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Category Archives: LTE

Fixed LTE: The Most Advanced Tool for Delivering Broadband Services

By Roderick Kelly

Making maximum use of coverage from towers with non-line-of-sight radio wave propagation improves the return on investment for fixed wireless access network operators.

Because of dense terrain throughout Maine, Redzone Wireless has deployed Telrad non-line-of-sight LTE radios. Two LTE radios are shown in this photo of a tower near Sanford, Maine. Photo courtesy of Redzone Wireless

Redzone Wireless in Rockland, Maine, began deploying a fixed LTE high-speed wireless broadband data network in 2014 to replace a network that was made for a mobile environment. With its undulating hills and heavily treed terrain, Maine is not the easiest state in which to deploy a wireless network. Obstacles between base station antenna sites and user devices that blocked line-of-sight radio wave propagation inhibited each site’s market potential.

In three years, Redzone has expanded its coverage to more than 100 communities, 40,000 businesses and 240,000 households throughout Maine through the use of fixed LTE.

“We ended up replacing our former network equipment with Telrad’s  fixed LTE radio access network, evolved packet core and customer premises equipment,” Jim McKenna, the president of Redzone, said. “As a result, we realized 25 percent greater coverage and increased speeds by 5 Mbps in a 20-megahertz-wide channel. The end-to-end solution also provided us with improved stability across the network. Fixed LTE also provided critical non-line-of-sight penetration to capture more market share per tower.”

Wireless Revolution, Evolution

In the early part of this century, small wireless internet service providers were eager to join the market, as unlicensed 2.4-GHz and 5-GHz bands provided an attractive business case. Telecom operators, on the other hand, were skeptical of anything in unlicensed bands because their business model was not set up to take on the risk of losing capacity caused by interference.
Since that time, some operators have fallen by the wayside or changed names, but many of the early adopters are still playing major roles in the evolution of wireless broadband. Various access technologies have been used: Wi-Fi, mesh, WiMAX, proprietary point-to-multipoint and now standards-based LTE. That’s the evolution.

For example, Wharton County Electric Cooperative (WCEC) in southeast Texas used WiMAX 802.16 wireless broadband technology for four years until a competitor began crowding the spectrum, making it a challenge to offer a high-quality service and higher throughputs to their customers.

As a result, WCEClooked for a better solution for its subscribers. The co-op settled on Telrad 4G/LTE dual-mode radios. “We understood that the upfront investment was slightly higher, but the quality of the equipment and therefore our service was much improved,” said Keith Beal, manager of information technology and metering for WCEC. “The range and capacity are outstanding. These are critical as we upgrade and grow our network.”

The challenge with Wi-Fi-based networks is that additional equipment is needed to meet increased capacity demand; increased interference between towers reduces capacity because of the unlicensed spectrum. LTE uses licensed or managed spectrum and avoids the problem. Operators find that the cost savings realized by using unlicensed radios is mitigated by losing capacity because of interference. The message? Base the purchase decision on network return on investment, not the cost of a radio. LTE is also the first non-line-of-sight technology that increases the market potential for each tower, something not often factored into the business plan when purchasing equipment.

Migrating to LTE resolves the interference issue because the 3.65-GHz spectrum is standardized. Having high confidence that the network is reliable and having downtime minimal provide an excellent blueprint for seamlessly working with, and not against, nature’s abundant beauty that often plagues operators, said Redzone’s McKenna.
So where is it all headed, and who will be the visionaries?

They will be the companies that build upon the engineering successes of their predecessors and that expand their networks to meet the growing demands of video streaming. That’s the revolution.

Market Trends

Fixed LTE can tackle six fixed wireless access market challenges:

Streaming video. Gone are the days of simply being connected, viewing web pages and shopping. Why? Because households and offices are streaming video to multiple devices simultaneously, which chews through operator capacity. The video evolution from standard definition to high definition to 4K will keep the pressure on capacity.

Software-defined radios.Service providers want to add capacity to their networks without a tower climb to upgrade equipment. One solution is to deploy software-defined radios, which allow for remote capacity upgrades without a truck roll.
Standards-based.Service providers of all sizes want to deploy quality, standards-based fixed broadband wireless access solutions at price points that generate profits, increase their return on investment and give them more vendor options and more exit value.

Changing how consumers buy broadband.Not many end users know the difference or effect of buying a 15-Mbps best-effort service compared with a 25-Mbps best-effort service. With multiple streams per household, operator capacity is being consumed with no increase in revenue. In rural markets, the trend will be for operators to offer packages based on the number of streams the customer wants supported, bringing clarity to the user about what they are actually buying.

Evolution path.Operators know that video is usurping capacity. LTE’s roadmap goes to LTE-Advanced, LTE-Advanced PRO and then 5G. Operators care less about what it’s called and more about how much more capacity can be delivered incrementally. LTE standards are driven by the 3rd Generation Partnership Project (3GPP) via the GSM Association.

Non-line-of-sight.At the end of the day, reaching end-users in any environment increases the market share per tower. LTE is a non-line-of-sight technology, and the standards will continue to advance and enhance this capability. Non-line-of-site also means never having to say “I can’t serve you,” which occurs afterspending operator time and energy to determine that the customer can’t be served. That represents a loss for both parties.

Fixed LTE is a Game-changer

Fixed LTE is not a technology that uses the same assumptions as other wireless technologies. In fact, it would be a disaster if this operator deployed a fixed LTE network using the same methodology and ideas as Wi-Fi or other proprietary technologies.

Here are some differences:

LTE makes use of hybrid automatic repeat request (HARQ), along with dynamic rate adaptation as part of a media access control (MAC) scheduler, to ensure consistent, reliable performance in a multipath, non-line-of-sight environment. Other wireless technologies lack this scheduling capability and try to avoid multipath propagation, which ultimately limits deployments to line-of-sight paths.

LTE isnon-line-of-sight technology. As Redzone experienced, a dense fixed wireless access deployment can result in unwanted self-interference. This is because professionally installed directional customer premises equipment is preferred, because of the link budget benefits. These higher-gain directional antennas translate to increased reliability along with higher modulation and coding, which ultimately improves the overall capacity of the sector. This can create challenges in a handover-enabled network, because directional subscribers can easily wind up interweaving in terms of sector associations, resulting in unnecessary inference. This can be managed through careful planning with the use of alignment tools, along with cell-locking.

The success of any deployment directly correlates with the radio network design. When radio planning is executed carefully, an operator can optimize coverage and throughput, which in turn provides a greater return on investment. For example, the antenna in a 3-GHz non-line-of-sight deployment needs to be two to three times higher than the tree canopy for an optimized sector implementation. This minimizes the attenuation by optimizing the angle of incidence.

Understanding how LTE works, in addition to using the proper network tools at the beginning of a project, provides the best chances for a successful installation, thereby eliminating reactive cleanup at the tower.

Roderick Kelly is cofounder of K+L Storytellers. For information about the fixed LTE wireless access equipment described in the article, visit www.redzonewireless.com.

LTE, LMR Combine for Future Public Safety Communications

By Wayne Wong

Next-generation public safety communications will more than likely pair narrowband LMR networks for voice with broadband LTE networks for high-speed data.

One of the hottest topics in the Land Mobile Radio (LMR) industry today is the use of private Long Term Evolution (LTE) high-speed wireless communications. Although a plethora of information can be found about LTE and how it will affect the LMR industry, many questions remain unanswered. A common question is, “Does the emergence of LTE mark the beginning of the end for traditional LMR standards such as P25 and TETRA?” Although this is a difficult question to answer, most experts believe the answer is “no.” However, many believe that a profound transformation is on the horizon, and everyone in the LMR community needs to understand what the changes may be.

Frontline Users

Every LMR industry segment will be affected in some way, but exactly how much LTE will affect an individual or organization will depend on what their roles are. For instance, frontline users, such as firefighters and police officers on the streets, will probably not care about LTE all that much. They are primarily concerned that whatever equipment they are given works reliably every time. It doesn’t matter if the underlying technology is LTE, P25, TETRA or analog. They just need a communications system that will be there when their safety is on the line.

Focus on Standards

LTE is well established in the consumer market, but enhancements to the standard to specifically address the needs of public safety and other critical communications are required. The 3rd Generation Partnership Project (3GPP) is in charge of the LTE standards and has been working hard during the past several years to incorporate the necessary changes to the LTE standards to address the needs of the public safety community.

Why the Demand for LTE?

The driving factor for adopting LTE in the LMR industry is the increased need for broadband data applications. For instance, many police departments are outfitting their officers with video cameras both for their safety and to document encounters in case questions or lawsuits arise from an incident. Most of these devices can only record events and cannot stream video in real time. There is an urgent need for real-time situational awareness, and an LTE-enabled recording device can relay the live video stream back to a command center where commanders can maintain real-time tactical situational awareness.

LTE technology enables extremely high-speed data communications that are not possible with current LMR technologies. LTE was designed to deliver high-bandwidth mobile data that allows mobile devices to stream video or transfer large amounts of data quickly. The enhanced data services of LTE are the main driving forces that make LTE attractive for public safety.

Public safety professionals need reliable communications to aid them in their lifesaving missions. Until recently, narrowband analog and digital LMR systems sufficed for most of their needs; however, many tasks today require broadband services (for instance, when these first responders need to access data-intensive applications, search databases or share videos). Modern smartphones on cellular networks are much more powerful communications devices than the typical LMR systems used by the public safety community. There is a clear need for rugged, easy-to-use devices designed to meet public safety requirements, as well as provide advanced features and services that enhance their agility on the job.

All of the leading LMR equipment manufacturers, including Motorola, Harris, Tait, Kenwood and Hytera, have already embraced LTE. Many of these manufacturers have either released or are about to release combined LTE/LMR solutions. With the rise in hybrid LTE/LMR devices, operators and maintainers will require test equipment to test both LTE and LMR equipment.

Role of FirstNet

On Feb. 22, 2012, the U.S. Congress created the First Responder Network Authority (FirstNet) with the passage of the Middle Class Tax Relief and Job Creation Act. The legislation allocated 20 megahertz of bandwidth in the 700-MHz band and $7 billion to support the construction of a nationwide broadband public safety network. The law mandates FirstNet to build, operate and maintain the first high-speed, nationwide wireless broadband network dedicated to public safety. The legislation also specifies that the network must be an interoperable platform used for emergency and daily public safety communications.


The three most influential public safety organizations in the United States, the Association of Public-Safety Communications Officials (APCO) International, the National Emergency Number Association (NENA), and the National Public Safety Telecommunications Council (NPSTC), have all endorsed LTE as the technological standard for the FirstNet national broadband network for first responders.

Around the World

LTE adoption is not limited to the United States. It is being adopted throughout the world as the technology of choice for nationwide broadband public safety networks. In the United Kingdom, the Emergency Services Mobile Communication Programme (ESMCP) will use LTE as its next-generation communications system for the three emergency services (fire and rescue, police and ambulance) and other public safety users. South Korea has deployed a dedicated nationwide public safety LTE network called SafeNet. Several other countries are expected to adopt nationwide LTE public safety networks.

3GPP Enhancements

LTE networks currently deliver extremely fast data, but current voice services do not have all the features required for mission-critical communications. As LTE technology evolves, it will include mission-critical voice communications. For the past several years, 3GPP has been working with LMR industry groups, such as APCO (with P25), the European Telecommunications Standards Institute (ETSI) (with TETRA), the TETRA and Critical Communications Association (TCCA) and the U.S. National Institute of Standards and Technology (NIST), to ensure broad representation on adding necessary features to support mission critical applications for the public safety community. Releases 121,2, 133,4and 145of the 3GPP LTE specification add significant features for true mission-critical functionality.

Two Features

Release 12 is one of the most comprehensive  standards that 3GPP has ever released, with a significant portion (about 70 percent) of its new features directly enhancing mission-critical applications in one way or another. Two main features have been added to address public safety applications: proximity services (ProSe) and group call system enablers. In addition, many new security features have been added to protect the system from unauthorized users, eavesdropping, denial of service attacks and other security risks.

ProSe allows mobiles to identify other mobiles in physical proximity and enables optimized direct device-to-device (D2D) calls (one-to-one). Direct D2D calls allow first responders to communicate with each other even when the network is down or where no network exists. Direct communication means mobiles can connect without transiting via the network, which saves valuable network resources. The 3GPP definition of proximity services also includes some features that are exclusively for public safety applications. The “user equipment to network relay” feature allows one mobile to act as a relay for another and provides access to network services outside the normal network coverage area. Another feature, “user equipment to user equipment relay,” allows one mobile to act as a relay point between two others and allows communication to take place without going via the network, even if the communicating mobiles are out of range for direct communication.

Other important features required for public safety and critical communications are mission-critical push-to-talk (MCPTT), mission-critical video (MCVideo) and mission-critical data (MCData), which were all finalized in Release 14.
Work on Release 15, including interoperability with legacy LMR technologies and continued additions to MCPTT, MCVideo and MCData, is underway, and the release is scheduled to be completed by the end of 2018.

LTE Replacement of LMR

The major LMR vendors are shifting their focus to LTE, but does that mean the end of innovation and support for LMR technologies? The consensus of industry experts is “no.” LMR will not be replaced by LTE any time soon, and all the venders will continue to innovate and support LMR technologies for the foreseeable future. Many factors favor LMR staying relevant for quite a long time; however, it is likely that LTE will augment instead of replace LMR for at least a decade or more.

Cost and Spectrum

The number one factor for LMR staying relevant is cost. Many LMR operators have just made the investment to convert from analog to digital systems, such as P25, TETRA and DMR (even though P25 and TETRA have been around for more than 20 years), while others are still running analog systems. This will remain the same for system owners considering LTE. The more likely scenario will have system owners augmenting existing LMR voice systems with LTE for data services. In fact, in the initial rollout of the FirstNet network, LTE is considered to be a complementary enabler to public safety systems that will sit on top of existing LMR voice systems. In addition to the cost of new equipment and infrastructure, LTE requires much more bandwidth than narrowband LMR systems and the need for sufficient spectrum is a barrier for scalable deployments around the world.

Technical Challenges

Other important factors are the technical challenges installers, maintainers and operators will face. One of the reasons LTE was selected as the technology of choice for broadband communications for the public safety sector is because it is the same technology that has been rolled out by commercial operators, so it should be well understood and easy to install, use and maintain. However, keep in mind that LTE systems for critical communications have special features and requirements that the commercial networks do not have to worry about. The primary concern is that it needs to be much more reliable, because lives are at stake. It also has to operate in conjunction with existing LMR networks that often occupy the same frequency bands. This can present challenging interference issues for system designers, installers and maintainers.

Handset Power

Other technical challenges include RF coverage and other system considerations. LMR handsets typically transmit with 3 to 5 watts of power, whereas, an LTE handset may only be capable of transmitting with about 1 watt. This translates directly into longer range for LMR systems. So, for an LTE network to provide the same coverage area as an LMR network, operators will need to install many more sites spaced closer together, thus resulting in higher equipment and maintenance costs. Because of infrastructure costs, a broadband network at 700 MHz will not be able to replace LMR in many locations across the United States because of RF propagation properties, and matching LTE to LMR coverage and reliability is just too cost-prohibitive.

Need for Second Network

In areas with existing LTE infrastructure, one may question why there is a need to build a second private network when the community already has an LTE network in place. The fundamental reason is that commercial LTE networks are not built to mission-critical standards of reliability. Another important consideration is that when a major incident occurs, many civilians get on the network and take up valuable network resources, leaving no bandwidth for the public safety professionals. In a worst-case scenario, the public may overwhelm the network, and all communications will be lost. This has happened many times in large disasters. There is no way to give preemptive priority to public safety traffic, so a dedicated private network for public safety is necessary.

Many questions and concerns about LTE must be addressed before it is accepted by the end users. LMR systems are a known quantity, and reliable voice communication is the number one requirement for any public safety system. The first question is reliability. Another basic question is how well will LTE be able to handle voice and data? These questions can only be answered with empirical evidence, once actual systems are in operation.

AT&T won the right to build out the FirstNet infrastructure, and all 50 states have opted in. However, it is highly likely that it will be many years, pe a decade or more, before the transition to LTE is made, and it may never fully replace LMR. It may just converge into a new hybrid LTE/LMR technology.

Test Considerations

Anritsu’s LMR Master S412E battery-powered LMR field analyzer can test both broadband LTE and narrowband LMR systems.

FirstNet public safety LTE in the United States will occupy two 10-megahertz-wide blocks of spectrum from 758 MHz to 768 MHz and its duplex spectrum offset +30 MHz away at 788 MHz to 798 MHz. These frequency bands lie adjacent to public safety narrowband spectrum for LMR at 769 MHz to 775 MHz and its duplex pair +30 MHz away at 799 MHz to 805 MHz. A recent study conducted by the U.S. Department of Homeland Security (DHS) suggests that LMR and LTE systems operating at the frequency bands above can coexist with proper engineering design practices and careful frequency planning.6Interference issues may still be of concern because the guard bands between the LTE and LMR spectra are only 1 megahertz wide. Some portions of the 700-MHz FirstNet bands may be heavily affected by passive intermodulation (PIM) interference generated by existing LTE cellular downlinks used by major wireless carriers. This means that all carriers operating those networks will need to ensure high-quality installations with special care taken to reduce or prevent PIM signal levels from degrading overall network performance.


LMR and LTE are quite different technologies and require different tools for testing and maintenance. Compared with LMR, LTE is a much more complex technology with its variable channel bandwidths and use of both multiple-input multiple-output (MIMO) communications and orthogonal frequency-division multiple access (OFDMA) modulation to support high data rates. LTE is definitely going to be used in the public safety and critical communications world. As previously mentioned, it is more than likely that LTE and LMR systems will coexist for some time. Supporting two separate networks can become challenging both in terms of personnel requirements and test equipment requirements. Both LTE and LMR systems have to contend with problems such as multipath and fading that degrade signal quality. Handheld test equipment that can deal with both the complexity of testing LTE networks and mapping bit error rate (BER) as well as the modulation fidelity of LMR networks is critical to providing technicians and engineers that install and maintain public safety communications systems with the confidence that these networks will work as expected. Such measurements often require a number of different tools, all of which must be carried into the field. Maintainers now have to train their crews to be proficient in two highly different technologies or employ two separate crews — one dedicated to LTE and one to LMR.

Next-generation public safety communications will more than likely pair narrowband LMR networks for voice with broadband LTE networks for high-speed data. Ensuring these networks are properly installed and maintained is critical to ensuring mission-critical public safety communications to keep the public safe. An instrument that can address this problem is Anritsu’s LMR Master S412E, the industry’s first and only battery-powered LMR field analyzer capable of testing both broadband LTE and narrowband LMR systems. It combines many of the tools needed to install, maintain and certify LTE and LMR systems into a single instrument with a single user interface. Multi-function analyzers such as the LMR Master S412E can significantly reduce the number of different tools technicians and engineers need to verify operation of wireless network infrastructure and to diagnose problems in the field.

1. 3GPP, “Understanding 3GPP Release 12: Standards for HSPA+ and LTE Enhancements,” Executive Summary, February 2015.
2. 3GPP, “Overview of 3GPP Release 12,” September 2015.
3. Flore, Dino; “Evolution of LTE in Release 13,” 3GPP article, February 2015.
4. 3GPP, “Release 13 Analytical View,” September 2015.
5. 3GPP, “Mission Critical Services in 3GPP,” June 2017.
6. Department of Homeland Security, “A Case Study of Interference Between Public Safety Long Term Evolution (LTE) And Public Safety 700 MHz Land Mobile Radio,” White Paper DHS-WP-PSC-13-06, March 2013.

Wayne Wong is the product manager for the LMR Master product at Anritsu. He has held various roles from senior hardware design engineer to field applications engineer during his 20 years in the test and measurement industry. Visit www.anritsu.com.


Gigabit LTE Growing Worldwide

The number of people with access to gigabit LTE has surged to 74 million, based on large-scale deployments across a number of countries, including the United States, South Korea and China, over the past few quarters,  according to the latest data in the Gigabit Monitor from VIAVI Solutions.

These deployments have turned gigabit LTE into the second most widely available form of gigabit internet, after fiber. Globally, fiber has increased its global share of gigabit deployments to 90.4 percent, however this includes a large volume of micro scale deployments, predominantly in the United States, where populations as small as 300 people are being served with gigabit internet.

In total, gigabit internet is now available to 301 million people across 49 countries. The volume of gigabit internet deployments has increased by 38 percent since May 2017. This means that 4.2 percent of the global population now has gigabit internet available to them.

Interestingly, the number of hybrid fiber coaxial (HFC) deployments each quarter is also now tracking closely with fiber rollouts, whereas fiber deployments outpaced HFC up until 2016.

The United States remains the country with gigabit internet available to the largest number of people, with gigabit access now available to over 64 million people. Following the U.S. are South Korea with access for 46.9 million, Spain with 30.1 million, China with 20.7 million and Canada with 15.7 million.

However, in terms of the percentage of population coverage, Singapore has the greatest gigabit coverage, with gigabit internet available to 95 percent of its population. Singapore is followed by South Korea with 93 percent, Moldova with 90 percent, Qatar with 78 percent and Spain and Portugal tying at 65 percent.

Since the beginning of 2017, gigabit internet has been introduced in nine countries for the first time. The new gigabit countries are Australia, Croatia, Estonia, Germany, Kazakhstan, Malta, Monaco, Oman and Russia.

“It is fascinating to see how public and private companies, and even governments are pushing for gigabit internet to become an economic enabler for their customers, citizens or their own businesses,” said Sameh Yamany, chief technology officer, VIAVI Solutions. “During the last 12 months, gigabit internet deployments have increased by 38 percent, demonstrating that the global pace of deployment is progressing strongly.”

“Beyond the top-line figures, the major story that we are seeing is how the shape of gigabit internet provision is changing,” Yamany continued. “For the first time, gigabit LTE has now become a significant force in gigabit provision, as 74 million people around the globe have access to it. But whether it is fiber, HFC, LTE or 5G in the near future, the onus is on service providers to ensure that the hoped-for speeds and experience match consumer expectations, which requires a robust discipline of network monitoring, testing and troubleshooting.”

The Gigabit Monitor is a web-based tool intended to showcase the state-of-play of gigabit internet provision across the world, based on publicly available data. This living database is updated regularly, based on deployment announcements and feedback from users. The site was launched in 2016 and tracks gigabit deployments since 2004. The Gigabit Monitor displays dynamically updated infographics showing the current state of gigabit internet provision in all 49 countries where it is available. Each country’s gigabit internet profile displays the estimated population coverage, global ranking, gigabit launches over time and a listing of local gigabit providers.

LTE Map Exposes Lack of Rural Competition

Urban areas benefit from robust LTE competition while rural areas have few competing carriers, according to a recently updated map of LTE coverage from Mosaik Solutions.

Many urban centers are shown having five or more LTE networks, while rural areas with one or two networks operating.

“In rural areas, this often might translate to little need to enhance coverage from a purely commercial standpoint,” said Andrew Miceli, VP global sales and marketing at Mosaik, in a post on LinkedIn. “I’m a big advocate for improving our rural coverage for a lot of different reasons, not the least of which is public safety, so I am hoping to see regulation and new innovation that is friendly to such investment in the very near future!”



LTE network Deployed in Deep Canadian mine

Ericsson and Ambra Solutions have collaborated on the deployment of an underground LTE network for the Agnico Eagle mining site, LaRonde, in Abitibi, Quebec, Canada.

Located 1.8 miles below the surface, the LTE network will provide data and voice mobility services across the site and enable several IoT use cases to improve safety and mining operations.

LTE cellular networks can provide data and voice mobility services over low frequency bands that allow a better propagation than any other available technology, delivering faster, more advanced wireless technology. A single LTE radio can cover up to 6km of tunnel, whereas it would take over 60 active Wi-Fi access points to cover the same area. The network in LaRonde, which is using the 850 MHz band, is the only private LTE network in Canadian underground mine.

The solution is based on the latest Ericsson Radio System portfolio of basebands and radio units, software upgradable to provide IoT capabilities for sensor-based applications and support 5G New Radio (NR) capability.

LTE networks open a new suite of capabilities and possibilities to cost effectively enable smart mining-related tasks for open pits or underground mines. Unlike other options, LTE networks allow the use of IoT sensors and devices to monitor, operate, and collect data throughout the mining site, for example related to air quality monitoring. This includes remote control operation of mining machinery, dispatch systems, emergency notification systems, access control systems, automated collection of data, ventilation fan monitoring and gas detection systems.

Graham Osborne, Ericsson Canada, said, “Our work with Ambra brings Ericsson technology to a specialized environment in a unique application. Deploying this underground LTE network will provide us with new learning opportunities in a novel application and how they can lead to future technologies and ideas.”