How Poor Connectivity Impacts Patient Outcomes

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When delivering first-rate care, every aspect of the patient experience is critical. And in today’s always-connected 5G world, much of that experience depends on pervasive, secure mobile device connectivity. Physicians, nurses, staff, patients, and visitors need seamless indoor wireless coverage.

As a result, the health of a hospital’s in-building wireless network is more important than ever — from the patient intake process to the delivery of accurate medical device results to secure transmission of electronic health records. So, what can healthcare IT professionals do to ensure a better-connected experience for patients, staff, and visitors?

Mobile Connectivity Matters

Spotty or nonexistent In-building mobile connectivity impacts the patient experience significantly. Consider if a patient is trying to use their smartphone to review laboratory test results or a family member wants to video chat with other family members about a loved one’s care. Moreover, many healthcare facilities now allow a bring-your-own-device (BYOD) policy, which means that physicians and staff must have secure and reliable 24×7 connectivity to the major mobile network providers to access electronic healthcare records and application data or to consult with a distant specialist about a patient’s treatment.

Now, consider cutting-edge technology use cases that are still on the horizon. Future healthcare technology might include remote surgery enabled by augmented reality (AR) and virtual reality (VR) or the use of complex artificial intelligence (AI) and machine learning (ML) algorithms to conduct patient diagnoses. Tomorrow’s healthcare providers will use the Internet of Things (IoT) to monitor and maintain diagnostic equipment and other medical devices. These applications require mission-critical, secure, reliable, and ubiquitous connectivity to ensure optimum patient outcomes.

Technology Evolution Concerns

The inconvenient truth is that hospitals and medical campuses are not built with mobile signal transmissions in mind. Neighboring structures, modern LEED building materials, energy-efficient windows, and unique interior layouts present physical challenges to device connectivity indoors. Compounding this situation is the nearly pervasive adoption of 5G technology, which is rapidly changing how we stay connected. In fact, the number of 5G subscribers is predicted to reach 8 billion worldwide by 2028, up from approximately 1.4 billion already.

As demand for 5G continues to grow, the need for greater network coverage and capacity requires new 5G radio frequency (RF) spectrum allocations. In response, the U.S. Federal Communications Commission (FCC) opened up new mid-band frequencies, such as the C-Band and Citizens Broadband Radio Service (CBRS), to supplement the higher mmWave frequencies already allocated for 5G.

Unfortunately, although these new mid-band frequencies offer an ideal mix of speed, capacity, and coverage for outdoor wide-area 5G networks, their signal characteristics are not necessarily ideal for in-building connectivity. In fact, the mid-band and higher spectrum 5G frequencies in use today are even less likely to penetrate building materials than the lower frequencies traditionally used for mobile communications. This means that signals from outdoor networks are blocked not only by neighboring buildings but also by interior walls, furniture, and other obstacles, leading to dropped calls and poor quality of service (QoS) inside buildings.

Plan for Today and Tomorrow

To ensure that patients, staff, and visitors can access 5G communications inside buildings and across campuses, existing in-building distributed antenna system (DAS) platforms must be updated or replaced to work with the new mid-band frequencies. If the DAS platform cannot be upgraded, this might require an expensive and time-consuming “rip and replace” project. On the other hand, those healthcare facilities with a modular, multi-band DAS may be able to add new frequency bands to their existing equipment. However, there will be some necessary modifications due to the particular characteristics of the new frequency bands.

Mid-band spectrum is well-suited for 5G wide-area network deployments because it provides access to larger channels compared to older technologies, which enables significantly greater capacity. Yet, wider channels consume more radio output power, resulting in a smaller coverage area per antenna due to weaker signals. This is compounded by the fact that the mid-band spectrum also offers a shorter signal propagation range than the previous mobile communications spectrum.

Moreover, interior building materials such as walls, cubicles, and furniture will further impede penetration of 5G frequencies throughout the building. For example, indoor C-Band coverage per antenna is roughly 15 percent of the coverage provided by legacy mobile frequencies at the same power level. In fact, in a typical building with furniture and sheetrock walls, an antenna providing a little more than 1,000 square feet of coverage with 4G in the legacy Advanced Wireless Service (AWS) band would only cover around 150 square feet with the 5G C-Band.

As a result of all these obstacles, achieving the same in-building coverage footprint will require changes in how the upgraded DAS equipment is configured. This might mean the addition of amplifiers that provide 4 to 10 times more output power per antenna to prevent “dead zones” where coverage drops off. Alternatively, if the legacy system already uses high-output power amplifiers, adding a fiber-to-the-edge overlay system to support the new 5G frequencies is another option. This allows high-speed data and voice transmissions to be carried all the way to the edge of the network, closer to the users, for enhanced connectivity and improved QoS.

With a common fiber infrastructure throughout buildings and across campuses, healthcare IT professionals can take advantage of the latest optical networking capabilities for wired local area networks (LANs). This fiber infrastructure provides optimized performance, minimum latency, and inherent data security to support IoT connectivity, AR/VR technologies, and new medical devices that require higher bandwidth. In addition, a fiber LAN enables more efficient building management systems, such as intelligent heating and lighting, or secure personnel access systems.

Improve Overall Experiences

Today’s patient experience is dynamically changing. Smartphones, tablets, laptops, and mission-critical medical devices need to work all the time, everywhere, throughout healthcare facilities. As the Tier 1 mobile service providers continue building their networks using mid-band 5G frequencies, in-building communications systems must evolve to keep pace. This evolution enables healthcare facilities to deliver a more pervasive, secure connectivity experience that facilitates BYOD mobility and provides sufficient bandwidth for the best possible patient experience and overall well-being.

How a More Sustainable DAS Speeds the Race to Net-Zero

Sustainability has become an urgent focus for many enterprises, governments, and communities worldwide. Yet as connectivity demands escalate, overall communications network electricity usage continues to rise. This means it is increasingly difficult for network operators to achieve sustainability goals and building owners to meet and building emissions compliance requirements on the road to achieving Net-Zero emissions.

At SOLiD, this emphasis on sustainability is nothing new. In fact, we have a history of offering reliable, sustainable solutions that contribute to a greener planet in several ways.

On Track to Sustainability

SOLiD sustainability begins with engineering excellence, resulting in DAS solutions designed to deliver the highest performance with the lowest carbon footprint. For example, the ALLIANCE edgeROU DAS platform supports the fully-occupied 280 MHz of the C-Band while consuming a maximum of 35 watts — just one-third the amount of energy required for alternative fiber-to-the-edge DAS remotes, despite providing a much higher RF output power.

Each edgeROU remote supports the entire bandwidth of up to four frequency bands, allowing each remote unit to accommodate more spectrum, frequency bands, and services from the public cellular networks. This means that in-building network managers need fewer SOLiD DAS remotes to achieve the same coverage and capacity as competing solutions. Plus, the ALLIANCE edgeROU is the smallest active DAS remote available.

As a result, with each remote consuming less energy, being smaller, lighter in weight, and with fewer remotes needed overall for seamless coverage, far fewer resources are consumed in manufacturing, shipping, and operating the ALLIANCE edgeROU platform. This makes it the industry’s “greenest” active DAS solution and the most affordable with a low total cost of ownership (TCO). Likewise, our SOLiD ALLIANCE high-power remote optic unit (HROU) solutions, such as the Mid-Band HROU_4000, include a power-saving function, allowing them to reduce power when traffic demand is low.

Modular Momentum

In addition to reducing resource consumption, there is another important aspect to the SOLiD sustainability track record as well. Because the SOLiD ALLIANCE platform is modular, network operators and building owners can easily replace, reuse, and upgrade individual components as needed to keep up with evolving telecom technologies, such as today’s 5G and tomorrow’s 6G mobile networks. This eliminates the significant time, expense, and waste generated by a rip-and-replace project to swap out an entire non-modular DAS system.

Moreover, the modularity of SOLiD DAS equipment allows us to ship all the system components to one place, where we assemble the head-ends before delivering the assembled system to our customer’s site. This enables us to recycle the component packaging rather than leaving that responsibility to network operators or system integrators who may not have ready access to recycling facilities.

Sustainable Innovation

For our society to achieve needed Net-Zero goals, we all have to do our part, including network operators, building owners, system integrators, and suppliers. Sustainable network solutions and practices provide powerful tools to aid the decarbonization of the worldwide economy — reducing the network’s carbon footprint and helping businesses make better choices to build a more sustainable model for the future.

For 25 years, SOLiD has continuously innovated to deliver best-in-class solutions for a globally complex, ever-evolving telecommunications industry. As rising connectivity demands drive the need for greater global sustainability, we will continue to innovate to deliver the most reliable, sustainable, and high-performance connectivity solutions on the market. To learn more, visit:


SOLiD Ramps Up O-RAN Business

October 4, 2023 – Today, SOLiD joined as a new radio unit (RU) partner for OREX®, NTT DOCOMO's global Open RAN service brand. NTT DOCOMO officially confirmed SOLiD's participation on September 27 while unveiling the new lineup of OREX services at MWC Las Vegas. OREX is DOCOMO's Open RAN service brand, developed in collaboration with multiple global vendors.

"The O-RAN market is poised for significant growth, attracting the interest of communication equipment companies," said Dae-Young Kim, Ph.D., Executive Vice President, SOLiD. "SOLiD achieved over 17 billion KRW in O-RAN-related sales last year, and it's among the few companies where the O-RAN business is translating into actual revenue."

In fact, the global O-RAN market is projected to witness substantial growth, with an estimated compound annual growth rate (CAGR) of 36.9%, increasing from $1.3 billion in 2022 to $8.9 billion in 2028, according to market research and consulting firm KSI.

SOLiD has recently demonstrated remarkable achievements in the O-RAN sector, including a series of successful demonstrations at the global O-RAN proof-of-concept event organized by the international O-RAN ALLIANCE standardization organization.

The open wireless network O-RAN technology disaggregates the hardware and software of wireless communication equipment, such as base stations, enabling interoperability between base station equipment from various manufacturers. This provides telecommunications companies advantages in expanded equipment options, reducing dependency on a single equipment provider, and lowering infrastructure deployment costs. Due to these benefits, both equipment companies and mobile network operators (MNOs) are working to advance O-RAN technology.

Leveraging its established O-RAN technology expertise both domestically and internationally, SOLiD has accomplished various milestones. In addition to becoming a partner in NTT DOCOMO's OREX, SOLiD has entered into a partnership with ASOCS, a leading provider of private 5G network software solutions, to offer O-RAN-compatible solutions. Moreover, SOLiD was exclusively selected for the mobile communication service modernization project at Signal Iduna Park, the home stadium of Borussia Dortmund in the German Bundesliga, and is actively setting up a network in an O-RAN environment in collaboration with German Telecommunication Company 1&1 Drillisch.

"SOLiD’s selection as an OREX supplier to NTT DOCOMO is a logical progression following the recent global O-RAN Plugfest," said Dae-Young Kim, Ph.D., Executive Vice President, SOLiD. "We are determined to maintain our strong market leadership position in the O-RAN market, which is expected to experience substantial growth in the future."

Mapping the Evolution to Multi-Operator Networks

Mobile networks are constantly evolving, and advancements in neutral host distributed antenna system (DAS) technology are keeping pace, enabling more efficient, scalable, and reliable connectivity. As a result, wireless in-building service quality is generally much improved over what it was in the early days of DAS, even as demand for mobile data skyrockets. And yet, to properly receive the latest wireless signal sources from multiple operators, in-building DAS systems must continue evolving to match mobile network operator (MNO) infrastructure transformations.

The growing adoption of 5G technology is driving the need for further changes in the mobile network, including greater cell site densification. However, more than 450,000 outdoor small cell nodes were already operating across the U.S. by the end of 2022, making new site build-out increasingly difficult. This challenging situation requires new approaches to network deployment and management.

Transformation Ahead

Today, in-building coverage is commonly provided by traditional neutral host DAS infrastructure shared by multiple operators. This familiar in-building coverage model has been used for many years and is universally accepted and proven. Although MNOs share the DAS equipment, they have their own radio access network (RAN) infrastructure, providing full visibility and control of the radio access network.

As MNOs face ever greater economic pressures and coverage mandates worldwide, the need to further drive down costs is inevitable even as they strive to densify coverage. Active RAN sharing helps MNOs reduce costs and avoid potential performance and maintenance problems caused by over-building their networks. This shared infrastructure approach to network deployment provides several benefits, from improved cost efficiencies to reduced environmental impacts.

When transitioning to an active shared RAN model in the future, MNOs will have various neutral host network configuration possibilities as follows, ranging from minimum to maximum sharing:


With a multi-operator RAN (MORAN), multiple MNOs share radios, antennas, towers, and power, but each has dedicated baseband units (BBUs). A ‘shared O-RU’ feature, which the O-RAN Alliance working group four is standardizing, is a cost-effective option in O-RAN networks. This configuration allows full visibility and control of BBU equipment but requires changes to fronthaul switches to enable multiple interfaces. A shared, multi-operator RAN deployment can be used with licensed spectrum for a public network or with Citizens Broadband Radio Service (CBRS) spectrum for private networks - either over general authorized access (GAA) channels or using priority access license (PAL) channels for dedicated bandwidth.

MORAN + BBU Sharing

The amount of RAN sharing increases marginally with MORAN + BBU sharing. This co-location model involves multiple operators sharing all RAN equipment while each MNO still uses its dedicated spectrum. This configuration helps reduce BBU and fronthaul costs but still limits the visibility of the RAN network.


Finally, with the multi-operator core network (MOCN) architecture, multiple MNOs share one or more CBRS channels to achieve maximum RAN sharing and cost efficiency. A key difference between MOCN and MORAN is the sharing of spectrum, allowing MNOs to pool spectrum allocations for greater resource efficiency. Although the lead operator in this deployment may have access to some dedicated spectrum channels and RAN control, this scenario affords limited visibility of the RAN for all other operators and GAA spectrum dependency.

DAS Evolution

As future mobile networks evolve to progressively greater architecture sharing, cost and efficiency benefits will increase, even as operator flexibility and control decrease. Likewise, these macro network changes will also impact how in-building DAS equipment operates, requiring DAS architecture to evolve as well. Future DAS architecture will share the distribution and intermediate layers between the DAS headend and the MNO networks.

When considering the difference in shared spectrum between DAS/MORAN and MOCN, MOCN will be an efficient solution for small venues or enterprise networks where coverage is more critical than capacity. We could also expect further enhancements from a neutral host DAS standpoint when converged with MORAN.

Currently, most neutral host DAS platforms use separate RANs for each MNO, but greater efficiency is possible if the RAN portion becomes MORAN. Fundamentally, RAN provides capacity, and neutral host DAS distributes capacity from multiple MNOs to multiple antenna points. In a case of extreme capacity sharing, neutral host DAS becomes more cost-efficient than MORAN because MORAN radios with a function of (Low) PHY will be more expensive than DAS radios. In fact, neutral host DAS with an O-RAN (eCPRI) interface to MORAN with BBU sharing could be the most efficient in-building solution.

A Solid Future

With the inevitable evolution of mobile networks, a RAN sharing model may eventually offer greater cost-efficiency when providing in-building coverage for small and medium-sized venues. This transformation won’t happen overnight, but when it does, SOLiD’s neutral host DAS will evolve to keep pace. In fact, SOLiD already offers Open RAN architectures to support private networks over CBRS. These next-generation architectures provide a logical stepping stone to future DAS components that work with RAN sharing.

SOLiD is leading this progression at the forefront of in-building technology advancements to ensure that DAS systems continue evolving in lock step with MNO infrastructure. Trust SOLiD to deliver the latest technologies for always-on, everywhere, in-building connectivity and interoperability testing for both public and private networks. To learn more, visit

SOLiD and ASOCS Unveil Joint O-RAN Solution for Private 5G Networks

Scalable, CBRS-compliant, Open RAN solution unleashes private 5G and industrial IoT for Industry 4.0 transformation

SOLiD, the leader in cellular in-building mobile coverage, and ASOCS, a leading provider of private 5G network software, today announced a partnership to deliver a complete O-RAN-compliant solution for private 5G and Industrial IoT (IIoT) networks. The joint solution enables rapid deployment of scalable private 5G campus networks with intelligent real-time positioning using the Citizens Broadband Radio Service (CBRS) spectrum.

The new private 5G network solution comprises the SOLiD CBRS O-RAN Radio Unit (O-RU), the ASOCS CYRUS® virtual O-RAN Distributed Unit (O-DU) and Centralized Unit (O-CU), and ASOCS Hermes NGP real-time positioning software. The CBRS-compliant solution, certified by the OnGo Alliance, empowers a range of mission-critical Industry 4.0 use cases, such as manufacturing automation, predictive maintenance, real-time asset tracking, and occupational health and safety.

The SOLiD CBRS O-RU complies with O-RAN ALLIANCE fronthaul specifications, supporting 4G LTE and 5G New Radio (NR) in standalone (SA) or non-standalone (NSA) architecture. The O-RU is compatible with various virtual or physical baseband products via an eCPRI interface. To improve private 5G network service agility, scalability, and efficiency, the SOLiD Fronthaul Multiplexer (MUX) technology eliminates the need for dedicated bandwidth for each RU, enabling more economical use of the CBRS spectrum.

“With the power of AI, the ASOCS software-as-a-service solution enables a cloud-based private 5G network with real-time indoor/ outdoor positioning intelligence to connect data-driven Industry 4.0 edge applications with high accuracy and low latency,” said Niv Zimmerman, vice president of solutions, ASOCS. “Together with SOLiD, we offer a unique, comprehensive solution for deploying private 5G and IIoT networks in a scalable model.”

“SOLiD is at the forefront of innovating connectivity with Open RAN architecture, changing how mobile network operators, system integrators, and manufacturers build tomorrow’s networks,” said Yong Hoon Kang, Ph.D., chief technology officer, SOLiD Americas. “The powerful combination of the SOLiD CBRS O-RAN Radio Unit and ASOCS software unleashes 5G to enable fast, turnkey deployment of robust and secure private in-building networks that transform the business environment.”

“With low latency, fast data speeds, high reliability, and solid security, the true promise of 5G over CBRS is to enable Industry 4.0 applications for greater productivity and profitability,” said Alan Ewing, executive director, OnGo Alliance. “The SOLiD and ASOCS collaboration is an outstanding example from two of our members of how 5G NR and CBRS come together to deliver exceptional performance.”

SOLiD and ASOCS have completed multiple interoperability tests proving the performance of their Open RAN technologies. To learn more, visit SOLiD and ASOCS in meeting room #1178 at MWC Las Vegas, September 26-28.


How New 5G Radios Impact In-Building Connectivity



Mobile 5G technology promises to deliver many innovative new services and capabilities, including higher mobile capacity, faster data speeds, and ultra-reliable low-latency connectivity. These advancements are made possible by fundamental changes in the communications network architecture. However, these evolutionary transformations also can affect how 5G networks perform in conjunction with in-building Distributed Antenna System (DAS) systems.

So, what do you need to know about 5G networks to ensure your building tenants, employees, and visitors continue to experience seamless, always-on mobile connectivity?

Introducing 5G NR

As mobile networks evolve from 4G to 5G, significant architectural changes transform how these next-generation networks operate. A key aspect of this transformation is an improved wireless air interface called 5G New Radio (NR), which enables high-capacity throughput delivery. This technology allows the 5G radio access network (RAN) to use radio frequency (RF) spectrum more efficiently for significantly faster and more responsive mobile experiences than legacy 4G LTE networks.

The newest spectrum released for use with 5G NR uses Time Division Duplexing (TDD) — a method of separating uplink (UL) and downlink (DL) transmissions. The TDD method enables UL and DL functions to occur on the same frequency, unlike Frequency Division Duplexing (FDD), which requires two separate RF frequencies to send and receive data. TDD allows the 5G NR to accommodate large blocks of contiguous spectrum, supporting larger channel widths to provide greater capacity and flexibility.

However, the new 5G spectrum exists at higher frequencies with shorter signal propagation, limiting coverage, particularly indoors. To take full advantage of the potential that 5G offers, network managers need to optimize in-building DAS deployments, which may require the replacement of existing antennas and coaxial splitters to ensure high quality for maximum service availability.

Maximize 5G In-Building Connectivity

When deploying and configuring a DAS system today, it’s critical that you consider all the available 5G frequencies used in adjacent macrocell networks and recognize how each frequency band will impact your in-building DAS deployment. To better understand 5G NR technology and the new frequencies that 5G networks use, download the technical brief How to Make the Most of 5G for Improved In-Building Connectivity

DAS Performance

Are You Maximizing In-Building DAS Performance?

DAS Performance

As 5G technology becomes more pervasive worldwide, consumers and business professionals alike expect mobile service with faster speeds, better coverage, and higher quality — anytime and anywhere — including in your building or event venue. By installing the latest distributed antenna system (DAS) technology, you can help ensure that your tenants, visitors, and employees continue to enjoy seamless in-building connectivity. Yet, how do you ensure you get the most benefit out of your DAS equipment?

Evolution to 5G promises more capacity and data speed, but to deliver on that promise, the Federal Communications Commission (FCC) has introduced an array of new frequency bands with varying propagation characteristics. Additionally, next-generation mobile technology enables new features and capabilities, such as ultra-reliable low-latency networks, which require substantial changes in network architecture. All of this means that 5G brings increasing complexity to today’s networks.

So how can you and your network manager make sense of it all to realize the maximum return on your DAS investment?

Call on SOLiD Support

At SOLiD, we offer a suite of support services tailored to each customer’s needs, ranging from help desk telephone support to remote monitoring and maintenance packages. Our experienced DAS experts take the time to fully understand your technical challenges in order to resolve any technical issues as quickly as possible.

The SOLiD commitment to customer service begins with our ‘ACT’ process, during which we Assemble, Configure, and Test the DAS equipment before shipping. This quality control practice significantly reduces the chance of out-of-box failures (historically less than 1%) that could impact deployment timelines and costs.

Our support services team comprises senior-level engineers with more than 15 years of work experience in DAS technology and the RF industry. Plus, the SOLiD support team is directly linked to our R&D department through a streamlined communications channel. This not only ensures that customer requests can be promptly reviewed and resolved but also provides accurate feedback for continuous product improvement.

With our remote support service, SOLiD engineers can help you resolve RF issues, such as unexpected noise or low power. Likewise, our support team can conduct a remote session through Microsoft Teams viewer, Ultraviewer, or AnyDesk to address firmware and DMS issues.

Help Us to Help You

We know your time is valuable, so we want to share a few tips to maximize your interaction with technical support:

  • Share as many details as possible about the technical problems you are experiencing. This allows our support engineers to better understand the issues for a successful conclusion.
  • When possible, provide prior notification of your need for remote support on critical issues. By allowing us a little extra time to prepare, our DAS experts can deliver more accurate support in a timely manner.
  • If you need remote support, be sure to have information on hand about your system, such as the model number and firmware version.
  • Instead of contacting your SOLiD salesperson, the fastest way to get help is to reach our support team directly. You can either call (888) 409-9997 and select option 2 or e-mail to create an automatic support ticket via the ticketing system.

No matter the size and configuration of your DAS deployment, the SOLiD team aims to ensure you get the maximum return on your investment with fast delivery, peak performance, and a suite of support programs to exceed your expectations. To learn more, visit:

Get in Sync with 5G


The ever-growing demand for mobile connectivity is driving a transformation in wireless technology. Without a doubt, the most significant shift happening right now is the adoption of 5G. Next-generation 5G technology allows enhanced mobile broadband (eMBB) to deliver faster speeds across a wide coverage area, opening the door to a wide array of innovative and profitable new use cases — from automated factories and autonomous vehicles, to smart homes and cities.

Many of the new applications that 5G technology enables rely on more stringent performance and lower latency than previous mobile generations were capable of delivering. Achieving these technical requirements, however, requires a fundamental change in how the network uses radio frequency (RF) spectrum. Evolution to 5G introduces new, larger spectrum bands that exclusively use Time Division Duplexing (TDD), versus the Frequency Division Duplex (FDD) timing sequence that legacy mobile communications technologies employ.

Additionally, network operators are building out more dense cell sites in order to deliver sufficient coverage, capacity, speed, and performance in 5G, making it crucial that all the radio access network (RAN) elements and user devices are seamlessly synchronized with each other. Furthermore, 5G also takes advantage of advanced RF optimization technologies, such as massive MIMO, dynamic spectrum sharing (DSS), beamforming, and carrier aggregation, which require accurate timing for proper operation.

Taken together all of these technical complexities contribute to a critical need for precise timing and synchronization in 5G networks.

Timing is Everything

A key difference with TDD spectrum usage is that both the uplink (UL) and downlink (DL) signals are transmitted on the same frequencies, as opposed to the FDD method that uses separate, paired frequency blocks to transmit and receive traffic. 5G technology relies on TDD bands to provide support for larger channel bandwidth and asymmetrical UL / DL channels to make more efficient use of valuable 5G spectrum.

Yet, with both uplink and downlink data transmissions on the same frequency, there is a much greater chance of interference, with any lack of synchronization between UL / DL frames making matters worse. That means that exact time and phase alignment between base stations is required in order to prevent signal interference and dropped calls with TDD. In fact, 5G new radio (NR) specifications introduce very stringent restrictions on TDD transmissions, with an absolute time synchronization margin of just 1.5µs, compared to a margin of 10µs in the previous FDD LTE environment.

These requirements are particularly important when accommodating new use cases. While many service providers typically follow a standard 80/20 rule for downloading and uploading content, this network parameter is likely to cause congestion as traffic patterns change, increasing the odds of interference. For example, faster 5G speeds are expected to continue driving more uplink traffic, such as cloud storage, or the practice of uploading selfie photos and videos in crowded entertainment venues.


To accommodate the need for precise synchronization with TDD, 5G networks use a highly accurate timing sequence called the Precision Time Protocol (PTP) that shares the same time reference from end to end throughout the network. The PTP function maintains time, phase, and frequency synchronization from the network core to the edge of the service provider’s network. This helps to ensure good quality of experience (QoE) for subscribers using the outdoor macro network.

Get in Sync

But what about service indoors where roughly 80 percent of all mobile voice and data traffic occurs? For those commercial buildings, multi-dwelling units (MDUs), and enterprise offices with a distributed antenna system (DAS) deployed in-building, the PTP assurance of 5G timing and synchronization ends where the DAS begins. To provide reliable 5G service and ensure QoE for indoor subscribers, in-building DAS infrastructure needs to support the timing sequence of TDD.

With the SOLiD ALLIANCE DAS platform 2W, 5W, 20W and Multi-Power Remote Optical Unit, synchronization occurs at the remote unit on the edge of the network, not at the system headend. Likewise, the edgeROU fiber-to-the-edge remotes synch at the edgeHUB typically located in the independent distribution frame (IDF) closet on each floor.

By synching closer to the mobile device, our system provides improved timing and synchronization for seamless connectivity, reducing dropped calls and interference in-building. Additionally, if a sync detection module should fail, the area of impacted coverage is minimized. Alternatively, other systems that sync at the headend can suffer from an extra delay caused by the distance from where they sync to user devices, as well as being vulnerable to total outages, resulting in a poor subscriber experience.

The SOLiD DAS platform not only matches exacting timing and synchronization to improve service quality — similarly to how user devices operate — but our DAS technology also minimizes latency in 5G and LTE networks. SOLiD ALLIANCE DAS minimizes latency by using analog RF over fiber, eliminating the need for analog to digital and digital to analog conversions, which can add significant signal delay and latency.

To learn more about how to get in sync with SOLiD, visit

Bringing True 5G Vision into Focus with the C-Band

The evolution to 5G is moving at a blistering pace.  In fact, the adoption of 5G is happening faster than any previous generation of mobile communications technology.  Yet we still have not realized the true vision of this new mobile technology.  In the U.S., this is primarily due to a shortage of suitable radio frequency spectrum.

To achieve the full potential of 5G, mobile network operators (MNOs) require broad, dedicated channels, ideally 100 MHz or larger.  The 5G standards permit channel bandwidths up to 100 MHz in frequency range 1 (FR1) below 6 GHz and up to 800 MHz in frequency range 2 (FR2) above 6 GHz, typically higher mmWave spectrum from 24 to 40 GHz.  All major network operators possess licenses in FR2, but building a network to provide ubiquitous coverage with mmWave is cost-prohibitive due to the very short transmission distances at high frequencies.  Therefore, FR1 bands large enough to support 100 MHz channels are the best alternative to provide wide-area 5G coverage that also offers true 5G capabilities.

Except for the 2.5 GHz BRS band used by T-Mobile, each of the legacy bands previously used for 3G and 4G typically provide just 10 to 40 MHz of bandwidth to each network operator, so they could not support 100 MHz channels.  As a result, the initial 5G deployments in the U.S. did not enable wireless service providers to maximize their networks' speed and capacity. Still, they did enable coverage maps showing large areas of 5G coverage.  Finally, the Federal Communications Commission (FCC) released additional spectra in the C-Band 3.7 to 3.98 GHz and 3.45 to 3.55 GHz to enhance the MNO's 5G capabilities.  The U.S. C-Band is a sub-set of the frequency band identified as n77 by the global 3GPP organization that spans 3300 MHz to 4200 MHz.

C-Band will offer significant improvements over the previously released millimeter-wave spectrum for wide-area 5G network deployments.  The n77 spectrum has already been used in 5G networks for two to three years by MNOs worldwide, and most 5G networks operate in this mid-band spectrum.  Here in the U.S., however, MNOs just recently started switching on their C-Band 5G networks after intense negotiations with the Federal Aviation Administration (FAA) over concerns about interference with airplane radar altimeters.

Now that the U.S. Tier One service providers are using C-Band in their 5G networks, it's important to ensure that existing mobile communications infrastructure is compatible — including your in-building distributed antenna system (DAS) equipment.  For building owners, enabling seamless 5G connectivity is crucial to keeping tenants happy as more subscribers adopt this next-generation technology and MNOs begin to turn off previous mobile generations.  And for those enterprises wanting to benefit from the latest innovations such as IoT connectivity, analytics powered by machine learning, and smart manufacturing, 5G private networks are the answer to achieving this as smoothly and efficiently as possible.

Learn the ABCs of C-Band

The C-Band was previously reserved for satellite TV transmissions. Still, with advanced digital encoding methods, the satellite companies can "repack" their broadcasts into the upper portion of the band to free up the lower portion for 5G.  Interestingly, after auctioning the frequency licenses last year, the FCC is making C-Band available in two phases as they clear the spectrum.  This means that MNOs' timeframes for the availability of 5G in the C-Band will vary considerably depending on their licenses, with roll-outs extending from early this year to the end of 2023 and different portions of the band being used in various markets.  In other words, the overall deployment picture is far from simple.  For example, one MNO received an initial spectrum allocation this year that will shift 80 MHz higher within the band in 2023.

C-Band offers greater capacity with an increased channel size, but the coverage area will be reduced or require more output power to achieve the same footprint as previous frequencies.  Additionally, the C-Band spectrum offers just one-fourth of the legacy mobile communications bands' signal propagation characteristics because it spans higher frequencies.  As a result, achieving the same coverage footprint with C-Band will require a higher effective output power from the antenna.

Likewise, the higher frequencies also do not penetrate building materials as well as lower frequencies.  This means that coverage from outdoor networks is less likely to provide service inside buildings.  On the plus side, in-building coverage systems, such as Distributed Antenna Systems (DAS), will have less outdoor network interference to overcome.

A dedicated in-building system can provide reliable C-Band coverage, but the interior building materials impede these higher frequencies.  In comparison to legacy mobile communications frequencies at the same power level, indoor C-Band coverage is roughly 15 percent per antenna.  For example, an antenna providing a little more than 1,000 square feet of coverage for a 4G 20 MHz channel in the legacy Advanced Wireless Service (AWS) band would cover a little more than 150 square feet with a 5G 100 MHz channel in the C-Band, assuming an office environment with sheetrock walls.

If you have an existing 4G DAS, it may or may not support the new frequencies.  However, even if it does, it will certainly require amplifiers that provide 4 to 10 times more output power to match the existing footprint.  Yet providing higher power is not feasible if the existing system already uses high output power amplifiers.  Under that circumstance, use an overlay system for the higher frequencies, engineered for specific coverage requirements.  With the SOLiD Link Budget Analysis tool, you can easily analyze factors unique to your deployment to maximize capacity and coverage.

SOLiD ALLIANCE DAS provides a modular high output power C-Band remote and a lower power fiber-to-the-edge (edgeROU) solution for overlay applications.  The modular high output power (20W) remote supports all 380 MHz of licensed C-Band and Auction 110 spectrum with up to 2x2 MIMO in one chassis.  The edgeROU also supports the full C-Band with 2x2 MIMO and is available with integrated antennas or external antenna ports.  These options enable at least three approaches to add C-Band to your coverage infrastructure.  The high-power remote may be integrated with your existing DAS on a remote-by-remote basis if the existing remotes are 2W or 5W.  The edgeROU with integrated antennas may provide a complete overlay solution as simple as deploying Wi-Fi.  The edgeROU with external antenna ports may integrate with your existing DAS at each antenna location either with the existing antenna, if appropriate, or by replacing the antennas with a model that supports both legacy bands and the C-Band.

All of SOLiD's C-Band amplifiers support the full instantaneous and occupied bandwidth.  Full band capability ensures that the system will support the initial spectrum allocations and later transitions when satellite incumbents release the upper end of the band in 2023.

To ensure that your in-building DAS platform is ready for 5G service in the C-Band, select a solution that supports the full C-Band frequency allocation from day one, with multiple output power options to meet the unique needs of your venue.

Transition to Tomorrow

As 5G advances and new frequency bands become available, in-building wireless systems need to keep pace or be left behind.  Today's building tenants and enterprise employees expect excellent quality of service everywhere, even indoors, and 5G is no exception.  Are you ready to support the C-Band to take advantage of the true 5G promise?

To learn more about how to upgrade your in building DAS system to fully realize 5G, watch our webinar “Are you ready for 5G mid-band?”

Supply Chain

Adapting to the New Normal to Fix a Broken Supply Chain

Supply Chain

No matter what industry you are working in right now, odds are you’ve experienced at least some impact from supply chain constraints during the past couple of years. When the world economy tried to reboot after being essentially shut down for more than 18 months, we all learned the hard way how interconnected the global supply chain truly is and how much that affects all of us.

Now, as we navigate the ‘new normal’ sparked by the global COVID-19 pandemic, new patterns in supply and logistics are emerging and changing how we predict shifting demand. Some of these patterns will be temporary, while others will set a new baseline for years to come. In other words, business-as-usual is a thing of the past; at least for now.

A Cloudy Forecast

Well-informed, long-range forecasting continues to be critical during this ongoing supply crisis. To date, our ability to work very closely with our customers on forecasting their demand for products means that SOLiD has not had to disappoint our customers by failing to meet delivery deadlines. However, it would seem that others are not doing as well in this regard, because some of their customers are coming to us with demand for products.

On the one hand, this is a good problem to have because we love to work with new customers. On the other hand, the fact that they did not forecast demand with us in advance means that excess inventory could become depleted. Those system integrators who can’t get equipment as needed because their usual DAS provider can’t deliver could find themselves in a situation where they recognize significantly reduced revenue for the fiscal year.

One thing is certain: supply chain diversity has never been more important. If your usual DAS provider has let you down this year, give us a call to discuss diversifying your sourcing with SOLiD.

Trust is a Two-Way Street

Of course, product demand forecasting is a collaborative relationship built on honesty and commitment. If a network operator or system integrator says they need equipment on a particular date, they need to be prepared to take it. Don’t expect your supplier to sit on the inventory when other customers are ready to take it now.

It’s crucial that we all work together to understand immediate market needs and service priorities. Fixing the broken supply chain requires a better understanding of which changes in customer demand mix are short-lived and which represent a “paradigm shift.” These insights are a key element of integrated business planning (IBP), capacity planning, and capital planning processes.

Supply of Patience

Clearly, the normal way of doing business simply isn’t happening right now. But because today’s global supply chain is so inextricably interconnected, we can’t just insist that “the hole is in the other side of the boat” — we will all sink together regardless. For example, the prolonged shortage of components such as semiconductors has resulted in lead times exceeding a year, with component suppliers demanding upfront payment. That means tying up capital investments in product delivery for as long as two years instead of the typical 3 to 4 months, requiring us to take on considerable risk.

Yet, despite the current situation, SOLiD is succeeding thanks to our close working relationship with good customers and partners. Careful collaboration on demand forecasting and delivery allow us to maintain clarity despite a cloudy forecast, as we all stock up on plenty of patience and perseverance for the long haul. To learn how to confidently diversify your sourcing with SOLiD to achieve your revenue goals, contact your local SOLiD sales representative, or visit