Monday, 15 November 2021

Will Distributed FD-MIMO be next big MIMO Enhancement?

We have looked at MIMO quite a few times in this blog. Back in February we looked at some of the advancements that Samsung and Ericsson had been showing here.

Last year, in a blog post, Samsung talked about Distributed Full Dimension MIMO (FD-MIMO). The key points were:

Around that time, the concept of Massive MIMO was proposed in academic papers. These papers proposed the idea of making the signal dimension at the base station much bigger by using a massive number of antennas such that all inter and intra-cell interference asymptotically go to zero. MU-MIMO performance would be improved significantly with a much lower interference level, therefore leading to capacity gain. It looked promising, but no one knew how to bring it to reality, since arranging 10s or 100s of antenna elements in the conventional way (i.e., in the horizontal plane) would lead to a base station that is longer than a bus, so obviously it was not going to work in a real deployment.  

An important breakthrough came when engineers at Samsung noticed that a concept called Active Antenna Systems (AAS), could be exploited to organize 64 or 128 antennas into a 2D active antenna array that is similar in size with a conventional 4-TX system as shown in the middle portion of Figure 1. Such a system is called a Full Dimension MIMO (FD-MIMO) system. Initial evaluation of the FD-MIMO system coupled with high-order MU-MIMO showed a capacity gain by a factor of 3-4 times for a 64 or 128-TX FD-MIMO compared to a 2-TX LTE system, as was summarized in a 2012 Globecom paper , “Fulfilling the promise of massive MIMO with 2D active antenna array”, and later in a 2013 IEEE magazine paper , “Full-dimension MIMO (FD-MIMO) for next generation cellular technology”. 

Samsung has been actively leading the FD-MIMO standardization process in 3GPP from the beginning, including the 3D channel model study in 2012 that paved the way for subsequent system design, the 4G LTE version of elevation beamforming and the FD-MIMO work from 2014, and more recently the 5G NR-MIMO version of FD-MIMO. Samsung has also been a leader in prototyping and testing the feasibility of the technology and was the first to demonstrate an FD-MIMO system supporting 12 simultaneous MU-MIMO users achieving a record aggregate capacity of > 20 bps/Hz in early 2015. These feasibility study result was later published in a 2017 IEEE JSAC paper , “Full Dimension MIMO (FD-MIMO): demonstrating commercial feasibility”.

Initial system level simulations show that the D-FD-MIMO system achieves up to 2 times cell average throughput gain compared to the FD-MIMO system, lifting both cell capacity as well as average user throughput. Such a cellular system can be flexibly deployed to “blanket” a given geographical area and provide better service for both outdoor and indoor users. 

We have developed a hardware prototype and performed field test to verify the feasibility and the performance gain of the D-FD-MIMO system. In the field test, 3 distributed LEGO MIMO RFUs and 7 UE emulators were used. When the number of active RFUs increased from one to three, the overall throughput improved by about 4 times.

A significant amount of work needs to be done before we can accurately quantify the benefits of the D-FD-MIMO technology, but these initial results are certainly promising and show a great potential for this new breakthrough of the MIMO technology.

Back in 2017, Samsung researchers also wrote a paper on this topic, Distributed FD-MIMO: Cellular Evolution for 5G and Beyond, which is available on arXiv here. Quoting from the paper:

Distributed Full Dimension MIMO (D-FD-MIMO) is an evolution of FD-MIMO. A D-FD-MIMO network assumes a cellular structure, where a cell is served by one BS and each BS is connected with a large number of antenna elements, of which individual elements are spatially distributed in the cell. One or more antenna elements are equipped with a digital port, and the signals transmitted and received from all the antenna elements within one cell are jointly processed to perform high order MU-MIMO operation.

Such a cellular system can be deployed outdoors in a city-wide area to provide service to both outdoor and indoor users. It can also be deployed inside the building to serve indoor users only. It is also suitable for providing service in a highly populated area, such as stadiums, shopping centers and airports, where a large number of the users are densely located.

Concepts relating to D-FD-MIMO includes distributed massive MIMO, CoMP (a.k.a. network MIMO) and distributed antenna systems (DAS). Distributed massive MIMO treats the entire network as one cell, featuring an enormous number of access points distributed over a large area, jointly serving all the users. pCell by Artemis can be seen as an implementation of the distributed massive MIMO albeit with a smaller scale in terms of the number of antennas. CoMP relies on the coordination among a few transmission points from the same or different sites to enhance User Equipment (UE) experience at the cell edge. DAS is initially proposed to improve coverage in an indoor cellular communication system, and is sometimes adopted in outdoor scenarios as well. One configuration for outdoor deployment is to have a few antenna arrays distributed throughout the cell to perform MIMO operations. Another DAS configuration deploys a number of individual antenna elements in a distributed manner in each cell of the network, which is similar to the D-FD-MIMO setting. Different from our system-level simulation approach, the analysis theoretically derives the asymptotic sum capacity when the numbers of UE and antennas in each cell both approach infinity with their ratio fixed, and assuming perfect uplink power control.

You can get the PDF of the paper here.

We have written about the Cell-Free Massive MIMO here and here. One of the realizations of D-FD-MIMO is as shown in Ericsson Radio Stripes. 

Researchers on this topic may also be interested in watching Wireless Future Podcast episode 13 on Distributed and Cell-Free Massive MIMO (embedded below). The description says:

In this episode, Erik G. Larsson and Emil Bjรถrnson discuss how one can create cell-free networks consisting of distributed massive MIMO arrays. The vision is that each user will be surrounded by small access points that cooperate to provide uniformly high service quality. The conversation covers the key benefits, how the network architecture can be evolved to support the new technology, and what the main research challenges are.

The description also contains some links and the discussion is also interesting to follow. You can jump on to the video directly here.

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Friday, 5 November 2021

Deutsche Telekom Launches Indoor Booster 5G Repeater


On his LinkedIn post, Dr. Alex Jinsung Choi, Deutsche Telekom Senior Vice President, Head of Strategy & Technology Innovation and COO of O-RAN Alliance announced the launch of Telekom Deutschland GmbH's Indoor Booster 5G in Bavaria. The post said:

This small low-power repeater brings 5G into offices and homes that did not have sufficient indoor coverage of mobile networks before. It enables customers to experience best streaming, gaming, education services, home office and video conferences with 5G indoors.

I am proud to announce that this new product is result of the cooperation of Deutsche Telekom with our strategic partner SK Telecom. SKT developed and launched 5G repeaters in 2019. In 2020, DT and SKT colleagues trialed a customized 5G repeater in a customer test in Germany which was starting point for the successful launch this year.

Furthermore, the Indoor Booster 5G is the first product of Techmaker GmbH, the tech joint venture of SK Telecom and Deutsche Telekom. I would like to thank all the many colleagues in Techmaker, SK Telecom and Deutsche Telekom who made the project a success!

We looked at SK Telecom's In-building 5G NR Repeaters couple of years back here.

The website explains the working of the booster as can be seen in the picture on the top. All information is in German and is translated using Google translate below: 

The 5G signal is picked up by an antenna on the outside and routed inwards by cable to a so-called booster. This only requires a 230V connection. This results in faster cell phone reception even in remote rooms with stable walls. You can continue to use the Indoor Booster 5G with your existing mobile phone contract.

The Indoor Booster 5G consists of an outside antenna and a booster inside. You should be authorized to have an antenna installed on your building and to grant access.

Couple of FAQ's have interesting info as well:

Why can you only rent the Indoor Booster 5G and not buy it?

Since the indoor booster reproduces the cellular signal, Telekom is the operator of the device and cannot transfer ownership of it to the customer.

Why do I have to commission the installation service?

Since the Indoor Booster reproduces the cellular signal, Telekom is responsible for the operation of the device and must ensure that the radio signal does not interfere with the cellular network. At the installation appointment, you will also be advised where the external antenna is best placed in order to achieve the best possible improvement in performance.

If you own one of these, we would love to hear from you about your experience.

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Thursday, 28 October 2021

AT&T Small Cells and Macrocells

It's been a while since I posted some small cell pictures from the USA. It's always nice of people to share their pics on Twitter and here are some of them I found interesting.

On it's website, Raycap has a case study with AT&T:

To see a range of solutions for concealing small cell wireless sites, look no farther than Dallas, Texas, home to AT&T corporate headquarters. Raycap worked with the carrier to complete two very different concealment projects.

  • Six custom-designed wall-mounted enclosures, designed, manufactured and painted to match the granite walls of AT&T’s buildings and provide 5G mmWave coverage around the AT&T Discovery District
  • Nearby, highly customized small cell poles were engineered to meet the carrier’s needs, the utility’s access requirements, and the city’s aesthetic guidelines—including an integrated image of the iconic Pegasus logo.

These two projects show how Raycap-led collaboration among all stakeholders can solve challenging wireless deployments: wall mounted, rooftop mounted, integrated in poles, and others.

You can download the PDF here.

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Sunday, 10 October 2021

Multi-sectorised sites and Small Cells help O2 UK handle Capacity in Busy Areas

Radio planning becomes essential in dense urban areas where operators don't only have to serve the highly mobile users but also slow moving pedestrians and users indoors. One some location in London, UK, is O2 UK's highest capacity Nokia site with six-sector low-band LTE in 800 and 900MHz in addition to high-band 4T4R L18/L21, 8T8R L23 as well as standard n78 8T8R 5G.

The site also features numerous high-end Commscope antennas with dual-beam panels that are needed to create six-sector LTE 800 and 900 MHz and then 24 port antennas that carry all the other including 8T8R 2300 MHz, 1800 MHz, 2100 MHz as well as n78 8T8R.

In addition, O2 has multitude of Nokia Small cells sprinkled across the City of London. While these come in all different shape and configurations. In many locations there are ones with directional antennas while there are others with omni-directional antennas as well.

The small cells are located on their own poles, rather than lamp posts and many of these also feature Wi-Fi access points as additional means to alleviate the capacity crunch. In fact they can also be mounted on-top of phone boxes, shops, side of buildings, etc. 

If this is an area of interest and you enjoyed reading the post above, you will no doubt enjoy watching this short video from Peter Clarke who has a great collection of infrastructure from UK and Ireland on his website here. Video as follows:

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Thursday, 30 September 2021

Metrocells to help Telstra Increase Density for Greater Capacity and Speed

We looked at Telstra's Small Cells some years back. While they were 4G only or 3G/4G back in those days, now small cells are also being talked about for 5G.

On their Q&A page on small cells, Telstra has explained what they mean by them. In fact we also wrote about how Telstra is using small cells to do EME testing here.

In their investor day this earlier this month, Telstra presented their T25 vision and the role of small cells in that. During the last three years, they’ve been talking about the journey of transformation that they have called T22. T22 was a strategy of necessity – a strategy designed to transform every aspect of Telstra. The new T25 strategy is being billed as a strategy for growth, which they have broken down into four pillars:

  • Provide an exceptional customer experience you can count on
  • Provide leading network and technology solutions that deliver your future
  • Create sustained growth and value for our shareholders
  • Be the place you want to work

As you can see in the slide above, Pillar 2 of their T25 strategy is focused on leading network and technology solutions that deliver the future. As they describe in their analyst day notes:

There is no doubt we are continuing to see rapid technology adoption and innovation. This is manifesting as a convergence between core telecommunications technology and software-based technology solutions.

What this means is that Telstra not only needs to continue to lead in telecommunications technology with the best networks, but also increasingly lead in the role that software plays in orchestrating and managing the network and integrating applications and services for customer solutions. 

Under T25 we will continue to invest in our network leadership in 5G with 95% population coverage and 80% of all mobile network traffic being on 5G by FY25. We also plan to double the number of metro sites leveraging small cell technologies to further densify and add capacity to the network and we will add at least another 100,000 square kilometres of mobile coverage to our national footprint to support regional and remote customers.

By FY24 we will have extended our 4G coverage to 100% of our network enabling us to continue to lead in composite coverage, speed and performance for 4G and 5G as we close 3G. This will set us up well for the early planning on 6G which will clearly be on the agenda by the end of our T25 program.

We will be a vastly different company because of our network leadership with 95% 5G population coverage, a densified small cell network and expanded regional coverage.

Hopefully, the end users will be the real winners with these network upgrades.

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Friday, 17 September 2021

Bigbelly's Telebelly Small Cells to Connect Rural and Urban Users


Bigbelly claims to be the world leader of smart waste and recycling solutions for public spaces. According to their website, they have a proven solution that has been deployed in 50 countries around the globe. When the company started back in 2003, the mission was to transform one of the least efficient and resource heavy operations - waste operations. Today, Bigbelly provides a public right-of-way platform to deliver smart solutions and host communications infrastructure.

Earlier this year, they announced that Telebelly, an integrated pole and antenna solution that expands the Bigbelly station’s service by offering enhanced wireless services to the communities it serves, is set to boost connectivity across UK cities following its decision to launch. The press release said:

The move is expected to accelerate growth of the UK’s small cell network, which is a series of small antennas attached to existing urban infrastructure within densely populated areas. It will also pave the way for 5G by making it easier for telecommunication companies to deploy a faster and more reliable service without relying on large-scale mast installations.

Telebelly, which is 4G and 5G capable, will also reduce visual clutter associated with the growing number of small cells currently secured externally to fixed structures such as streetlights, as it is securely and internally housed.

Bigbelly anticipates interest in Telebelly from UK local authorities, which are seeking solutions for their public spaces that utliise, wherever possible, existing or multi-purpose infrastructure.

Councils, mobile network operators and other third parties are now able to consider the existing 2,500 Bigbelly units in operation across the UK, as well as new locations, for potential Telebelly sites. Wherever a public waste bin is appropriate, a Telebelly may be the solution to hide small cells in plain sight.

Meanwhile their press release in Australia announced:

Today Bigbelly Solar, Cellular Asset Management Services, and Smartsensor Technologies, Bigbelly distributor in Australia, announce they have deployed a number of Telebelly Wireless cabinets, a hybrid telecom and waste management cabinet to benefit the community providing waste services and wireless coverage.

Bigbelly Solar says this is a global first, with Blackman Park in the municipality of Lane Cove being the first one in the world to go live.

The Lane Cove council commented: “Lane Cove has been using Bigbelly compacting waste bins successfully in the community to help provide more capacity and a cleaner environment compared to conventional litter bins. The integration of this solution with mobile connectivity allows us to additionally provide much needed mobile service in currently underserved locations.”

Bigbelly Solar says the benefit of these units is that they blend in with the surrounding environment and matches the recognisable form of an adjacent big belly waste bin.

Not only does the community benefit from the increased mobile coverage footprint, each new Telebelly station now features a Bigbelly high capacity solar-powered waste compactor, complete with hands-free capabilities.

In addition to providing 4G voice and data services, the Telebelly could also be configured to provide Internet of Things (IoT) connectivity and Wi-Fi. A strong and reliable wireless connectivity not only provides a telecom advantage; such a service improves safety and security around public spaces.

Telecommunications have played an integral part during the recent Covid-19 crisis, allowing Australians to continue to work from home and stay connected with friends and family.

For those living in areas with limited coverage due to topography, small infrastructure solutions allow mobile operators to utilise public spaces such as parks and community ovals with coverage while also providing waste solution for the community’s benefit. Bigbelly Solar says these smaller solutions will reduce congestion on the network thus allowing mobile operators to provide mobile coverage in homes and businesses.

Meanwhile in the USA, where their Smart Waste & Recycling solution has been deployed in all 50 states, they deployed Telebelly small solutions in Milwaukee last year. Their blog post says:

The City of Milwaukee first connected with Bigbelly when a major wireless carrier reached out regarding siting challenges ahead of a significant event in the area. The event was fast approaching, and the city required a solution to host small cell in those central, inevitably high-traffic locations. The City looked to solve the all-too-common problem of hiding small cell infrastructure in a manner with the least visual impact. In other words: their complex technology needed to hide in plain sight.

Like many central locations, these high-traffic downtown areas were deemed to be “aesthetically sensitive.” Project approval was fully contingent on the Telebelly’s concealment solution: its ability to be compact, efficient, safe, and self-effacing.

The City was excited about the Telebelly’s multipurpose capabilities, such as small cell hosting, smart waste, IT hosting and more. But most importantly, Milwaukee was intrigued by the Telebelly’s ubiquitous form factor; its simple & understated aesthetic is inherently non-intrusive. This was essential to their form factor challenge.

Within six months of the initial conversation with the wireless carrier, the Telebellies were installed and ready to go! Already, both wireless carriers and the City are thrilled with the installation & performance of their new fleet, and assert that the Telebelly units are an excellent solution for areas which are traditionally difficult to permit.

Readers of this blog will no doubt be aware of many different solutions for both the scenarios listed above, coverage and capacity, that I have covered over the years with similar solutions. It remains to be seen how operators and councils embrace it. 

Embedded below is a detailed video from them from Smart Cities Week 2020, discussing "Smart Alternatives to Small Cell Deployment":

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Friday, 10 September 2021

Ericsson's Street Solutions

Ericsson’s announced that their Street portfolio offers operators and other service providers an opportunity to seamlessly bring connectivity to where it is needed. Part of the Ericsson Radio System, the street solutions are an integrated part of the network, with feature parity and end-to-end performance. 


In a recent press release they announced:

5G deployments are accelerating across the country at a faster rate than expected. According to Ericsson’s annual mobility report, by the end of 2021, 25 percent of the global population will have 5G coverage. In North America, more than 360 million 5G subscriptions are anticipated in the region by 2026, accounting for 84 percent of mobile subscriptions.

However, connectivity can suffer in dense urban environments, and as 5G comes to U.S. cities, urban rollouts are grappling with challenges like how to deploy non-intrusive sites, how best to utilize all frequency layers, and how to streamline site permitting and installation. Many sites need to expand 5G capacity, and hotspots and streets need strengthened capacity in both low, mid and high-band to build a complete 5G network as traffic grows.

Powered by Ericsson Silicon, these new solutions are:

  • Street Radio 4402: Designed to turn a streetlight into a low- or mid-band 5G site in 15 minutes, these compact radios are an industry-unique collaboration with Ubicquia, boosting 4G and 5G experience with zero footprint;
  • AIR 4435: The world’s smallest 4T4R street antenna-integrated radio is designed for minimum footprint and easy installations, adding excellent mid-band capacity to macro coverage gaps;
  • Street Macro 6705: A complete mmWave base station with integrated RAN Compute is an industry-leading end-to-end solution with low visual impact.

Ericsson Street Solutions also include transport solutions for any 5G street site, with wired and wireless backhaul and fronthaul solutions. And zero footprint power systems for street and hotspot sites are 100 percent carry to site, with low maintenance and operations costs.

A brochure with all the necessary details is available here.

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Saturday, 28 August 2021

Samsung's 3GPP-Compliant PS-LTE Network

After having been discussed for years by others, Samsung finally announced back in April that they are powering the world’s first 3GPP-compliant nationwide public safety LTE (PS-LTE) network in Korea, in collaboration with leading mobile operators.

A press release from them said:

This PS-LTE network, operating in the 700MHz spectrum, offers fast and reliable connectivity to first responders in over 330 public safety organizations and agencies, including police, firefighters, emergency medical services and the military.

The deployment includes Samsung’s Mission-Critical Push-to-Talk (MCPTT) with multimedia broadcast capabilities, known as evolved Multimedia Broadcast Multicast Service (eMBMS). This enables simultaneous transmission to up to 2,500 user devices per cell, which is more than twice the volume of devices supported by previous generation technologies.

In this buildout, the PS-LTE network was also interconnected with the existing LTE-Maritime (LTE-M) and LTE-Railway (LTE-R) networks that were already operating in the 700MHz spectrum.

With nationwide coverage, the network serves as a unified platform that helps ensure interoperability among various public safety institutions. This delivers real-time accessibility and enhanced communications capabilities among public safety agencies and personnel in emergency situations.

They also released an Infographic and a Whitepaper.

In a recent Networks Techtalk, Timothy Paul discussed Samsung’s latest end-to-end MCPTX solutions that provide powerful data and video communications capabilities designed for first responders and public safety officials. The video of that is embedded below:

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Friday, 13 August 2021

MatSing's High-Capacity RF Lens Antennas

We have looked at the Lens antennas in a few blog posts indirectly. The most recent being Facebook's SuperCell while others being Altaeros’ Autonomous Tethered Aerial Cell Tower and Verizon's U.S. Bank Stadium

In a recent press release, MatSing announced that it has been selected by the Dallas Cowboys and its network provider AT&T, along with ExteNet Systems, to provide mobile capacity antenna coverage for AT&T Stadium for the upcoming NFL season. Selected extract as follows:

These antenna upgrades will further enhance the exceptional experience provided by AT&T for fans in AT&T Stadium. This deployment follows a test run with reduced crowds during last season. This selection was made due to the capacity of MatSing technology to work with the AT&T systems at the stadium.

Following the installation of 20 MatSing lens antenna by ExteNet covering the Stadium’s entire seating bowl and field with 4G and 5G broadband mobile coverage, the fans and patrons will now experience never seen before performance with their smart devices in the stadium.

“With data demands of cell phones continuing to grow exponentially, driven by new apps and technology, our legacy DAS infrastructure could not keep up with those demands,” explained Cowboys CIO Matthew Messick. “AT&T introduced us to MatSing’s antenna technology, and immediately knew their technology would give us the necessary capabilities with room to grow.”

“Operating the largest indoor DAS network in the United States at AT&T Stadium provides us a unique opportunity to enable the best possible fan experience at one of the NFL’s most iconic venues,” added Rich Coyle, President & Interim CEO, ExteNet Systems. “We thank the Dallas Cowboys for trusting us with this opportunity, and MatSing for providing the clear winning technology for our mobile broadband needs.”

MatSing's spherical lens antennas are based on a unique patented technology that allows a single antenna to provide up to 48 high-capacity coverage sectors, replacing up to 48 traditional antennas with a single lens. Unlike other current solutions, like under-seat antennas, the MatSing lens antennas installed in the roofing structure typically have a clear line-of-sight path to potential users. This significantly reduces the number of antenna locations, as lens antennas can also reach farther than traditional antennas, providing better AT&T coverage and less interference at a lower cost and complexity for the team.

“A smoother Internet experience able to handle modern-day demands of streaming and social media sharing awaits Cowboys fans when they return to AT&T stadium,” added Michael Matytsine, MatSing co-founder and EVP of Operations. “Even when the stadium is at full capacity, lens antennas will provide a smoother data experience with fewer interruptions for fans who have embraced streaming and sharing as an intrinsic part of their stadium experience.”

AT&T, ExteNet and MatSing will continue to work with the Cowboys to maintain and test the lens equipment ahead of the season, ensuring its readiness for wider use by fans in AT&T Stadium.

MatSing lens antennas have also been present in the inauguration's of US presidents. The one from this year is in the Tweet above while the one from last election in 2016 is available here.

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Friday, 6 August 2021

Panorama's ESN Antennas

It feels like last year when I was involved in testing some emergency networks but it was a long while back.

Believe it or not, your mobile network is only as good as the antennas. How often have I come across networks that try and add some cheaper antennas to cut down the costs but the loss of coverage, especially on the edges is a far bigger loss than saving some money on the antennas. 

The UK's Emergency Services Network (ESN) is moving along nicely, though far slower than most people expected it to. One of the important pieces of the puzzle is different types of antennas that are needed on the blue light vehicles. The image on the top nicely summarises these antennas and a brochure with details is available from Panorama here. In fact you can check out all different types of antennas here.

The following videos provide an idea on how these antennas look and work

Do check out other posts below related to ESN on our blogs.

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