The last time we were together, we discussed the prospects for urban backhaul in 2014. True, it will be a very exciting time in the 70 GHz and 80 GHz E-band frequencies. The promise of small cells is finally coming to fruition after the hype cycle had all but chewed and spit them out. Remember when you first heard of DSL and cable modem? By the time you could get one, the media had stopped talking about them for at least two years. But we’re digressing.
For years and years, microwave and millimeterwave radio technologies have coexisted without very much overlap in either their markets or applications. Microwave radio served telephone company needs (e.g., long distance backhaul, mobile access aggregation) for the bulk of its implementations with some vertical deployments for oil and gas, public safety and utilities organizations. Typically, licensed bands in service ranged from 6GHz to 42GHz—with 11GHz and under popular for long haul; 18-38GHz trendy for short urban hops. Generally, millimeterwave radio is considered to be between the 60GHz and 80GHz bands and found its applications confined to those for intra-campus communication from building to building for universities, civic centers, other government conglomerations and large, spread-out (i.e., 1 to 5 miles) corporate facilities.
- October 8, 2013
- Aviat Networks, backhaul, frequency bands, Ian Marshall, microwave, Radio spectrum, small cell, Spectrum, Telecommunications, White Paper, wireless
Small cell will enable mobile usage in dense urban environments but will need a backhaul solution to make it possible. Photo credit: Ed Yourdon / Foter / CC BY-SA
The Case for Small Cell Backhaul
As the search for frequency bands with suitable capacity for small-cell backhaul continues, frequency bands above 50GHz start to appear attractive because they offer both high-bandwidth availability and short range owing to their inherent propagation characteristics. The white paper available at the bottom of this blog examines spectrum in the 57-64GHz range to see whether it can be of use for small cell backhaul.
In many countries, the frequency range 57-66GHz is split into a number of discrete bands with differing requirements and conditions of use and/or licensing. These differences will be highlighted where applicable.
From a global point of view, the use of this spectrum by Fixed Services (FS) is being addressed by the ITU-R in its draft report on Fixed Service use trends in WP5C, which is currently under development and states:
57 GHz to 64 GHz
The radio-frequency channel and block arrangements of these bands for FS are defined in Recommendation ITU-R F.1497.
In 2011, around 700 links were in use in this band in a few administrations. The majority of the links are used for fixed and mobile infrastructure.
The air absorption around 60 GHz is over 10 dB/km. This condition restricts the hop length; on the other hand, the spectrum reuse efficiency is high. This feature makes the band suitable for small cell mobile backhaul.
Clearly, a global reported usage of 700 links would suggest a great deal of underutilization, although with unlicensed use in many countries it is difficult to know whether these figures are accurate or not. Regardless, there are reasons as to why this could be the case, while noting that the ITU-R believes this band has potential for small cell backhaul.
One factor is that this spectrum is not allocated solely to the Fixed Service. In fact, in many countries the Fixed Services have no access to this spectrum at all. A more detailed country-by-country breakdown follows. Please sign up below to receive the entire white paper.
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Figure 1: Aviat Networks’ senior network engineer Ivan Zambrano shares his first microwave radio path plan on the occasion of his 28th anniversary with the company.
Recently, Aviat Networks was privileged to mark a milestone for one of its longest tenured and most distinguished employees, Ivan Zambrano. For 28 years, Ivan has dedicated his professional life to providing education and expert analysis to the microwave backhaul community, on the behalf of Aviat Networks and its corporate predecessors. As a senior engineer, Ivan teaches network transmission courses and other topics around the world on a regular basis.
However, Ivan got his start in the field. In fact, he still has the very first microwave radio path plan he ever created for a television station in Louisiana (Figure 1).
Together with the legendary Dick Laine (Figure 2), the two veteran microwave communications professionals have a combined 97 years of experience in the field. Unbelievably, Ivan actually has seniority over Dick (in the company at least). Dick has only been with us for a mere 26 years!
Figure 2: Dick Laine (left) and Ivan Zambrano have a combined 97 years of microwave experience.
To help celebrate the occasion, Aviat Networks CEO, president and board member Michael Pangia took some time to personally congratulate Ivan (Figure 3). So here’s to you Ivan! We’re all looking forward to at least another 28 years!
Figure 3: Aviat CEO Michael Pangia and Ivan.
If you’d be interested in having Ivan or Dick lend a hand (or bend an ear) on your microwave project, let us know by dropping a note below. Give us an idea about the type of training or consultation you need and any other pertinent details about the project.
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Ryan Bruton: Aviat Networks senior international marketing manager.
As the summer in the Northern Hemisphere quickly draws to a close, we can look back to the beginning of the season to see what was on the mind of the backhaul market. Our international marketing manager, Ryan Bruton, gave an interview to CommsMEA covering the trends in backhaul for this time period.
In microwave backhaul, for the African market, radio links are averaging around 40 kilometers in length, says Bruton. This is due in part to climatological conditions, but other factors could also be involved, he says. However, in the Middle East, the typical microwave backhaul links are above this average—also partially due to the atmosphere and geography.
Another big trend Bruton sees this summer in backhaul includes the barriers to fiber being used in the Middle East and Africa markets. Accordingly, fiber is very difficult to trench over kilometers and kilometers of open desert. The terrain is inhospitable and very tough on fiber due to high heat and arid conditions. Not to mention bringing in the equipment necessary to install long fiber routes can be a very large obstacle if the paths lay some distance away from existing roads and other infrastructure. Going through the lush flora of Africa, such as in Nigeria, trenching fiber presents a different yet also nearly insurmountable set of barriers, with massive stands of sometimes-centuries-old trees. And clearcutting tropical rainforest to make way for a fiber backhaul route is neither cheap nor “green.”
Microwave is both the more cost-effective and greener alternative compared to fiber-optic technology for wireless backhaul. Currently achieving about 50 percent of the total market share for backhaul worldwide, microwave certainly is a driver for mobile and other wireless network operators.
Then there is always the potential for fiber to fall victim to so-called “backhoe fade,” a euphemism for the accidental cutting of fiber lines by misguided digging operations. But there is always the potential that fiber cuts are not accidental. In any event, fiber is vulnerable to cuts over the entire course of a route—from Point A to Point B. Microwave sites are isolated to a single spot where they may be assailable. At least operators have the option of “hardening” their microwave sites for maximum uptime, whereas, again, this would be too cost prohibitive in the case of fiber over an entire route.
- August 9, 2013
- Africa, backhaul, Cape Town, device availability, LTE, microwave, network investments, Nigerian Communications Commission, South Africa, technology
Africa’s only dedicated LTE event, LTE Africa 2013, took place in Cape Town this July 2013, bringing operators, vendors, mobile device makers, regulators and standardization bodies together under one roof to discuss LTE. On the agenda were the opportunities LTE can bring, obstacles to deployment, monetization challenges, current African success stories and future directions that LTE may take in Africa.
At the conference, operators grappled with the opportunity they face with LTE. What emerged as the main challenges for operators were spectrum, monetization and device availability—at the right price—for the African market.
In many exchanges, policymakers and regulators were beseeched to make spectrum available for LTE. Dr. Ernest Ndukwe, former CEO of the Nigerian Communications Commission, said, “Unless African leaders create an environment which encourages broadband network investments and makes it easy for companies to roll out broadband services, the situation is unlikely to change in the near future.” Operators were equally concerned about monetization of LTE so as to be able to recover their CAPEX—not to mention OPEX. (Others have not fully recovered their investments on 3G yet!)
Nonetheless, they are now expected to move to LTE. It was clear that operators would need to innovate how they do business by implementing new pricing strategies such as “value bundling” solutions, which would move them away from the cost-per-megabyte pricing tariff they firmly cling to today. Finally, a mobile device priced correctly for the African market has been earmarked as the enabler needed for massive adoption of LTE in Africa.
However, the conference was not all gloom and doom as operators who have successfully implemented LTE, such as Smile, MTC and others, shared information on how they made it possible. They highlighted how they implemented LTE. One of the key areas they focused on was in what way they backhaul LTE traffic.
Successful implementations revealed that for Africa—considering Africa’s demographics—practical and cost-effective implementation of LTE does not allow for 100 percent fiber backhaul, especially since realistic throughput demands of a typical three-sector LTE site max out at about 150 Mbps. With microwave systems easily able to reach 400 Mbps and even 2Gbps, microwave is more than capable of catering to an LTE site’s requirements and is undoubtedly the technology of choice for LTE backhaul except at sites where fiber already exists.
Microwave has cost benefits when deploying in areas lacking fiber, and it can be a cost-effective way to connect rural areas. Microwave also has the benefits of being quicker-to-deployment compared to the trenching needed for fiber. By 2017, industry analysts foresee that microwave backhaul will account for more than 50 percent of all LTE cell sites in Africa.
Technical Marketing Manager, South Africa
- July 30, 2013
- backhaul, custom survey, Ethernet, internet, Internet Protocol, microwave, microwave antennae, MIMO, Mobile network operator, network throughput, quantifiable data, TCO, Total Cost of Ownership
The general mobile industry sentiment has typically been that the capacity bottleneck is the biggest challenge in backhaul. Thus, the focus has been on adding more capacity to address the surge of 3G and now 4G traffic. So you might think that this concern would rank first, particularly among microwave-centric operators, who are often looking to maximize their network throughput. We recently commissioned the experts at Heavy Reading to do a custom survey to get some quantifiable data to clarify this key question and a few others.
85 mobile operators were selected and surveyed globally, including a good cross-section from both developed and emerging markets. The respondents were screened to ensure that they all had a stake in microwave-specific backhaul: 93 percent had deployed microwave and the rest had plans to deploy it. In fact, 45 percent were categorized as heavy microwave users—those where more than 50 percent of their cell sites were served by microwave backhaul.
So we asked this select group, which consisted of mostly planners, engineers and strategy leaders, “What is the biggest challenge your company faces regarding the future development and deployment of microwave backhaul?”
The results were interesting in that “total cost of ownership” actually eclipsed “increasing capacity” as their biggest challenge, as shown in the pie chart of survey responses below.
- July 11, 2013
- ACM, Africa, backhaul, Cell C, IP, LTE, MIMO, mobile cellular networks, MTN, Quality of service, South Africa, throughput improvement, Time-division multiplexing, Vodacom
LTE has been moving more and more to the forefront in mobile cellular networks around the world. Africa, and particularly the Republic of South Africa, is the latest hotbed of LTE rollouts, with the leading country operators of Vodacom, MTN and Cell C coming online since late in 2012. In conjunction with these LTE access rollouts, our technical marketing manager in the region, Mr. Siphiwe Nelwamondo, has been authoring a series of columns on enabling LTE in a leading regional technology media Internet site, ITWeb Africa.
Naturally, his focus has been on backhaul. In the first installment of his series, Mr. Nelwamondo looked closely at the backhaul requirements of LTE. Chief among these requirements are speed, Quality of Service (QoS) and capacity. He concluded that it is too early to close the book on the requisite parameters for supporting LTE backhaul. Part two of the features, he examined the basis on which microwave provides the technical underpinnings for LTE backhaul—especially as related to capacity. More spectrum, better spectral efficiency and more effective throughput were Mr. Nelwamondo’s subpoints to increasing capacity.
Having more spectrum for microwave backhaul is always nice, but it’s a finite resource and other RF-based equipment from satellites to garage door openers is in competition for it. Bettering spectral efficiency may be accomplished by traditional methods such as ACM and might be increased through unproven-in-microwave techniques like MIMO. Throughput improvement has wide claims from the plausible low single digit percentage increases to the more speculative of upping capacity by nearly half-again. Data compression and suppression are discussed. The truth is LTE, while data-intensive, probably will not require drastic measures for backhaul capacity until at least the next stage of LTE-Advanced.
If indeed capacity increases are necessary in the LTE backhaul, number three and the most current piece of Mr. Nelwamondo’s contains additional information. Nothing is better than having something bigger than normal or having many of the standard model. As the analogy applies to LTE microwave backhaul, bigger or wider channels will increase capacity, of course. A larger hose sprays more water. Or if you have two or three or more hoses pumping in parallel that will also support comparatively more water volume. The same is true of multiple microwave channels.
However, the most truly and cost effective capacity hiking approach is proper network planning. Mr. Nelwamondo points out that in Africa—more than some places—mobile operators are involved in transitioning from TDM planning to IP planning. While TDM planning was dependent on finding the peak traffic requirement per link, IP planning allows the flexibility to anticipate a normalized rate of traffic with contingencies to “borrow” capacity from elsewhere in a backhaul ring network that is not currently being utilized. Along with several other IP-related features, this makes determining the capacity a lot more of a gray area. Some operators solve this by simply “over-dimensioning” by providing too much bandwidth for the actual data throughput needed, but most cannot afford to do this.
The fourth and final entry in Mr. Nelwamondo’s series will appear soon on other LTE backhaul considerations of which you may not have thought. Sign up below to be notified when it is available. [contact-form-7 404 "Not Found"]
Microwave backhaul is being reassessed as a strategy for small cell LTE traffic aggregation on business campuses. Photo credit: cbmd / Foter.com / CC BY-NC-ND
Small cells get all the press! As LTE rolls out in networks on every continent except Antarctica, small cells are grabbing headlines in technology trades and geek fan-boy blogs across the Internet. They’ll be needed sooner or later to provide LTE access in all those places around corners of buildings on business campuses, in urban parks surrounded by concrete canyons and other inaccessible locations. But little or only passing thought is paid to the ways in which small cell traffic will be aggregated back to the main network.
However, in a new FierceWireless ebook, microwave backhaul is pointed out as one of the critical strategies to provide throughput for all the small cell traffic to come. Microwave was here before small cell. And it’s such a good fit for small cell, if it had not already existed, we’d have to invent it now! Our director of product marketing, Stuart Little, tells FierceWireless that microwave meets the capacity needs of LTE backhaul. And Fierce adds modern microwave technology is changing the perceptions of its use for small cell backhaul.
Neither sleet nor rain nor changing K factors at night will stop microwave from small cell service. Specifically, Little tells Fierce that rain has little to no effect on microwave at the lower frequencies, and where it does have some effect in the higher bands, different technical techniques can help mitigate it. To find out more about small cell microwave backhaul, we recommend any of the Aviat blogs and related articles below. Or just read the FierceWireless ebook.
- June 10, 2013
- Aviat Networks, backhaul, Capital expenditure, Denver, FirstNet, microwave, public safety, public safety communications, public safety community, public safety network
In the effort to build out the nationwide Public Safety Broadband Network, stakeholders are making themselves heard. They were heard at the Public Safety Broadband Stakeholder Conference held last week, June 4-6, 2013, outside of Denver, Colo., hosted by the Public Safety Communications Research lab. It brought to the surface the many competing agendas local public safety network operators, the First Responder Network Authority (FirstNet), wired and wireless vendors and even mobile app developers contend with.
Aviat Networks had a chance to sit down with Tammy Parker, editor of FierceBroadbandWireless, during the conference to discuss some of these issues, such as the debate on the effectiveness of fiber optic technology in backhauling public safety networks. The fact is that microwave indeed will be a key element in the design and implementation of the FirstNet mission-critical network. And fiber does not provide the reliability and survivability needed. In the commercial mobile telecom space, the poor survivability of fiber is tolerated, but when it comes down to crunch time when lives are on the line, public safety operators will take microwave over leased fiber.
Randy Jenkins, Aviat director of business development, expanded on this vital decision for public safety operators to make between microwave and fiber. “As a vendor vested in the public safety community for more than 50 years, Aviat understands its responsibility to find innovative ways of offering microwave solutions that can save CAPEX and OPEX in support of the biggest challenge FirstNet is addressing—not enough money. Aviat is bringing backhaul innovation to this program.”
The bottom line is that backhaul is always the bottleneck in any network planning. In that case, it’s important for public safety operators to address that aspect first, according to Tony Ljubicich, Aviat’s vice president of sales and services.
If you would like to hear more about how Aviat Networks is making microwave backhaul the best choice for FirstNet-ready public safety, leave your contact information and reference the upcoming webinar on public safety broadband backhaul for a major statewide network. We’ll let you know when it’s scheduled.