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.

Sunday, 6 March 2016

Current-State and Future of In-Building Tech

From a talk presented by John K. Bramfeld (@johnbramfeld) in Wireless Training Seminar & Networking Event - DASpedia West. The talk was 60 minutes but there are just 26 slides; most of the info was in the commentary. Anyway, it is an interesting presentation.



Friday, 26 February 2016

"Vehicular CrowdCell" or "Vehicular Small Cell" and the 5G plan


In the recent Mobile World Congress, Vodafone and BMW introduced the Vehicular CrowdCell concept, a small cell providing coverage in the car when people are in it and outside when the car is parked. The presentation is embedded later on in the post.


The following is from the BMW press release:

...the BMW Group is unveiling the research project “Vehicular CrowdCell”. This project extends the concept of the “Vehicular Small Cell” presented last year in Barcelona. While the “Vehicular Small Cell” is a mobile femtocell that optimises the mobile radio reception inside vehicles, it is now also capable to enhance the capacity and coverage of mobile radio networks. The BMW Group is teaming up with peiker and Nash Technologies to present a prototype of the “Vehicular CrowdCell” integrated into a BMW research vehicle.

The rapid growth of mobile data traffic, e.g. due to the increasing use of multi-media services such as music or video streaming with mobile devices, requires even more powerful mobile radio networks in the future. One strategy to increase the capacity and coverage of future networks is the integration of a large number of small cells and relays in addition to the existing base stations.

In 2015 the BMW Group, together with its partners peiker and Nash Technologies, presented the world’s first mobile femtocell in a vehicle. The “Vehicular Small Cell” optimises the reception available to mobile devices inside vehicles via the vehicle’s aerial. Now the concept has been extended to create the “Vehicular CrowdCell”. Based on data traffic and coverage demands, the mobile femtocells are dynamically activated to locally enhance mobile radio networks.

The benefits of Vehicular CrowdCells in practice.
One possible application of “Vehicular CrowdCells” are car-sharing fleets – in particular with electric vehicles. Here, a large number of vehicles spread over cities and regions could serve as local radio relays when parked. If one or more users are located close to a mobile femtocell, it is activated on demand in order to increase the bandwidth or provide additional network coverage. In such a way, the performance of the existing network can be dynamically optimized. Benefits for mobile phone users in hotspots include a higher data rate and the absence of reception white spots – especially in areas where the signal coverage is low.

“The “Vehicular Small Cell” will optimise in-vehicle connectivity of mobile devices for our customers,” explains Dr. Peter Fertl, project manager at the BMW Group. “At the same time, the integration into a network of “Vehicular CrowdCells” will enable the ubiquitous and seamless availability of high-quality mobile radio connections outside the vehicle as well.”

Nash innovations have more details about the earlier version of this, The "Vehicular Small Cell" here and here.

Before we go any further, check out the Vodafone presentation embedded below:



I wrote a blog on this topic back in May 2014 here. In that article I mentioned that for a small cell in the car, the biggest challenge is backhaul. One approach is to use one particular frequency for backhauling to the small cell and then the small cells output another frequency. This approach was mentioned in another blog post here. In this approach, TD-LTE was used for backhaul and it created an FDD LTE small cell inside the train.

Why do I think this kind of approach work with 5G. In my other post about 5G spectrum, I mentioned that 5G will need multiple frequencies. Low frequencies for coverage, high frequencies for capacity and very high frequencies for very high speed throughput's. Because the very high frequencies, do not travel very far as compared to the low frequencies (with the same power), beamforming would be used. These very high frequency beams can be directed towards the Vehicular small cells, which in turn would create a much larger cell at a lower frequency.

This approach would typically only be used in urban environments as in rural areas there is plenty of unused spectrum (until more uses are found - quite possible with the IoT device explosion). The small cells would also need advanced sensing and SON capability to work in harmony with the macro network.

If you have an opinion, feel free to add it in the comments section.

Saturday, 6 February 2016

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.

Sunday, 24 January 2016

Wireless densification via HetNet orchestration


According to a whitepaper that was published late last year by ThinkSmallCell:

There are commonly thought to be three ways to densify wireless traffic capacity:
1. More spectrum (expensive, limited)
2. More spectrally efficiency (e.g. LTE rather than 2G)
3. More spatial reuse (i.e. small cells)
But there is also a fourth aspect which can deliver significant additional benefit
4. Orchestration and tighter control. (e.g. SON (Self Organising Networks), traffic steering/shaping across and between all available wireless resources)

This has been a key factor driving replacement of outdated macrocells with “Single RAN” basestation equipment that supports all generations of radio interface. These specifically address (1) and (2) above. What’s needed next is investment in tools and equipment that provides similar flexibility for (3) and (4), scaling to cope with an influx of small cells and introducing real-time management and co-ordination across all available wireless technologies, both cellular and Wi-Fi.

While we dont generally hear a lot about SON nowadays, I know most of the vendors have implemented some or the other aspects of SON in their equipment. Orchestration can definitely have a much bigger impact than SON by itself on the densification.

In 5G, we talk about 'edgeless cells', 'no-edge networks', etc. Orchestration of the network will have a big part to play in this too.

Anyway, here is the whitepaper embedded below and available to download from Slideshare