July 20, 2017 —
When someone places a call to 9-1-1, the call-taker needs to know the caller’s location — and quickly. It is usually the first or second question the call-taker asks, according to Brian Fontes, CEO of the National Emergency Number Association. The association, which identifies itself as NENA: The 9-1-1- Association, is a membership organization of people who work in 9-1-1- call centers and others who seek to improve 9-1-1 emergency number service.
“We live in a connected world, and it is going to become more connected with the internet of things,” Fontes said, speaking during a conference session at the Las Vegas Convention Center in March. “We need a sea change from what has previously been done to identify the location of someone placing a 9-1-1 call.”
Fontes recalled that in the 1990s and early 2000s, 9-1-1 systems used two methods of automatically determining a caller’s location when the call came from a wireless device. One involved direction-finding using intelligence in the network, along with radio signal triangulation with the cell phone and cell towers. The second, which came later, used the Global Positioning Service earth-orbiting satellites to provide locations, which used more intelligence in the handsets, although some intelligence remained in the network. But, Fontes said, callers remain tethered to their service provider, and therefore to whomever the service provider is, in turn, tethered to, to provide location accuracy.
The most recent efforts to improve location accuracy move beyond the world of the carrier, Fontes said. He reported that, even though the FCC rules are placed upon the wireless service providers, the most current rules enacted by the FCC take a look at indoor location. Fontes cited the statistics that there are 240 to 250 million wireless calls to 9-1-1 annually, 70 to 80 percent of or which are wireless. He said that more than 50 percent of U.S. households are wireless-only homes, not counting offices and other locations. “The number of calls coming from indoor locations is certainly a factor to be dealt with when you’re trying to locate somebody making a 9-1-1 call,” he said.
Fontes said that wireless carriers, NENA and Association of Public Safety Communications Officials (APCO) have agreed to steps that carriers can take to look beyond their networks to improve location accuracy. “That’s a big risk, because once you move outside of a network, the control that the carriers have slips away,” he said. “And yet, the requirements for location accuracy imposed by the FCC are imposed on the carrier. So now, what can be done and what is being done?”
Wireless devices connect through a variety of technologies, including Bluetooth, Wi-Fi, sensors and beacons. Fontes explained that within their environment, wireless phones have the capability of interacting with many other wireless access points that can provide better location capabilities.
“Earlier, I checked to see how many Wi-Fi hotspots in the convention center my phone was detecting,” he said. “I think there are about a dozen, maybe 14. Each of those has various levels of strength that provide some capability of determining where I am vis-à-vis those hotspots. In addition to that, we should take a look at the advent of beacons and sensors. The price of beacons and sensors is decreasing, making it much more affordable to be included in a variety of products.”
Fontes spoke of the possibility of having sensors dispersed in a transient type of environment to provide some location capabilities for a particular event.
Fixed Location and Address
He said he bought a microcell to use in a secondary residence to improve wireless coverage. The microcell registered with the wireless carrier’s database, providing its fixed location and address, which greatly improves 9-1-1 location accuracy. “As part of the agreement with the carriers, the FCC recognized and codified in its regulations the use of a database that’s being developed by the carriers to provide that list, the National Addressing Database, whether it’s Wi-Fi hotspots, picocells, beacons or sensors,” Fontes said.
As the database becomes more populated, Fontes said, the capabilities of working to improve location accuracy for the individual advances remarkably, particularly in comparison with the technologies of location accuracy — whether network-based solutions or GPS — especially indoors.
Outdated Voice-centric Service
Fontes said that in large part, technology from the previous century supports 9-1-1 service, and that means it is voice-centric. “How ridiculous is that?” he asked. “The voice call is the start of a series of responses in the public safety family of services that provides the response to emergency situations.”
With the eventual establishment of a nationwide public safety broadband network based on Long Term Evolution (LTE) high-speed wireless data technology, Fontes said the goal is to provide seamless links among the smart technologies that all of us have at our fingertips, smart technology in the 9-1-1 center and the smart technology used by the field responders via the new network. The new network is being built by AT&T under a contract awarded by a federal agency, the First Responder Network Authority (FirstNet).
LTE technology supports video and texting. Fontes said that when an audio-visual component is added to any type of communication, it is possible for experts to pick up cues that others’ eyes may not detect. “When that 9-1-1 call comes in — perhaps it’s a horrible situation in a school or a mall or whatever — with a video and voice component, you may be able to push that video, that voice off to others who are experts in detecting what’s going on in the environment, while the 9-1-1 professional is dealing with what needs to be addressed in the dispatch context.”
Fontes said texting is critically important. He said only 10 to 15 percent of 9-1-1 centers enable texting. “We have 37 million to 42 million Americans who are deaf, hard of hearing or speech-impaired who rely on texting,” he said. “In addition to that, we know of unfortunate situations where texting would be safer than speaking — whether it’s a mass incident type of a situation, such as a mass shooting, or domestic violence.” He said in such situations, a caller with texting might be better able to survive than if the caller had to use voice.
“We have a long way to go,” Fontes said. “It’s politics. It’s money. The easiest part of all of this is technology. I’m grateful for all of those who have worked so hard to improve the technological capabilities that enable field responders to respond to emergencies with greater information, and for the standards work that’s being done by all of these organizations. I hope that in the context of what is happening in public safety at large, we as a nation will improve our next-generation 9-1-1 to make it in fact 21st-century technology.”
Brian Fontes spoke on March 27 at the International Wireless Communications Expo’s Network Infrastructure Forum during the in-building wireless session moderated by the author.
July 11, 2017 —
Verizon has successfully transmitted its first live Voice over LTE (VoLTE) call over its commercial Category M1 (Cat-M1) network with the help of Ericsson and Qualcomm Technologies, which is said to be an important moment in the evolution of IoT connectivity. Cat-M1 is a 3GPP-based technology that is designed to allow low-power Internet of Things devices to communicate over licensed spectrum
Cat-M1 can extend the reach of an IoT device across Verizon’s LTE network, whether it is a data-only or voice-enabled product.
In April of this year, Verizon launched the first nationwide commercial 4G LTE Cat-M1 network, which spans 2.4 million square miles, designed to provide scale, coverage and security for customers seeking wireless access solutions for IoT.
Verizon’s Cat-M1 network is built on a virtualized cloud environment, which enables IoT deployment and nationwide scaling. Cat-M1 is a new class of LTE chipset that is designed for sensors, which requires less power and supports an array of use cases ranging from water meters to asset trackers to consumer electronics.
The low bandwidth use cases for Cat-M1 chipsets demand new types of data plans, including low rate, multi-year plans to match the longer useful life of devices.
In 2016, Verizon launched a limited commercial Cat-M1 network.
AT&T Shows VoLTE Call on Cat-M1/LTE-M Network in Demonstration
At the Mobile World Congress in Barcelona in February of this year, AT&T demonstrated a VoLTE call on Cat-M1/LTE-M technology using technology from Qualcomm Technologies and Ericsson’s radio and core network.
AT&T plans to extend the technology into its mobile network to enhance existing and new IoT use cases requiring voice services. The demonstration shows that the technology is mature and ready for commercial deployment in operator networks.
The demonstration used Qualcomm Technologies’ MDM9206 LTE modem, designed to support Cat-M1/LTE-M, as well as Ericsson LTE Radio Access Network, Ericsson IP Multimedia Subsystem (IMS), Ericsson Evolved Packet Core (EPC) and Ericsson User Data Management network infrastructure and new software.
July 13, 2017 —
In March, the First Responder Network Authority (FirstNet) awarded AT&T a contract to build the first nationwide public safety broadband network for emergency first responders. The network will use Long Term Evolution (LTE) high-speed wireless data technology on frequencies in the 700-MHz band. Eventually, the network will supplant the use of existing public safety frequencies. As the FirstNet network evolves, public agencies and building owners will have to assume the burden of bringing network coverage indoors at venues so first-responder radios will work in all locations. In many instances, jurisdictions will require in-building coverage. The following information explains the convergence of public safety frequencies in connection with the new FirstNet standard and the requirements for systems that support the network’s wireless coverage inside buildings.
Despite the current use of lower frequencies in the range of 150 MHz to 900 MHz to support public safety radios, the in-building coverage challenge remains unsolved. Even at these low frequencies, building construction materials can block outdoor radio signals from penetrating indoors. Underground areas, such as basements, are impossible to cover from the outside; outdoor radios dominate the airwaves; and energy-efficient, Leadership in Energy and Environmental Design (LEED)-certified buildings make matters worse. In the United States, LEED-certified buildings enclose 2.5 billion square feet, and this year, approximately 45 percent of nonresidential building construction will be green (environmentally friendly).
As a result, in-building wireless systems are a must for ensuring clear and consistent radio coverage for building occupants and first responders. Many local governments mandate the use of in-building wireless systems for public safety systems in buildings larger than a certain size, but even existing systems will be in for a revamp as the FirstNet network comes online.
Existing public safety networks and radios operate in several public safety radio communications frequency bands, including the 150-MHz, 450-MHz and 800/900-MHz bands. In effect, the United States is a patchwork quilt of public safety communication networks. With the advent of the FirstNet public safety broadband network, these will all begin to converge around 700-MHz LTE. LTE is now the dominant technology used in commercial cellular networks, but a lot of work is being done to further make use of LTE’s benefits. The results also will affect FirstNet LTE.
For example, mobile operators are always looking for more radio-frequency spectrum to expand bandwidth and provide their users with faster throughput. Once they have derived all the capacity they can with new cell sites, sector-splitting and carrier aggregation, the next thing is to consider using unlicensed spectrum to further expand available bandwidth. LTE in unlicensed spectrum (LTE-U), licensed-assisted access (LAA), and MulteFire computer software and firmware offer ways to use unlicensed spectrum that will deliver bandwidth more from current technology.
LTE-U protocol enables mobile operators to increase bandwidth in their LTE networks by using the unlicensed frequency bands in the 5-Hz range — bands that Wi-Fi devices also use. Licensed-assisted access is the name given to the Third-Generation Partnership Project (3GPP) effort to standardize the use of LTE in Wi-Fi frequency bands. LTE-U is an implementation of LAA. The MulteFire LTE technology developed by Qualcomm operates solely in unlicensed spectrum and uses self-organizing functionality; LAA aggregates unlicensed spectrum with an anchor in licensed spectrum.
Unlicensed LTE protocols will play a significant role in boosting LTE bandwidth and throughput while serving as a key component for connecting the internet of things (IoT). Ideally, in order to speed deployment and deliver an economical solution, public safety, wireless IoT devices, and cellular services will all operate on a converged network (see Figure 1).
FirstNet’s public safety broadband network will make use of the same LTE network, so it’s possible that, in some cases, the 700-MHz public safety frequency may already be supported by some in-building wireless systems (although the frequencies used for the FirstNet network are not the same as the 700-MHz frequencies in use by cellular carriers today, so this would be true in a limited number of cases). In many instances, however, it will be necessary to rip and replace existing in-building wireless systems to facilitate the support of the FirstNet network.
What does this all mean for those considering buying or upgrading an in-building wireless system? There are three basic requirements:
1. Support 700-MHz FirstNet frequencies while still supporting existing cellular and IoT frequencies. Ideally, the solution should support public safety, cellular and IoT frequencies in a single system. This will simplify both deployment and maintenance, while keeping costs down. A truly wideband distributed antenna system (DAS) can support any frequency from 150 MHz to 2700 MHz, so it could support many different frequencies with a single layer of equipment, including 700-MHz FirstNet communications. And, this solution could seamlessly support future services.
2. Use fiber infrastructure. Many current DAS solutions use coaxial cabling or a hybrid architecture that combines fiber and coax cabling. An all-fiber infrastructure is easier and less costly to deploy, and often it can make use of fiber-optic cable already in place in the building.
3. Have a simple architecture. Many DAS products have a dizzying array of parts because of their inherently narrowband architecture, making it difficult for information technology (IT) staff to both deploy and maintain them. Building owners and contractors should look for DAS solutions that mirror IT data infrastructure with a limited number of system elements so it is familiar and easy to understand.
Meeting the FirstNet Challenge
The move toward FirstNet public safety infrastructure represents both a challenge and an opportunity for building owners. The challenge is that many in-building wireless systems will have to be upgraded or deployed because some existing systems support other frequencies, but not the 700-MHz frequencies the new FirstNet network will use, and some buildings lack any kind of indoor coverage solution. But the good news is that the need to support the new public safety broadband network offers the chance to deploy a single, converged in-building wireless system that supports all wireless traffic. The FirstNet network will take several years to roll out. It is not too early now to begin planning how to support it.
James Martin is vice president of operations at Zinwave. Prior to joining Zinwave, Martin was senior manager at TE Connectivity (formerly ADC/LGC Wireless) for more than 16 years. His leadership helped TE Connectivity emerge as a top-tier DAS manufacturer in the wireless space. Early in his career, he was employed at Hughes Network Systems and was responsible for the design, deployment and optimization of more than 500 macro cell sites across the southeastern United States. During this time, he was also instrumental in defining the first small cell systems designed and deployed by Hughes Network Systems. Contact James Martin at email@example.com
June 14, 2017 —
Good indoor wireless communications coverage plays an important role in supporting cellular internet-of-things (IoT) operations. IoT services have many communications standards to choose from. They also have three ways to deliver coverage indoors.
A variety of approaches have been promoted and trialed for wide-area wireless for the internet of things (IoT) — the term that has emerged to refer to the network of devices that keeps a smart home running, a business campus interconnected or a disabled vehicle in communication with its road service provider. Among the contenders for hegemony in this fast-growing domain are the Dash7 Alliance protocol, Sigfox network technology, Weightless connectivity technology, LoRa (long-range) spread-spectrum technology, RPMA (random-phase multiple-access) spread-spectrum technology and even 2G digital cellular technology, to name only some. Each comes with self-proclaimed strengths and weaknesses.
The 3rd Generation Partnership Project (3GPP), the standards body that delivered Long Term Evolution (LTE) high-speed wireless communications , has included two variants of LTE in its Release 13 for use in the IoT context: Cat M1 (Category M1 — the “M” originally stood for “metering” and referred to smart metering using IoT) and NB-IoT (narrowband IoT). It is likely that multiple standards will be used, because there is a wide variety of use cases (ways to use a system to accomplish a particular goal). Devices that support the LTE Cat-M1 standards for IoT have just started shipping over the last several months, and they benefit from having the broad support of the existing cellular network providers that have deployed LTE, or plan to.
The ecosystem for LTE Cat-M1, specifically, is a little ahead of NB-IoT, which means modules, devices and network support are already available. The NB-IoT devices are “coming soon.”
In October 2016, Verizon claimed to have made the first LTE Cat-M1 call. Meanwhile, in San Francisco, AT&T claimed to have placed a fully commercial LTE Cat-M1 site in operation. AT&T’s Glenn Lurie in 2015 announced that the carrier was chasing IoT via cellular-only solutions based on LTE. Winning General Motors’ connected car business through the OnStar program gave AT&T instant scale, and AT&T has been charging forward ever since. Other carriers have been working on it, but they have not been as vocal about their efforts for as long as AT&T has. LTE-based IoT solutions are also seeing traction in Europe, with Tier 1 operators such as Vodafone giving their endorsement.
To put IoT over cellular in context, there are a number of competing methodologies for connecting IoT devices, from fixed line to wireless. It is when we consider the competing low-power, wide-area network (LPWAN) solutions — Sigfox, Weightless, RPMA, Dash7 and LoRa — none of which is LTE-based, that we can see why LTE-based IoT is gaining such traction: It can be applied to existing LTE networks as a software upgrade and therefore is much easier (and less costly) for operators to deploy.
So what are the markets going to look like, and where will the lion’s share go? Some say that cellular IoT solutions could reach as high as a 90 percent market share, which makes sense only given the robustness and prevalence of today’s LTE networks.
According to a new research report from IoT analysis firm Berg Insight, global shipments of cellular IoT devices will grow at a compound annual growth rate (CAGR) of 22.7 percent from 155.6 million units in 2016 to reach 530.1 million units in 2022. Other researchers report the number even higher.
LTE-based IoT and Coverage
LTE-based IoT (LTE Cat-M and NB-IoT) devices offer a number of advantages over standard 3G and 4G technologies. The big three are extended battery life, lower cost and better coverage. Coverage is our focus in this article.
LTE-based IoT delivers better coverage primarily because of a substantially better link budget. The link budget is an important measure for power calculation. It calculates the power received at the receiver (device) and accounts for gains and losses along the way. A link budget essentially indicates how bad the signal can be from the tower to the device (and vice versa) and still allow the system to communicate.
A cellular IoT link budget (~ −164 dB) is about 20 dB better than standard 3G and 4G technologies (~ −144 dB). This provides coverage to an area approximately seven times larger (in an open environment). A 20 dB improvement will also result in better in-building penetration.
Standards bodies worked to ensure a better link budget for cellular IoT for good reason. With 3G and 4G, operators continue to struggle to provide good in-building coverage from external macro networks. A recent Zinwave study showed that 66 to 83 percent of workers have “frequent” or “sometimes” bad cellular coverage. More than 45 percent of warehouse workers reported frequent problems connecting.
Everyone agrees these numbers are unacceptable, yet the problem is becoming more pronounced as mobile adoption continues to grow. We do everything over mobile now. All tools are mobile, and being disconnected is not an option. One can easily imagine how ineffective any mission-critical business operation would be if it had to rely on such poor connectivity metrics. Even non-mission-critical operations are nonstarters at that level of connectivity.
LTE-based cellular IoT solutions are new on the market, with the first commercial deployments begun in the last six months. In spite of the improved link budgets and wider coverage areas, these technologies are subject to the same in-building penetration challenges and resulting coverage problems as cellular.
Sigfox, for example, has a link budget of 159 dB. This provides a phenomenal coverage area — about 20 kilometers. As you can see in the illustration in Figure 1, just three towers can cover all of metropolitan Melbourne, Australia.
When you read the fine print of the coverage map however, it tells a slightly different story: “This map is only a guide and not a guarantee of service level. Coverage estimation based on computer prediction in outdoor location [emphasis added] for device class U0 (maximum output power level is defined in SIGFOX Ready™ certification requirements.”
This is not a slight on Sigfox. All of these technologies are outside-in, and they are all subject to the same laws of physics, attenuation and propagation. The operator of one of the best cellular networks in the world, Verizon Wireless, makes a similar statement about coverage: “Customer equipment, weather, topography and other environmental considerations associated with radio technology also affect service and service may vary significantly within buildings.”
In-building IoT Options
According to the most recent Ericsson Mobility Report, there will be about 18 billion wireless IoT devices in 2022. Of those, one in eight (or 2 billion units) will be wide-area reliable, and pervasive in-building coverage is needed to support the 30 percent compound annual growth rate (CAGR) that Ericsson is projecting, along with most experts covering IoT, as seen in Table 1.
Fortunately, solutions exist. There are three ways coverage can be delivered indoors in the IoT context: wired-to-router, wireless mesh and wireless boosters.
For many applications, the simple solution of a wired-to-router network will suffice. If the on-premise IoT solution is simply making use of a wide-area wireless-enabled router or gateway in which the on-site sensors and nodes are connected via wire, then an antenna could be run to the exterior of the building. To provide coverage to a single fixed point, this is a fine option (see Figure 2).
However, for the antenna to pick up signal, there must be some service available to the exterior of the building. There are also some limitations around equipment placement — the antenna run cannot be too long because of the attenuation of the signal over the length of the coaxial cable.
Wireless Mesh Network
Some IoT networking technologies implement a form of mesh capability, allowing for a string of pearls style approach to coverage. In this model, each network node becomes both a sensor and a gateway for other devices.
Some applications can leverage this capability quite well. 802.15.4 (Zigbee) is one such networking technology that makes use of mesh capability (see Figure 3).
There are two main weaknesses with this approach to extending the IoT network and coverage.
First, because each node becomes a full-time participant in the communications path, the nodes must be on all the time. This makes a battery-powered mesh network difficult to maintain. Battery life for a node can decrease from 10 years to only a few months, depending on where it sits in the network and how often it is used. Keep in mind, if a single node goes down in the network chain, all of the nodes after it are incommunicado. This is mostly a non-issue where nodes are powered, as with most smart home applications, for example.
Zigbee, having mesh capability, is a great technology for the connected home, where battery-powered devices are less common and thus are not limited to the lifespan of a battery. A Zigbee-enabled smart home battery-powered device might last only 12 to 18 months.
The second issue is latency. Each node introduces latency into the network architecture. Depending on the type of application and messaging layered on top of the network infrastructure, this could be a problem. Messages time out and real-time applications suffer. Even the smallest, localized smart home network based on Zigbee, with powered nodes, struggles to maintain and support low-latency applications. Higher latencies limit the types of applications that can be deployed over the network.
Wireless Boosted Network
Smart signal boosters can offer a highly attractive alternative for bringing cellular IoT coverage indoors. A good smart signal booster is transparent to the cellular network: It simply relays the external coverage internally, with so little delay that it is invisible to the cellular network. The cellular devices inside the building just receive good signal, improving both voice and data signals.
A smart signal booster is inherently different from older repeater technology because it is approved by the FCC to boost gain to 100 dB, 1,000 times greater than levels allowed with analog bidirectional amplifier (BDA) repeaters. Smart signal boosters have been approved by more than 200 global carriers for use on their networks because they are guaranteed to be network-safe, and they won’t interfere with the macro network or other wireless devices on the network.
In an LTE-based IoT infrastructure, smart signal booster technology offers significant advantages. For one, it is transparent to the network. There is no additional latency or setup required. A device could be installed in a concrete bunker, and with the right smart signal booster, the device would appear on the network as if it were sitting in a wide-open coverage area with no structural obstacles. For mission-critical business solutions that rely on real-time communications, this is an important option.
Also, unlike mesh networks, IoT nodes that are inside the coverage bubble of a smart signal booster don’t have to do any additional work, so they can be much lighter weight in terms of capability. They can operate as intended, waking only when prompted, or on a timer. This delivers the 10-year battery life desired by the IoT industry.
Buildings with IoT solutions being serviced by a smart signal booster have a lot of flexibility, because nodes can be added or subtracted without any special setup or configuration, which is another advantage. They can be fully mobile and not rely on tethering from a cable or network connection (see Figure 4).
Yet another advantage is that, unlike other options (e.g., simply adding an antenna to the IoT router), data and voice applications will benefit with the right smart signal booster. Not only will the IoT node be connected in a high-speed low latency connection, voice calls over LTE will be improved.
Because LTE-based IoT offers a number of advantages from an architectural, financial and efficiency perspective, it is not surprising to see the momentum in adoption and device shipments. But one cannot underestimate the critical importance of good indoor coverage to support cellular IoT operations. In a simplified way, Figure 5 illustrates the effect of poor indoor coverage on industries with mission-critical operations.
As LTE-based IoT emerges as a favored option, organizations should consider themselves on notice to resolve these issues in their systems. The good news is affordable and flexible options are available that can address virtually any indoor coverage challenge, large or small.
Joe Schmelzer is senior director of products at Nextivity. He has developed a variety of products and industrial devices for chipset vendors, original equipment manufacturers and service providers, including products for Sony, Qualcomm, Google, Verizon Wireless, AT&T, Dell and HP. He enjoys speaking opportunities and writing. For more information, visit www.cel-fi.com.
May 22, 2017 —
MulteFire technology creates new wireless networks by operating Long Term Evolution (LTE) high-speed wireless data technology as a standalone system in unlicensed or shared spectrum. The MulteFire Alliance, a membership organization that defines and promotes MulteFire technology for small cells operating solely in unlicensed spectrum, completed the MulteFire Release 1.0 specification in January. The Alliance is an open, international organization dedicated to support the common interests of its members, developers and users in the application of LTE and next-generation mobile cellular technology in configurations that use only unlicensed radio spectrum.
With MulteFire deployment, private and public vertical venues, vendors in the internet of things (IoT) vertical market, businesses and property owners can create, install and operate their own private or neutral-host MulteFire network in the same way that they do with Wi-Fi. MulteFire technology incorporates high-quality LTE services and functionality supporting voice and data IP services locally, independently as a private network or interworking with existing mobile networks to provide secure, seamless service as a neutral host — or both.
Today, in-building neutral host wireless solutions are common in the context of Wi-Fi and distributed antenna system (DAS) deployments and are occasionally employed in macro-cell environments. However, the neutral-host option — a common deployment serving subscribers from multiple operators — has rarely been adopted in the deployment of licensed-band small cells. MulteFire technology has the potential to unlock the adoption of small cells and enable neutral-host deployments on a much larger scale.
New Business Opportunities
MulteFire technology creates new business opportunities that allow new markets with specialized needs to benefit from the LTE technology and ecosystem. These vertical markets include large enterprises, sports and entertainment businesses, health care services, identity management vendors, public venues (malls, airports), hospitality businesses, transportation services, machine-to-machine (M2M) applications, IoT applications, seaport management, gas detection, manufacturing, logistics providers and the public sector (first responders, smart grids, military bases and barracks, universities, hospitals and education authorities). Each of these vertical markets can create customized applications and quality of experience (QoE) for its users.
The standalone LTE system is suitable for any radio-frequency spectrum band that requires over-the-air contention for fair sharing, such as the global unlicensed spectrum band at 5 GHz or shared spectrum at 3.5 GHz in the upcoming Citizens Broadband Radio Service (CBRS) band in the United States. MulteFire’s 4G LTE technology is tightly aligned with 3GPP standards and builds on elements of the 3GPP Release 131 and 3GPP 142 specifications for licensed assisted access (LAA) and enhanced licensed assisted access (eLAA), augmenting standard LTE to operate in global unlicensed spectrum. Enhancements, such as listen-before-talk (LBT), have been designed to efficiently coexist with other spectrum users, such as Wi-Fi or LAA.
The LTE-based technology enables the full range of LTE services including VoLTE (voice), high-speed mobile broadband (data), user mobility and IoT optimizations. It promises LTE-like performance with the simplicity of Wi-Fi-like deployments. As with mobile networks, MulteFire technology enables full mobility as a user walks around a building; the technology enables seamless handover between small cells as required. MulteFire technology will also interwork with external mobile networks to provide service continuity when users leave the area where MulteFire service is available.
The standalone LTE network deployment can operate anywhere, without additional regulatory approval, costly spectrum or specialist expertise. It uses many of the sophisticated features designed into LTE to deliver high performance, seamless mobility and resilience, even in highly congested environments. As with Wi-Fi, multiple MulteFire networks can co-exist, overlap, or be friendly neighbors in the same physical space.
MulteFire technology unleashes enormous potential for the wide adoption of small cells, especially indoors. Additionally, it could form a useful multi-operator solution for building owners at a lower cost than today’s DAS by acting as a neutral host or single-operator enterprise solution.
The following are the MulteFire technology’s key performance advantages, thanks to the use of LTE technology:
Its end-to-end architecture extends from general design to support for various deployment modes. Its radio air interface, including frame structure and uplink transmission scheme make use of eLAA robust anchor carrier design, LBT design, and key procedures such as random access procedure, mobility, radio resource management (RRM) measurement and paging.
The better radio coverage that MulteFire technology provides retains LTE’s deep coverage characteristics in an unlicensed band, targets control channels to operate at cell-edge SINR of −6 dB and adds a 5 dB to 6 dB link budget advantage over carrier-grade Wi-Fi.
Its enhanced capacity in denser deployments offers significant gains (~2X) over the 802.11ac baseline, and it makes use of LTE link efficiency and media access control (MAC).
The seamless mobility the MulteFire technology delivers brings carrier-grade LTE mobility to unlicensed and shared spectrum, supports backward and forward handover (as Rel. 12), and provides seamless and robust mobility between MulteFire nodes themselves for all use cases and when moving between a MulteFire radio access network (RAN) and a macro network, depending on deployment model. It provides service continuity to wide-area networks (WANs) when moving to and from a neutral-host deployment.
MulteFire technology has increased robustness because forward handover enables recovery when radio link failures occur. It also has enhanced radio link failure triggers, and it uses LTE mature self-organizing network (SON) techniques.
Owning and operating a MulteFire network that uses unlicensed spectrum has many benefits, whether it is deployed as a standalone network or interworks with existing mobile networks. The use of the LTE-based technology provides secure, seamless service and the MulteFire deployment can act as a neutral host that offers voice over LTE (VoLTE), high-speed mobile broadband and LBT, all with LTE-like performance. Additionally, MulteFire technology’s Wi-Fi-like simplicity makes it a powerful tool for any organization that does not require hiring expert implementers.
MulteFire systems can operate anywhere, even in congested Wi-Fi and LTE environments where they can co-exist and overlap. A MulteFire system seamlessly hands over between small cells as necessary to provide users with better mobility and to ensure that they stay connected to their information. When a user leaves the MulteFire network area, the MulteFire equipment interworks with external mobile networks to provide service continuity.
Moreover, there are a number of specialized customers that require high reliability, safety and mass connections with ubiquitous coverage. MulteFire technology will build a solid foundation for future smart connection in vertical scenarios, including broadband and IoT. The first specification release, Release 1.0 is a testament to the merits of deploying cellular technologies in unlicensed and shared spectrum.
MulteFire Release 1.1 is expected to be released in late 2017. It will have new features for optimized IoT and further enhancements for coverage, spectrum efficiency, mobility, and shared spectrum. Looking ahead, MulteFire technology will continue to be enhanced with new features that introduced in phases and target enriched scenarios, services and additional spectrums.
With permission, this article uses extensive passages from the MulteFire Release 1.0 Technical Paper from the MulteFire Alliance. For more details and to request a copy of the MulteFire Release 1.0 Technical Paper, visit www.multefire.org/specification/release-1-0-technical-paper-download/.