Small Cells in BT Phone Boxes

Picture Source: Andy Sutton

In a news announcement yesterday, Vodafone said that they are planning to install 4G and 5G equipment to the underside of thousands of manhole covers across Britain to boost connection speeds in the busiest urban areas and meet the public’s insatiable demand for mobile data.

According to the report, Vodafone, which has hundreds of thousands of Cable & Wireless-branded manholes as part of its network, has developed the subterranean plan alongside Swedish telecoms equipment group Ericsson. The system is known internally as The Vault.

Attaching antenna equipment to the base of a manhole cover can boost the signal across a 200-metre radius, according to Vodafone, and could be critical in supporting future “smart city” technologies such as connected traffic lights. Installation does not require planning permission, which speeds up network build.

Vodafone and Ericsson have developed two types of system. One attaches equipment to the base of existing Victorian-era cast iron manhole covers. Another is a bespoke reinforced unit the size of a water butt that is sunk into the ground underneath a purpose-built cover.

We have blogged about Small cells infrastructure underground and in manhole covers. The following posts are related to that:

• Small Cells & Wi-Fi in the pavements & roads
• Underground Small Cells
• NTT Docomo's Underground LTE Small Cells with possibility to deploy 5G in future

Phone boxes, which are connected to the power supply, are a useful tool to boost demand on high streets and in rural areas. Vodafone has signed a deal with BT’s wholesale division to install 4G antennas in phone boxes, and has kitted out one on Edinburgh’s Princes Street to improve coverage in time for the Hogmanay celebrations on New Year’s Eve.

The picture on the top from Andy Sutton is from Small Cells World Summit back in may. He says, "New life for old kiosks, KX100+ accommodating a 4G LTE small cell for enhancing mobile area capacity density"

ThinkSmallCell has a nice picture of the top of the KX100+ phone booth. In it's report on the Small Cells World Summit 2018, David Chambers says the following:

BT had the largest demo with a full size telephone box equipped with a small cell hidden in the roof space. Although only one Nokia small cell was fitted, the unit could accommodate several from different network operators. Each site is backhaul with either 100Mbps or 1Gbps managed Ethernet and transmits above head height using an omnidirectional antenna. It would seem we will shortly be making phone calls from telephone boxes again, just without realising it.

It would be interesting to see some more of these old phone boxes converted into small cell towers.

See also:

• Vodafone News: Vodafone lifts lid on manhole covers to improve mobile coverage

Here is a tweet containing picture of Ericsson's vault radio system for anyone interested:

If I can briefly be a bit naughty, here's a diagram from E/// of the vault radio system. pic.twitter.com/1FMgwtofRM

— lightspeed (@lightspeed2398) December 11, 2018

CCS MultiPoint-to-MultiPoint (MPtMP) mesh wins Small Cell Forum Award

Picture Source: Lightspeed via Twitter

CCS recently won Small Cell Forum award for "Excellence in Commercial Deployment (Urban) category" for  Ultra-Fast, Next-Generation Backhaul Network in London’s Square Mile.

Absolutely delighted to have just been named Winner of the Excellence in Commercial Deployment (Urban) award at @SmallCell_Forum Small Cell Awards! #SCFAwards18 #SCWSWorld pic.twitter.com/jgCDJQesRd

— CCS (@CCS_multipoint) May 22, 2018

David Chambers, ThinkSmallCell wrote an in-depth article on this topic last year (here) but since then lot more small cells and new WiFi points have come up. The picture on the top shows the CCS Metnet backhauling a Wi-Fi hotspot and a Nokia Flexizone small cell from O2. Only recently has CCS declared that the City of London project is up and running. As pointed out in the article:

• CCS frames Metnet as the “world’s only self-organising 5G microwave backhaul”. Operating in the licensed 28GHz band, Metnet nodes are said to be unobtrusive and easy to install, with a wide field of view to minimise the need for radio unit installation.
• The CCS launch declaration also indicated that Nokia Flexi Zone small cells are being used for 4G connectivity, which is then carried over Metnet. This appears to be the first time Nokia has been referenced in connection with the City contract, with previously identified partners including Cisco Systems as a provider of access points for the Wi-Fi network, and Virgin Media for delivering core fibre links.

While the London deployment is in 28GHz band, the solution is also available in other bands as follows:

A more detailed datasheet is available here.

Finally, here is a nice video of the London Square Mile Deployment

CW Seminar on DAS vs Small Cells

I mentioned about the CW seminar in my earlier post here. The event is over so here are a few takeaways from the seminar.

The good news about CW Small Cells events is that David Chambers (ThinkSmallCell) does a very comprehensive summary. For this one, its available here.

For a limited time (for non-members), the presentations from the speakers is available on CW website here.

I wanted to highlight few takeaways and stats that were quoted during the seminar as follows:

• The 5 challenges of deploying small cells: compelling event, capacity, complexity, coverage, cost
• 90 operators now offer unlimited service with voice, SMS & Data
• Due to European roaming charges having been scrapped, there is 300% growth in European roaming traffic since last year.
• Average consumption is 1.9Gbytes/month forecast to be 15.8Gbytes by 2022. Finish operator Elisa is already running at an average of 18GB/month
• Modern inbuilding systems are 2T2R with many older installation still using SISO.
• 40% of the workforce will be freelancers, temps, independent contractors and solopreneurs by 2020 (Not sure if this is UK or worldwide figure)
• 39% of millenials say they interact more with their smartphones than they do with theur significant others, parents, friends, children or co-workers
• By the end of 2017, around 14000 co-working spaces will be in operation worldwide
• 67% of people around the world use a personal device at work to some degree

I have highlighted Opencell's view on DAS vs Small Cells in the earlier post here. This Tweet below also shows the comparison points

Good comparison between DAS & Small Cells by Graham Payne of @youvegotnetwork at @cambwireless #CWSmallCell pic.twitter.com/wE8MChjPSB

— Parallel Wireless (@Parallel_tw) December 7, 2017

Bob Slorach, from Wireless Infrastructure Group (WIG), drew some clear guidelines about building size, pointing to the needs of buildings between about 50000 to 300000 sq. ft. This represents a huge unmet demand of around 2 Billion sq. ft. in the UK alone.

As can be seen in the picture above, picocells can serve smaller venues while a 5 watt small cell (microcell) with distributed RF can satisfy the 100 - 300K sq. ft. venues. For bigger venues, a higher power unit would be required. It would also justify to have a neutral host solution so the costs could be distributed and coverage is available for everyone.

Adis Omeragic, Special Projects Manager at EE, shared his side of the story. While his slides are still not on the site (they are expected to be available), I have emnedded a tweet below.

Some very clear and concise points made by Adis Omeragic of @EE regarding DAS and Small Cells at @cambwireless #CWSmallCell pic.twitter.com/wNTlmbPNol

— Parallel Wireless (@Parallel_tw) December 7, 2017

Some of the points he made were, while passive DAS may no longer be used, active DAS will be around. Only about 5% of DAS deployments in the UK have all four operators connected as of today.

According to Adis, DAS displacement is slow because of lack of roadmap alignment between macros and small cells. Small cells upgrade path is very limited. DAS allows Carrier Aggregation, Multi-technology and multi-band capability, SON features which are more common in macros, etc.

Due to the new features like 4x4 MIMO and even Massive MIMO, things may start going in favour of small cells.

One final point that was discussed in the panel was whether VoWiFi is good enough so there is no longer a need for residential or enterprise femtocells.

While the panelists agreed that VoWifi is good enough for residential, it may not be good enough for enterprises. I disagree. If the enterprise has designed their WiFi networks properly, this may not be much of an issue.

There is other issue of the lack of devices and operators support for VoWiFi. As EE pointed out, they only support it for post-paid customers, on direct contract with them. So pre-paid, MVNO and partner customers wont benefit. Also, its supported in limited number of devices.

DAS vs Small Cells for In-building coverage

Small cells vs DAS has been a topic of discussion for a long time. ThinkSmallCell covered this topic back in 2014. I don't think things have changed much.

Recently I came across ClearSky and Opencell. They both have a slightly different approach to providing in-building coverage solutions. Instead of focusing on having neutral host small cells with MOCN or other network sharing approach, they act as neutral host providers responsible for integrating small cells from multiple operators within the building.

ThinkSmallCell has a detailed write-up of Opencell and Clearsky Technologies. What impressed me is the Opencell article saying (emphasis mine):

This isn’t a true neutral host where a single set of small cells is shared by all operators and routed through a central gateway. Each small cell is connected directly to its host operator – there is no shared gateway switch  through which all traffic is concentrated.

Instead they use Enterprise Small Cells to provide in-building cellular service from all four UK networks at a 75% lower price than DAS including basestations. Parallel sets of small cells are installed, one set for each operator. Typically a single dedicated LAN is used with a single separate fibre backhaul through the Internet. Each installation is designed, commissioned and maintained directly by the OpenCell team.

A 24/7 Data Centre with fault and performance monitoring service constantly tracks operation and identifies problems. We can remotely diagnose and fix issues, and will attend next day to fix or replace faulty hardware. We charge an initial setup fee and an ongoing operational support rate. There would also be a callout fee and additional cost for major changes, such as when the building is redeveloped, layout changed or new tenants are introduced.

It can be 75% cheaper to install enterprise small cells from multiple operators rather than install DAS. Again, I am sure there is a point till which it would make sense to do this. After that, it would be cheaper to have a DAS solution.

In couple of weeks, Cambridge Wireless is hosting a seminar on this topic, 'DAS and Enterprise Small Cells - Competition or Collaboration?'. I am hoping to hear more details about this.

In the meantime, if you would like to explore more about this topic, see the links below.

• Multi-operator enterprise small cells commercially live with OpenCell - ThinkSmallCell
• ClearSky lights up Clearwater Beach Resort with multi-operator Small Cells - ThinkSmallCell
• Small cell deployment supports all four nationwide operators - RCR Wireless
• The three key differentiators between DAS and Small Cells for Enterprise - ThinkSmallCell
• DAS and Small Cells solutions become more intertwined - ThinkSmallCell
• Six ways to achieve multi-operator Small Cells - ThinkSmallCell
• Quick tutorial on Mobile Network Sharing Options - The 3G4G Blog
• Tutorial: An Introduction to Macrocells & Small Cells - Telecoms Infrastructure Blog

Small Cells World Summit 2017 Summary

I realised that I never got round to writing a summary post for Small Cells World Summit 2017. In fact I was waiting for summaries for various publications before writing a post but there was much less coverage this year.

Having said that, there were reasonable number of operators and most major vendors present. Small cells have sort of gone mainstream from their niche as many operators are now talking of small cells for 5G (mainly higher frequencies).

Anyway, here are some links with what I found interesting that you can explore further.

Here are some things ThinkSmallCell reported. Full report here:

SCWS, now in its 9th year, remains a regular feature of the small cell calendar. Now a two day conference, attendance was lower than some years ago but stable with noticeably more system integrators/installers actively participating. There was a little more focus on business enablers rather than technology this year, addressing deployment issues and neutral host opportunities for enterprise, urban and rural sectors.
...
The scope of SCWS is intended to embrace all of Small Cells, DAS and (Public Access) Wi-Fi. We saw one or two more DAS vendors participate but there was relatively little public Wi-Fi content. Perhaps that reflects the limited interest for that in Europe, as we saw at the recent Wireless Broadband Congress. The program included a few keynote speakers from operators (EE, O2, ATT, KDDI, Softbank) and some industry verticals (AEG, which operates the O2 dome and other stadiums; Grange Hotels etc.)       

Many mature small cell products are available today for both 3G and LTE. Form factors continue to shrink, software is becoming further automated and refined. The backhaul conference stream has been dropped with CCS now the most prominent independent small cell backhaul vendor.
...
The event provides an excellent opportunity to meet and reconnect with industry players, both old and new. The emphasis and participation has evolved over the years, but it remains a key focal point to assess the current state of play for the industry.

Here are some things The Mobile Network reported. Full report here:

The day before the Summit started Nokia assembled a few journalists in a meeting room and gave them a portfolio update. Of note in this was the revelation that the company will be shipping tens of thousands, in fact more than 50 thousand, of its Mini Macro cell sites to Sprint. This is on top of another wide scale roll out of the boxes – which are 2x20W sites in a 5 litre box – in China and Japan where the vendor expects to ship another 40,000. There are 3,000 headed to Brazil, as well, to be deployed as an underlay under Ericsson macro cells.
...
One notable aspect of the event was the amount of talk about using small cells in rural, in dense indoor and in other hard to reach areas. Mansoor Hanif spoke of some of the work BT is looking at to enable it to spread coverage to hard to reach areas. There is a real range of work, best summed up in this picture.

Of note is its work with TIP, where it hopes to be able to plug in open base stations as part of its Kuha community-run small cells programme – as per its project on the island of Harris supported by Nokia at the moment. With Lime Microsystems it is delivering a software defined radio base to Open Source, and hopes to attract developers to build applications on top of the Lime SDR platform. Hanif wants to move the cycle for introducing a new feature into a network from months to weeks – but he added that he doesn’t think any operator has the skills to manage that internally – hence the move to Open Source.
...
KDDI’s Fumio Watanabe presented some findings from the operators trials of mobile mmWave systems. The operator’s field trial use 40GHz and 60GHz bands, with a user moving between different bands and being “handed over” between access points. This sort of mobility requires dual interband connectivity and multi-site CoMP to handle the mobility between different sites and bands as a user goes out of line of site of an access point.

It may also require some architecture shifts Watanabe said, including the likes of ICN and MEC.
...
Backhaul provider CCS has a couple of things going on. First, it is involved as the backhaul provider to Telefonica O2’s deployment of outdoor WiFi and cellular small cells in the City of London. Steve Greaves, CEO, said that the company will support 450 small cells and 150 WiFi access points by siting its backhaul nodes at 30 Virgin media fibre points – with each backhaul node supporting 3-5 WiFi access points. The backhaul nodes are providing 1.2Gbps capacities at 24/26/28 GHz bands.

Greaves is also enthused by an upcoming product launch from CCS, as the company enters the 60GHz band with a 10Gbps product. Greaves says that CCS will go beyond products from the likes of Siklu, by modifying the basic WiGig chip that providers currently use, to add tighter carrier grade SynchE 1588, and greater interference control. The product will not be available until early 2018, he added.

Another interesting aspect of the City of London deployment – the concession model between the City of London and Telefonica – means that Telefonica must host other operators’ small cells within the deployment if asked. But these may not be on the same pole as Telefonica’s small cells, given there is a limit of two boxes per pole. From a backhaul perspective – that obviously introduces more complexity – as Telefonica must introduce a V-LAN for each operator, with different QoS.

Virgin Media Business, by the way, has 100,000 cabinets in London alone, and wants to use them to act as potential hosts for small cells, by adding a small pole to the cabinet, said its adviser Paul Coffey. The company is also looking at enabling neutral host model using its street infrastructure. Its wholesale business supplying backhaul to the UK’s operators already runs to £150 million per year, Coffey said.

Related Posts:

• Nokia Kuha: Community-run Small Cells
• Small Cell Forum Awards 2017 Winners
• Telecoms Infrastructure Blog: Flying Small Cells are here...
• Drone cells are becoming a reality 

Huawei Lampsite 3.0

Huawei Lampsite post has been the most popular post on this blog. Hence its about time I add more up to date info on this product.

According to this ThinkSmallCell post:

Huawei, which has already seen a lot of success with its Lampsite 2.0 product, announced a version 3.0 at MWC this year. It was already possible to separately associate the independent radios at each radio head with a different network operator, using the same physical equipment to serve two operators. But the limitation had been that the operator had already approved and installed Huawei as one of their existing RAN vendors.

One of the big differences with Lampsite 3.0 is that it can also accept RF inputs from external basestations, so you could connect an Ericsson or Nokia (or third party Small Cell). Each RF node is capable of sharing up to 240MHz of RF bandwidth across up to four bands, easily catering for multi-operator, multi-mode and multi-band.

According to Huawei's pres release for MWC 2017:

Huawei launched its next-generation indoor mobile broadband solution, LampSite 3.0, at this year's Mobile World Congress (MWC) in Barcelona. This award-winning solution comes complete with a suite of groundbreaking features that drive digital transformation and more fully enable the indoor digital economy, including support for on-demand concurrence of multi-band, more flexible multi-carrier aggregation, distributed MIMO, and 256 QAM.

In the past three years, LampSite 1.0 and 2.0 have seen large-scale global deployment. With the development of 4G networks, more and more stadiums, transportation hubs, shopping malls, and exhibition halls have leveraged these solutions to make huge improvements in their indoor networks. Success stories are everywhere. The Beijing Capital Airport deployed more than 2,200 LampSites in three months, and within 24 months after deployment, mobile traffic grew by a factor of 67. In the Dubai Mall, the largest shopping mall in the world, LampSite enables per-user downlink speeds over 90Mbps, a record only broke by Singapore Marina Bay Sands Hotel, which uses LTE carrier aggregation technology to reach speeds of 251Mbps.

Additionally, LampSite was chosen by Fira Gran in MWC 2016 to upgrade its DAS network in Hall 1, Hall 3 and Hall 6. Even at peak times, attendees can stream and share HD video without a second's lag. Global carriers around the world have chosen LampSite to maximize their indoor broadband performance.

From LampSite 1.0 and 2.0, to today's 3.0, Huawei has set three key initiatives in its mission to enable the indoor digital economy, which will also help carriers and enterprises accelerate the pace of their digital transformation:

Build a Better Indoor Experience: With the rapid development of mobile Internet, a variety of new services continue to emerge, such as 4K video, AR and VR. Meanwhile, the demand for better user experience continues to grow. LampSite 3.0 breaks through a series of key RF technology bottlenecks to provide better indoor experience. By supporting multi-band concurrent signals, more flexible multi-carrier aggregation, distributed MIMO, 256 QAM and a host of other innovative technologies, LampSite 3.0 provides a solid user experience with speeds up to 2Gbps. Beyond speed, with dynamic capacity adjustment technology, it can easily cope with growth in traffic demand, enabling one-time deployment and long-term evolution. Compared to DAS, it can reduce cost per bit by 30% to 40%.  

Activate the Industry Ecosystem: In most cases, installation requirements for indoor networks can be strict. Governments and building owners often require one-time deployment, a collective effort between multiple carriers. This places a lot of pressure on carriers to adopt more robust, future-proof solutions. 

For the first time in the industry, LampSite 3.0 provides up to 240MHz full-bandwidth capabilities, which enables indoor digital networks to support multi-carrier sharing scenarios. Effective deployment of shared digital infrastructure like this involves greater collaboration between property owners and different industry players, but it also enables all parties to share in the digital dividends of the indoor economy. For example, this model gives enterprises, building owners and even investors the option to deploy indoor networks themselves, then lease them to operators, creating shared success across the entire industrial ecosystem. Best of all, when four carriers share the network, LampSite 3.0 leads to considerable cost savings, reducing TCO for each carrier by up to 70%.

Enable Business-to-Vertical  (B2V) Opportunities: Powered by an open digital capability platform, the LampSite solution can provide accurate indoor location services. This enables carriers to surpass traditional B2C and B2B service boundaries with an immense range of vertical applications, such as intelligent shopping malls and intelligent airports. In addition to high-precision indoor cellular positioning, LampSite 3.0 enables indoor IoT, big data and other technological innovations, helping open doors to an endless array of B2V fields. 

Many vendors are now pushing for Neutral Host solutions and Huawei is no exception. As I have mentioned in my other post, network sharing will be very important for 5G and many operators are already exploring neutral host solutions.

According to another ThinkSmallCells post:

Huawei Lampsite 3.0 is a distributed radio system which supports four radio heads per remote node, and adds the capability to feed the system from an external basestation (which could be a Nokia or Ericsson), thus making it more like a multi-operator DAS solution. There is also a “Lite” version for individual shops or restaurants.

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:

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.

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.

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

Small Cells & Wi-Fi in the pavements & roads

Back in October last year, Thinksmallcell reported that Vigin Media in UK is deploying WiFi in pavements.

ISPreview reports that:

Ordinarily most operators prefer to install WiFi access points above ground, not least because it helps the 2.4GHz signal to propagate, but telecoms infrastructure owners like Virgin Media have a lot of manholes around the place that can also be used (makes it easier to tap directly into their core capacity links) and apparently this approach can still cover an area of up to 80 metres.

The use of a submerged rainproof access point, which sits beneath a specially developed resin cover, is certainly a different twist on the usual deployments. Never the less Virgin Media are also using plenty of traditional access points too, which have been discreetly installed on local street furniture.

Wireless antenna maker Kathrein has teamed with Ericsson and Swiss operator Swisscom to develop an in-ground antenna system that will help provide additional wireless coverage in densely populated areas. The technology, called the Kathrein Street Connect, was developed to help operators deploy additional cell sites in places where site acquisition is difficult due to zoning issues.

Kathrein designed the antenna while Ericsson provided the radio. The rugged solution was designed to withstand deploying in streets with heavy vehicle traffic. Currently there are 17 sites piloting the technology in Switzerland with plans for commercial deployment in 2016, said Jim DeKoekkoek, product line manager for antennas and filters at Kathrein, in an interview with FierceInstaller.

Kathrein also has a video on Youtube explaining this:


Its interesting to see that pavements and roads may become the new battleground for providing connectivity through Wi-Fi and Small Cells.

Related Posts:

• Telecoms Infrastructure Blog: NTT Docomo's Underground LTE Small Cells with possibility to deploy 5G in future
• Telecoms Infrastructure Blog: Underground Small Cells

The role of Wi-Fi in evolving mobile ecosystem

Came across this old presentation from the Cambridge Wireless FWIC 2015 by Plum consulting. I have written many posts on these topics but this is going to be a hot area for discussion for the coming months and year(s). In fact you might be seeing more on these topics in the next few months on this blog.

Here is the presentation from Plum embedded below.

You can read more about the Cambridge Wireless Future of Wireless international conference in a blog post by ThinkSmallCell here.

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.


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.

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.

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.

Progress on WLAN and Small Cellin China Unicom from Zahid Ghadialy

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.

Shared Smallcell Networks from Zahid Ghadialy

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

• 3GPP Network Sharing Enhancements for LTE - Unwired Insight
• Active RAN sharing business models can bring benefits to towercos as well as operators - Analysis Mason
• LTE Network Sharing - Alcatel Lucent
• BIPT guidelines for infrastructure sharing
• Active RAN Sharing - NEC
• Case Study: RAN Sharing in Poland

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.

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:

• Case Study: Deployment scenarios with DAS, RRH, Small Cells and Wi-Fi
• HetNet Strategies with Oi Brazil