent International Business Times article, US operator AT&T is trying something similar to deal with the struggle to provide enough wireless data are large venue events to please customers. The mobile operator says that drones known as "Flying Cell on Wings (COWs)" could make all the difference. The idea would be that the drone would be tethered to the ground so they would hover in one place, sort of like a portable hovering small cell. 

Finally, Ericsson and China Mobile conduct world’s first 5G drone prototype field trial. In their recent press release it says:

In the trial, held in Wuxi in China’s Jiangsu province, a drone was flown using operator’s cellular network with 5G-enabled technologies and with handovers across multiple sites. In order to demonstrate the concept’s validity in a real-world setting, the handovers were performed between sites that were simultaneously in use by commercial mobile phone users.

The potential use cases for this technology include mission-critical applications such as support for emergency services. However, end-to-end low latency needs to be guaranteed by the operator’s network to ensure the safety and reliability of such services.

I am sure we will be hearing more on this topic soon.

Tuesday, 2 August 2016

Small Cells: Best solution for rural coverage?

I drive around the UK a great deal. While I rely mostly on my phone to call and message/text, I also use it to check tweets, Facebook, emails and most important of all as a Satnav (I'm a big fan of Waze). I often end up in scenarios where I have no coverage so a wrong turn results in my Satnav route failure. This can mean I have to drive around for miles before I can get back on route.

In most countries (including UK) when an operator mentions its coverage, its means population based coverage. The problem is that one may have reasonable coverage in a big town/cities but not on small roads and villages but the operator would have still met their coverage obligation. However this will be changing, at least in UK, with the announcement by EE that they will do a 95% geographic coverage. Kudos to them!

Picture Source: Point-Topic

This map I came across recently shows the rural challenges in Europe for providing connectivity. Whilst not that detailed, I can definitely say from a UK point of view, there are many places outside big towns and cities that have coverage gaps.

As can be seen above, a similar problem is present in Africa and Carribean and Latin America (CALA). In these regions, in addition to the coverage gap, affordability and lack of relevant content are also major issues.

To put it simply in most countries, there is that last 10% of the population for whom coverage is not deemed feasible for the operator.  The problem is that the investment would generally outweigh the revenues. The installation (site, backhaul, etc.) and the maintenance cost would almost always outweigh the profits.

This is one of the challenges that Parallel Wireless* is trying to solve.

What if you can make the deployment very simple and reduce the installation cost and have minimal maintenance cost?

The operator would be far more willing to give it a try. There was an announcement between Parallel Wireless and Telefonica I+D for exactly this reason recently. The small communities wherein these small cells are deployed also have a vital role to play. Not only could they help by making sites available, they can have directly report any issues that would arise. An example of this can be seen in the picture above, demonstrating a small cell deployment in a community center.

An important thing to bear in mind is the support for different types of backhaul for small cells. While cellular/LTE backhaul can allow quick deployment, additional type of backhaul can become available much quicker than anticipated. The small cell deployment should be flexible enough to be able to handle this new change.

A real life example of the above statement can be seen in the picture from a recent site survey.

Finally, I would like to embed this video that explains the Parallel Wireless Rural Solution very well.

Please feel free to add your suggestions in the comments below.

*Full Disclosure: I work for Parallel Wireless as a Solutions Architect. This blog is maintained in my personal capacity and expresses my own views, not the views of my employer or anyone else. Anyone who knows me well would know this.

Sunday, 24 July 2016

LIGHT-Net: China Unicom's mobile service booster

Another presentation from the Small Cells Word Summit 2016. China Unicom refers to LIGHT-Net. The definition of LIGHT-Net can be seen above but based on the translation of the press release here, LIGHT-Net stands for LTE Technology Innovation and Network Evolution Solutions. Continuing from the press release:

Experts said, LIGHT-Net will have five characteristics: First, the asset-light (the Low-cost) , the software-defined (SDN) to achieve a flexible network, reducing CAPEX and OPEX ; followed by intelligence (the Intelligent) , will enable the network automatic planning, optimization and automatic interference avoidance; third is green (green) , to achieve low power consumption, low radiation, low noise; fourth is efficient (High-efficiency) , improve resource scheduling capabilities and spectrum utilization efficiency; the fifth is close (Tight) , to achieve macro-micro coordination and heterogeneous integration.
Overall, LIGHT-Net research program can be divided into three steps. The first stage, based on the interference coordination LIGHT-Net microsite deployment: the introduction of micro-station deployment, absorbing macro hotspot network data traffic; the introduction of interference coordination technology to solve interference problems caused by increased cell. The second phase, enhanced collaboration processing, macro and micro interoperability: Promoting co-processing technology macro and micro cells, pico cells between the cell edge coverage to enhance performance and user access experience. The third stage, an access integration, multi-stream merge: the ideal backhaul carrier aggregation, non-ideal backhaul dual link technology between macro and micro HSAP / LTE -system multi-stream merger.

I think the small cells maybe Huawei's lampsite as I had mentioned earlier.

Anyway, the presentation is embedded below. As usual, if you have more details, please add as comments below.

Saturday, 9 July 2016

MEC, Small Cells & IoT

Here is a presentation from Vodafone on how Mobile Edge Computing and Small Cells can play a big role in Internet of Things.

Vint Cerf, who is universally recognised as one of the founding fathers of Internet recently said that there will be 1 Trillion devices on the net by 2036, many of them being IoT devices.

This presentation also lays out use cases for IoT. As always, I am interested in hearing your thoughts.

Sunday, 26 June 2016

Underground Small Cells

Following on from my earlier post on 'Small Cells & Wi-Fi in the pavements & roads', here are some more details about these underground small cells, see video below.

From Ericsson's press release:

Swisscom and Ericsson have deployed the world’s first vault site for LTE and small cells in Switzerland. Some 250 further rollouts are due in the country’s cities during 2016.

Swisscom and Ericsson have proved that city manholes can be used worldwide to improve capacity with small cells – even below street level – using the Ericsson Vault Remote Radio Unit and Kathrein’s Street Connect, an in-ground microcell antenna system. The use of existing street manholes where fiber and power already exists lowers total cost of ownership by 50 percent.

This, the world’s first vault site for LTE and small cells has been approved by the Swiss authorities, and 250 new rollouts are due during 2016 in the country’s cities. The solution effectively addresses cities’ needs by enabling the reuse of existing assets and underground space.

This site solution offers the best network capabilities in Switzerland by supporting the upcoming rollout of 5G.

Here is the video:

Monday, 6 June 2016

MulteFire: A double-edged sword

MulteFire has been a lot in news recently. ThinkSmallCell published a whitepaper and an interview with Stephan Litjens, Chairman of MulteFire Alliance, outlining its objectives and roadmap. Light Reading held a webinar, which is available here for anyone interested. The overview of the webinar says that the attendees will learn how MulteFire:

  • Delivers LTE-like performance with WiFi-like deployment simplicity
  • Compares to other LTE technologies operating in unlicensed spectrum
  • Coexists harmoniously with other technologies in unlicensed spectrum, including Wi-Fi
  • Broadens the LTE ecosystem to existing and new wireless providers
  • Provides a neutral host to serve any user

I agree with LTE-LAA and MulteFire and they both have a potential to deliver amazing speeds and capacity for the operators and any service providers who would use it. While it is a great technology enhancement, MulteFire can potentially disrupt the industry as we know today. Let me explain.

Picture courtesy of Keith Parsons

The way every one is seeing MulteFire is that operators can use the freely (or nearly free) 5GHz spectrum that is available. While there are or will be some restrictions, it could be used with low power indoors. The WiFi service providers have been eyeing this spectrum from a log time and 802.11ac is one such standard that makes use of this spectrum.

The end user does not necessarily understand the technology very well. Even though Wi-Fi enhancements are quite good and complex, from an end users perspective, Wi-Fi is free and "why should I have to pay so much for Wi-Fi?" ThinkSmallCell wrote an article on this topic back in January here.

The same consumer will have no issues generally paying for a MulteFire kind of technology as the origin of that is from the cellular world. While I have seen articles suggesting that MulteFire is more efficient than Wi-Fi protocols, I think we can disregard the efficiency angle from this particular post.

My first point here is that end users may be more willing to pay for MulteFire than for Wi-Fi.

The second point is that there is nothing stopping these Wi-Fi service providers from using MulteFire. As that would be a standard out of the box technology, possibly available as small cells, they can use it in conjunction with their Wi-Fi hotspots to provide more 'premium' coverage. Of course they will have to use different parts of spectrum for both these technologies. So here is a possibility of Wi-Fi service providers providing limited mobile services.

Now there is nothing stopping a large Wi-Fi SP to become an MVNO and use 4G/5G for high mobility connections and Wi-Fi / MulteFire for low mobility connections.

This does not just stop here. Many big warehouses and industrial complexes use private LTE networks. In this case they lease the network from a company that may also have chunk of licensed spectrum they bought. In some cases some operators are also providing commercial networks with pico cells / small cells. With MulteFire being widely available, these businesses / warehouses can use out of box small cells with any available devices supporting the technology.

Here there will be disruption with the value of these private licensed spectrum falling to a very low value. These private LTE network providers will have to up their game and compete against new entrants. The focus would change from technology and hardware to services.

There is a possibility of similar kind of disruption happening in testing arena where the only reason some test & measurement companies charge so much is because of technology being niche. Mass availability of small cells in license exempt spectrum may change this equation.

While these are just my thoughts, I am hoping that you would provide your view in the comments so we can have a healthy discussion on this topic.

Friday, 13 May 2016

Small Cells Deployment Stories

I recently got an opportunity to hear about the small cell deployment studies, organised as SCWS pre-conference workshop. The combined slides from the presentation are embedded below and available to download from Small Cell Forum page here.

Friday, 6 May 2016

HetNets On The Bus

Earlier in March, I helped organise 'The Gigabit Train' seminar'. The intention was to look at the connectivity options inside the trains and its monetisation. While connectivity in the trains is challenging, thinking back about it, due to a predictable route it can be sometimes easy to deploy. It could be more of a challenge for cars and buses that go through unpredictable routes and conditions.

I also discussed the "Vehicular CrowdCell" or "Vehicular Small Cell" concept here to look at some advantages of such a solution option.

Some of you may be aware that I recently joined Parallel Wireless. We were selected by M1 Limited, Singapore’s most vibrant and dynamic communications company, to support its WiFi-On-The-Go service as a part of the HetNet trial.

This is the architecture of the On-Bus Hetnet. Some of you would find it self-explanatory.

The mobile operators in Singapore are looking for innovative technologies to address spectrum scarcity as subscriber demand is growing rapidly with smartphone penetration reaching 130 devices per 100 people. Maximizing utilization of the spectrum and easing network congestion in areas with heavy human traffic is necessary to meet Infocomm Development Authority of Singapore (iDA) vision of connecting the whole nation as a part of world’s-first Smart Nation initiative.

Real-time HetNet orchestration and traffic prioritization is made possible by HetNet Gateway (HNG). All bus riders receive seamless, high throughput connectivity from an on-bus multi-mode LTE/Wi-Fi Converged Wireless System (CWS) small cell with integrated backhaul including licensed assisted backhaul.  By enabling carrier aggregation for backhaul, the end user throughput can be increased 10 times (up to 300 Mbps) allowing transit passengers to enjoy multimedia content without buffering.

Here is a presentation that gives the complete story:

Some questions on this demo from Linkedin:

Q: Does seamless handover are available with no drop in data throughput through out the travel route of Bus? 
A: Yes, handover is seamless, no dropped data or voice calls. This was one of the iDA trial requirements. We can do seamless VoLTE to VoWiFi handover and back.

Q: What is the maximum data rates does the system accommodate for all seamless data transfers? Does the system support motion video play from N/W. If so of what bandwidth and data rates? 4. How many users does the system support and what data rates?
A: It will depend on the backhaul. We can increase backhaul capacity with CA on 4G + to 300 Mbps shared bandwidth.

Q: This seems to be a relay device ( a femto or pico grade small cell with UE backhaul). an their innovative hetnet gateway for traffic engineering ( LBS support ). 
A: Our in-vehicle unit is a Small cell (LTE/Wi-Fi for access) with any backhaul incl UE backhaul. The HetNet Gateway, in addition to performing 3G, 4G, WI-Fi gateway functionality and real-time SON with ICIC, will also do the traffic engineering.

And demo from inside the bus:

Further reading:

Sunday, 10 April 2016

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.