Category Archives: Backhaul

Public Safety Broadband Communications Is More than LTE

By Louis Lambert

The nationwide public safety wireless broadband network to be built by contractors to the First Responder Network Authority (FirstNet) on Band 14, which is 20 megahertz of radio-frequency spectrum in the 700-MHz band, promises to deliver advanced wireless capabilities for U.S. public safety agencies. The network will deploy LTE high-speed wireless data that uses orthogonal frequency-division multiplexing as its radio access technology, along with advanced antenna technologies. With AT&T as the FirstNet prime contractor, state and local first responder organizations are making plans on how to deploy FirstNet within their jurisdictions.

LTE-based broadband services represent the next generation for public safety communications. This is not to suggest that legacy land mobile radio systems are going away any time soon, however. For decades, land mobile radio communications have been the mainstay for police, fire and emergency medical services. In fact, many state public safety communications officials expect to maintain their land mobile radio systems even as LTE comes on stream. Their main concern is that LTE many not reach outlying or rural areas of their jurisdictions where land mobile radio still works.

At the same time, there are public safety communications applications better-suited to unlicensed frequency bands rather than occupying capacity on the LTE Band 14 network.

Video surveillance is a good example.

Video cameras — both point-tilt-zoom or bullet-types — installed at intersections and high-traffic spots throughout urban and suburban areas each generate multimegabit-per-second internet protocol (IP) data streams. How much data is generated from each camera depends on the frame rate, resolution and recording interval.

The problem is that rolling up data from all the cameras covering a wide area and delivering those signals to a monitoring center over the FirstNet public safety broadband network would occupy an inordinate amount of network capacity at the expense of other first responder broadband communications.

Wide-area Operation at 4.9 GHz

In this instance, video surveillance traffic is handled better over a point-to-multipoint microwave radio system operating in the FCC-designated, licensed public safety frequency band from 4940 MHz to 4990 MHz (the 4.9-GHz band). A point-to-multipoint deployment such as this would work in parallel with FirstNet.

The main advantage of this approach is that round-the-clock, high-bandwidth services such as video surveillance can be offloaded from the LTE backbone, thereby freeing up capacity for critical communications during emergencies.

Here’s how it works.

The point-to-multipoint 4.9 -Hz system configuration consists of one or more base stations or sector controllers that connect with multiple remote terminals collocated with, and connected with, video cameras at the various monitoring locations within the sector controller coverage area. Multiple sector controllers can be installed at the same tower or mounting location to achieve 360-degree area coverage.

Point-to-multipoint systems in video surveillance applications should exhibit some key performance characteristics, including:

  • High capacity— Base stations or sector controllers are configured to handle hundreds of remote units with as many as hundreds of megabits per second throughput for every sector. Several base stations may be needed for coverage depending on the jurisdiction, geography of the area and the number of installed cameras.
  • Low latency— Video transport requires low latency, or delay, for a high-performance surveillance system to operate in real time or in near-real time. Latency is desirable in the low millisecond range over connections between the remote terminals and the sector controller.
  • Ease of installation— All-outdoor compact radios that operate with power over Ethernet (PoE) in small form factors with different mounting options have important attributes for rapid deployment.
  • Reliability – Systems should be installed and left to operate with little or no maintenance.
  • Lowest total cost of ownership— High-performance, cost-effective systems involve the fewest base stations that can serve the largest number of remotes.

Public safety communications organizations benefit from this approach in numerous ways. They have no spectrum costs because the 4.9-Hz band is available to all local public safety jurisdictions. They save on capital expense because with a high-performance point-to-multipoint system, fewer base stations connect with hundreds of camera sites over a wide area. Such systems have adaptability because cameras are fixed assets and point-to-multipoint systems are designed for connecting large numbers of fixed assets with high capacity, especially for data uploads.

The systems have flexibility because point-to-multipoint wireless links offers the benefit of being able to move cameras with remote terminals to new locations as coverage needs change. Point-to-multipoint systems that emulate fiber-optic performance (Redline calls it Virtual Fiber broadband wireless communications) achieve high performance with high-speed, low-latency

secure connections for real-time video feeds. In many cases, a combination of wireless and fiber cable, where available, provide the best business balance. Easy-to-install, high-reliability radios that require no special technical skills to deploy remote units and that have zero maintenance costs offer the advantage of low operating expense.

Backhaul Alternatives

At the same time, hauling voice, data or video traffic from the edge of the network back to the core (ergo, the term backhaul) is required in every wireless network whether LTE or land mobile radio is used as the access technology between the base station and the user equipment.

In such networks, all traffic — voice, data or video — ultimately is carried as IP data over the radio frequency to a hub or junction from which these IP signals are routed to a designated monitoring center, a network operations center or an internet peering point.

Fiber-optic cable is an ideal backhaul medium where the cable runs directly to the tower or close to it. However, fiber cable is not available everywhere and is expensive to install, especially in rural areas. In these instances, a point-to-point microwave radio system is the best alternative.

Such point-to-point radio systems are available in licensed and unlicensed frequency bands and can perform at fiber-like speeds. Determining which point-to-point system is right for the application is a function of available spectrum, desired throughput capacity, transmission distance and upfront and operating costs.

First responder organizations can benefit from using point-to-point systems that offer spectrum options, such as systems available in sub-6-GHz unlicensed bands from TV white space (UHF 470-698 MHz) to frequencies between 4.9 GHz and 5.8 GHz for both line-of-sight and non-line-of-sight transmission. Where RF interference may be a problem in certain areas and where line-of-sight transmission is needed, point-to-point systems operating in licensed bands between 6 GHz and 30 GHz frequencies offer a better solution.

Lightweight, compact, all-outdoor radios allow first responder organizations to deploy them on existing structures. The use of the same radio at each end of a microwave hop saves capital expenditures, and simplifies installation and activation. First responders that cover wide areas can realize reliable, high-speed communications over long distances (50 miles or more) with point-to-point systems operating in the 4.9-5.8 GHz band.

In the end, public safety communications organizations can obtain significant operational and economic benefits by deploying readily available, high-performance, cost-effective wireless broadband technologies that complement the FirstNet LTE Band 14 nationwide public safety broadband network.

Louis Lambert is vice president of business development for Markham, Ontario-based Redline Communications, a provider of wide-area wireless networks for the most challenging applications and locations. His email address is


Is Your Public Safety Backhaul Network Up To Task?

By Fai Lam, Marketing Director, IP/Optical Networks, Nokia

With the growing sophistication and increased level of security threats, the need for better situational awareness and closer cross-agency collaborations has become ever more pressing. Accordingly, public safety agencies are evolving their mission-critical communications infrastructure toward the highly efficient, flexible capabilities of internet protocol (IP) to enhance first responder effectiveness and safety. The bedrock for this evolution is a new, converged backhaul network architecture grounded in Internet Protocol/Multi-protocol Label Switching (IP/MPLS), atop packet microwave and optical transport infrastructure.

The demands are high. Public safety agencies looking to evolve to IP/MPLS require a mission-critical communications network that meets a set of stringent requirements (see Fig. 1). It must be reliable and resilient in order to ensure uninterrupted communications even in the face of severe storms, floods, terrorism and other type of unexpected emergencies. To provide effective response, enhanced situational awareness becomes essential. Consequently, the new network also needs to have flexible service convergence to adopt new applications, including fourth-generation wireless technology of  LTE that can offer increased channel capacity and improved spectrum efficiency, and network scalability to accommodate growing video and data traffic. To protect communications investment, it also must be fully interoperable with existing land mobile radio (LMR) systems and applications such as simulcast, and be ready to continue to evolve as necessary.



Fig. 1: Public safety backhaul network evolution requirements

Dependable Communications 24 x 7 x 365

Like its TDM-based predecessor, an IP/MPLS-based backhaul network offers constant, reliable and secure communications to connect first responders with one another, the dispatch center and the data center, ensuring that all public safety personnel are connected 24 hours a day, 7 days a week, 365 days a year.

While legacy backhaul networks are typically based on a traditional access-aggregation-core ring architecture, the packet-based paradigm of IP-MPLS backhaul allows flexible deployment of inter-connected rings. This multi-ring topology, coupled with dynamic IP/MPLS, can restore traffic at SONET speed using fast re-route (FRR) capability when one node or link in the ring goes down. Moreover, during multi-fault scenarios, which are not uncommon during natural disasters, it can rapidly re-establish critical communications with a secondary label switched path (LSP) with remaining network connectivity. Therefore, a multi-ring IP/MPLS network allows better availability and resiliency, with much less chance of one incident – a storm or other disaster – disrupting critical communications.  Combining SONET-speed restoration and multi-fault resiliency with other protection mechanisms – including pseudowire and control hardware redundancies, non-stop routing and services, deterministic QoS, microwave link adaptive modulation and 1+1 protection switching – critical traffic will be preserved even under inclement conditions.

Convergence Flexibility and Network Scalability

An integral element for enhancing situational awareness is broadband communications that give first responders and dispatch center personnel a 360 degree perspective on any event with high-definition video, drones and other rich data applications such as geographic information system (GIS). A new LTE radio system is central to this broadband infrastructure. In addition, public safety agencies can deploy advanced applications such as high-definition CCTV and sensors to gather greater quantities of data for advanced analytics such as gunshot detection and facial recognition, allowing them to act more effectively.

Broadband communications give first responders and dispatch center personnel a 360 degree perspective on any event with high-definition video, drones and other rich data applications such as geographic information system (GIS).

The key for supporting all of these features is the convergence flexibility provided by IP/MPLS backhaul. The use of IP/MPLS virtual private network (VPN) services can accommodate all public safety applications with complete segregation and security (encryption can be enabled with ease for sensitive applications) over the same network, resulting in improved network operational efficiency when compared with the paradigm of disparate networks. This paradigm is commonly known as network segmentation. Furthermore, the support of IP VPN and service-aware stateful firewall in the IP/MPLS platform also facilitates controlled, secure communications between different agencies for closer collaborations. Additionally, other government agencies and operations will be able to attain budget savings by using the spare capacity. With highly customizable classification policy, deterministic multiclass QoS in IP/MPLS treats all traffic with the appropriate priority, and ensures no performance degradation for critical applications in a properly designed network.

Complementing the VPN and QoS capabilities is network scalability. As video and data traffic grow, the backhaul network capacity needs to be able to scale up. An IP/MPLS platform with integrated microwave awareness and WDM networking support, together with a unified network services platform, simplifies the process of deploying additional microwave channels or optical Ethernet links. The unified network services platform facilitates network and services management across IP/MPLS, optical and microwave domains, attaining optimal operational efficiencies and agility.

Investment Protection 

As governments worldwide continue to face budget constraints, they need to invest prudently with a long-term horizon. Ultimately, IP/MPLS backhaul will offer public safety agencies of today the migration capability to gracefully bridge the past to the future with full interoperability with critical legacy applications in use today, full network scalability to 10 Gb/s, and even 100 Gb/s link coupled with wavelength-division multiplexing (WDM) optics when necessary, and software-defined networking (SDN) to prepare for future capabilities requirement such as insight-driven automation and optimization. Accordingly, public safety agencies can continue to use current life-critical applications such as LMR system and simulcast without disruptions, and adopt new technologies with no constraints. This approach protects agencies’ overall communications investment, and offers an evolvable foundation for more advanced (e.g. LTE) public safety communications capabilities.

Public safety is in the middle of momentous changes. The familiar LMR radio in every police car, on every fire engine and in every ambulance will eventually give way to a new generation of ruggedized devices that look like smartphones and tablets. Critical data and video will play an expanding role, alongside critical voice, in first responders services. The backhaul network that ties everything together must work even harder and stretch beyond today’s capabilities. This is creating the need for a new approach to continue delivering life-critical communications, whether that be voice, video or data. With converged IP/MPLS backhaul, government agencies at all levels around the world are ready to strengthen public safety, increase operational efficiency, improve collaborations between jurisdictions and agencies at all levels, and augment city services – all while benefiting from an efficient, future-ready platform for future network expansion, ready to embrace emerging applications to address new communications needs.

Marketing Director Fai Lam is responsible for promoting Nokia’s IP/Optical Networks portfolio to enterprises and governments. A seasoned professional in networking and communications technology, Lam has helped industries such as power utilities with their transformation projects. He has held positions in product development, product line management, business development and marketing. His marketing campaigns have resulted in major market penetration and product awards. Lam holds a B.Eng. in Electrical Engineering from the University of Victoria in British Columbia, an MBA from the University of Ottawa, and is a Registered Professional Engineer in Ontario, Canada.

Turning Their Backs on Wireless Backhaul, Operators Look to Fiber

By The Editors of AGL

Mobile Experts has released its 2017 report analyzing why wireless backhaul is not growing commensurate with the uptick in outdoor small cell deployment.

Why are carriers ignoring the time-to-market benefits and cost benefits of wireless backhaul? In this analysis, Mobile Experts answers that question and reveals how operators are creating a backbone for 5G, not just filling a 4G hole.

“Leading operators take this position because top mobile operators like Verizon, AT&T, NTT DoCoMo, China Mobile, SKT, and so on, have several LTE bands with overlapping plans to upgrade small cells,” said Joe Madden, Mobile Experts principal analyst. “They have a long-term view, like a roadmap, and they’re not calculating ROI based on a single upgrade.”

Fiber options continue to evolve toward 40 Gbps and even 100 Gbps options as the industry nears 5G and Massive MIMO, and wireless options are evolving as well to support 1-2 Gbps even in NLOS cases, and higher throughput from mmWave options.

The report provides guidance for suppliers to know when to enter the small cell backhaul market. In particular, it provides a forecast of the expected throughput requirements for small cells in the 2020-2022 timeframe, showing the forecast for throughput levels ranging from 100 Mbps to 5 Gbps. Multiple small cell types are considered, including integrated small cells, eCPRI RRH units, CPRI-based RRH, and distributed Radio Systems (DRS).

There is still a play for wireless backhaul in the future.

“By 2022,” Madden said, “16 percent of all small cells shipped will use wireless transport—an increase from a lower percentage in 2016 and 2017, and with the millions of small cells in our forecast this is finally becoming a market for suppliers to look at again. There is potential growth in wireless transport, as operators are starting to discover the limits of the utopian ‘all fiber’ deployment.”

Power, Backhaul Keys to Hurricane Recovery — T-Mobile’s Coltrain

By J. Sharpe Smith

Power and Backhaul can be the two biggest challenges to restoring wireless networks, Chris Coltrain, T-Mobile manager, engineering operations, told the audience during the AGL Local Summit in Fort Worth last week.

Coltrain had just come back from three weeks living on a barge in Puerto Rico, working on bringing the carrier’s network back online when he spoke on the panel, “The Carriers Talk Back: How Can You Better Serve Them?”

He served on the carrier’s strike team going into Houston for Hurricane Harvey and deploying into Miami for Hurricane Irma, as well as spending three weeks in Puerto Rico for Hurricane Maria. Coltrain was among dozens of T-Mobile experts on the island, whose specialty is to fix communications systems after natural disasters. Additionally, 100 members of T-Mobile’s Emergency Volunteer Team were deployed to help with recovery efforts.

“The storms in the season this year are like nothing I have ever seen before. Puerto Rico’s hurricane was like a 500-mile wide tornado that wiped the island clean.” Chris Coltrain, T-Mobile.

Carriers had problems keeping their towers up and running after Harvey because the flooding forced them to use boats to get fuel to the generators.

“Hurricane Harvey was two storms in one. You had the wind event that damaged some aerials and some towers, and then you had the flooding that took place in Houston,” Coltrain said. “We could get sites on the air. We had backhaul, but we couldn’t readily get fuel to them.”

The major problem experienced after Irma was a large power outage but the electric companies got the lights back on fairly quickly, he said.

Upon landing in Puerto Rico, Coltrain was presented with a situation with massive power outages, which wasn’t going to go away as quickly. Exacerbating the problem, there was a minimal number of generators and a severe shortage of diesel fuel.

“Puerto Rico brought in new challenges. Everything we needed was either a half-million-dollar plane ride or 14 days away,” he said.

Since then 130 portable generators have been deployed on the island fueled by thousands of gallons of fuel that have been delivered to the island. A total of 12 freight aircraft brought supplies and personnel to the island. Additionally, multiple barges brought trucks, cells on wheels (COWs), cells on light trucks (CoLTS), RVs and diesel trucks.

Another big problem was backhaul. T-Mobile and the other carriers all depended on an aerial fiber provider, which lost 90 percent of its lines.

“Every carrier has to rebuild their AAV [alternative access vendor] tower backhaul networks,” Coltrain said. “We are using any type of technology we can find, from RADWIN hops to licensed microwave hops to Gilat and VSAT, which is extremely limited. The network in Puerto Rico is going to be limited to voice and text for some time.”

So far, T-Mobile engineers have restored service at more than 220 sites including San Juan, Guaynabo, Toa Baja, Bayamón, Ponce, Carolina, Ceiba, San Germán and Rio Grande.

As of Oct. 20, AT&T said it had deployed 17 mobile cell sites, five emergency communications portables and nearly 600 generators. Further, as of Oct. 26, coverage had been restored to 65 percent of the population, and 13 million calls and 6.5 million texts a day week were being processed on the AT&T network.

By Oct. 11, Vanu had three satellite-based cell sites up and running for AT&T in Puerto Rico with 30 soon to be set up.

“All the carriers have been good at getting coverage where we need to get coverage, but there were people that are still out of touch,” Coltrain said.

The ordeal in Puerto Rico is far from over. It is expected to take 18 months to restore electricity to the entire island, because of the 1950’s technology that is in use there. Until the power comes back, 45,000 to 50,000 gallons of diesel will be burned a week to keep the towers running. With diesel costing up to $5 a gallon, the price of communications will be high.

Coltrain advised the tower companies at the conference that they should provide generators at every site to be used on a shared basis by the carriers.

“You can provide us with shared generators,” he said. “During a disaster, you have to have power and you have to have backhaul.”

Beyond getting the networks back online, carriers are helping the people on the island financially.

T-Mobile has pledged $10,000 to Team Rubicon, a veteran-run disaster relief organization, for hurricane recovery efforts, for every Major League Baseball postseason home run, and an additional $1 every time consumers tweet using #HR4HR. Beginning with Game 1 of the World Series, T-Mobile upped its pledge $20,000 for every home run. Coincidently, the teams had slugged a World Series record 24 out of the park for a $480,000 donation.

Verizon increased its support for Puerto Rico and the U.S. Virgin Islands, as well, from $1 million up to $5 Million, as the magnitude of recovery and relief efforts became clear, according to Verizon Chairman and CEO Lowell McAdam.

J. Sharpe Smith is a Senior Editor for AGL eDigest. He joined AGL in 2007 as contributing editor to the magazine and as editor of eDigest email newsletter. He has 27 years of experience writing about industrial communications, paging, cellular, small cells, DAS and towers. Previously, he worked for the Enterprise Wireless Alliance as editor of the Enterprise Wireless Magazine. Before that, he edited the Wireless Journal for CTIA and he began his wireless journalism career with Phillips Publishing, now Access Intelligence.

SON Backhaul Connects London Observation Wheel’s Wi-Fi Service

By J. Sharpe Smith

UK wireless operator O2 has selected Cambridge Communication Systems to provide the backhaul for the new Wi-Fi system serving the Coca-Cola London Eye, a high-profile, cantilevered observation wheel. A Metnet self-organizing network (SON) microwave backhaul will provide backhaul connections to the tourist attraction’s thirty-two closed capsules as the rotate above the London skyline.

The high-tech Farris wheel is a novel communications challenge, but it is as a good showcase for the use of SON and mesh architecture in the backhaul of wireless signals. The 28-GHz network, using eight CCS nodes installed around the edge of the wheel, connects to 16 Cisco Wi-Fi access points, which provide coverage across the thirty-two capsules. The CCS nodes connect back to two nodes at the central hub, which connect back to the network of Merlin Entertainment, which owns the wheel, and the internet.

CCS developed a new antenna system for the project, giving 360-degree coverage when it rotated around the wheel. The CCS SON algorithm detects the best possible configuration while managing self-interference, and the internal sync mode helps to distribute stable GPS to the other moving nodes.

Metnet Lays Foundation for Backhauling 5G, Smart Cities

CCS is positioning its Metnet nodes to be the backbone of the 5G small cells and the smart cities of the future.  Earlier this year CCS began the deployment of a Wi-Fi network in the City of London’s financial district, known as the “Square Mile.”

The network comprises more than 400 small cells deployed on lampposts, street signs, buildings and CCTV columns to provide service for the 400,000 city workers and 10 million annual visitors.

The Metnet system operates in a single frequency channel with no radio frequency planning required. Each node has a wide 270-degree field of view and supports multiple connections, so there’s no need for manual alignment.

J. Sharpe Smith is senior editor of the AGL eDigest. He joined AGL in 2007 as contributing editor to the magazine and as editor of eDigest email newsletter. He has 27 years of experience writing about industrial communications, paging, cellular, small cells, DAS and towers. Previously, he worked for the Enterprise Wireless Alliance as editor of the Enterprise Wireless Magazine. Before that, he edited the Wireless Journal for CTIA and he began his wireless journalism career with Phillips Publishing, now Access Intelligence.